MOBILE PLANT FOR THERMALLY TREATING A CONTAMINATED OR UNCONTAMINATED FEED STREAM, PROCESSES THEREOF AND USES OF PRODUCTS THEREOF
Mobile plant, for thermally treating a feed stream, comprising a first unit designed for heating the feed oil (Unit I); ii. a second unit comprising a rotating reactor designed to perform the thermal processing (pyrolizing) of the feed oil and a vapour solid separator (Unit II); and iii. a third unit (Unit III) that is a product separation unit and that is preferably configured for recycling at least part of the treated feed stream (heavy oil), recovered in Unit III, into Unit I. The first unit and/or the second unit is (are) configured for injecting a sweep gas in the feed oil and/or in the rotating reactor, and/or the second unit is configured in a way that the rotating reactor may work under positive pressure. The processes for thermally treating a feed material by using a mobile plant. The uses of the processes for various environmental and non-environmental applications. Processes for manufacturing the mobile plants. Uses of oil containing resins (such as cracked and/or polarized oils) for cleaning purposes and other specialty applications.
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The invention relates to a mobile plant comprising a reactor for thermally treating a contaminated or uncontaminated feed stream such as a feed oil. The mobile plant may also produce oils to be used inter alia for cleaning tank bottoms for ships, tank farms and equipment fouled by heavy hydrocarbons material.
The present invention also relates to a process to thermally treat used lubricating oils, waste oils, oily tank bottoms, heavy oils or bitumen in a rotating kiln operating under pressure with the injection of a gas, preferably of a sweep gas into the reactor of the mobile plant or its feed stream.
The present invention also relates to the use of oils with resins, such as cracked or polarized oils, for cleaning equipment or materials that are fouled or contaminated with hydrocarbons or with other contaminants.
The present invention, also relates to the use of the mobile plant for preparing specialty oils and the use of these oils in specific applications.
The processes of the invention may be used in various environmental applications and the products thereby obtained are useable in various environmental ways such as fuels, specialty oils, for cleaning fouled equipment and materials, and site specific applications.
BACKGROUND OF THE INVENTIONWaste oils, especially used lubricating oils (ULO), are considered a threat to the environment, and are classified as a hazardous product in most jurisdictions. The Environment Protection Agency (EPA) states that: “One gallon of used lubricating oil can pollute a million gallons of water.”
Presently water and/or steam is (are) used to clean ships, fuel tanks, tank farm bottoms and other equipment that is fouled by oils and/or by other hydro-carbon residue. This means that the water used has to be separated from the oily residues and then the residues treated or burned in cement kilns. The burning of the oily residues is bad for the environment and a waste of the hydrocarbon resources.
There are many processes to treat waste oils. Up until the December 2001 report to the European Commission of the Environment by Taylor Nelson Sofres titled “Critical review of existing studies and life cycle analysis on the regeneration and incineration of waste oils”, and the Nov. 19, 2008 European union directive, there was priority given to re-refining processes recycling used lubricating oils (ULO) into lubricating oils base-stocks in the European Union as well as in the rest of the World. Consequently many re-refining processes were invented and used. The commercial re-refining processes used in Europe are described in the Taylor Nelson Sofres report. These and others are described in a book by Francois Audibert titled “Waste Engine Oils, Re-refining and Energy Recovery”, (Elsevier, Amsterdam, 2006). Among the processes that regenerate ULO into lubricating oil base-stocks, some, such as the acid clay processes, were abandoned or legislated out because of the disposal costs, both financial and environmental, of the by-products such as spent acid and clays.
Lube oil regeneration processes, using solvent extraction or vacuum distillation as their primary process, require a finishing step, such as hydrotreating, which entails the purchase of hydrogen or building a hydrogen unit. Usually, the quality of their feedstock determines the quality of their products. Waste oil compositions are variable, and can change even within a shipment. Re-refining processes usually require extensive laboratory analyses of both the waste oil entering the plant, to determine the amount of chemicals to add in their pre-treatment processes, and of the product lubricating oils to ensure consistent product quality. Because of their high capital and operating costs, these plants must be close to large population centre and/or serve a large collection area, and usually require government subsidies to be viable.
When the used oil is to be used as fuel, chemical treatment of ULO to extract heavy metals, sulphur and chlorides is legislated and requires considerable laboratory analyses because of the constant variations in feedstock compositions.
In some very specific and rare applications, ULO is cleaned, dewatered, tested and its additive package is topped-off, before the lube oil is used again without leaving the plant site. Again, these applications require extensive laboratory analyses.
The re-refining processes alluded to in the previous section aim to recover lubricating oils from the used oil feed streams. There are processes aimed at destroying the metal-containing additives in waste oils, and make environmentally acceptable products such as fuels. Corresponding proposed stationary reactors, operating at atmospheric pressure, are mentioned in the following patent literature.
Canadian Patents Nos. 1,309,370, and 2,112,097, and in U.S. Pat. Nos. 5,271,808 and 5,795,462 (Shurtleff) disclose an apparatus and a method that are provided reclaiming a useful oil product from waste oil, such as used lubricating oil. The apparatus comprises an oil feed means, a boiler, a heater and a separating means. The heater is used to heat the waste oil in the boiler to a temperature such that heavier hydrocarbons remain unvolatilized, trapping contaminants therewith. The separating means separates the volatilized lighter hydrocarbons from the unvolatilized heavier hydrocarbons and contaminants.
U.S. Pat. No. 5,871,618 and Canadian Patent No. 2,225,635 (Kong at al.) discloses an apparatus and a process for reclaiming fuel oil from waste oil. The apparatus comprises a thermal cracking unit for cracking the high boiling hydrocarbon material into lighter, lower boiling, material so as to separate hydrocarbon vapor products from viscous materials; a condenser/heat exchanger for condensing the hydrocarbon vapour products to the liquid state; a fuel stabilization unit for chemically treating the condensates so as to give an oil product and solid sediment; and a polishing unit for forming a high quality fuel oil by physically removing solid contaminants. According to the present invention, high quality fuel oil can be obtained together with an environmentally innocuous solid ash cake, through a simple and efficient process.
U.S. Pat. No. 5,362,381 (Brown et al.) discloses a process in which waste lubricating oil is reprocessed into commercially usable diesel fuel and naphtha by thermocracking. A thermocracker unit is fired with sludge removed from the principal pool of oil undergoing vaporization. The vapours are separated from liquids in a primary distillation tower with precisely controlled heating. Resultant vapours are partially condensed. Resultant liquids flow downward through a secondary distillation tower into a reboiler which is heated by a flue gas bypass with an auxiliary burner. Vapours leaving the secondary distillation tower are partially condensed and resultant fluids are passed to a light ends flash tank. Gases from the flash tank fuel the auxiliary burner. Liquids are collected and stored for selling as naphtha. Hot liquids are withdrawn from the reboiler and are immediately cooled to atmospheric conditions. Liquids within specification are stored in a diesel storage tank for further use and sale. Off-specification products are stored in a reflux storage tank and are pumped and heated and sprayed downward in the primary distillation tower for washing the tower and for reprocessing in the thermocracking unit. Some light ends are mixed with sludge in a storage tank. The mixture is pumped as sludge fuel to the burner in a fire tube in the thermocracking unit.
U.S. Pat. No. 5,885,444 (Wansborough et al.) discloses a process for thermally cracking waste motor oil into a diesel fuel product is provided. The thermal cracking process uses low temperature cracking temperatures from 625 to 725 degrees Fahrenheit with ambient pressure to generate a column distilled fraction of diesel fuel mixed with light ends, the light ends being flashed off to produce a high quality #2 diesel fuel. The process further provides for removal from the cracking vessel an additional product stream which, when filtered, is suitable for use as a #3 fuel oil and that can be further blended with a bunker oil to yield a #5 fuel product.
Canadian Patent No. 2,242,742 (Yu) discloses a process and apparatus for the reclaiming and re-refining of waste oils. The process comprises raising a temperature of a feed mixture of fresh waste oil and a recycled non-volatile residue to a range of 400 to 490 degrees Celsius for a time sufficient to cause pyrolysis of the heavy hydrocarbons contained in the feed mixture, but insufficient to permit substantial undesired polymerization, oxidation and dehydrogenation reactions to take place in the feed mixture; cooling the resulting pyrolized waste oil mixture to a temperature in the range of 300 to 425 degrees Celsius, and maintaining the temperature while allowing volatile components in the pyrolyzed waste oil mixture to evaporate, leaving a non-volatile residue containing the contaminants; condensing the evaporated volatile components to form a reclaimed oil product; and mixing the non-volatile residue with fresh waste oil to form more of the feed mixture and repeating the temperature raising, cooling, evaporation and mixing steps on a continuous basis, while continuing to condense volatile components evaporated from the pyrolyzed waste oil mixture. The apparatus comprises a heating unit, a container, a condenser and pumping equipment and piping. The process and apparatus of the present invention generate #2 diesel fuel, gasoline and coke from waste oil. In this patent, the reactor advantageously operates under positive pressure.
Among the problems common to stationary reactors in waste oil applications are coking of the reactor walls, which impedes heat transfer from the heat source to the oil to be treated, and fouling of the equipment, not only in the reactor but also upstream and downstream of the reactor.
U.S. Pat. No. 6,589,417 and Canadian Patent No. 2,314,586 (Taciuk et al.) disclose a process by which used oil is treated in a reactor to remove contaminants. The reactor comprises a rotating vessel housed within a heating chamber. The inside of the vessel is indirectly heated by conduction through the vessel walls. The vessel contains a permanently resident charge of non-ablating, coarse granular solids. Within the vessel, the oil is vaporized and pyrolyzed, producing a hydrocarbon vapour. Coke is formed as a by-product. Contaminants, such as metals and halides become associated with the coke. The coarse granular solids scour and comminute the coke to form fine solids. The fine solids are separated from the coarse solids and are removed from the vessel. The hydrocarbon vapours are separated from any fine solids and are routed to a vapour condensation system for producing a substantially contaminant-free product oil. The contaminant-rich solids are collected for disposal. This process operates at a negative pressure in the reactor.
Rotating kilns, operating under vacuum, are suggested in processes designed to thermally crack bitumen, heavy oil, rubber tires, oil shale and oil sands, coal or refinery distillation column bottoms.
Canadian Patent No. 1,334,129 (Klaus) discloses an invention that relates to a process and apparatus for the pyrolysis of bitumen. The process involves spraying preheated bitumen into a generally horizontal cylindrical rotating reactor which is heated from the outside and which contains grinding bodies. The bitumen is heated to the pyrolysis temperature and thereby forms a gaseous product and a solid pyrolyzed coke. The solid pyrolyzed coke is removed from the reactor walls by the grinding bodies and the resulting small particles are continuously removed from the reactor through ports in the reactor wall.
U.S. Pat. No. 4,473,464 (Boyer et al.) discloses a method for producing a distillable hydrocarbonaceous stream and carbonaceous agglomerates from a heavy crude oil by charging the crude oil and finely divided carbonaceous solids to a rotary kiln with the crude oil and carbonaceous solids being charged in a weight ratio from about 0.6 to about 1.5; tumbling the crude oil and finely divided carbonaceous solids in the rotary kiln at a temperature from about 850 F to about 1000 F for up to about 30 minutes to produce a vaporous stream and agglomerate particles containing a residual portion of the crude oil and finely divided carbonaceous solids; separating the agglomerate particles into a product portion of a desired particle size range and a recycle portion; grinding the recycle portion to produce the finely divided carbonaceous solids and heating the finely divided carbonaceous solids prior to recycling the carbonaceous solids to mixture with the crude oil, an improvement comprising: supplying at least a major portion of the heat required in the rotary kiln by heating the crude oil charged to the rotary kiln thereby eliminating the heating of the finely divided carbonaceous solids prior to recycling.
U.S. Pat. No. 4,439,209 (Wilwerding) discloses an apparatus for the continuous non-oxidative thermal decomposition of heat-dissociable organic matter to a solid carbon residue, particularly activated carbon, and a mixture of gaseous products, without substantial coking or tar formation. The apparatus involve a cylindrical rotating drum in a substantially horizontal position, into which feed material is introduced at one end and products recovered at the other end. An axial temperature gradient, increasing in the direction of flow, is maintained within the drum, enabling the exercise of a high degree of control over the reaction to fully convert the feed into the desired products.
Indirectly fired rotating kilns are usually considered inefficient means to convey heat into a reactor. Some propose heating the reactor feed with a hot stream. The hot stream can be circulating gas, liquid or solids.
U.S. Pat. No. 5,423,891 (Taylor) proposes a direct gasification of a high BTU content fuel gas from a hydrocarbon content solid waste material W which may include some glass content is effected by preheating heat carrier solids HCS in a flash calciner to a temperature capable of thermally cracking the hydrocarbon content of the solid waste material W directly into the high BTU content fuel gas. The HCS are separated from the products of combustion and fed into a gas sealed refractory lined horizontal axis rotary kiln retort concurrently with the solid waste W. Momentary contact and mixing of the solid waste W with the HCS in the rotary kiln in the absence of oxygen is sufficient to directly thermally crack the solid waste material into the high BTU gas product. Separated HCS are returned to the flash calciner for reheating. A trommel, coupled directly to the output of the rotary kiln retort and having a trommel screen with mesh openings smaller than glass agglomerates, but sized larger than the HCS, permits separation of the HCS and discharging of glass agglomerates from the downstream end of the trommel screen to prevent shut down of the direct gasification unit. Direct gasification of steel industry waste water treatment plant sludge, automobile shredded refuse ASR, municipal solid waste MSW and refuse derived fuel RDF and oil mill scale is effectively achieved, irrespective of glass content contaminant.
U.S. Pat. No. 4,512,873 (Escher) discloses a process in which the residues obtained in the hydrogenation of oil, especially heavy oil, or of coal are subjected to low temperature carbonization in a drum, preferably a rotary drum, at temperatures between approximately 400 degrees Celsius and approximately 600 degrees Celsius, by means of a carbonization gas after the separation of the condensable portions and heating to temperatures between approximately 600 degrees Celsius and approximately 950 degrees Celsius, which is introduced into the low temperature carbonization drum. The gas is heated to temperatures between approximately 600 degrees Celsius and approximately 950 degrees Celsius indirectly by flue gases arising from the combustion of oil or gas, for example, of excess carbonization gas. The residue to be carbonized at low temperature is introduced into the hot gas in a finely dispersed state and preferably atomized.
From a practical point of view, it is difficult to ensure the integrity of the seals of both the main reactor and the coke incinerator when there is a circulating stream of solids. When produced gas is circulated to heat the reactor feed oil to cracking temperatures, large amounts of circulating gas is required, compared to the fresh feed stream.
Attempts have been made to provide the industry with a transportable plant able to purify contaminated oils and refine oils in general.
U.S. Pat. No. 4,039,130 (Hogan) proposes a portable skid mounted fully equipped topping plant for the distillation of gasoline and diesel fuel from crude oil feed, equipped with its own power supply, capable of producing its own electricity and power requirements, utilizing fuel from crude oil feed, and designed for automatic operation and equipped with an automatic shut-down system. The system input is crude oil (not waste oil) and its stated output is diesel.
U.S. Pat. No. 5,316,743 (Leblanc) proposes a portable refinery including a refining vessel (a system similar to a horizontal distillation tower) a heater for providing heat to the refining vessel, dewatering devices, and a storage tank mounted on a skid which can be quickly and easily transported to a reservoir of petroleum products to refine the petroleum or waste petroleum into diesel grade fuel at the reservoir. It works At about 630 degrees Fahrenheit or about 330 degrees Celsius.
U.S. patent application No. 2009/0095683 A1 (Zulauf) proposes a mobile fuel filter for removing sulfur-containing compounds from a diesel fuel. The system and methods are for the removal of sulfur containing compounds that provide for the production of fuel streams having concentration of less than 15 ppm.
U.S. Pat. No. 7,510,647 (Evans) proposes a mobile fluid catalyst injection system and a method of controlling a fluid catalyst cracking process is provided. In one embodiment, a mobile fluid catalyst platform and a flow control device coupled to the platform and a flow control device coupled with an outlet of the reservoir and adapted to control the flow of catalyst from the reservoir to a fluid catalyst cracking unit (FCCU).
U.S. Pat. No. 7,951,340 (Brons et al.) propose an atmospheric and/or vacuum resid fractions of a high solvency dispersive power (HSDP) crude oil are added to a blend of crude oil to prevent fouling of crude oil refinery equipment and to perform on-line cleaning of fouled refinery equipment. The HSDP resid fractions dissolve asphaltene precipitates and maintain suspension of inorganic particulates before coking affects heat exchange surfaces.
U.S. Patent No. 2010/0147333 (Wright et al.) propose non-high solvency dispersive power (non-HSDP) crude oil with increased fouling mitigation and on-line cleaning effects includes a base non-HSDP crude oil and an effective amount of resins isolated from a high solvency dispersive power (HSDP) crude oil, and method of making same. Also, methods of using such non-HSDP crude oil for on-line cleaning of a fouled crude oil refinery component, for reducing fouling in a crude oil refinery component, and in a system capable of experiencing fouling conditions associated with particulate or asphaltene fouling.
None of those prior art mobile plants was effectively commercialized due to several drawbacks such as not being able to treat a wide variety of waste oils, providing readily useable products with no environmentally harmful by-products.
Particularly, as mentioned in U.S. Pat. No. 4,039,130, a major problem to overcome in the construction of such a compact unit is that of providing sufficient heat in an economical manner to raise the crude oil to the temperature necessary for distillation. Conventional salt bath, steam, and other heaters which have heretofore been used were undesirable because of their weigth, cost, and other factors. A direct fired heater could not be used because such heaters unavoidably get hot spots which cause the tube to burn through, causing the oil being processed to bet set on fire, thereby endangering the entire plant.
There was therefore a need for a process allowing for the on-site treatment of the oils coming from the cleaning of fouled equipment and/or materials. None of the prior processes used cleaning oils containing a high concentration of resins (polarized hydrocarbons) as cleaning agents for fouled equipment and materials that have deposits of hydrocarbons and other materials such as asphaltenes, tars, coke, salts, dirt, gums, and resins.
There was therefore a need for a transportable flexible and viable process unit that addresses at least one of the drawbacks of existing technologies.
There was also a need for a transportable unit that can destroy the harmful components in waste oils.
There was additionally a need for a transportable unit that can destroy the harmful components in waste oils while making products and by-products.
The was also a need for a transportable unit that can destroy the harmful components in waste oils while making products and by-products that are useful and environmentally friendly and commercial way.
There was further a need for a transportable unit that can destroy the harmful components in waste oils while making products and by-products that are useful, environmentally friendly and of a commercial interest.
There was also a need for a transportable unit that can destroy the harmful components in waste oils and that can be operated in a commercial way.
Additionally, there was a need for a viable, safe and flexible process that can destroy the hazardous components in waste oils while making products and by-products that are all environmentally friendly.
There was also a need to have a process for cleaning in an efficient and environmentally friendly for fouled tank farms and boat reservoirs and equipment with products that can be treated on premises.
There was further a need for adequate amounts of a cleaning oil which can dissolve and/or combine with fouling material to remove it. There was a need to dispose of the materials coming from the cleaning process in an environmentally friendly manner.
There was a need for a viable and flexible process that can destroy the hazardous components of ULO and produce useful products with little or no by-products to dispose of in industrial landfills or incinerators.
There was also a need for a mobile plant that may efficiently treat oil spills on site, without harmful by-products.
There was also a need for a mobile plant that may efficiently treat drilling muds on site, without harmful by-products.
There was also a need for a mobile plant that may efficiently treat waste oils, particularly in remote mining, tank bottom, without producing harmful by-products.
SUMMARYA mobile plant for thermally treating a feed stream, the mobile plant comprising:
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- i. a first unit designed for heating and/or dehydrating and/or degasing the feed stream (Unit I);
- ii. a second unit (Unit II) comprising a rotating reactor designed to perform the thermal processing (such as pyrolizing) of the feed stream entering the rotating reactor and a vapour solid separator (Unit II); and
- iii. a third unit (Unit III) that is a product separation unit and that is optionally configured for recycling at least part of the treated feed stream (heavy oil), recovered in Unit III, into Unit I and/or into Unit II,
- and wherein optionally:
- Unit I and/or the second Unit II is (are) configured for injecting a sweep gas in the feed oil and/or in the rotating reactor, and/or
- Unit II is configured in a way that the rotating reactor may work under positive pressure.
Use of a mixture containing resins, such a mixture having the capacity of dissolving and/or combining with deposits in fouled equipment and/or oily materials such a mixture being preferably oils containing resins (polarized and/or cracked oils), for cleaning fouled equipment and materials containing hydrocarbons and other fouling materials such as asphaltenes, tars, coke, salts, dirt, gums, and resins; the concentration of polarized and/or cracked oils in the oils being preferably superior to 5% weight and more preferably superior to 20% weight; the resulting mixture including agglomerates extracted during the cleaning step are advantageously treated and/or recycled into the process performed on the site with a mobile plant.
For the purpose of this document, the following definitions are adopted:
“Feed stream” is a constituted of liquids and/or of solids, preferably the feed stream is a feed oil, that is selected in the group constituted by a contaminated oil and/or an uncontaminated waste oil, wherein the oil is advantageously a synthetic oil, a natural oil, a vegetable oil, an animal fat oil. The feed stream may also be constituted of oily tank bottoms, oily water, marpol, asphalts, oily beaches, contaminated soils, oil sands and/or tars, heavy oils, tires, process oils, used lubricating oils, and any mixture containing one or more of these oils.
“Sweep gas” is any non-reactive or substantially non-reactive gas, preferably it is an inert gas such nitrogen or water steam; it has surprisingly be found that such gas not only have as sweeping effect in the reaction zone of rotating operating reactor, but helps to control the positive pressure. This may incidentally increase the safety of the operation and/or improve the efficiency of the process.
“Contaminants”: in waste oils, the most common contaminant is water. Other contaminants include, but are not limited to, sand, clay, engine wear products, and decomposition products from oils, greases and/or additives.
“Diesel”, “gasoil” or “fuel oil”: in the context of this process are oils mainly made up of hydrocarbons with boiling points between 100 and 500 degrees Celsius, according to ASTM D-86 or according to ASTM D-1160.
“Naphtha” is a light oil with a 90% point (ASTM D-86) around 160 degrees Celsius, and a specific gravity between 0.65 and 0.8.
“Used Lubricating Oil” (ULO): Oils or greases that were used as lubricants, usually in engines, and were discarded. Examples would include car engine oils, compressor oils, and diesel engine oils among others. Lubricating oils generally contain additives, which are carefully engineered molecules added to base oils to improve one or more characteristic of the lubricating oil for a particular use. Used lubricating oil is classified as a hazardous product in many jurisdictions because of its additives and contaminants.
“Substantially non-reactive gas” means a gas that does not readily interact with the feed or product oils in the reactor.
“Waste oils” means oils or greases that are discarded. They include ULO as well as a wide range of other oils such as marpol, refinery tank bottoms, form oils, metal working oils, synthetic oils and PCB-free transmission oils, to name a few.
“Consistent shapes” means shapes so they can stay on the narrow shelves and/or each other, while protecting the reactor wall from direct contact with the relatively cold feed. In the meaning of the invention, the expression consistent shapes also means:
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- a multiplicity of physical elements having substantially the same form;
- a multiplicity of physical elements having substantially the same form and substantially the same size; or
- a multiplicity of physical elements having substantially the same size, provided those forms are compatible in such an extent that are globally symmetrical and stay substantially constant during rotating inside the rotating kiln; and a multiplicity of physical elements having shapes that permit that plates sit upon each other, preferably in such a way that there is no space or substantially no space between them.
“Dynamical wall”: the multiplicity of plates of consistent shapes results, because of the rotation, in a continuously reconstructing wall.
“Thermal processing” is preferably at least one of the followings: evaporating, cracking, drying, pyrolizing and thermocleaning.
The “height of a shelve” is the distance between the attachment point of the shelve on the reactor wall and the end of the shelve directed to the center of the reactor.
The “width of a shelve” is the measurement of the distance between the two sides of the shelve on a direction perpendicular to the height of the shelve.
“Oils containing resins” is a mixture of oils that contain cracked and/or polarized oils.
“Plates” is substantially flat or a flat piece of a solid material such as stone or metal or other material non-ablating at reactor operating conditions or a smooth flat thin piece of material. In the context of this invention, substantially flat means also slightly concave or convex in at least one direction of the plate and on at least one face of the plate, more preferably the curve plate is adapted to the form of the reactor. Substantially also means that a plate may be for at least 70%, preferably for at least 80%, more preferably for at least 95% of its surface, flat.
A first object of the present invention is constituted by the family of mobile plants for thermally treating a feed stream the mobile plant comprising a first unit designed for heating the feed oil (Unit I), a second unit comprising a rotating reactor designed to perform the thermal processing (pyrolizing) of the feed stream and a vapour solid separator (Unit II); and a third unit (Unit III) that is a product separation unit and that is preferably configured for recycling at least part of the treated feed stream (heavy oil), recovered in Unit III, into Unit I. In these mobile plants the first unit and/or the second unit is (are) advantageously configured for injecting a sweep gas in the feed oil and/or in the rotating reactor, and/or the second unit is advantageously configured in a way that the rotating reactor may work under positive pressure.
Those mobile plants are particularly suited for treating a feed stream that is a feed oil, and more preferably a contaminated oil or an uncontaminated oil.
According to a preferred embodiment, the mobile plants of the invention, when used for thermally treating a feed oil, are configured in a way that the first unit contain no sub-unit for chemically treating, preferably for purifying, the feeding stream before its injection into Unit II.
Advantageously, is designed to remove the water from the feed oil when water is present in the feed stream (oil).
According to a preferred embodiment, the rotating reactor is one of the reactors described in the PCT patent application No. WO 2011 143 770, published on Nov. 24, 2011.
As a matter of example, the rotating reactor comprises:
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- a. a rotating kiln, which rotating kiln preferably containing plates;
- b. a heating system;
- c. at least one shelf on the reactor wall;
- d. a charge of plates of consistent shapes;
- e. means for bringing the mixture to be thermally processed on the surface of at least part of the plates;
- f. means for removing the solids from the reactor, preferably either through entrainment with the exiting vapours, or through a separate solids exit, or both;
- g. means for recovering the reaction and straight run products; and
- h. means for venting the gas obtained by the thermal processing outside the reactor zone.
In the meaning of the present application, the charge of plates may be constituted of various type of plates, each plate of a particular type being consistent in form with the form of other plates of the same type. The charge of plates may be constituted by an assembly of plates of the same type and consistent in form.
Advantageously, at least one shelf is placed on the reactor wall in such a way to keep a uniform distribution of the plates along the reactor length. In the rotating kiln, the at least one shelf is preferably either parallel to the center axis of the reactor, when the reactor is horizontal, or slanted with respect to the centre axis when the reactor is slanted or not slanted.
Said means for bringing the mixture to be thermally processed on the surface of at least part of the plates, are configured in a way to bring the mixture on the surface of at least more than 10% of the plates, preferably on the surface of at least more than 30% of the plates, and more advantageously on the surface of about 50% of the plates present in the reactor.
According to a preferred embodiment, the reactor and its internals for thermal processing is configured to rotate around its centre axis, the axis forming with the horizontal an angle that is less than 45 degrees, preferably less than 30 degrees and more preferably this angle is about 5 degrees and more advantageously the angle is of 0 degree.
Advantageously, in the mobile plants of the invention, the center axis of the rotating kiln is horizontal or slanted and the angle is maintained constant except in the case wherein solid agglomeration occurs or when the reactor is cooled down after operation.
Said reactor is preferably configured in a way that the walls of the reactor are directly and/or indirectly heated and/or in a way that the reactor is configured in a way that the inside of the reactor is directly and/or indirectly heated.
The heat source is advantageously generated by electricity, a hot oil and/or gas stream, or obtained from the combustion of gas, naphtha, other oily streams, coke, coal, or organic waste or by a mixture of at least two of these.
According to other embodiment, the reactor is configured in a way that the inside of the reactor is indirectly heated by an electromagnetic field and/or the inside of the reactor is directly heated by a hot gas, liquid or solid stream, electricity or partial combustion of the feedstock, coke, products or by-products.
The heating means advantageously comprise at least one heating system external to the walls of the reactor, which is usually the case of an indirectly fired kiln.
Advantageously, the external walls of the reactor are at least partially surrounded by one or more burners and/or exposed to combustion gas and/or hot solids.
According to another embodiment, the walls of the reactor are surrounded by a fire box, and the fire box is stationary and contains one or more burners.
In the rotating kiln, one or more shelves are advantageously attached to the internal walls or the external walls of the reactors. The shelve (s) is (are) are preferably attached to the wall of the reactor in a way allowing for the thermal expansion of the shelves with minimum stress on the reactor walls and on the shelve(s). According to a specific embodiment, the shelve(s) is(are) held by T shaped clamps. Advantageously, the shelve(s) is(are) symmetrically attached to the internal wall of the reactor the shelve(s) is(are) attached to the internal wall in a designed and/or random pattern of the reactor.
The number of shelve(s) that is(are) disposed, per square meter of the internal surface of the reactor, on the internal wall of the reactor ranges advantageously from 1 to 40, preferably from 2 to 20.
The number of shelve(s) that is(are) disposed, per square meter of the internal surface of the reactor, on the internal wall of the reactor ranges advantageously from 1 to 50 units, more advantageously from 2 to 20, preferably from 3 to 15 and this number is more advantageously about 4.
The number of shelves in the reactor depends on the weight and/or on the size and/or on the form of the plates and/or on the maximum operating temperature of the reactor wall and/or on the material the shelves and plates are made of.
The space between two shelves represents from 0 to 100% a preferably from 5 to 100% of the radius of the cylinder.
Advantageously, the space between two shelves represents from 10 to 100% of the radius of the cylinder; this space is preferably about 25% of the radius of the reactor that is preferably a cylinder.
According to a preferred embodiment, the distance between two shelves represents from 5% to 100% of the circumference of the inner wall of the reactor that is preferably a cylinder, more preferably a cylinder with conic ends.
According to another preferred embodiment, the distance between two shelves represents from 10 to 100%, this space being preferably about 25% of the circumference of the inner wall of the reactor that is preferably a cylinder. The form of the shelves is preferably selected in the group constituted by flat, concave, convex, spiral and slanted.
According to a preferred embodiment, the shelves are slanted in relation to the reactor axis, the angle between the reactor axis and the shelves is the same as that between the reactor axis and the horizontal, and preferably the angle between the reactor axis and the horizontal can range from 0 degree to 30 degrees and is more preferably 0 degree.
Advantageously, the height and/or the width of the shelves is calculated and depends on at least one of the following parameters: the space between the shelves, the space between the supports (the “T” brackets), the material the shelves are made of and the weight of the plates. Preferably, the height or width of the shelves ranges from 1 to 8 cm. More preferably, the height or width of the shelves ranges from 1.5 to 4 cm, and the width is preferably about 2.5 cm, more preferably about 2.
According to another embodiment, the width and the height of the shelves are selected in order for the shelves to be able to retain 2 to 3 plates. Advantageously, the height of the shelves is at least about the thickness of the plates, preferably about twice the thickness of the plates.
The shape of the plates of the charge is advantageously selected among the group of parallelograms, such as square, rectangles, lozenges, or trapezes. More advantageously, the plates of the charge are rectangular, triangular, hexagonal or octagonal. The shape of the plates of the charge may be perfect or imperfect, or about perfect.
According to a preferred embodiment, all the plates present in the rotating kiln have about the same size and shape.
The volume of the plates of the charge present in the reactor may represent from 1 to 25% of the internal volume of the reactor. Advantageously, the volume of the plates of the charge present in the reactor represents about 4%, of the internal volume of the reactor.
According to another embodiment, the charge of the reactor is constituted by flat and/or slightly curved metal plates of consistent thickness and shape.
Plates having a melting point which is at least of 100 degrees Celsius, and more preferably that is of at least 150 degrees Celsius above the reactor wall maximum operating temperature in the thermal processing zone, are particularly suited.
Advantageously, the plates are heavy enough to scrape coke or other solids off the reactor wall and/or off other plates.
According to a preferred embodiment, most of plates and preferably each plate present in the rotating kiln, has a density that is superior to 2.0 g/cm3, preferably superior to 3.0 g/cm3 and more preferably comprised between 5.5 g/cm3 and 9.0 g/cm3.
The means for bringing the mixture in contact with at least part of the surfaces of the plates are advantageously, spraying means and/or a conveyor.
Means for bringing the mixture in contact with at least part of the surfaces of the plates are spray nozzles that spray the mixture onto the surface of the plates of the charge when the feed stream is liquid and/or mixture of liquid and/or gas are particularly suited.
The means for bringing the solids outside the reactor is (are) advantageously entrainment with the product gas, scoop(s), screw conveyors and/or gravity.
The means for bringing the solid outside the reactors comprise an exit hopper arrangement attached to the solids exit tube.
According to a preferred embodiments, the rotating reactor has two exits: one for the solids and one for the gas/vapours and entrained solids obtained. The gas/vapours obtained may contain entrained solids.
The rotating kilns used as constitutive element of the mobile plants of the invention are equipped with means for avoiding accumulation of solid in the reactor and/or for plugging of any of the exits.
The means for avoiding accumulation are advantageously a screw conveyor in the solids exit tube, or a slanted solids exit tube.
According to a preferred embodiment, the reactor is a cylinder, or a cylinder with two conic extremities, or two cones attached by their basis, or a sphere. Preferably the reactor is a heated cylinder having a length to radius ratio ranging from 1 to 20 and preferably ranging from 2 to 15, more preferably this ratio is about 10.
The rotating kilns used in the mobile plants may comprise a feeding line positioned about the longitudinal central axis of the reactor, the feeding line being attached to the internal walls of the reactor by attachment means that allow the feeding line to stay immobile despite the rotational movement of the reactor. Said attachment means may comprise a tube and/or at least a ring surrounding the feeding line, the surrounding tube and/or surrounding ring(s) being attached to the internal wall of the reactor and leaving at least part of the feeding line not surrounded. The diameter and/or the constituting material of the surrounding tube and/or of the surrounding ring(s) is (are) selected in order to allow the thermal expansion of the feeding line.
According to a preferred embodiment, the attachment means comprise a second tube and/or at least a second ring surrounding the first tube and/or the at least first ring surrounding the feeding line, the second surrounding tube and/or the surrounding ring(s) being attached to the internal wall of the reactor and to the external surface of the first tube and/or of the at least first ring surrounding the feeding line and leaving at least part of the feeding line not surrounded by support rings.
The length of the attachment means of the second tube and/or of the at least a second ring is advantageously about the distance between the external wall of the second tube and/or of the at least a second ring to the internal wall of the reactor. Wherein the length of the attachment means of the second tube and/or of the at least a second ring may be superior, preferably for at least 10%, more preferably superior for at least 20%, to the distance between the external wall of the second tube and/or of the at least second ring to the internal wall of the reactor. Alternatively, the length of the attachment means of the first tube and/or of the at least first ring to the second tube and/or to the at least a second ring is about the distance between the external wall of the first tube and/or of the at least first ring to the internal wall of the second tube and/or to the at least a second ring. According to another embodiment, the length of the attachment means of the first tube and/or of the at least first ring to the second tube and/or to the at least a second ring is superior, preferably for at least 10%, more preferably for at least 20% to the distance between the external wall of the first tube and/or of the at least first ring to the internal wall of the second tube and/or to the at least a second ring. Some, preferably each, of the attachment means are articulated to their attachment point.
The reactor is advantageously configured in a way that reactor feed is made laterally trough one end of the reactor, and the exits of the vapours obtained during the thermal processing is positioned on the same end or at the opposite end of the reactor. The reactor feed may be made laterally trough one end of the reactor, and the exits of the cokes obtained during the thermal processing is positioned on the same end or at the opposite end of the reactor. Alternatively, the reactor feed is made laterally trough one end of the reactor, and the exits of the vapours obtained during the thermal processing is positioned on the same end or at the opposite end of the reactor.
According to a preferred embodiment, the mobile plant of the invention are configured in a way that the rotating kiln have heating means inside allowing the thermal processing to occur on the plates that are heated on the external walls of the kiln.
The shelves may also be attached to the exterior surface of the kiln.
According to another preferred embodiment, the external walls of the kiln face the internal wall of the stationary housing.
The feeding of the mixture may be on the top of the reactor and is thus preferably at equal distance of each end of the reactor.
The exit of the vapour may be positioned on a side of the walls of the reactor and preferably at equal distance of both ends of the reactor.
The exit of the coke may be positioned on a side of the walls of the reactor and preferably at equal distance of both ends of the reactor.
The exit of the solids may be on the bottom of the reactor and preferably is at equal distance of each end of the reactor.
The rotating kiln rotates around its centre axis, the axis may be horizontal or slanted.
In the mobile plants of the invention, the first unit advantageously comprises:
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- means to heat, and possibly filter, the feed stream
- means to dehydrate the feed stream and to at least partially condense the vapours exiting the dehydrator
- means to separate the water, light oils and non-condensable gas
- means to send the non-condensable gasses to fuel
- means to inject additives, if required
- means to introduce the hot oil recycle stream
In the first unit the feed stream is preferably a waste oil and the dehydrator is heated either by direct contact with the hot heavy oil recycle stream, by an electric heater mounted in a sleeve in the dehydrator and/or by a circulating dehydrator bottom oil stream in a heat exchanger or heater.
In the mobile plant, Unit II preferably contains:
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- means to further preheat the reactor feed stream,
- means to inject a sweep gas, either into the reactor feed stream or directly into the reactor,
- means to feed the reactor feed stream into the reactor,
- a rotating kiln containing plates and operating under pressure,
- two reactor exits: one for vapours and entrained solids, and one for solids.
In the mobile plant, Unit III preferably contains:
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- means to separate the solids from the vapours exiting the kiln, preferably heated in a second enclosure,
- means to remove residual solids from the vapours exiting the reactor,
- means to cool, and to partially condense the reactor products,
- means to separate the reactor products into a specified product slate, and
- means to cool the liquid products.
According to a preferred embodiment, in the mobile plants of the invention only unit I, or only unit II or only unit III is mobile.
According to another preferred embodiment, only units I and II are mobile, or only units II and III are mobile.
In the third unit, the means to separate the solids from the vapours exiting the reactor can be a stationary box, heated cyclones and/or a self-refluxing condenser. The means to separate the reactor products into specification product cuts can be a succession of flash drums, (a) distillation column(s) operating under pressure, at atmospheric pressure and/or under vacuum. The means of cooling the reactor products are conventional equipment such as heat exchangers with cooler oil streams and/or cooling water and/or air coolers.
A second object of the present invention is constituted by the processes for thermally treating a feed material by using a mobile plant as defined in the first object of the present invention.
The processes of the invention are using a mobile plant for thermally treating a feed stream and comprises the following steps:
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- i. a first step wherein the feed stream is heated and/or dehydrated and/or degased (Step I);
- ii. a second step the heated feed stream is thermally processed (pyrolized) and the resulting thermally processed streamed is treated by a vapour solid separator (Step and
- iii. a third step (Step III) that is a product separation step wherein part that of the treated feed stream (heavy oil), recovered in Step III may be recycled, into Step I or II.
Unit I and/or unit II is (are) configured for injecting a sweep gas in the feed oil and/or in the rotating reactor, and/or the second unit is configured in a way that the rotating reactor may work under positive pressure.
According to a preferred embodiment, in the processes:
-
- a) the rotating kiln operates under a positive pressure that is preferably of at least 1 psig and for producing the following components: coke and non-condensable gas and/or heavy oils and/or wide range diesel oils and/or naphtha, each of those produced components being recovered separately or in the form of mixtures of at least two of these components, wherein in the process a sweep gas, that is an inert gas or a substantially non-reactive gas, is injected into the rotating kiln or in the oily feed stream entering the rotating operating kiln; or
- b) the rotating kiln operates under a positive pressure that is preferably of at least 1 psig and for producing the following components: coke and non-condensable gas and/or heavy oils and/or wide range diesel oils and/or naphtha, each of those produced components being recoverable separately or in the form of mixtures of at least two of these components; or
- c) the rotating kiln operates for producing the following components: coke and non-condensable gas and/or heavy oils and/or wide range diesel oils and/or naphtha, each of those produced elements being recoverable separately or in the form of mixtures of at least two of these components, and wherein in the process a sweep gas, that is an inert gas or a substantially non-reactive gas, is injected into the rotating kiln or in the feed stream entering the rotating operating kiln.
The feed material is advantageously an oily feed that is preferably a contaminated oil or an uncontaminated oil.
Among the oily feed is selected among: contaminated or uncontaminated oils, waste oils, used lubricating oils, oily tank bottoms, Marpol, heavy oils, bitumen and other heavy oils, coal, oil sands, asphalts, chemically pre-treated oils or mixtures of at least two of the latter, are of a particular interest.
During the process, the vapours and the solids exiting the rotating kiln in function may advantageously be routed to vapour solid decantation means.
According to a preferred embodiment, the vapour solid separation means are a stationary box and/or a heated cyclone for the heavier solid and/or cyclone(s) to separate most of the solids present in the vapours exiting the rotating kiln from the vapours; the cyclone treatment following advantageously the treatment by one or several cyclones.
The solids present in the vapours exiting the rotating kiln may be: coke, metals, sand, dirt, asphaltens, preasphaltens, sulphurous compounds, heavy polymers such as gums and/or resin, salts, cokes containing various compounds such as sulphur, halogen and metal; each of these solid component being alone or in mixture with at least one of the latter component.
The vapour-solid separation equipment, preferably the separation box an or the cyclones, is (are) preferably heated, at a temperature that is(are) above the temperature of the vapours exiting the kiln, preferably this temperature is up to about 300 degrees Celsius, more preferably up to 200 degrees Celsius, advantageously up to about 20 degrees Celsius, more preferably up to 10 degrees over the temperature of the vapours exiting the kiln.
The vapour solid separation equipment, preferably the cyclones and/or the separation box, are advantageously heated at a temperature that is at least 10, and preferably at least 20, degrees below the cracking temperature of the vapour.
The solid exiting the rotating kiln may be a dry coke, for example this coke preferably contains less than 2 weight percent of oil.
According to an advantageous embodiment of the processes of the invention, most, preferably more than 50%, more preferably more than 90%, of the coke is removed from the vapours exiting the rotating kiln, and, in the case wherein the feed oil is an used oil, up to 99.5% of the coke is removed from the vapour exiting the rotating kiln.
The vapours exiting the vapour solid separating equipment, such as cyclone(s), are advantageously partially condensed in a self-refluxing condenser and/or in a wash tower, to complete the solids removal from the reactor products.
The vapours exiting the last step wherein solids are advantageously eliminated, and this step takes preferably place at the top of the condenser and/or of the wash tower, are routed to product separation, while the recovered heavy oil containing the residual solids exits at the bottom.
The heavy oil, resulting from the process containing the residual, is recycled preferably in a dewatering step, when present, and/or in the oil feed entering at the beginning of the process, and/or in the oil feed entering the rotating kiln feed.
The recovered heavy oil and the fractionators bottoms oil positioned in the product separation section can also be used as back flushing oils to clean fouled equipment.
The positive pressure, in the rotating kiln, may advantageously range from 1 to 4 atmospheres, preferably this pressure range from 1.2 to 1.5 atmospheres (absolute).
According to a preferred embodiment, the feed oil, before entering the rotating operating reactor, is heated, preferably at a temperature that is at least 20 degrees Celsius under the cracking temperature of the feed oil.
The water present is advantageously removed from the feed oil, before the feed oil enter the reactor. The water removal is preferably performed in a flash evaporator, from the feed oil, before the feed oil enter the rotating kiln.
The processes of the invention may also be used for the thermal processing of a feed oil that is an oil, which according to its history and/or according to its origin, was, before entering the rotating kiln, chemically treated, or slightly chemically treated, to reduce its metal content, preferably the feed oil is treated by at least one acid and by at least one base, the acid being advantageously a sulphur acid and/or a phosphoric acid. The feed oil may also be an oil that was physically and/or chemically pre-treated before entering the process.
In the heating step(s), that may be performed in step I and in step II the is(are) accomplished in a heater and/or by heat exchange with a hot oil stream, a hot thermal fluid, by the injection of a hot gas, by direct contact with a hotter oil stream, or by a combination of at least two of these methods.
According to a preferred embodiment, the reactor feed stream resulting from the heating of the feed oil is, before entering the rotating operating reactor, sprayed unto metal plates in a rotating kiln that contains metal plates, wherein it is thermally cracked and/or vaporized.
The reaction products that exit the rotating kiln may comprise hydrocarbon vapours and other vapour present in the reaction zone of the rotating operating kiln and solid coke.
The reaction products exiting the rotating operating kiln are advantageously swept out of the rotating operating reactor as soon as possible, preferably in 5 seconds to 60 minutes, more preferably in about 5 minutes; the residence time is a function of at least one of the following parameters: feed oil composition, the reaction pressure, the temperature and/or the desired product slats.
The reaction products, when swept out of the rotating, are heated advantageously heated at a temperature that is advantageously slightly over the temperature at the exit of the reactor.
According to a preferred embodiment, most of the coke is removed from the hydrocarbon stream exiting the rotating kiln, before the oil is condensed preferably in a vapour/solid separator and then advantageously in cyclones and/or in a wash tower or in a self-reflecting condenser.
The hydrocarbon product stream is advantageously condensed and separated into specified products.
According to preferred embodiments of the processes of the invention:
-
- at least part, and preferably all, the non-condensable gas produced in the rotating operating kiln is used as fuel on site; or
- at least part, and preferably all, the naphthas present in the feed oil and/or produced in the rotating kiln is used as fuel on site.
When a sweep gas is used, the sweep gas used is preferably a superheated steam. The sweep gas may represent in weight up to 30% of the weight of the feed oil, preferably up to 10%, and more preferably between 0.5 and 5% of the weight of the feed oil.
The cyclones used to separate the coke and other solids are advantageously positioned outside of the rotating operating reactor but inside a second heated enclosure, the second kiln communicating or not with the first reaction's zone in order to benefit of a warm hot flue gas flow surrounding the cyclones.
At least part of the purified oils thereby recovered may be used on the site or sold to clean heat exchanger(s) or other fault equipment.
The residence time in the rotating kiln ranges from 3 to 15 hours, and this time preferably range from 2 minutes and 30 minute.
The demetalisation rate of the total liquid oil products (heavy oil, wide range diesel and naphtha) recovered during the process is advantageously of at least 90%, preferably of at least 95% and more preferably of at least 99%. The total recovered oil contains less than 60 PPM of metal.
The metals mainly present in the recovered total oil products are mainly copper, iron and zinc, the other metals being at a level that may be as low or inferior to 1 PPM. Chrome, vanadium, cadmium, nickel and lead, originally present in the feed stream, being during the process mainly concentrated in the recovered coke, the concentration may reach up to 99% weight.
According to a preferred embodiment, the gas recovered from the rotating kiln being mainly composed of hydrocarbon, preferably alkanes and/or of alylenes. The gas and the naphtha produced are advantageously used as fuel on the site to satisfy the energy self sufficiency of the plant in function.
The recovered oil is characterized in that is has no sulphurous content or has less than 3000 ppm of the sulphur in the mixture.
The processes of the invention allow for Marpol to be injected in the feed oil that is preferably of the type present in the bottom of ship fuel tank. Said specific amount of Marpol may advantageously represent from 10 to 95% of the weight of the feed oil and the feed oil may be replaced by a Marpol (no direct injection).
The limited amount of water present in the oily products represent up to 98% weight of the feed oil, provided the oil is at a temperature lower than its vaporisation temperature at line pressure
The processes of the invention are particularly suited for treating limited amount of oily products containing up to 99% weight of the feed oil.
The processes of the invention are particularly efficient due to the fact that the rotating kiln contains a charge of plates and at least part of the surface of the plates is used to perform the thermal treating. Advantageously, the thermal processing is performed on at least part of the surface of the plates in movement. Preferably, the processes of the invention are used for thermal processing of a mixture, wherein thermal processing is performed on at least 5%, preferably on at least 10% of the surface of the plates and/or on at least 5%, preferably on at least 10% of the plates.
It has been surprisingly discovered that during thermal processing of a mixture, wherein the plates when moving inside the reactor clean the walls of the reactor, and avoid reactor wall failures.
It has been also surprisingly discovered that during thermal processing of a mixture the plates protect at least part of the walls of the reactor and that the plates contribute to the uniformity of temperatures conditions in the reactor.
It has been further discovered that during the thermal processing of a mixture in the plates contribute to the heat transfer taking place from the heated walls to the surface of the plates, particularly to the heat transfer taking place on the surfaces of those plates wherein thermal processing occurs.
A third object of the present invention, is constituted by the uses of a process as defined in the second object of the present application, for:
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- treating wastes oils such as used lubricating oils, form oils, metal treating oils, refinery or transportation oil tank bottoms; and/or
- destroying hazardous and/or toxic products; and/or
- reusing waste products in an environmental acceptable form and/or way; and/or
- cleaning contaminated soils or beaches; and/or
- cleaning tar pit; and/or
- use in coal-oil co-processing; and/or
- recovering oil from oil spills; and/or
- recovering PCB-free transformer oils.
The uses of a process of the invention for treating used oils and to prepare:
-
- a fuel, or a component in a blended fuel, such as a home heating oil, a low sulphur marine fuel, a diesel engine fuel, a static diesel engine fuel, power generation fuel, farm machinery fuel, off road and on road diesel fuel; and/or
- a cetane index enhancer; and/or
- a drilling mud base oil or component; and/or
- a solvent or component of a solvent; and/or
- a diluent for heavy fuels, bunker or bitumen; and/or
- a light lubricant or component of a lubricating oil; and/or
- a cleaner or a component in oil base cleaners; and/or
- a flotation oil component; and/or
- a wide range diesel; and/or
- a clarified oil; and/or
- a component in asphalt blends,
are also of a particular interest.
A fourth object of the present invention is constituted by the uses of the products, preferably of the diesel, and heavy oils, obtained in a process, as defined in the second object of the invention, for cleaning fouled equipment such as tank bottoms or other reservoir contaminated with hydrocarbons and other fouling materials such as asphaltenes, tars, coke, salts, dirt, gums, and resins.
The uses for cleaning equipment and materials contaminated with hydrocarbons and other fouling materials such as asphaltenes, tars, coke, salts, dirt, gums, and resins are of a particular interest.
According to the uses of the invention, the cleaning of the fouled equipment is performed without water and/or without a need to separate water from the residue of the cleaning. Also the invention permits the use of higher temperatures and the heavy polarized oils allow for a higher efficiency for removing fouling materials containing hydrocarbons.
Advantageously, the residue from the cleaning and the oil, thereby obtained, can then be pumped out and treated.
A fifth object of the present application is constituted by the use of a mobile plant, as defined in the first object of the present application, on the site wherein contaminated oil is present in contaminated equipment, to produce heavy polarized oils to clean the contaminated (equipment) tanks on the site and equipment and then treat the residue of the cleaning into heavy oils to obtain commercial products and more oil to continue the cleaning process.
Among those uses, those wherein contaminated oil is present in a contaminated equipment, to perform effective periodic cleaning of a contaminated equipment such as tank farms and refinery equipment, are of a particular interest.
These uses of a mobile plant, may be performed on the place wherein contaminated oil is generated or on a specific place (storage unit) close to other places wherein various contaminated oils are generated and with reduced transport of waste oils which are hazardous material.
The uses of a mobile plant, to treat waste oils in regions with low density of population, for example near out of the way mines or industrial complex and where the volumes of oils to be treated at any given time is low and the cost of transporting the oils is high or could lead to ecological disasters during the transport, are also of a particular interest.
According to a preferred embodiment of the uses of the invention, the waste oils treated are most of the waste oils in these regions are burned or thrown away which is very bad for the environment.
Also of a particular interest are those uses of a mobile plant wherein the mobile plant is transported on a periodic basis and/or when necessary, for example in the case of an irregular production of contaminated oils or in the case of an accidental environmental contamination, in these regions to treat the oils and sell the product in the region.
Advantageously, are the uses of mobile plant of the invention wherein the mobile plant or at least one unit, preferably at least unit II, of the mobile plant, is built within a standard 45 feet high cube container.
Preferably the mobile plant and is transported by truck, rail, airplane, submarine or boat.
A sixth object of the present application is constituted by the processes for manufacturing the mobile plants as defined in the first object of the present invention, wherein the process comprises assembly by known means the constituting elements of the reactor.
Advantageously, in the manufacturing processes, the known assembling means comprise at least one of the following means: screwing, jointing, riveting and welding.
Those manufacturing processes, comprises manufacturing steps wherein Unit I and/or Unit II and/or unit III are attached on the platform of a mobile vehicle such as truck, wagon, plane, ship.
DETAILED DESCRIPTION OF THE INVENTIONThe waste oil feedstock can contain up to 20% water in an emulsion, and up to 10% naphtha. Free water should be separated at the tank farm. The feed oil can be chemically pre-treated before entering the plant, however, it is usually not required.
The feed oil (1) is filtered (2) and heated to approximately 90 degrees Celsius (3). If necessary, the waste oil feedstock may be filtered again or put through a decanter to remove as much solids (12) as possible before entering the dewatering unit. The feed oil is sprayed into a pre-flash drum (4) where a pool of oil is kept hot by means of a re-boiler heater (5). The water and naphtha in the feed oil are evaporated and exit the flash drum from the top of the vessel. The water and naphtha are cooled and condensed (6) and the water (7), naphtha (8), and possibly gas (9) are separated and pumped to the tank farm. The de-watering system can operate at pressures up to 90 kPa gauge, and hot oil temperatures up to 260 degrees Celsius.
The hot and dry oil from the flash drum is heated (10), either through heat exchange or put into a vacuum column. It is then routed to the reactor. A gas stream (11), representing between 0.1 and 10% wt. of the reactor feed stream, is introduced into the dry waste oil feed stream to the reactor. When used lubricating oils are processed, the steam injection rate should be around 4% wt. on dry feed. The gas stream serves many functions: It changes the flow regimes of the reactor feed stream and prevents fouling and plugging of the piping and spray nozzles. It reduces the oil's residence time in the reactor, thereby reducing the incidence of secondary reactions, or over-cracking, resulting in more stable product oils. It can also be part of the stripping gas stream in the product distillation unit.
The combined oil and gas stream is introduced into the reactor through one or more spray nozzles (14) within the rotating kiln (13) as described in the Canadian Patent Application No. 2,704,186. The kiln rotates within a combustion chamber (15) which is fired by temperature controlled burners (16). The rotating kiln has internals and is kept at the desired temperature such that the vaporization and thermal cracking of the feed oil takes place before the liquid can reach the kiln wall. The thermal process produces hydrocarbon vapours and small solid particles that contain most of the sulphur, all of the excess carbon, some of the halides and almost all of the metals that were in the feed oil.
The reactor operates at a positive pressure up to 90 KPa(g). The kiln operating temperature is determined by the quality and quantity of the waste oil, and by the quality and quantity of the desired products. It can vary between 380 and 4600 degrees Celsius for used lubricating oils feeds, and up to 550 degrees Celsius, when bitumen or heavy oils are treated.
The hydrocarbon vapours and the coke particles exit the reactor and enter a box and/or cyclone (16) separators where the solid particles are removed from the hydrocarbon vapours. In a preferred mode, the vapour-solids separators are in a heated chamber (18) or heat traced to prevent dew point condensation and plugging of the equipment. The coke (31) and other solids drop by centrifugal force and gravity, cooled (30) and stored. The coke and other solids exiting the reactor are non-leachable.
The hydrocarbon vapours enter a flash drum (19) and self-refluxing condenser, or scrubbing tower (20) assembly, where any remaining coke is removed. The heavy oil from the bottom of the flash drum is recycled to the reactor feed or mixed with the distillation column bottoms. The vapours from the reactor are partially cooled (21) and enter the product separation unit (21). The vapours exiting the top of the main distillation column are cooled (22) are the product gas (23), naphtha (24) and water (25) are separated.
The water is sent to storage or to the water treatment unit. After treatment, it can be re-used in the steam generation unit. Some of the naphtha is used as reflux to the main distillation column, the rest is sent to storage. It will later be used as fuel in the plant. The gas is consumed on site as fuel in the plant.
The diesel fraction (27) is pulled as a side cut, through a stripper, cooled (26) and sent to storage.
The column bottoms or heavy product (28) can either be recycled to the cracking vessel, or cooled and sold as de-metalized, low sulphur, heavy fuel oil. When heated the heavy oil is very effective as backwash oil in the plant. It permits on-stream cleaning of fouled equipment and minimises the need for chemical pre-treatment of used oil feeds.
Although the present invention has been described with the aid of specific embodiments, it should be understood that several variations and modifications may be grafted onto the embodiments and that the present invention encompasses such modifications, usages or adaptations of the present invention that will become known or conventional within the field of activity to which the present invention pertains, and which may be applied to the essential elements mentioned above.
Detailed Description of Rotating Kiln that May Advantageously be Used in the Mobile Plant of the Invention
Preferred Embodiments of the ReactorThe invention is that of the indirectly fired rotating kiln (1), represented on
The plates carry the heat from the reactor walls and provide a hot surface where the reactions take place. The plates are lifted and kept against the reactor walls by shelves (3). Depending on the thickness of the plates, the shelves can be designed to hold one, two or more rows of plates. As the kiln rotates, the plates fall off the shelves or off the plates below, presenting the face that was against the reactor wall to the oil spray.
As they slide over each other, the metal plates become a surface that protects the reactor walls from direct contact with the relatively cold oil spray and from the resulting thermal shock. Also, as they slide down the reactor, the plates scrape the reactor walls and each other clean of coke and avoid bridging of the depositing coke. The coke released is entrained out of the reactor with the hydrocarbon gas or is removed by the scoops, hopper and solids exit.
The shelves are attached to the reactor walls with clamps (6), represented on
The clamps (6) are shaped like a T as represented in
Scoops (10) are attached to the kiln wall at the exit end of the kiln to remove heavier coke that may have deposited on the bottom of the kiln. The scoops are pipe sections with one end closed, and the other end cut on a slant, to allow any hydrocarbon vapours to escape before the coke falls into the hopper (11). The scoops are sized small enough so that the metal plates cannot enter with the coke. As the reactor rotates, the scoops turn upside down and dump their load of coke into a hopper mounted on the solids exit tube (12). To ensure that none of the plates block the coke exit from the reactor, the hopper has a metal grid (13) that will deflect any plate towards the bottom of the kiln. The solids exit tube (12) has a screw conveyor (15) to push the coke out of the reactor. The solids exit tube can be above the vapour exit tube (14), within the vapour exit tube, below the vapour exit, or even at separate ends. There must be at least two exits from the kiln to ensure that the reactor exit is never obstructed. In normal operation, the coke will exit the reactor mostly through the vapour exit (14). The scoops are required when the feed to the kiln is interrupted and there are no vapours to carry the coke out, or when there is a surplus of coke, or the coke is wet or heavy.
The reactor is an indirectly fired rotating kiln, heated by the burner 5, and containing a charge of metal plates that carry the heat from the reactor walls and provide a hot surface where the reactions take place. The plates are lifted and kept against the reactor walls by one or more shelves, wide enough to hold two plates. As the kiln rotates, the plates fall off the shelves, presenting the face that was against the reactor wall to the oil spray. The metal plates protect the reactor walls from thermal shock, and scrape the walls and each other clean of coke. The shelves are attached to the reactor walls with clamps to reduce stress due to differential thermal expansion between the reactor walls and the shelves. Both the plates and shelves increase the heat transfer area from the heat source to the reaction site.
In the test apparatus, used lubricating oils or other oils from a collection depot are sprayed into a horizontal or slanted rotating kiln 10′ in diameter and 8′ long in order to thermally crack and vaporize the oil or the chemicals within it. The kiln has 4″ fins welded in continuous spirals, 8″ apart, to the inside of the kiln walls. A 1″ wide shelf is attached to the fins, and a charge of 4″ equilateral triangular metal plates is added.
As the kiln rotates, the shelf pushes and raises the blades along the reactor wall. As they reach just past the 5′ height, they flip as they fall at the top of their run, presenting their hot side to the oil being sprayed on them.
Upon contact with the hot plates, the oil is thermally cracked and/or vaporized. The coke formed is either entrained with the vapours out of the kiln or it deposits on the plates. The plates, sliding against the reactor wall or on each other, scrape the coke free, and it is entrained out of the reactor with the vapours. Most of the coke exits the reactor with the hydrocarbon vapours; the residual coke is removed by the scoops, hopper and solids exit.
Four scoops are welded to the reactor wall at the exit end. They are made from 4″ piping, 6″ long, with one end plugged, and the other end cut on a slant. A hopper protected by a metal cage above it, receives the coke dumped by the scoops. The cage deflects any scooped up plate back into the reactor. The hopper receives the coke and drops it into the coke exit tube. A screw conveyor, on the bottom of the coke exit tube, carries the coke out of the reactor.
When the reactor feed is used lubricating oil, the recovered gas is 5% weight of the feed and has an average molecular weight of 42, the recovered liquid is 92% weight of the feed and has an average specific gravity of 0.83 and the solids are 3% weight of the feed and have a specific gravity of 1.7. These numbers depend on the feedstock composition, and on the reaction temperatures and pressures.
The plates are lifted from the plate bed (24) by the shelves (20). In this illustration, the reactor (25) is supported by two horizontal cylinders (26) and is heated externally with gas or naphtha burners (27). The reactor rotates inside a heating chamber, which is stationary (38). There are various options for the heating chamber. It could be a section of a hot stack, where the stack gas needs to be cooled before clean-up, for example. A seal (37) is shown around the rotating kiln and the stationary wall of the heating chamber. It is useful to keep the feed pipe in place with support rings (28), as illustrated on
This reactor would be used for feedstocks that contain solids such as sand.
The reactor actually has four shelves, but only two are shown here (20). The other two shelves would be on the section not shown. The feed enters the reactor in pipe 21, it is pushed along the feed line with a screw conveyor and is projected unto the hot plates (23) through the end of the pipe or slits in the pipe (22).
The plates (23) are rectangular and are about as long as the reactor section where they are installed when the reactor is heated. The plates are lifted from the plate bed (24) by the shelves (20). In this illustration, the reactor (25) is supported by two slanted cylinders (26) and is heated externally with gas or naphtha burners (27). The reactor rotates inside a heating chamber, which is stationary (38). A seal (37) is shown around the rotating kiln and the stationary wall of the heating chamber. The gas and entrained coke leave the reactor through the gas exit pipe (29). The solids that are too heavy to be entrained out of the reactor by the gas, slide long the reactor floor, through the screens (36), and are scooped up by the scoops (30). Accumulated solids are scooped up, along with residual coke, by shovels (30), are dumped into a hopper (31), and are carried out of the reactor with the help of a screw conveyor (32) inside the solids exit pipe (33). There is a seal (34) between the rotating reactor and the product exit box (35).
The product exit box is stationary. A first separation of solids and vapours occurs in the product exit box (35).
This reactor could be used for liquid feedstocks and/or feedstocks that contain solids such as sand. The reactor actually has four shelves, but only two are shown here (20). The other two shelves would be on the section not shown. The feed enters the reactor in pipe 21, and is projected unto the hot plates (23) through the end of the pipe or spray nozzles (22).
The plates (23) are rectangular and are about as long as the reactor section where they are installed when the reactor is heated. The plates are lifted from the plate bed (24) by the shelves (20). In this illustration, the reactor (25) is supported by two truncated cones and a cylinder (26) and is heated externally with gas or naphtha burners (27). The reactor rotates inside a heating chamber, which is stationary (38). A seal (37) is shown around the rotating kiln and the stationary wall of the heating chamber. The gas and entrained coke leave the reactor through the gas exit pipe (29). The solids that are too heavy to be entrained out of the reactor by the gas, slide long the reactor floor, and are scooped up by the scoops (30). Accumulated solids are scooped up, along with residual coke, by shovels (30), are dumped into a hopper (31), and are carried out of the reactor with the help of a screw conveyor (32) inside the solids exit pipe (33).
There is a seal (34) between the rotating reactor and the product exit box (35). The product exit box is stationary. A first separation of solids and vapours occurs in the product exit box (35). This shape of reactor allows the plates to slide back towards the entrance and scrape the walls, other plates and the shelves clean of coke and other deposited solids.
The reactor actually has four shelves, but only two are shown here (20). The other two shelves would be on the section not shown. The feed enters the reactor in pipe 21, it is either pumped or pushed along the feed line with a screw conveyor and is projected unto the hot plates (23) through spray nozzles or slits in the pipe (22). The plates (23) are rectangular and they not only flip when falling off the shelves, but also slide along the shelves, scraping coke off the shelves and reactor walls.
The plates are lifted from the plate bed (24) by the shelves (20). In this illustration, the reactor (25) is supported by two slanted rollers (26) and is heated externally with gas or naphtha burners (27).
The reactor rotates inside a heating chamber, which is stationary (38). A seal (37) is shown around the rotating kiln and the stationary wall of the heating chamber. The gas and entrained coke leave the reactor through the gas exit pipe (29). The solids that are too heavy to be entrained out of the reactor by the gas, slide along the reactor floor, and are scooped up by the scoops (30). Accumulated solids are scooped up, along with residual coke, by shovels (30), are dumped into a hopper (31), and slide out of the reactor through the slanted solids exit pipe (33). There is a seal (34) between the rotating reactor and the product exit box (35). The product exit box is stationary. A first separation of solids and vapours occurs in the product exit box (35).
Description of the Mobile PlantThis example of a mobile thermal cracking plant can process 50 barrels per stream day (BPSD) of used lubricating oil or heavy fuel left as a tank bottom. All the essential equipment is mounted in a container, or on a flat-bed truck, or on the bridge of a ship.
The waste oil feedstock (1) is pumped with P-101, to stream (2), the feed to V-102, the dehydrator. P-103 pumps dehydrator bottom oil (3) through H-104. The oil exiting H-104 is separated into two streams, one (stream 4) returning to V-102, providing the heat required to vaporise the water in the feed oil, and the second stream (5) is the reactor feed oil.
Water, stream (6) is heated, becomes steam (7) and injected into stream (5). The combined stream (8) is injected into the reactor (R-120), where the oil is thermally cracked and/or vaporized. The vapours and coke exiting the reactor, stream (9), are routed to one or more heated cyclone(s), Cy-121, where the coke drops out in stream (10), and the vapours, stream (11), are sent to a dephlegmator (AC-124). The heavy oil, containing traces of coke is pumped with P-123 out of V-122, in stream (12). The vapours exiting the dephlegmator (13) are routed to a column pre-flash drum, V-130.
The liquid from the pre-flash drum, stream enters the column, C-131, a few trays, maybe 4 trays, from the bottom, while the vapours from V-130, stream (15), enters the column below the bottom tray, and provides the vapour flow to the column.
The heavy oil exiting the column, stream (16), is pumped out of the column with P-133, joins stream (12), and the combined heavy oil stream (17) is cooled in AC-136, and sent to storage.
Further up in the column, around tray 7, the gasoil cut, stream (19) is drawn from the column, pumped with P-139, air cooled in AC-132, and sent to storage stream (20).
The column overhead vapours, stream (21), are routed to an air cooler, AC-134, in which the naphtha cut and the steam are condensed. Stream (22), containing water and liquid naphtha along with non-condensable gas enter V-135, a three phase separator. The non-condensable gas, stream (23), serves as fuel in the plant.
The naphtha, stream (24), is pumped out of V-135 with P-138. It separates into two streams: stream (25) is the reflux to the column, providing the liquid flow in the top section of the column, while stream (26) is product naphtha sent to storage and/or serves as fuel in the pant.
P-137 pumps the water (or condensed steam) to a treatment facility or to storage, stream (27).
The column, C-131, is transported in the horizontal position, sitting on three supports: S1, S2, and S3. The supports are 6 feet high and have a semi-circular shape at the top to hold the column in place. Support S1 is the pivot around which the column can be raised and lowered. S1 also serves as part of the column's skirt, when the column is vertical.
The pumps are on pallets and are put either on the back end of the flatbed or under the column. The rest of the space under the column is a storage area for the piping that is removed for transport, and will be hooked-up when the plant is on site.
The air coolers are on a rack above the two three phase accumulators, V-135 and V-106. The air coolers are on supports and rails, and can slide out once the plant is on site.
A heat exchanger, E-109, is not shown on the simplified flow diagram. It cools the vapours exiting the dephlegmator and heats the reactor feed stream, reducing the heat required in the reactor R-120.
A second flatbed or container truck would carry the control room and instrument switch boards, along with an enclosed flair and a fork lift truck. The flare would be installed at a safe distance from the plant once on site.
Advantages of the Use of a Rotating KilnIn order to understand the advantages of the invention, it may be useful to explain why the invention was necessary and how it progressed.
In the kiln above, at first, the oil was sprayed on a charge of ceramic balls. For the reaction to occur, the kiln had to be over heated because the charge impeded heat transfer to the reaction sites. Furthermore, the ceramic balls were too smooth and light to scrape the coke off the reactor walls. The balls exploded into dust because of the thermal shock between the cold oil and the hot reactor wall. The reactor had to be shut down to remove the coke and ceramic dust that caked the reactor wall and bottom. The reactor runs were less than a day long.
The solids charge was changed to a number of coarse granulated solids charges. They were more effective in scraping the coke off the reactor walls but soon the coke stayed trapped within the charge, again impeding the heat transfer to the reactor sites. The temperature at the reaction site varied as the coke built up within the charge. The run times increased to 3 to 4 days before the reactor had to be shut-down.
The solids charge was replaced by off-spec cultivator blades: equilateral triangles, with 6″ sides, made of carbon steel. The blades were effective in keeping the reactor walls clean but the temperature in the reactor continued to vary. A shelf was attached to the reactor wall and the reaction temperature became steady and easier to control, allowing for a specific slate of products of consistent qualities. The reactor walls stayed free of coke and run times increased to 6 weeks or more.
Thermal cracking is an endothermic reaction. Since the oil spray was directed to the hot metals plates, the coke deposited on the metal plates instead of the reactor walls. The blades not only removed the coke that formed on the reactor wall, they protected the reactor wall from coke depositing there in the first place. The shelf pushed the metal plates higher and longer against the reactor wall. The reaction surface area and its temperature could be increased without over firing the kiln.
There was a conveyor to transport the coke from the bottom of the reactor to the exit tube. The conveyor was enclosed, protecting the coke and hydrocarbon vapours from the heat source. This caused the coke to be wetted by the condensing oil, and to agglomerate. This apparatus resulted in the formation of coke-oil plugs that obstructed the exit tube and cause over pressuring of the reactor. The enclosed conveyor was replaced with scoops, open to the kiln heat, dumping dry coke into the new coke exit tube. The coke exit tube was separated from the vapour exit to avoid re-entrainment of the fines into the product vapours or plugging of the only exit from the reactor and over-pressurizing the reactor.
EXAMPLES Mobile Plant for Thermally Treating a Feed Oil, that is a Contaminated OilThe mobile plant represented on
The mobile plant comprises and a rotating reactor having the following specifications:
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- Reactor cylinder internal diameter: 5′
- Reactor cylinder length: 20′
- Heat released: 0.5 MMBtu/hr
- Conic section heights: 2.5′
- Housing external size: 7′ high 6′ wide and 26′ long
The following examples illustrate some of the operating conditions that could be used in a mobile plant:
Examples 1, 2 and 3 were tests performed using dry waste oil drawn from the same drums to eliminate test result differences due to variations in feed oil quality as much as possible.
Example 1 was performed with the injection of 5% weight. water added to the 16 l/h reactor feed oil.
Example 2 kept the same oil feed rate and operating conditions as in example 1 but without water injection into the reactor.
In example 3, the oil feed rate was increased by 50% to 24 l/h, again without water in the reactor feed.
Example 4 was performed on the same kiln but with a different oil sample.
Example 1Refer to Table 1—Example 1 for a summary of the operating conditions and feed and products rates and analyses. The waste oil streams tested contained used lubricating oils as well as other oily streams such as metal working oils, transmission fluids, greases, form oils, and any number of unknown waste oil streams.
Notes (1) The oil feed is 95% of the reactor feed stream, while the water entering the kiln makes up the other 5%. The steam injected into the reactor feed stream is condensed in the distillation column overhead. All the product yields are calculated on a dry oil basis.
A dewatered waste oil stream of 16 L/min is injected in an indirectly fired rotating kiln, containing metal shavings at 490 degrees Celsius reactor exit temperature.
The seals on the kiln were changed to permit pressures above atmospheric in the reaction zone. Steam was also injected into the reactor at the rate of 5% weight on dry oil feed.
As shown on Table 6, a 72% conversion of the 350 degrees Celsius+ fraction into lighter oils, gas and coke was observed. Over 95% of the metals entering the reactor exits with the coke.
Example 2Please refer to the Table 2, Example 2 for a summary of the operating conditions and feed and products rates and analyses.
The waste oil streams tested contained used lubricating oils as well as other oily streams such as metal working oils, transmission fluids, greases, form oils, and any number of unknown waste oil streams.
A dewatered waste oil stream of 16 L/h is injected in an indirectly fired rotating kiln, containing metal shavings at 490 degrees Celsius. This stream was drawn from the same barrel as in Example 1. The seals on the kiln had been changed to permit pressures above atmospheric in the reaction zone. There was no steam injection into the reactor for this test.
As shown on Table 5, a 69% conversion of the 350 degrees Celsius+ fraction into lighter oils, gas and coke was observed. Over 95% of the metals entering the reactor exits with the coke.
The main difference between these two examples is in the gasoil make: in example 1, the gasoil in the products was 56.5% weight, a gain of 30.5% weight on feed oil. In example 2, the gasoil make was 46.8% weight of the products, a gain of only 20.8% weight on feed oil. The injection of steam into the reactor may have impeded the secondary reactions in which the gasoil present in the reactor is cracked, producing naphtha and gas. The operation of the reactor during example 1 was more stable than for example 2 in that temperatures and pressure swings were calmed. The wide range diesel oil produced was lighter in colour and more stable in example 1 than example 2.
Example 3Please refer to the Table 3—Example 3 for a summary of the operating conditions and feed and products rates and analyses.
The waste oil streams tested contained used lubricating oils as well as other oily streams such as metal working oils, transmission fluids, greases, form oils, and any number of unknown waste oil streams. The oil in this test was taken from the same drums as for examples 1 and 2. However, the analytical data differs a little from the previous examples. This confirms that waste oil feedstocks can change in properties, even when pulled from a single tank.
A dewatered waste oil stream of 24 L/h is injected in an indirectly fired rotating kiln, containing metal shavings at 490 degrees Celsius. The seals on the kiln were changed to permit pressures above atmospheric in the reaction zone. There was no steam injection during this test.
As shown on Table 6, a 61% conversion of the 350 degrees Celsius+ fraction into lighter oils, gas and coke was observed. Over 95% of the metals entering the reactor exits with the coke.
In this example, the feed rate was increased by 50% over the first two examples, and there was no steam injection. Although the conversion of heavy oil is lower than in the first two examples, 61% of the 350 degrees Celsius+ oil was cracked, the gasoil gain was 28% weight, higher than for example 2, and slightly lower than in example 1. See Table 6. Increasing the feed rate by 50% also reduced the secondary reactions but operation of the reactor was difficult because of pressure swings and decreasing temperatures in the steal chip bed.
Example 4Please refer to the Table 4—Example 4 for a summary of the operating conditions and feed and products rates and analyses.
The waste oil streams tested contained used lubricating oils as well as other oily streams such as metal working oils, transmission fluids, greases, form oils, and any number of unknown waste oil streams. This oil was heavier than the feed oil in the previous three examples.
A dewatered waste oil stream of 6.7 L/h is injected in an indirectly fired rotating kiln, containing metal shavings at 490 degrees Celsius. The seals on the kiln were changed to permit pressures above atmospheric in the reaction zone. Steam was also injected into the reactor at the rate of 0.5% weight on feed.
As shown on Table 6, a 79.5% conversion of the 350 degrees Celsius+ fraction into lighter oils, gas and coke was achieved. The gasoil make was 70% wt., an increase of 57% of the feed oil. Over 95% of the metals entering the reactor exits with the coke.
Please refer to the Table 5 for a summary of the heavy oil conversion and gasoil product gains in the four test previously described.
These examples show that the injection of a sweep gas, in this case steam, results in a more efficient conversion of the heavy oil into gasoil, or wide range diesel fuel. A more stable operation and constant reaction temperature are obtained when the reactor is operating under pressure, instead of a vacuum. Also, conversion of the heavy oil into gasoil is increased when a sweep gas is injected into the reactor.
The following two examples illustrate how the heavy oil, produced from used lubricating oil treated with the process, surprisingly proved to be effective in cleaning fouled equipment.
Example 5Used lubricating oil was being treated in a unit with a rotating kiln and heat exchangers became plugged. The exchangers were too hot to open or to treat with acetone. It was decided to try back washing the exchangers using the heavy oil, directly from the bottom of the wash column, because that oil, at 350 degrees Celsius, was hot and the pump could develop up to two atmospheres in pressure. The heat exchangers were unplugged and clean in a matter of minutes. The fouling material, along with the heavy oil, were routed back to the dehydration vessel where they mixed with fresh used oil feed and became reactor feed oil.
Example 6When the same heavy oil was first tested as a component in a flotation oil, although the flotation oil tanks had been cleaned prior to the test, the oil arrived at the flotation cells very dark and containing gums and solids. Although the lines had been flushed before the test, the new oil had cleaned the remaining deposits out of the flotation oil feed system. The new oil proved to be more effective than hot water and steam as a defouling agent.
Advantages of the ProcessThis waste oil thermal cracking process has many advantages over other waste oil cracking or reuse processes:
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- It is simple and easy to operate.
- It is flexible and can treat a wide variety of waste oils, not just used lubricating oils from service stations and the like.
- About 99% of the metals and 75% of the sulphur, present in waste oil, exit the process with the non-leachable coke before the vapours exiting the reactor are condensed. The sulphur and metals do not enter into the finished oil products.
- All the products from this process are safe and can be sold in current markets. There is no product or by-product to dispose of in incinerators or industrial waste dumps.
- The heavy oil produced can be used to back-flush and clean heat exchangers and other equipment on site. There is no need to pre-treat the waste oil feedstock to prevent equipment fouling. Therefore, the laboratory analyses and chemicals required by the waste oil feed pre-treating unit are not needed, neither is their spent chemicals disposal.
- The oil used to clean equipment on site and containing fouling material can be processed in the mobile plant and reused.
This waste oil thermal cracking process has many advantages over waste oil recycling processes:
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- It is simple and easy to operate.
- It is flexible and can treat a wide variety of waste oils, not just used lubricating oils from service stations and the like.
- The products do not need to meet the stringent specifications of lubricating oil base stocks. This eliminates the need for careful selection of feedstocks, leaving most waste oils to be disposed of into the environment.
- The additives in the waste oil feedstocks are destroyed and about 99% of the metals and 75% of the sulphur, present in waste oil, exit the process with the non-leachable coke before the vapours exiting the reactor are condensed. There is no need to dispose of the heavy oil fraction, containing most of the metals and sulphur.
- All the products from this process are safe and can be sold in current markets. There is no product or by-product to dispose of in incinerators or industrial waste dumps.
- The heavy oil produced can be used to back-flush and clean heat exchangers and other equipment on site. There is no need to pre-treat the waste oil feedstock to prevent equipment fouling. Therefore, the laboratory analyses and chemicals required by the waste oil feed pre-treating unit are not needed, and neither is their spent chemicals disposal. The resulting soiled back-flushing oil can be recycled to the dehydration unit, and/or to the reactor, and reused. There is no need to treat waste water and/or to dispose of oily wastes in industrial dumps or landfills.
- It is viable in smaller plants, with a smaller collection radius and does not need to be subsidized by governments.
Presently water is used to clean ships bunker reservoir, tank farm bottoms and other equipment that is fouled by heavy oils and/or other hydro-carbon residue. This means that the water used has to be separated from the oily residues and then the residues treated or burned in cement kilns. The burning of the oily residues is bad for the environment and a waste of the hydrocarbon resources.
The present invention can take the residues and produce diesels, additives for asphalt and heavy oils that can be used to clean the residues. By using these oils to clean the tank bottoms and other reservoir the cleaning process is more efficient and there is no need to separate water from the residue. All the residue and the oil can then be pumped out and treated.
By having a mobile plant it would be possible to produce the heavy polarized oils to clean the tanks and equipment and then treat the residue and heavy oils to obtain commercial products and more oil to continue the cleaning process. Thus the mobile plant permits more effective periodic cleaning of tank farms and refinery equipment and other places with reduced transport of waste oils which are hazardous material.
Also a mobile plant can also be used to treat waste oils in regions with low density of population, near out of the way mines or industrial complexes and where the volumes of oils to be treated at any given time is low and the cost of transporting the oils is high or could lead to ecological disasters during the transport. Presently, most of the waste oils in these regions are burned or thrown away which is very bad for the environment. A mobile plant would be transported on a periodic basis in these regions to treat the oils and sell the product in the region.
The mobile plant could be built within a standard 45 feet high cube container and thus could be easily transported by truck, rail or boat.
In summary some of the advantages of the new thermal processing apparatus include:
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- A steady and controllable reaction temperature,
- A specified product slate of consistent quality,
- Protection of the reactor wall from stress and failure due to thermal shock or hot spots,
- Preventing coke from depositing and sticking on the reactor walls and internals,
- Longer run times, shorter shut-downs, less maintenance cost,
- Safer operation,
- A steady and controllable reaction pressure, and
- Minimizing of the thermal stress on the reactor walls and/or on the internals.
Some of the major advantages of the mobile plant of the invention is:
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- the short residence time of the treated oil in the reactor; and
- the production of polarized mixture having a high cleaning power in respect of heavy oils.
The use of a mobile plant, including a rotating kiln, allows the treating of waste oils on site, producing a hot oil that can be used to clean equipment and tanks at the site. The resulting stream of hot oil with fouling material is then fed into the mobile plant.
The treated oils thereby obtained may be directly used with no cool down or only with a slight cool down.
Due to the original configuring of the mobile plant only one or 2 distillations towers(s) are needed and moreover only distillation with a reduced height are necessary; this feature is of a particular importance if the distillation tower is transported with the mobile plant; however the necessary distillation plant may be fixed for example in or nearby the collecting area.
The mobile plant is particularly efficient in cleaning tanks and equipment in remote areas since it can use the waste oil to be treated to produce the oil used to clean the equipment, and treat the resulting stream on site. It allows the treating of waste oils, into useful products without having to transport possibly hazardous liquids.
Some embodiments of the invention may have only one of these advantages, some embodiments may several advantages and may have all of simultaneously.
Advantages of the Process of the InventionThis is a simple process that can treat a wide variety of waste oils and make useful and environmentally friendly products.
It has been surprisingly found that the sweep gas allow to the control of the reaction rate and the quality of the treated oil thereby obtained.
This process is in energy equilibrium. When used lubricating oils are processed, the produced gas and naphtha are consumed on site, and there is little or no need to purchase fuel, or to use the more valuable wide range diesel or heavy oil products from the plant. There is also no naphtha to dispose of.
When produced, the wide range diesel is a light amber colour. The produced diesel is unstable and will darken with time or when exposed to air. The diesel deteriorates much faster, within days instead of months, if there is no inert gas injection into the reactor inlet. Injection of inert gas results in a higher yield of diesel oil (from 78% vol. to 82% vol. of the total liquid product) and lower yield of naphtha (from 10% vol. to 6% vol. of the total liquid product).
Depending on the sulphur content in the feed oil, the sulphur in the diesel produced could be below the 0.1% wt., now specified in Europe for home heating oil.
The heavy oil is a low sulphur fuel. It can be sold as bunker fuel, or as a specialty oil. It is also used as backwash oil in the process plant. Plants that process waste oils face constant fouling of their equipment. Used lubricating oil re-refining facilities usually pre-treat their feedstock with chemicals to remove as much of the metals and solids as possible. They have to test each truck load entering the plant and must add the purchase of chemicals and the disposal of spent chemicals to their operating costs. Thermal cracking units that treat used lube oils, are usually much smaller than re-refiners. They have frequent shutdowns to remove coke deposits and clean heat exchangers. In this process, heat exchangers can be cleaned while the plant is on stream using the backwash oil on site. The solids exit the plant with the coke.
The sulphur and metals, released in the cracking reactions, are attached to the coke. The coke is removed from the vapour oil stream as it leaves the reactor. Therefore the sulphur and metals are not present when the oil is condensed into liquid fuels. This is why the oil products leaving the plant are low in sulphur and metals, when compared to products from other used oil thermal cracking facilities. The metals in the coke are thought to act as catalysts in the deterioration of the oil products. The diesel oil produced with this process are more stables than oils produced in other thermal cracking units. The coke is non-leachable and can be disposed of in landfills. It can also be blended in asphalts or cements.
This is a dry process: there is no liquid level in the reactor. The reactor temperature is not limited to the boiling point of the oil feed. This process can treat a much wider variety of waste oils than the conventional thermal cracking units. As an example: synthetic oils are increasingly used as base oils. They are more stable than conventional base oils and do not need to be changed as often to keep engines in good running order. Less oil changes mean less feedstock to used lube oil plants and the feedstock they get contains more contaminants. In a conventional plant, since the reactor temperature is limited to the boiling point of the oil, the more stable oil will require a longer residence time to crack, which limits the plant throughput and profitability.
The process is very flexible. Since the reactor temperature can be changed to suit, this process can be used to treat waste oils that are not necessarily used lubricating oils such as refinery tank bottoms. It can also treat oils that have a high propensity to form coke such as bitumen or marpol.
The reactor in the process is under pressure which results in a more stable operation, and consistent product quality and quantity. A rotating kiln under positive pressure is safer because there will be no oxygen ingress into the reactor, which, if left undetected, could result in an explosion. In the event of a leak, oily vapours would exit into the firebox and would burn in an environment designed to contain flames.
One of the safety features of this process is that there is no vessel containing large amounts of oil in this process. Residence times are low.
The only vessel that might contain large amounts of oil is the dewatering flash drum. It is under a steam atmosphere. In an emergency the equipment can be drained within minutes, and steam or another inert gas, is already present in the reaction and product separation units.
The present invention can take the residues and produce diesels, additives for asphalt and heavy oils that can be used to clean the residues. By using these oils to clean the tank bottoms and other reservoir the cleaning process is more efficient and there is no need to separate water from the residue. All the residue and the oil can then be pumped out and treated.
By having a mobile plant it would be possible to produce the heavy polarized oils to clean the tanks and equipment and then treat the residue and heavy oils to obtain commercial products and more oil to continue the cleaning process. Thus the mobile plant permits more effective periodic cleaning of tank farms and refinery equipment and other places with reduced transport of waste oils which can be hazardous material.
Also a mobile plant can also be used to treat waste oils in regions with low density of population, near out of the way mines or industrial complex and where the volumes of oils to be treated at any given time is low and the cost of transporting the oils is high or could lead to ecological disasters during the transport. Presently, most of the waste oils in these regions are burned or thrown away which is very bad for the environment. A mobile plant would be transported on a periodic basis in these regions to treat the oils and sell the product in the region.
The mobile plant could be built within a standard 45 feet high cube container and thus could be easily transported by truck, rail or boat.
Also cleaning with oil is better for corrosion purposes and leaves no water residues in the equipment, which could become safety hazards when the equipment is put back into service.
Among the products are cracked heavy oils that can be used to dissolve and clean the fouling agents deposited in equipment. The cleaning oil, along with the foulants removed from the equipment can be treated in the mobile plant, making useful products.
Although the present invention has been described with the aid of specific embodiments, it should be understood that several variations and modifications may be grafted onto the embodiments and that the present invention encompasses such modifications, usages or adaptations of the present invention that will become known or conventional within the field of activity to which the present invention pertains, and which may be applied to the essential elements mentioned above.
Claims
1. (canceled)
2. The mobile plant according to claim 160, for thermally treating a feed stream, wherein the feed stream is:
- a feed oil, that is more preferably selected in the group constituted by a contaminated oil and/or an uncontaminated oil, wherein the oil is advantageously a synthetic oil, a natural oil, a vegetable oil, an animal fat oil, marpol, heavy oil, oily tank bottoms, used oil, oily water and/or emulsions, and any waste oil and/or the mixtures of at least two of these; and/or
- a solid feed mainly constituted of a solid material that may advantageously be selected in the group constituted by oil sands, shale oil, tires, contaminated soils, oily beaches, solids containing oil, asphalts and tars, and/or the mixtures of solids and oil.
3. The mobile plant according to claim 160, for thermally treating a feed stream, wherein the first unit contains no sub-unit for chemically treating the feed stream, advantageously the first unit contains no sub-unit for purifying the feeding stream before its injection into Unit II.
4. The mobile plant according to claim 3, for thermally treating a feed stream, wherein, in Unit I and/or in Unit III, a chemical treatment, such as the injection of a anticorrosive agent, is performed.
5. The mobile plant according to claim 4, wherein Unit I is designed to remove the water from the feed oil when water is present in the feed stream (oil).
6. The mobile plant according to claim 160, wherein the rotating reactor comprises:
- a. a rotating kiln;
- b. a heating system;
- c. at least one shelf on the reactor wall;
- d. a charge of plates, the plates being preferably of consistent shapes;
- e. means for bringing the mixture to be thermally processed on the surface of at least part of the plates;
- f. means for removing the solids from the reactor, preferably either through entrainment with the exiting vapours, or through a separate solids exit, or both;
- g. means for recovering the reaction and straight run products; and
- h. means for removing the vapours obtained by the thermal processing outside the reactor zone.
7. The mobile plant according to claim 160, comprising:
- a. a rotating kiln;
- b. a heating system;
- c. at least one shelf on the reactor wall, the at least one shelf being either parallel to the center axis of the reactor, when the reactor is horizontal, or slanted with respect to the center axis when the reactor is slanted or not slanted;
- d. a charge of plates of consistent shapes;
- e. means for bringing the mixture to be thermally processed on the surface of at least part of the plates;
- f. means for removing the solids from the reactor, preferably either through entrainment with the exiting vapours or through a separate solid exit, or both;
- g. means for recovering the reaction and straight run products; and
- h. means for venting the gas, obtained by the thermal processing, outside the reactor zone.
8. The mobile plant according to claim 7, wherein at least one shelf is placed on the reactor wall in such a way to keep a uniform distribution of the plates along the reactor length.
9. The mobile plant according to claim 7, wherein the at least one shelf is either parallel to the center axis of the reactor, when the reactor is horizontal, or slanted with respect to the centre axis when the reactor is slanted or not slanted.
10. The mobile plant according to claim 7, wherein the means for bringing the mixture to be thermally processed on the surface of at least part of the plates, bring the mixture on the surface of at least more than 10% of the plates, preferably on the surface of at least more than 30% of the plates, and more advantageously on the surface of about 50% of the plates present in the reactor.
11. The mobile plant according to claim 160, wherein the reactor is configured to rotate around its centre axis, the axis forming with the horizontal an angle that is less than 45 degrees, preferably less than 30 degrees and more preferably this angle is about 5 degrees and more advantageously the angle is of 0 degree.
12-15. (canceled)
16. The mobile plant according to claim 160, wherein the reactor is configured in a way that the inside of the reactor is indirectly heated by an electromagnetic field.
17. The mobile plant according to claim 16, wherein the inside of the reactor is directly heated by a hot gas, liquid or solid stream, electricity or by partial combustion of the feedstock, coke, products or by-products.
18-20. (canceled)
21. The mobile plant according to claim 160, wherein shelves are at least partially replaced by a row of legs or protuberances to support the plates.
22-23. (canceled)
24. The mobile plant according to claim 160, wherein the shelve(s) is(are) held by T shaped clamps.
25-26. (canceled)
27. The mobile plant according to claim 24, wherein the number of shelve(s) that is(are) disposed, per square meter of the internal surface of the reactor, on the internal wall of the reactor ranges from 1 to 40, preferably from 2 to 20.
28-29. (canceled)
30. The mobile plant according to claim 6, wherein the space between two shelves represents from 0 to 100%, preferably from 5 to 100% of the radius of the cylinder or, in the case of a cone, of the maximum radius of a cone.
31-48. (canceled)
49. The mobile plant according to claim 6, wherein the plates are heavy enough to scrape coke or other solids off the reactor wall and/or off other plates.
50-55. (canceled)
56. The mobile plant according to claim 160, wherein the gas/vapours obtained contain entrained solids.
57-80. (canceled)
81. The mobile plant according to claim 160, wherein the first unit comprises of feed preheat and/or dehydration equipment and/or a degasing equipment, preferably the first unit comprises:
- means to heat, and possibly filter, the feed stream; and/or
- means to dehydrate the feed stream and to at least partially condense the vapours exiting the dehydrator; and/or
- means to separate the water, light oils and non-condensable gas; and/or
- means to send the non-condensable gasses to fuel; and/or
- means to inject additives, if required; and/or
- means to introduce the hot oil recycle stream.
82-159. (canceled)
160. A mobile plant for thermally treating an oily feed stream, the mobile plant comprising: wherein:
- i. a first unit (Unit I) designed for heating and/or dehydrating and/or degassing the oily feed stream;
- ii. a second unit (Unit II) comprising a rotating reactor designed to perform the thermal processing of the oily feed stream, entering the rotating reactor, and a vapour solid separator; and
- iii. a third unit (Unit III) that is a product separation unit and that is optionally configured for recycling at least part of the treated feed stream, recovered in Unit III, into Unit I and/or Unit II,
- Unit I and/or Unit II is (are) configured for injecting a sweep gas in the feed oil and/or in the rotating reactor;
- Unit II is configured in a way that the that the rotating reactor may work under positive pressure;
- the vapour-solids separation equipment is configurated to be heated at a temperature that is at least 10 degrees below the cracking temperature of the vapour; and
- the sweep gas injected in the feed and/or in the rotating reactor represents in weight up to 30% of the weight of the feed oil.
Type: Application
Filed: Feb 6, 2013
Publication Date: Dec 24, 2015
Applicant: ENVIROLLEA INC. (Calgary, AB)
Inventors: Lucie B. WHEELER (Calgary), Louis BERTRAND (Outremont)
Application Number: 14/765,374
