SURFACE VERTICAL RETORT AND PROCESS TO OBTAIN OIL AND GAS FROM PYRO-BITUMINOUS OIL SHALE AND/ OR MATERIALS CONTAINING ORGANIC CARBON COMPOUNDS

Abstract

The invention relates to a surface vertical shaft retort (100), heated by an external source, which includes (i) a multifunctional central pipe (110), (ii) a top sealing device (120), (iii) a load distribution system (130), (iv) a retorting vessel (140) with an annular shaped bed (141) furnished with a set of load pipes (142), spaced among themselves, to form a collecting chamber to gather gas and mist (143), a hot gas injector (144), a cold recycle collector (145) and distributor (146), and a bed control and unloading mechanism (147), (v) a plenun chamber (150), (vi) a device for heat recovery of the spent shale (160) containing a piping network (162)for recirculation and spraying of the retorting water and accumulation hoppers (161) and (vii) a device for dry bottom sealing (170). In addition, this patent application comprises a process to obtain oil and gas from pyro-bituminous oil shale and/or materials which contain organic compounds using the referred surface vertical retort heated by an external source (100) through the following steps (a) load supply, (b) sealing of the load supply, (c) load distribution, (d) gathering and removal of gases and mist, (e) heating and drying of the load, (f) reinjection of gas stream from the cold recycle gas from stage (i), (g) load pyrolysis, (h) injection of the gas stream from the hot gas recycle, (i) removal of the cold gas recycle stream, (j) heat recovery of the spent shale, (k) discharge of the bed with annular shaped, (l) cold gas recycle injection (m) mixture of the cold recycle stream with water vapor stream, (n) collection in the accumulation hoppers of discharged spent shale, (o) spraying of the recycled retorting water, (p) vapor generation by the contact of the recycled retorting water with the retorted material deposited in the accumulation hoppers and (q) dry discharge of the spent shale, and bottom sealing.

Description

FIELD OF THE INVENTION

The invention relates to a surface vertical shaft retort (100) heated by an external source, which includes (i) a multifunctional central pipe (110), (ii) a top sealing device (120), (iii) a load distribution system (130), (iv) a retorting vessel (140) containing an annular-shaped bed (141) furnished with a set of load pipes (142), spaced among themselves, to form a collecting chamber to gather gas and mist (143), a hot gas injector (144), a cold recycle collector (145) and distributor (146) and a bed control and unloading mechanism (147), (v) a plenun chamber (150) (vi) a device for heat recovery of the spent shale (160) containing a piping network (162) for recirculation and spraying of the retorting water and accumulation hoppers (161) and (vii) a device for dry bottom sealing (170). In addition, this patent application comprises a process to obtain oil and gas from pyro-bituminous oil shale and/or materials which contain organic compounds using the referred surface vertical retort (100) heated by an external source through the following steps (a) load supply, (b) sealing of the load supply, (c) load distribution, (d) gathering and removal of gases and mist, (e) heating and drying of the load, (f) reinjection of the cold-gas recycle stream from stage (i), (g) load pyrolysis, (h) injection of the hot-gas recycle stream, (i) removal of the cold-gas recycle stream, (j) heat recovery from the spent shale, (k) discharge of the annular-shaped bed, (l) cold-gas recycle injection (m) mixture of the cold recycle stream with water vapor stream, (n) collection in the accumulation hoppers of discharged spent material, (o) spraying of the recycled retorting water, (p) water vapor generation by the contact of the recycled retorting water with the retorted material deposited in the accumulation hoppers and (q) dry discharge of the spent shale , and bottom sealing.

BACKGROUND OF THE INVENTION

Nowadays, considering the global population, which exceeds seven billion people, an accelerated mobility to more advantaged social classes and greater offer of products that consume energy, there is an increase in the demand for fossil fuels, triggering a price raise and/or causing shortage of such commodity, leading to a substantial economic impact worldwide.

There is a wide range of ways to obtain the energy required to meet the global energy demand. However, despite the advances in the development of new technologies to produce energy from different sources, such as renewable sources, oil is still the main source used, especially due to its importance as a transportation fuel, and it is not likely to be replaced by another source.

Oil is an energy source with universal reach, which has been in large use for more than a century. However, a decline in its production capacity, as well as an increase in its price, is already noticeable.

Easily accessible oil land fields, which allow low cost and environmentally-safe production of oil, have been facing production declines and new findings have become rare. There are, nevertheless, continental platforms where findings increasingly occur, especially in deep waters and, in many cases, such as in Brazil, under a thick layer of salt.

There are significant technological challenges and high costs to access such reserves and, consequently, produce oil, and reduce possible environmental impacts.

Pyro-bituminous oil shale, a type of ore nearly available in the entire planet, which contains kerogen, a hydrocarbon which displays a long chain of carbons, is deposited in equivalent or even superior potential reserves in comparison to those existing now in the form of liquid oil. This ore has great potential to fulfill the additional demands for liquid hydrocarbon in the worldwide energy matrix.

It is understood that researchers have been dedicated to develop new processes in order to obtain hydrocarbon from pyro-bituminous oil shale, creating processes linked to the oil shale physicochemical properties, which are different for each of the oil shale deposits (VOLKOV, E. and STELMAKH, G. The stages of research on creating commercial units for processing the oil shale fines. Oil Shale. A Scientific-Technical Journal (Estonian Academy Publishers) 16 (2): 161-185, 1999).

Most of these processes have only gone as far as the experimental stage in laboratories. A few others have achieved subsequent stages, such as the development of pilot units, prototypes and semi-industrial stages. Nonetheless, most of them were later abandoned because they posed technical and/or economic problems which could not be overcome.

Currently there are only a few processes in developmental and/or in industrial scale production stage.

In general, the process to obtain hydrocarbon from pyro-bituminous oil shale occurs through a process of pyrolysis of the rock, basic principle of all processes. The kerogen, organic matter that originates oil and gas, is found, in solid form, inside the mineral matrix of the rock. When the ore is heated to a specific temperature, the molecule of kerogen is decomposed (fragmented into chains with smaller numbers of carbons), forming a mixture of hydrocarbons and others gases.

The existing processes worldwide may be classified into two main categories: processes that are performed on the surface and those which are performed in the subsurface, also known as in situ.

The subsurface processes (in situ), despite being based on the premise of eliminating mining and ore processing, thereby reducing costs with these activities and with the recovery of the mined area, do not reach economically viable levels. The greatest difficulty found by the in situ processes is related to heat transfer, which impacts the control of the process and the use of oil/gas existing in the deposit, and, as a result, reduces the deposit exploitation. Also, in relation to the environment, in situ processes present a high potential of groundwater contamination by oil, gas and chemical products used to open slits in the oil shale layer which cannot be fully removed from the retorting site.

In the surface processes, oil shale needs to be previously mined, crushed and classified to meet the range of particle size requested by the particular process which it will undergo. All these operations and their related operations (dust and noise suppression, mined area recovery, etc.) contribute towards an increase of the final cost of the produced oil.

The surface processes can also be classified according to the range of the particle size of the material to be processed. Therefore, there are processes that operate with fine materials (particles), usually below 10 mm, and processes that operate with granular material, generally between 10 mm and 75 mm.

The surface processes that operate on the base of a fine grain size are normally performed in horizontal retorts (reactors) or with small rotational inclination, similar to calcination kilns in the cement industry. These processes generally use the burning of the spent shale inside the retort as a source of heat, which can be complemented by an external source to the retort such as the burning of a portion of the pyrolysis products or by the return of the ashes from the combustion of the spent shale performed externally.

On the other hand, processes which do not require a complementary source of heat are typically used in deposits which present oil shale with high level of organic matter in the form of ligneous and kerogen.

Fluidized bed reactors have been tested recently. They use the recirculation gas technique and require the load to be in a much finer particle size, generally less than 2 mm. No promising data have yet been shown regarding this process, though.

The processes performed with fine particle size generally produce high density and high viscosity oil, which displays a high level of fine particles in the produced oil, making it difficult to filter, and presenting a lower yield factor in comparison to the processes operated with granular materials.

As an example of a process that operates with oil shale fines, there is the retorting process Galoter, from Estonia, capable to process 3,000 tons per day on a horizontal rotational retort, similar to a clinker furnace that operates with an oil shale particle size below 25 mm. The Galoter process has a yield around 75% in oil on the standard Fischer assay, and is considered complex and of difficult operation (QIAN J. and WANG J. World Oil Shale Retorting Technologies—China Petroleum University—Beijing 100101 China, 2006). The improved version of the Galoter process, named EnefiT process, uses the heat from the ashes of the burned oil shale for pyrolysis, adding new peripheral equipment and making it more complex and difficult to operate.

Also, the retorting process ATP (Alberta Taciuk Process), developed by UMATAC Industrial Processes, which was originally developed to process tar sands and was, subsequently, adapted to process pyro-bituminous oil shale, uses a horizontal rotational retort and operates with oil shale with a particle size below 25 mm. The process has a yield around 85% in oil on the standard Fischer assay.

For information purposes, other processes which operate with fine particles, such as Tosco II, Lurgi-Ruhrgas, Oil Tech, Chevron STP (fluidized bed), Shell Spher (fluidized bed) and Kentort H (fluidized bed),were operated only to the pilot stage or are currently discontinued due to various technical problems.

The retorting processes that operate with granular material generally use fixed vertical retorts (reactors), i.e. non-rotational ones, containing various load sealing systems, several constructions of retorting vessels to perform the pyrolysis stage and different retorted material discharge systems.

The necessary heat for effecting the pyrolysis stage can be produced internally, by burning the loaded material, whether it be complemented or not by burning the by-products of the pyrolysis (so-called combustion gas), or externally, by the heating in a furnace of a portion of the gas stream that is recirculated to the retort. However, in the processes that use the internal combustion (gas combustion) to generate the necessary heat for the pyrolysis stage, part of the products is burnt and the produced gas is contaminated with the by-products of the combustion.

As an example of the process by external heating there is the PetroSix, technology developed by Petrobras (Petróleo Brasileiro), with a processing capacity of 6,200 tonnes per day in an industrial retort that processes oil shale with a particle size between 10 mm and 70 mm and has a yield around 85% in oil on the standard Fischer assay. Furthermore, the PetroSix retorting process uses a system of dry sealing on top and a hydraulic sealing at the bottom (spent shale exit from the reactor) which results in significant water consumption in the process and, as a result, brings major difficulties in applying this process in regions with poor water availability. Additionally, in the PetroSix process, all the required heat for the retorting is provided by a furnace, external to the reactor (retort), in the form of hot recycle. Due to the low recovery of heat from the spent shale, the energy efficiency of the retorting process of PetroSix is impaired.

Another retorting process called Keviter process, a technology developed by an Estonian company, Viru Keemia, has the processing capacity of 1,000 tonnes per day, operating oil shale with a particle size from 10 to 125 mm. In this process, the load supply, the gravity flow and the sealing are very similar to the PetroSix process, including the use of sealing with water at the bottom of the retort; however, the required heat for the oil shale pyrolysis is provided by two rectangular combustors located in the middle of the cylindrical reactor, characterizing it as a gas combustion process. In these combustors, process gases are injected and the combustion of these gases provides the necessary heat for the oil shale pyrolysis. The oil vapors and the gas produced in the pyrolysis, along with the combustion gases, are removed by two collectors on the retort upper side. Part of the process gas is injected into the retort bottom to recover the spent shale heat which descends by gravity from the pyrolysis zone. The spent shale is not burnt and contains organic matter residues; the gas resulting from the process is poor, contaminated with nitrogen and carbon dioxide. The oil yield in the Keviter retorting process is 75% on the standard Fischer assay.

The retorting process Fuschun Generator Type (gas combustion), technology developed in China, has been used for over 70 years. Its processing capacity is small, 100 tonnes per day, operating with oil shale particles in the range of 10 to 75 mm. The oil yield is 65% on the standard Fischer assay.

The Fushun retort presents a stricture in the middle of the reactor which separates the retort into two parts, the upper portion, where the oil shale is pyrolyzed, and the lower portion, where the spent shale is burnt.

At the bottom of the pyrolysis zone a hot recycle, preheated in an external furnace, is injected to complement the necessary heat for the pyrolysis of the oil shale. The produced gas has poor quality, contaminated by nitrogen and carbon dioxide, which limits reuse. In addition to this, the process yield is greatly reduced because part of the oil is burnt inside of the reactor (retort). This is considered to be a small capacity process and poses major environmental issues.

There is also the Paraho process, which works with indirect heat, similar to Petrosix process, distinguished only by its equipment/device's features. This process was tested on a semi-industrial scale and after a testing period, the activities were discontinued.

Other retorting processes which use granulated material, for instance, the Union process (oil shale supply through the bottom of the retort and removal through the top of the retort) and RedLeaf (large volumes deposited on the surface and enveloped), are also known by experts in the subject.

Regarding patents that describe technologies for the extraction of hydrocarbons from pyro-bituminous oil shale, several documents can be found, but each of them describes completely distinct processes and equipment when compared to the present invention, which is original and offers a wide range of advantages over the prior art.

The US patent application US 2009/0050532 describes a shale oil extraction technology (SOT—Shale Oil Technology) which has a vertical retort with gravity-based outflowing and sealing by rotating valves, as well as distribution of the material by inclined septa (flow interference) of internal combustion.

The American patent U.S. Pat. No. 4,151,047 provides an apparatus for the supply of pyro-bituminous oil shale into a series of retorts, where each retort is equipped with a rotational distribution spout and a central supply channel, such retort being radially arranged from a distribution oil shale central tower. At least one hopper communicates with a central supply channel, linking it to the retort and being laterally displaced in relation to the retort longitudinal axis. Furthermore, conveyor belts are provided to transfer the oil shale from the central distribution tower to the hoppers of each retort.

The Brazilian patent PI 8606369, held by Petrobras—Petróleo Brasileiro SA and expired in Dec. 22, 2001, deals with the improvement in the equipment and in the process to obtain oil, gas and by-products from pyro-bituminous oil shale and other hydrocarbons impregnated materials. This patent describes a retorting process, called PetroSix, which uses a retort containing (a) a rotational top sealing system consisting of two apparatus in series with rotating vanes to transport the material horizontally from one apparatus to the other, (b) an anti-segregation mechanism composed by a rotor that distributes the material in a single point, (c) hot gases injection device comprised by six ducts of irregular hexagon shape, transversal to the bed held in shell sockets diametrically opposed, (d) a discharging device consisting of concentric annular steel plates, disposed at a predetermined distance from each other, there being deflectors over the gaps between the steel plates in the shape of inverted V that prevent the free flow of material, (e) a retorting vessel that operates with a continuous moving bed in a complete circular section from the top of the bed to the annular steel plates of the discharge mechanism and (f) a removing and bottom sealing device comprising an inclined flight conveyor filled with water which effects the sealing.

The American patent U.S. Pat. No. 3,519,539 relates to an oil shale retorting process conducted through a vertical retort, where the gas recycle is used to cool down the spent shale in a cooling zone, air is mixed with gas recycle and the mixture burns in an internal combustion zone (gas combustion) above the cooling zone.

The American patent U.S. Pat. No. 4,029,220 refers to an apparatus to load the particulate material into a container that contains rotational load distribution facilities to distribute the loaded particulate material in the retort, which means that the load distributor can provide greater uniformity on the distribution of various particles sizes and can also provide and maintain a production line with the desired profile and in the container height. The distribution facility includes a hopper with a plurality of chutes rigidly fixed, extending downwards with lower discharging portions that discharge in concentric circular zones in the production line. The distribution facility includes a segmented portion at the hopper junction and the chutes which divide the material from the discharged load into the hopper in the proportion of the circular zone in the production line, which is supplied by the chute. The distribution facility operates completely filled with the supplied material (full capacity) to provide particulate mass flow through the chutes and to avoid the segregation among the larger and smaller particles of the loaded material, deposited on the bed level.

The American patent U.S. Pat. No. 5,041,210 relates to an oil shale retorting process on a vertical retort, where the gas recycle containing the produced steam and gas is separated from the exhaustion gas of the retort and is used to heat the oil shale. Steam exists in a quantity (in volume) of gas recycle of at least 40% and, preferably 70%. The minimum particle size of pyro-bituminous oil shale is so that the particles are retained on a screen with openings of ¼ inch. The maximum particle size is so that the particles are capable of passing through a screen with openings of 3 inches.

Given the challenges of the prior art, as above summarized, the applicant of this patent request has developed a surface vertical retort (100) with an external heating source and a process to obtain oil and gas from pyro-bituminous oil shale and/or materials which contain organic compounds, performed by the operation of the mentioned retort (100).

FIGURE DESCRIPTION

FIG. 1 shows a frontal view of the surface vertical retort (100), according to this invention, where it is shown:

the multifunctional central pipe (110).

the top sealing device (120).

the load distribution system (130).

the retorting vessel (140).

the plenum chamber (150).

the device for heat recovery of the spent material (160).

the device for dry bottom sealing (170).

DESCRIPTION OF THE INVENTION

The present invention relates to a surface vertical shaft retort (100), heated by an external source, which includes (i) a multifunctional central pipe (110), (ii) a top sealing device (120), (iii) a load distribution system (130), (iv) a retorting vessel (140) containing an annular-shaped bed (141) furnished with a set of load pipes (142), spaced among themselves, forming a collecting chamber to gather gas and mist (143), a hot gas injector (144), a cold recycle collector (145) and distributor (146) and a bed control and unloading mechanism (147), (v) a plenun chamber (150) (vi) a device for heat recovery of the spent shale (160) containing a piping network (162) for recirculation and spraying of the retorting water and accumulation hoppers (161) and (vii) a device for dry bottom sealing (170). In addition, this patent application comprises a process to obtain oil and gas from pyro-bituminous oil shale and/or materials which contain organic compounds using the referred surface vertical retort (100) heated by an external source through the following steps (a) load supply, (b) sealing of the load supply, (c) load distribution, (d) collection and removal of gases and mist, (e) heating and drying of the load, (f) reinjection of gas stream from the cold-gas recycle from stage (i), (g) load pyrolysis, (h) injection of the hot-gas recycle stream, (i) removal of the cold-gas recycle stream, (j) heat recovery of the spent material, (k) discharge of the annular-shaped bed, (l) cold-gas recycle injection (m) mixture of the cold recycle stream with the water vapor stream, (n) collection in the accumulation hoppers of discharged spent material, (o) spraying of the recycled retorting water, (p) vapor generation by the contact of the recycled retorting water with the retorted material deposited in the accumulation hoppers and (q) dry discharge of the spent shale, and bottom sealing.

In one particular embodiment, the invention refers to an externally heated surface vertical shaft retort (100) of large capacity, particularly about 5,000 to 10,000 metric tonnes per operation day, consisting of:

• (i) a multifunctional central pipe (110) which defines the retorting annular-shaped bed (140) with the deviation of the cold-gas recycle and the collection and removal of the dust collected during the gas transportation;
• (ii) a top sealing device (120) comprised by a flow switcher (121) by alternating batches, supply/emptying independent hoppers (122) with sealing valves (125), optionally, with injection of inert gas and a flow controller/metering system (123) placed underneath the valves at the junction (124), the stated controller/metering system consisting of shell, stationary table and rotor equipped with blades;
• (iii) load distribution system (130) positioned below the stationary table, which consists of one rotational distribution hopper (131) divided into circular sectors proportional to the concentric annulus in the bin that will be supplied; such circular sectors dispersedly supply the tubular chutes (132), which discharge in free fall between the chutes ends and the load level in the bin (134), distributing the material continuously and uniformly in the annular space of the bin, located between the bin shell and the multifunctional central pipe (110); moreover, the distribution system comprises a series of septa in concentric trunk-conical shape (133) arranged around the multifunctional central pipe (110) between the load level in the bin (134) and the supply pipes assembly (142);
• (iv) a retorting vessel (140) with an annular-shaped bed (141) comprising a set of supply pipes (142) spaced among themselves, in a collecting gas chamber (143) equipped with nozzles in the retort shell (148), where the full bed (141) of granular material is disposed between the lower end of the supply pipes (142), spaced among themselves, and the bed movement mechanism (147). The mentioned bed movement mechanism (147) placed at the bottom of the bed (141) comprises a plurality of radial tables (149A) in circular sector shape with gaps among them; the gaps among the tables are entirely obstructed by a coverage in ridge-shaped cap (roof) (149B) and supported on a set of radial beams (149C), being the mentioned radial beams (149C) still supported on the retort shell and on the multifunctional central pipe (110); additionally, on the tables, (149A) a set of interconnected scrappers (149D) with angular shuttle movements driven externally to the retort shell; a hot gas injector (144) (hot-gas recycle) composed of drilled radial (144A) circumferential (144B) ducts with variable rectangular section which are housed in nozzles in the external retort shell and are supported in holders in the multifunctional central pipe (110); such ducts (144A e 144B) of the gas injector (144) are also covered by plates in ridge-shaped cap (144C) to direct the solid flow, cold-gas recycle collector (145) radially lagged, formed by radial (145A) and circumferential ducts (145B) with an irregular pentagon-shaped section with its lower portion open and positioned below the hot gas injector (144), where the radial ducts (145A) are connected by nozzles to the multifunctional central pipe (110) and supported at the opposite end by the wall of the retort shell. Alternatively, the radial ducts (145A) of the cold-gas recycle collector (145) can be connected to external pipes to the retort shell wall and supported in the multifunctional central pipe (110). Furthermore, the retorting vessel (140) has a cold-gas recycle distributor (146) formed by drilled radial and circumferential ducts (146A) with irregular pentagon-shaped sections located above the hot gas injector (144), being the radial ducts (146B) connected by nozzles to the multifunctional central pipe (110) and supported, in the opposite end, by the wall of the retort shell, and can, optionally, be supported in the multifunctional central pipe (110) and connected to external pipes to the retort. The retorting vessel (140) also provides a dust removal device (112) (dragged by the cold-gas recycle), positioned at the nozzles height (111) of the gas collector (145) with the multifunctional central pipe (110), internally to it, comprising a segment of a smaller diameter pipe, with a diameter from 40% to 90% of the multifunctional central pipe (110) and concentric to the said central pipe (110). In addition, the dust removal device (112) is open at its lower portion and sealed at its upper portion;
• (v) a plenun chamber (150), located below the moving bed mechanism (147), containing nozzles (151) in the retort shell for the entrance of a stream of cold-gas recycle;
• (vi) a device for final heat recovery of the retorted material (160), consisting of a network of pipes with sprinklers (162) of water supplied through the multifunctional central pipe (110) or through the retort shell and trunk-conical shaped accumulation hoppers (161), located below the free space, sectioned on the sides in order to intersect each other; and
• (vii) devices for dry bottom sealing (170), attached to the accumulation hoppers' (161) exit, which consists of a flow metering system (171), consisting of a stationary table and a rotor equipped with blades arranged inside the accumulation hopper (161), optionally containing a water sprinkler located below the mentioned metering system (171), a stationary table, a system of sealing valves (172) which consists of an upper valve (172), an intermediate link/accumulation neck (173), which can optionally inject inert gas, and a lower valve (172) and direction chute (174) for a continuous transport system.

In an alternate embodiment, this patent application also reflects a process to obtain oil and gas from pyro-bituminous oil shale and/or materials containing organic compounds through the use of a vertical retort (100), being the process to obtain oil and gas performed through the following steps:

• (a) supply of a load of oil shale particles previously prepared and/or materials containing organic compounds, at the top sealing device (120), being the referred preparation of previous load a comminution and classification in the intermediate range from 5 to 100 mm.
• (b) sealing of the supply through the top sealing device (120), allowing flow of solids into the retorting vessel (140) without the occurrence of the entrance of air or the exit of existing gases from inside, optionally with the application of inert gas.
• (c) uniform distribution of load particles, on the transversal section of the retorting vessel bed (140), avoiding the segregation of the particles;
• (d) collecting and removal of gases and oil mist in a collection chamber (143) among supply pipes (142) spaced from each other, being the gas removal performed through the nozzles (149) to the exterior of the retort;
• (e) heating and drying of the load by heat exchange performed by the contact between the mixture of the ascending gas in the bed above the distributor of the cold-gas recycle and the simultaneous cooling of the gas stream with the consequent formation of oil mist. The ascending stream consists of the mixture of hot gas stream with the gas stream produced by the pyrolysis process and the gas stream with temperatures of 300 to 400° C., reinjected in step (f) and preheated by the heat exchange with the retorted load, diverted from the bed located below the hot gas injector (144);
• (f) reinjection of the gas stream with temperatures between 300 and 400° C., (cold-gas recycle) by the cold-gas recycle distributor (146), homogeneously, above the hot gas injector (144);
• (g) pyrolysis of the load;
• (h) injection of a gas stream at temperatures above 480° C. (hot-gas recycle) into the middle of the bed by the hot gas injector (144), placing the hot gas stream in contact with the preheated load in order to promote the pyrolysis;
• (i) removal of the cold-gas recycle stream, preheated by the contact with the retorted material by the cold-gas recycle collector (145) before reaching the height where the injection of hot-gas recycle is carried out, towards the multifunctional central pipe (110) or the pipes attached externally to the retort shell;
• (j) heat recovery of the retorted material through the passage of the cold recycle mixed with the steam generated by the contact of the retorting recycled water with the retorted material deposited in the accumulation hoppers;
• (k) uniform discharge of bed material along the cross section of the retorting vessel (140) by the bed movement mechanism (147);
• (l) injection of a gas stream with temperatures below 20° C. (cold-gas recycle) in the plenum chamber (150);
• (m) mixture with the water steam stream generated in the accumulation hoppers (161);
• (n) gathering of the discharged bed in the accumulation hoppers;
• (o) spraying of the recycled retorting water;
• (p) steam generation by the contact of the recycled retorting water with the hot retorted material deposited in the accumulation hoppers (161), being such contact caused by the water spraying in a sprinklers network (162) located above the hoppers (161); and
• (q) dry discharge of the retorted material and bottom sealing, ensuring the controlled flow of solids in the accumulation hoppers (161), to the system of sealing valves (172) and, subsequently, to direction chutes (174) in a continuous transport system; said dry discharge may optionally use sprinklers of recycled retorting water for additional cooling, if required.

The used materials and loads in the process to obtain oil and gas can be oil shale, its derivatives and/or materials which contain organic compounds.

The technology described by the present invention, the retort, its devices and the process to obtain oil and gas provide a series of mechanical and processes innovations which increase the energy recovery contained in the ore and eliminates the need of an external water supply in the retort.

EXAMPLES

Process to Obtain Oil and Gas from Pyro-Bituminous Oil Shale

The retorting process, called PRIX, took place inside the surface vertical shaft retort (100) of the invention and comprised the steps of heating the ore to a temperature of approximately 500° C., by an externally heated gas stream, producing gas, oil and water vapor. The heat supplied by the gas stream with temperatures around 480° C. is composed by the processing gas and is distributed along the transversal section of the retort through radial and circumferential injectors. The gas flowed in a counter flow direction to the oil shale and drained by gravity. Simultaneously to the heating, the gas promoted the removal of the products generated by the pyrolysis of the oil shale. The larger portion of the cold stream injected in the plenum chamber (150) along with the steam generated in the cooling system of the spent shale, partially heated, was captured by the stream separation system before reaching the height where the hot gas injector is located and deviated to the bed part situated above the hot gas injector.

Subsequent to the generation and removal of the products, the oil shale, now called spent shale (retorted), flowed to the lower part of the retort. At the bottom part of the spent shale bed, a gas stream at low temperature was injected in order to cool the spent shale down, while recovering part of the heat contained in the spent shale.

In a region below the injection of hot gas stream, a stream of gas at low temperature which was injected into the bottom of the bed, now already heated by the heat recovered from spent shale, was removed from the bed by a collector device.

The gas stream then passed through a dust collector device, which removed most of the dust dragged out of the retort.

After the dust removal, the gas was reintroduced into the upper bed by a distribution device. At this point it was mixed with the effluent gas from the pyrolysis region and flowed to the top of the bed, providing heat for drying and heating of the raw oil shale that flowed in counterflow.

Reaching the top of the bed, the gas stream was collected in a chamber where it was removed for external processing by nozzles in the retort shell. After passing through the pyrolysis zone, the descending mass of spent shale passed by the collector of cold-gas recycle and came in contact with the ascendant gas stream at low temperature, warming it and resulting in the progressive reduction of its temperature until it reaches the bed control and movement mechanism. The flowing of the oil shale bed in the process was adjusted by the bed control and movement mechanism which, through a shuttle movement of the scrapers located on the radial tables, made the homogeneous transfer of the retorted material bed, to the bottom of the retort.

The spent shale, cooled by the gas stream at low temperature, passed through the control and movement mechanism and was deposited into hoppers, where it received an additional cooling provided by a spray of water which, vaporized, was mixed with the gas stream at low temperature.

When sufficiently cooled for future handling and transportation by solids transport equipment, the spent shale was removed and forwarded to the external environment by the dry discharge system and bottom sealing.

Throughout the process above described, the following conditions were essential to maximize the oil recovery and the thermal efficiency in the processing:

uniform distribution of particles in the oil shale bed throughout all retort sections, providing homogeneous flow of the gas stream;

the bed density remains slightly thickened during the course of the load from the top to its discharge, ensuring good permeability for the gas stream flow without causing excessive head loss;

uniform discharge in every point, moving the oil shale bed at the same speed throughout the cross section, ensuring that each oil shale layer has the same process conditions;

cooling the hot gas containing the generated oil, by the oil shale that flows in countercurrent, being so fast as to provide conditions for the super saturation of the gas, essential for the formation of mist; and

retention of the mist formed by the bed, that is reinforced by the water vapor generation in the retort bottom with the recycle of retorting water.

Top Sealing System

The top sealing system (120) of the invention aimed at the continuous loading of oil shale load with an intermediate particle size, ranging from 5 mm to 100 mm, in a reactor containing gases, whether toxic or not, mainly: hydrogen sulphide, carbon monoxide and hydrocarbons.

The load system was formed by alternating batches between two hoppers. However, both the load reaching the system and its flow to the inside of the retort were made continuously.

Each of these hoppers was equipped with sealing valves, one in the entrance nozzle and another in the exit nozzle, and received, alternatively and continuously, the oil shale load, previously prepared.

A device inserted into the load transfer chute to the hoppers alternates, along the cycles, the oil shale flow from one or another hopper. The hopper that receives the load has the top valve open and the bottom closed. On the other hand, the other hopper necessarily has the top valve closed and the bottom open, allowing the oil shale to be transferred to the inside of the load bin with controlled flow by the flow metering system. When the discharge ends, the control system detects the event and commands a new round, by inverting the function of each hopper, i.e., from load to unload and vice versa.

The sealing was performed so as to avoid the output of gases to the atmosphere or the inlet of air to the bin, during the transfer of the load into the retort, by the controlled injection of inert gas into the hopper. The hopper which received the load was then closed, completing a cycle. A control system supervised the operations.

Over the hoppers is located the flow switcher device, to which the hoppers were connected, always in pairs and installed side by side. The particulate material, whose flow was released by the bottom valve of one of the hoppers, passed through the pipe and rested on the table that prevents its free passage. The ratio among the diameter of the table, the pipe diameter and the distance between the edge of the pipe and the table were previously defined. The spin of the rotor produced a dosed flow of material to the load distribution system.

Load Distribution System

The rotational hopper, with circular sectors previously dimensioned, received the load, evenly discharged throughout the periphery of the flow metering system's table of the top sealing device. Each circular sector of the rotational hopper presented a particular capacity, proportional to the area of the annulus which was supplied. Each of the tubular chutes discharged in a specific area of an annulus above the trunk conical septa. The lower end of each tubular chute has a turning radius properly positioned to discharge into a defined annulus.

The septa in trunk conical shape were sufficient to cover the entire bin area defined by the material bed formed between the multifunctional central pipe and the bin shell. Furthermore, a level control assured that the deposited material below the end of the chutes would not have contact with the chutes themselves, eliminating the possibility of jam.

Separation Recycle System

The separation of cold recycle from hot recycle was made by the use of a circular multifunctional central pipe whose axis coincide with the retort axis. In a bed height, just below the injection of hot recycle, where the cold recycle was already sufficiently warmed, there is a collector formed by metallic radial beams in format and layout adequate to the collection of cold recycle stream.

The collector beams are connected to the multifunctional central pipe, so that the gases collected through the openings pass to the inside of the multifunctional central pipe. When moving towards the multifunctional central pipe, the dust, dragged by the gas stream, was removed by the device designed for its removal.

Passed the pyrolysis bed, the cold recycle stream, returned via graded pipes for the heating bed of raw oil shale through a distributor physically similar to the collector already mentioned. The passing of the cold recycle directly from the bottom bed to the top bed avoided all technical inconveniences of the mixture of cold recycle stream with hot recycle stream in the pyrolysis zone. Optionally, the deviation can be performed by ducts external to the retort shell.

Cooling System of Spent Shale

In the cooling system of the spent shale, the retort has interconnected hoppers that receive the spent shale coming from the bed control and movement mechanism which, besides having transferred the spent shale, has also distributed the material among the hoppers in each cycle of the operation. The hoppers have irregular trunk-conical shape that interconnects in their upper part.

Each hopper has in its upper part a network of pipes equipped with water sprinkles.

The recycled retorting water that came into contact with the spent shale promoted its cooling and generated water vapor. The water vapor stream ascended in the existing free space between the top of the hoppers and the discharge mechanism (plenum chamber), mixed to the gas stream of the cold recycle and ascended through the spent shale bed up to the cold recycle collector.

Bottom Sealing System

The discharge of the oil shale consisted in removing the solid particles already processed, with no escape of gases and/or vapors contained in its interior while preventing the entrance of air.

The bottom sealing system aimed to continuously discharge the particles, sized in the range up to 100 mm, while maintaining the sealing of the retort. Each of the nozzles ending on the hoppers was provided with two valves separated by a duct (neck), both with sealing function. Above the upper valve, in the interior of each hopper, a flow metering system device kept the hopper full on its control level and, with this valve in open position and the lower valve closed, continuously discharged, at regular flow, the material from the hopper to the duct (neck) between the valves. When the duct reached its maximum level, the upper valve closed and the lower valve opened.

The valves of the bottom sealing system operated in programmed mode, i.e., the entire sequence of operations was commanded by a controller.

Claims

1-44. (canceled)

45. Above ground vertical shaft retort, with heating by an external source, comprising:

(i) a multifunctional central pipe;

(ii) a top sealing device;

(iii) a system of load distribution;

(iv) a retorting vessel having an annular shape bed filled with a set of load pipes, spaced among themselves, to form a collecting chamber to gather gas and mist, a hot gas injector, a collector and a distributor of cold recycle and a bed movement mechanism;

(v) plenun chamber;

(vi) device for heat recovery of spent shale containing a piping network for recirculation and spraying of the retorting water as well as accumulation hoppers; and

(vii) device for dry bottom sealing.

46. The retort according to claim 45, comprising a capacity between 5,000 and 10,000 metric tonnes per day.

47. The retort according to claim 45 wherein the top sealing device comprises a flow switcher which alternately feeds and empties independent hoppers of the accumulation hoppers with one or more sealing valves, above a stationary table having a rotor equipped with blades.

48. The retort according to claim 45, wherein the load distribution system is placed below a stationary table, and comprises a rotating hopper with proportional sections each having tubular chutes.

49. The retort according to the claim 45, wherein the retorting vessel with annular shape bed comprises a set of supply pipes in a gas collection chamber equipped with nozzles in a shell of the retort, wherein the supply pipes are separated from one another, and a granular material is disposed between a lower end of the supply pipes and a bed movement device.

50. The retort according to claim 49, wherein the bed movement device placed in the bottom of the bed comprises a plurality of radial tables in circular shaped sectors with gaps among themselves, these gaps are covered by a ridge-shaped cap.

51. The retort according to claim 49, wherein the bed movement mechanism also comprises a set of scrappers disposed over the tables and interconnected to each other, wherein angular shuttle movements are driven externally to the retort shell.

52. The retort according to claim 45, wherein the plenun chamber is located below the bed movement mechanism and includes nozzles on a shell of the retort for admitting a stream of cold-gas recycle.

53. The retort according to claim 45, wherein the device for final heat recovery of the spent shale, which is further comprised of a piping network for recirculation and spraying of retorting water and accumulation hoppers, is located below the free space, and includes a trunk-conical shape sectioned on the sides.

54. The retort according to claim 45, wherein the device for dry bottom sealing is attached to an exit of the accumulation hoppers and further comprises a flow metering system including a stationary table having a rotor equipped with blades arranged inside the accumulation hopers.

55. A process to obtain oil and gas from pyrobituminous oil shale, materials containing organic compounds or both,—comprising:

providing a retort including a multifunctional central pipe; a top sealing device; a system of load distribution; a retorting vessel having an annular shaped bed filled with a set of spaced load pipes, a collection chamber a hot gas injector, a collector, a distributor of cold recycle and a bed movement mechanism; a plenun chamber; a device for heat recovery of spent shale containing accumulation hoppers as well as a piping network for recirculation and spraying of retorting water; and a device for dry bottom sealing;

supplying a previously prepared load;

sealing the supplied load;

distributing the load;

collecting and removing gases and mist;

heating and drying the load;

re-injecting the cold gas recycle stream;

pyrolyzing the load;

injecting a hot-gas recycle stream;

removing a cold-gas recycle stream;

recovering heat from the pyrolyzed load;

discharging the annular shaped bed;

injecting a cold recycle stream;

collecting, in the accumulation hoppers, discharged pyrolyzed load;

spraying recycled retorting water;

generating steam by contacting the recycled retorting water with the pyrolyzed load deposited into the accumulation hoppers;

mixing the cold-gas recycle stream with the generated steam; and

dry discharging the retorted material and bottom sealing.

56. The process according to claim 55, wherein supplying the previously prepared load comprises supplying a comminution and classification in the intermediate range between 5 and 100 mm.

57. The process according to claim 55, wherein sealing of the supplied load allows flow of solids into the retorting vessel without introducing air or expelling any gases existing inside.

58. The process according to claim 55, wherein distributing the load further comprises uniformly distributing load particles on a transversal section of the retorting vessel bed.

59. The process according to claim 55, further comprising providing the retorting vessel with annular shape bed with a set of supply pipes in a gas collection chamber equipped with nozzles in a shell of the retort and wherein collecting and removing gases and oil mist occurs in a collection chamber among supply pipes separated from each other and wherein removing the cold-gas stream further comprises removing the cold-gas stream through the nozzles to the exterior of the retort.

60. The process according to claim 55, wherein reinjecting the gas stream further comprises reinjecting the gas stream with temperatures between 300 and 400° C. and homogeneously by the cold-gas recycle distributor, above the hot gas injector.

61. The process according to claim 55, wherein recovering heat from the discharged pyrolyzed load further comprises recovering heat through the passage of the cold-gas recycle stream mixed with the steam generated by the contact of the retorting recycled water with the pyrolyzed load deposited in the accumulation hoppers.

62. The process according to claim 55, wherein discharging the annular shaped bed further comprises evenly discharging the annular shaped bed throughout the transversal section in the retorting vessel with the bed movement mechanism.

63. The process according to claim 55, wherein injecting the gasses stream further comprises injecting the gasses stream at temperatures below 200° C. in the plenum chamber.

64. The process according to claim 55, wherein generating the steam further comprises contacting the recycled retorting water with the discharged pyrolyzed load deposited in the accumulation hoppers and wherein the water spraying in a sprinklers network located above the hoppers causes the contacting and discharging of the cooled spent shale, under flow control, to a sealing valves system.