Abstract: A process is described for reducing the viscosity of heavy hydrocarbon oils which comprises separately heating a stream of heavy hydrocarbon oil and a stream of gas, mixing the hot gas and hot heavy hydrocarbon oil under pressure and immediately thereafter passing the heavy oil/gas mixture through a small nozzle or orifice such that a substantial pressure drop occurs across the orifice and the heavy oil/gas mixture is ejected from the orifice as a spray in the form of fine oil droplets entrained by highly turbulent gas flow. This spray is discharged into a confined reaction zone from which the oil of reduced viscosity is collected.

Abstract: A method of producing and upgrading crude oil in flowable form which is characterized by the steps of forming hydrogen from methane gas and hydrogenating only a portion of the crude oils and produce a less viscous bottom stream that is then admixed with the remainder of the crude to form a flowable crude and transporting the flow of crude to a refinery.

Abstract: The severity of visbreaking of an oil is increased without increasing the instability of the product by incorporating into the feedstock a catalyst preferably supported on a porous substrate. The catalyst is the elemental form or compound of an element selected from the group consisting of selenium, tellurium and sulfur.

Abstract: A process is disclosed for increasing the molecular weight of hydrocarbons and/or derivatives thereof by contacting them with an active hydrogen-containing system which comprises generating a hydrogen-containing plasma at a pressure of at least 5 mm and allowing contact of said hydrocarbons and/or derivatives thereof in liquid form with the plasma-generated system and recovering therefrom a product having an increased average molecular weight.

Abstract: The invention relates to a process of catalytic hydrovisbreaking of a hydrocarbon charge comprising the following stages:a) Mixing the charge to be treated with a gas containing hydrogen in an amount sufficient for carrying out the hydrovisbreaking reaction,b) introducing into the hydrogen-hydrocarbon charge mixture an amount of a catalytic composition that is sufficient for obtaining a content of metals in the charge to be treated ranging from about 10 to 2,000 ppm by weight in relation to the weight of the charge, said catalytic composition being obtained with a method comprising the following stages:1) subjecting to a thermal treatment under the globally reducing atmosphere of a gas containing hydrogen, the mixture obtained by contacting, in any order, at least one compound other than a sulfide of at least one metal with a hydrocarbon charge containing asphaltenes and with at least one organic polysulfide2) heating the product resulting from statge (b) in the presence of a gas containing hydrogen, andc) su

Abstract: Disclosed is a method for cracking a hydrocarbon material. The method includes introducing a stream including a hydrocarbon fluid into a reaction zone. A microwave discharge plasma is continuously maintained within the reaction zone, and in the presence of the hydrocarbon fluid. Reaction products of the microwave discharge are collected downstream of the reaction zone.

Abstract: A process for treating an organic stream containing a non-distillable component to produce an organic vapor stream and a solid which process comprises the steps of: (a) contacting the organic stream containing a non-distillable component with a hydrogen-rich gaseous steam having a temperature greater than the organic stream in a flash zone at flash conditions thereby increasing the temperature of the organic stream and vaporizing at least a portion thereof to produce an organic vapor stream comprising hydrogen and a heavy stream comprising the non-distillable component; and (b) reacting at least a portion of the heavy stream comprising the non-distillable component in the presence of hydrogen in a pyrolysis zone to produce a thermally stabilized volatile organic stream comprising hydrogen and a solid.

Abstract: A process for the conversion of a heavy hydrocarbon oil in the presence of hydrogen and a catalyst or additive is described. It is shown that conversion can be increased by injecting an anti-foaming agent or a solution of anti-foaming agent in light oil into the reactor. Significantly better results are obtained when the anti-foam or the solution of anti-foam is injected directly into the top section of the reactor.

Abstract: A hydroconversion process is described in which a feed slurry comprising a heavy hydrocarbon oil and an iron compound additive is contacted with a hydrogen-containing gas in a hydroconversion zone at hydroconversion conditions to convert at least a portion of said oil to lower boiling products. The process is characterized by the use of an iron compound having particle sizes of less than 45 .mu.m, preferably with at least 50 wt % of particles of less than 5 .mu.m.

Abstract: This invention relates to a process in which the addition of a substantially inert solvent to a heavy petroleum stock permits high conversion hydrocracking and hydrogen addition to be accomplished in the absence of catalyst or additive.

Abstract: Plant for the hydrocracking of a feedstock of high-molecular hydrocarbons comprising a fluidized bed of particles within a chamber, injection tube for injecting a fluidizing gas into the bottom of the chamber, tube reactor means on said container for letting said fluidizing gas escape, and a plasma torch of a gas containing hydrogen, which is suitable for injecting the plasma inside the chamber into the fluidized bed of particles.

Abstract: A process for producing metallurgical coke from a hydrocarbon residuum characterized by high vanadium and high sulphur contents comprises coking a hydrocarbon residuum in a coking drum in the presence of an additive selected from the group consisting of carbonates and hydroxides of sodium, potassium and calcium and mixtures thereof and an oxidizing agent selected from the group consisting of water, carbon dioxide and mixtures thereof.

Abstract: A process for treating a temperature-sensitive hydrocarbonaceous stream containing a non-distillable component to produce a hydrogenated distillable hydrocarbonaceous product and a heavy product comprising the non-distillable component while minimizing thermal degradation of the hydrocarbonaceous stream which process comprises the steps of: (a) contacting the hydrocarbonaceous stream with a first hydrogen-rich gaseous stream having a temperature greater than the hydrocarbonaceous stream in a flash zone at flash conditions thereby increasing the temperature of the hydrocarbonaceous stream with minimal thermal degradation and vaporizing at least a portion thereof to provide a hydrocarbonaceous vapor stream comprising hydrogen and a heavy product comprising the non-distillable component; (b) contacting the hydrocarbonaceous vapor stream comprising hydrogen recovered from step (a) without intermediate separation with a hydrogenation catalyst in a hydrogenation reaction zone at hydrogenation conditions to increase

Abstract: This invention provides a method for extending the catalytic dewaxing cycle time of a refined waxy lube stock. The method, in its broadest aspect, requires the additional refining step of thermally treating the refined waxy stock or precursor thereof for about 0.1 to about 2.0 hours at elevated temperature and at a pressure of 0 to 3000 psig (pounds per square inch gauge), and recovering an upgraded waxy stock having a reduced content of trace compounds that contain metals, nitrogen, sulfur and oxygen.In a specific embodiment of this invention, a vacuum residuum is thermally treated at a temperature of about 700.degree. F. to 950.degree. F. prior to solvent deasphalting and solvent extraction, and the waxy bright stock so formed is catalytically dewaxed with extended cycle time.

Abstract: The invention is a pyrolysis furnace for cracking heavy oils to olefins. The furnace includes a convection zone and a radiation zone. In parallel streams, the heavy stream and a stream diluent are heated in the convection zone to the point of partial thermal cracking while in the other stream a lighter oil and steam are cracked to produce olefins. The hot, olefinic light stream is then mixed with the heated heavy stream and further cracked in the radiation zone.

Abstract: An improved method of controlling catalyst inventory in the reactor of an ebullated bed process has been discovered. Pressure differentials are measured to calculate a catalyst inventory characterization factor. Aged catalyst is withdrawn and fresh catalyst added in an amount to reestablish the value of the factor.The catalyst to oil ratio is maintained despite changes in bed ebullation, gas and liquid holdups and oil residence time changes.

Abstract: A solvent extract obtained from a conventional hydrocarbon oil solvent extraction process, e.g., one employing furfural as the extraction solvent, is cooled to a temperature providing, following a secondary decantation of the cooled extract, a pseudo raffinate containing most of the non-aromatics and a pseudo extract possessing a hydro-aromatic content of H.sub.alpha hydrogen of at least 20 percent of the total hydrogen content. The pseudo extract is ideally suited as a hydrogen-donor for a variety of refinery operations such as visbreaking. The pseudo raffinate is suitable as a co-feed for such catalytic cracking operations as fluidized catalytic cracking (FCC) and thermofor catalytic cracking (TCC) and can be recycled to the extraction unit to produce more lube oil.

Abstract: Crude oils are normally so viscous that they cannot be pumped through pipelines without periodic heating. The usual practice is to pump the oil from one heat station to another, with part of the crude oil being used to generate heat. This problem is solved by reducing the viscosity of the crude oil. The viscosity reduction is effected using reactors for partially cracking crude oil, mixing the partially cracked oil with incoming crude oil, separating gases from the liquid in the mixture in a flash vessel, condensing the gases to yield liquid hydrocarbons, and mixing the latter with untreated crude oil and liquid residue from the flash vessel to yield a flowable, relatively low viscosity mixture. Coke produced in the reactors is periodically reacted with superheated steam to yield hydrogen, which is used to improve the quality of some of the residue from the flash residue. The thus treated flash vessel residue is used to feed the reactors.

Abstract: A process for the thermal conversion of various fossil organic materials such as heavy crude oils, heavy petroleum fractions or refining residues, is described. According to the invention, the charge is subjected to thermal processing in the presence of a minor proportion of at least one radical-generating monooxygenated compound, containing at least one heteroelement selected from sulfur, and nitrogen and in which the oxygen is borne by said heteroelement. The conversion is improved with a composition comprising a hydrogen donor diluent and this monooxygenated compound in a weight ratio of 0.2:1 to 400:1. The invention is useful in the petroleum industry and the coal industry and particularly in the process of hydrovisbreaking.

Abstract: A non-catalytic process for the conversion of a hydrocarbonaceous stream containing less than about 5 weight percent halogenated organic compounds which process comprises: (a) reacting the hydrocarbonaceous stream in the presence of hydrogen in a reaction zone at reaction conditions including an elevated temperature selected to convert at least a portion of the halogenated organic compounds to more highly hydrogenated organic compounds; and (b) recovering a hydrocarbonaceous product stream containing lower halogen content.

Abstract: Methane and liquid hydrocarbon feeds boiling above 350.degree. C. are reacted by feeding finely divided droplets into hot gas at not more than 2 MPa containing at least 50% volume methane and not more than 15% volume hydrogen.

Abstract: Disclosed are hydroconversion processes catalyzed by aromatic-metal chelate compositions which are deficient in hydrogen, are cross-linked, and which are comprised of two or more heteroatoms, wherein at least one of the heteroatoms are part of a 5 to 6 member heterocyclic ring, and wherein the metal constituent is selected from Groups III, IVB, VB, VIB, VIIB, and VIII of the Periodic Table of the Elements, and the heteroatom is selected from sulfur, oxygen, and nitrogen.

Abstract: Disclosed is a method for accelerating the exchange of hydrogen between a hydrogen donor and a petroleum resid to be subjected to cracking, visbreaking, or coking. Acceleration is effected by incorporating an aqueous solution of ammoniun sulfide into the mixture of donor and resid and subjecting the mixture to a period of heat-soaking at an elevated temperature.

Abstract: A hydrofining process (preferably hydrovisbreaking process) comprises contacting a substantially liquid hydrocarbon-containing feed stream, which contains Ramsbottom carbon residue and materials boiling in excess of about 1000.degree. F. at atmospheric conditions, with a free hydrogen-containing gas and a catalyst composition comprising at least one catechol compound of molybdenum. Preferably the catechol compound of molybdenum is prepared by reaction of a compound comprising molybdenum and oxygen with a catechol compound under non-reducing conditions.

Abstract: Disclosed is a process for the thermal cracking of heavy oils, which comprises a thermal cracking step of contacting a heavy oil with a fine powder of a porous material fluidized by a fluidizing gas to mainly obtain a light oil and a regenerating step of gasifying and removing coke adhering to the fine powder taken out from the thermal cracking step while fluidizing the fine powder by a molecular oxygen-containing gas and a steam-containing gas, the fine powder being circulated between the two steps, wherein fine spherical particles having a pore volume of 0.2 to 1.5 cm.sup.3 /g, a specific surface area of 5 to 1500 m.sup.2 /g, an average pore size of 10 to 10,000 .ANG. and a weight average size of 0.025 to 0.25 mm, in which these properties are stably maintained at the temperature adopted for the thermal cracking, are used as the fine powder, and a hydrogen gas is made present at the thermal cracking step, the partial pressure of hydrogen is maintained at about 0.5 to about 5 Kg/cm.sup.

Abstract: This invention concerns a process for the thermal treatment of hydrocarbon charges having a high content of asphaltenes in the presence of additives which prevent coke formation. The additive according to the invention is a salt of a metal selected from V, Mo, Cr, W, Fe, Co and Ni at a concentration between 100 and 2500 ppm of metal relative to the charge either in the form of a suspension of solid particles, in solution or as an emulsion. These additives prevent the coke formation in all thermal treatments of which the temperature is above about 420.degree. C., such as viscoreduction or hydro viscoreduction.

Abstract: A process for the selective production of petrochemical products by thermal cracking is disclosed. The process includes feeding methanol to a thermal cracking atmosphere of hydrocarbons in such a way that the ratio, as carbon atoms, of methanol and at least one starting hydrocarbon is at least 0.05:1, thermally cracking the at least one starting hydrocarbon at a cracking temperature of from 650.degree. to 1300.degree. C., and quenching the resulting reaction product.

Abstract: A hydrocarbon-containing feed stream, e.g., a heavy oil or residuum, is contacted under suitable reaction conditions with free hydrogen, hydrogen sulfide and at least one olefin polymer, preferably polypropylene or polystyrene, so as to produce a hydrocarbon product stream having increased API.sub.60 gravity and lower content of heavies. Generally, the amounts of impurities (sulfur, nitrogen, nickel and vanadium) contained in the feed stream are reduced in this hydrotreating process.

Abstract: A liquefaction process for coal lignite or heavy oil is disclosed utilizing a hydrogen-donor solvent. The preferred hydrogen-donor solvent is recovered as a vapor from the liquefaction mixture. The preferred method for converting the vapor into active hydrogen-donor solvent form involves passage of the vapor over a catalyst bed positioned in the vapor space of the catalyst vessel. Novel apparatus for so positioning the catalyst bed is also disclosed.

Abstract: Heavy hydrocarbon oil is subjected to hydrogen donor diluent cracking under conditions of high temperature, moderate pressure and short residence time.

Abstract: This invention relates to a process for converting solid carbonaceous material, such as coal, to liquid and gaseous hydrocarbons utilizing methane, generally at a residence time of about 20-120 minutes at a temperature of 250.degree.-750.degree. C., preferably 350.degree.-450.degree. C., pressurized up to 6000 psi, and preferably in the 1000-2500 psi range, preferably directly utilizing methane 50-100% by volume in a mix of methane and hydrogen. A hydrogen donor solvent or liquid vehicle such as tetralin, tetrahydroquinoline, piperidine, and pyrolidine may be used in a slurry mix where the solvent feed is 0-100% by weight of the coal or carbonaceous feed. Carbonaceous feed material can either be natural, such as coal, wood, oil shale, petroleum, tar sands, etc., or man-made residual oils, tars, and heavy hydrocarbon residues from other processing systems.

Abstract: In an expanded bed reactor, the expansion of the bed is automatically controlled by automatically changing the rate of speed of a recycle pump for the reactor. The bed is preferably provided with both high and low level bed detectors, and a further detector for determining abnormally high levels.

Abstract: An extraction residue obtained by solvent deasphalting of a residual oil is mixed with a carrier gas and thermally cracked at a temperature of 400.degree. C. to 600.degree. C. in a tube-type cracking apparatus to obtain cracked oil and pitch. The use of the carrier gas, which may be either an inert gas such as nitrogen or a reactive gas such as hydrogen, permits a flow velocity through the cracking apparatus sufficient to substantially prevent coking. Preferably, the cracking conditions are controlled so that the yield of cracked oil is not more than about 30 to 35%.

Abstract: A delayed coking process having improved liquid yield and liquid product distribution relative to coke yield is characterized by the absence of heavy recycle. The coker feedstock is heated in the coker furnace and led to the coker drums where coking takes place and the vaporous effluence are passed to a fractionator from which the heavy gas oil fraction is removed as product. Process heat is conserved by indirect heat exchange of the feedstock with the coking products prior to the feedstock entering the coking furnace. A further improvement in liquid yield and selectivity is obtained by adding a solvent or diluent to the feedstock and this may be either a hydrocarbon fraction such as a coker distillate, a light gas oil or another fraction having an end point below 450.degree. C.; in addition, it may be used in conjunction with a reactive or nonreactive gas such as nitrogen, steam, hydrogen or hydrogen sulfide.

Abstract: A two-stage hydrotreating process comprises the steps of (1) contacting a liquid hydrocarbon-containing feed stream, which contains nickel, vanadium and Ramsbottom carbon residue, with hydrogen and a solid inorganic refractory material (preferably alumina) for at least partial removal of Ni and V, and then (2) hydrovisbreaking the intermediate product stream from step (1). Preferably, step (2) is carried out in the presence of at least one decomposable compound of a metal, preferably a molybdenum dithiophosphate.

Abstract: A hydrotreating (hydrovisbreaking) process comprises the step of contacting under suitable conditions (A) a substantially liquid hydrocarbon-containing feed stream containing more than 0.1 weight-% Ramsbottom carbon residue, (B) a hydrogen-containing gas and (C) a liquid catalyst composition, which has been prepared by mixing (a) water, (b) at least one alkali metal sulfide or hydrogen sulfide or ammonium sulfide or hydrogen sulfide and (c) at least one molybdenum-oxygen compound, wherein the atomic ratio of S:Mo in this liquid catalyst composition is in the range of from about 0.6:1 to about 3.0:1, preferably from about 0.8:1 to 2.3:1. Preferably, (b) is (NH.sub.4).sub.2 S and (c) is MoO.sub.3.

Abstract: An antifouling compound comprising a phthalocyanine compound is disclosed for use in high temperature coke producing petroleum reactions wherein said coke is unwanted and acts as a fouling agent in the associated reaction apparatus.

Abstract: A process is disclosed for converting a heavy hydrocarbon oil feedstock to produce a high yield of lower-boiling hydrocarbons, wherein a residuum fraction of the effluent from a hydrogen donor diluent hydrocracking reactor is deasphalted using a low-boiling solvent and at least the highest-boiling fraction of the deasphalted oil is recycled to the hydrogen diluent hydrocracking zone.

Abstract: A process for the conversion of heavy hydrocarbon feedstocks which are characterized by high molecular weight, low reactivity and high metal contents comprising feeding the feedstock to a hydrodemetallization zone where the feedstock is contacted with hydrogen and a catalyst capable of demetallizing organometallic complexes of high molecular weight and cracking resistance, thereafter removing the effluent from the demetallization zone and feeding same to the thermal cracking zone where the effluent is contacted with hydrogen and thereafter feeding the product from the cracking zone to a hydrocarbon conversion zone where the product is contacted with hydrogen and a catalyst capable of cracking molecules of high cracking resistance.

Abstract: Heavy petroleum oils such as resids are subjected to visbreaking in the presence of a hydroaromatic hydrogen donor solvent having an aromatic and alpha-to-aromatic proton content each of at least 20 percent of the total solvent hydrogen. The amount of donor solvent is from 0.1 to 50, preferably 0.1 to 20, weight percent of the heavy oil feed. The visbreaking may be carried out at relatively high severities as the use of the donor solvent reduces coke formation as well as producing a product of reduced viscosity, pour point and sedimentation characteristics. Reaction severity is usually in the range of 250 to 1500 seconds ERT at 800.degree. F. (427.degree. C.) but may range up to 15000 seconds ERT. Suitable solvents may be obtained from catalytic cracking process, for example, FCC cycle oils, slurry oils and main column bottoms.

Abstract: A thermal cracking process for producing petrochemical products from hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300.degree. to 3000.degree. C. comprising steam; feeding a mixture of methane and hydrogen to the hot gas in such a way that a methane/hydrogen molar ratio is over 0.05; further feeding starting hydrocarbons to the hot gas comprising the methane, hydrogen and steam so that the starting hydrocarbons containing hydrocarbon components of higher boiling points are, respectively, fed to higher temperature zones; subjecting the starting hydrocarbons to thermal cracking while keeping the cracking temperature at 650.degree. to 1500.degree. C., the total residence time at 5 to 1000 milliseconds, the pressure at 2 to 100 bars, and the partial pressure of hydrogen, after thermal cracking of a hydrocarbon comprising hydrocarbon components whose boiling point exceeds 200.degree. C., at least 0.

Abstract: A process for hydrotreating carbonaceous materials is disclosed. The carbonaceous material is contacted with steam and with empirical hydrates of alkali metal hydrosulfides, monosulfides, or polysulfides. The process hydrocracks, hydrogenates, denitrogenates, demetallizes, and desulfurizes. In a preferred embodiment, hydrogen sulfide is co-fed to the reaction zone.

Abstract: In this process ethylene is prepared by pyrolytically cracking ethane in a pyrolytic cracking furnace having a plurality of elongated serpentine-situated thermal cracking tubes which have a longer run life as a result of the selective cracking of a C.sub.3 to C.sub.12 hydrocarbonaceous material at conditions sufficient to selectively place a coat of amorphous relatively smooth coat of coke on the interior walls of the thermal cracking tubes and thereby mask the catalytic effect of iron, nickel, both iron and nickel, or other metal catalytic sites indigenous to the walls of the furnished tubes. In this manner, the amount of cracking time realized for each particular furnace before regeneration of the same is increased by 20 to 50%.

Abstract: In methods of manufacturing olefines by thermally cracking hydrocarbons, there is disclosed a thermal cracking method for producing olefines from hydrocarbons, characterized in that hydrocarbon in burnt with oxygen in the presence of steam to generate a high-temperature gas containing steam of 1500.degree.-3000.degree. C., methane and hydrogen are supplied into the high-temperature gas containing said steam, with the molar ratio of methane to hydrogen in said high temperature gas being 0.05 or more, then hydrocarbon to be cracked is supplied into said high-temperature gas containing said methane, hydrogen and steam, so that the hydrocarbon is subjected to thermal cracking by maintaining the partial pressure of hydrogen at more than at least 0.1 bar at the outlet of a reactor, under conditions of reaction temperature, 800.degree.-1200.degree. C. and residence time in the reactor 5-300 milli second, and then the reaction product is cooled in a rapid manner.

Abstract: A thermal cracking process for producing olefins from hydrocarbons which comprises the steps of burning hydrocarbons with less than the theoretical amount of oxygen in the presence of steam to give a hot gas of from 1400.degree. to 300.degree. C. comprising steam and hydrogen prior to reaction; feeding to the hot gas comprising the steam and hydrogen, a mixture of methane and hydrogen so that a methane/hydrogen molar ratio in said hot gas is over 0.05; further feeding a starting hydrocarbon to the hot gas mixture comprising the methane, hydrogen and steam; subjecting the starting hydrocarbon to thermal cracking while keeping the partial pressure of hydrogen at least 0.1 bar at the outlet of a reactor, the temperature at 800.degree. to 1200.degree. C., and the residence time at 5 to 300 milliseconds; and quenching the resulting reaction product.

Abstract: A hydrogen donor solvent selected from the group consisting of a full range crude oil and an atmospheric topped crude oil is used in a hydrovisbreaking process. The heavy fraction being processed is heated in the presence of hydrogen and the solvent under suitable hydrovisbreaking conditions. As a result, the amount of heavies in the feed to the hydrovisbreaking process is substantially reduced.

Abstract: A visbreaking process for the conversion of heavy residual petroleum charge stocks is provided in which an organic sulfur compound containing a thiol sulfur is added to said petroleum charge stock and the visbreaking reaction is carried out at increased severities in the presence of highly aromatic petroleum refinery hydrogen-donor materials which are characterized by an H.sub.Ar proton content between about 20 and 50 percent and an H.sub..alpha. proton content of at least about 20 percent. Typcial hydrogen-donor materials include FCC main column bottoms, clarified slurry oil and light cycle oil.

Abstract: A thermal cracking process for selectively producing petrochemical products from hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300.degree. to 3000.degree. C. comprising steam; feeding hydrogen to the hot gas; further feeding starting hydrocarbons to the hot gas comprising the steam and hydrogen so that the starting hydrocarbons containing hydrocarbon components of higher boiling points are, respectively, fed to higher temperature zones so as to thermally crack the respective hydrocarbons under different conditions while keeping the cracking temperature at 650.degree. to 1500.degree. C., the total residence time at 5 to 1000 milliseconds, the pressure at 2 to 100 bars, and the partial pressure of hydrogen, after thermal cracking of a hydrocarbon comprising hydrocarbon components whose boiling point exceeds 200.degree. C., at least 0.1 bar; and quenching the resulting reaction product.

Abstract: A hydrocarbon containing feed stream, e.g., a heavy oil or residuum, is contacted under suitable reaction conditions with a carbon monoxide containing gas, so as to produce a hydrocarbon stream having a reduced level of metal impurities, especially nickel and vanadium compounds, and an increased API.sup.60 gravity, essentially in the absence of a catalyst or extractant.

Abstract: There is disclosed a system for measuring and controlling the concentration of hydrogen in hydrogen recycle processes used in oil refineries and petrochemical plants. The system is intended to reduce the amount of hydrogen and hydrocarbon vapor circulating in such systems, thus reducing the quantity of utilities needed to operate such systems. Specifically, there is a savings of compressor power and fuel required for heating. The system is dependent on the recognition that a decrease in cooling medium temperature results in an increase in hydrogen flow, which can be decreased to the minimum permissible without endangering catalyst activity and stability and product yield if hydrogen concentration is monitored, and that partial pressure is the key parameter.