Abstract: Catalyst for steam cracking reactions consisting of pure mayenite having the general formula: 12CaO.7Al2O3 having an X-ray diffraction spectrum as indicated in Table I, obtained with a preparation process comprising the following steps: dissolution of salts containing calcium and aluminum with water; complexing of the dissolved salts by means of polyfunctional organic hydroxyacids; drying of the solution resulting from the completing in order to obtain a solid precursor product; calcination of the solid precursor product at a temperature ranging from 1300 to 1400° C. for at least two hours.

Abstract: A process for the coproduction of purified benzene and ethylene is provided. The method comprises providing a first mixture comprising benzene, toluene, and one or more C6 to C7 non-aromatics and separating the majority of the benzene and the one or more C6 to C7 non-aromatics from the majority of the toluene to form a second mixture containing benzene and at least a portion of the one or more C6 to C7 non-aromatics. Thereafter at least about 80% of the C6 to C7 non-aromatics in the second mixture are cracked while maintaining essentially no cracking of benzene to produce a cracked product containing ethylene, propylene and pyrolysis gasoline comprising olefins, di-olefins and benzene. The pyrolysis gasoline is preferably hydrotreated and then fractionated to form a purified benzene product comprising at least about 80 wt % benzene. The purified benzene can be used as a feed to a liquid phase or mixed phase alkylation and/or to produce ethylbenzene or cumene.

Abstract: A process to increase the non-volatile removal efficiency in a flash drum in the steam cracking system. The gas flow from the convection section is converted from mist flow to annular flow before entering the flash drum to increase the removal efficiency. The conversion of gas flow from mist flow to annular flow is accomplished by subjecting the gas flow first to at least one expander and then to bends of various degrees and force the flow to change directions at least once. The change of gas flow from mist to annular helps coalesce fine liquid droplets and thus being removed from the vapor phase.

Abstract: A process for treating hydrocarbon feed in a furnace, the process comprising: (a) heating hydrocarbon feed, (b) adding water to the heated feed, (c) adding dilution steam to the heated feed to form a mixture, (d) heating the resulting mixture and feeding the resulting heated mixture to the furnace, wherein the water in (b) is added in an amount of from at least about 1% to 100% based on water and dilution steam by weight.

Abstract: The invention concerns a stripping method for extracting solid fluidized particles whereby the particles to be stripped are subjected to a first stripping in a first chamber (9), then at least a second stripping in a second chamber (10) wherein are provided solid/gas separating means allowing the gaseous fluids derived from the second stripping to directly pass through from the bottom to the top but preventing them from going up again into the first chamber (9). The invention also concerns a device for implementing said method.

Abstract: A hydrocarbon cracking process and apparatus for recovering ethylene from hydrocarbon raw material streams. More particularly, the hydrocarbon cracking process and apparatus of this invention utilizes a furnace with a convection section and a radiant section in which the hydrocarbon feedstream is cracked by heating it to a particular temperature and then is self-quenched.

Abstract: A crude oil feedstock or crude oil fractions containing pitch feedstock is pyrolyzed in a pyrolysis furnace.

Abstract: This invention discloses improvements on previous inventions for catalytic conversion of coal and steam to methane. The disclosed improvements permit conversion of petroleum residua or heavy crude petroleum to methane and carbon dioxide such that nearly all of the heating value of the converted hydrocarbons is recovered as heating value of the product methane. The liquid feed is distributed over a fluidized solid particulate catalyst containing alkali metal and carbon as petroleum coke at elevated temperature and pressure from the lower stage and transported to the upper stage of a two-stage reactor. Particulate solids containing carbon and alkali metal are circulated between the two stages. Superheated steam and recycled hydrogen and carbon monoxide are fed to the lower stage, fluidizing the particulate solids and gasifying some of the carbon. The gas phase from the lower stage passes through the upper stage, completing the reaction of the gas phase.

Abstract: Materials that consist at least in part of aluminum quasi-crystals whose composition is represented by the general formula:

Abstract: Systems, processes, and reactors for the catalytic reforming of naphtha are provided. Embodiments of the invention include reactors comprising monolithic catalyst having honeycomb-type structure that allows for improved efficiency, productivity, and reaction selectivity over conventional catalytic reforming technology.

Abstract: The present invention provides a pyrolysis tube for enhancing the yield of olefins and reducing a coking tendency in steam cracking of hydrocarbons. According to the present invention, the pyrolysis tube is characterized in that a plurality of mixing blades made by twisting two ends of a plate in opposite directions are included therein. The yield of ethylene is thereby improved and the coking tendency is reduced by mixing a fluid flow, improving a heat transfer rate and shortening a residence time of the reactants therein.

Abstract: The cracking of hydrocarbon fractions, for example to obtain low olefins, in particular ethylene, is performed in reaction tubes that are at least partially coated with catalyst. The catalyst can promote gasification of coke with water vapor after the water-gas reaction in CO, CO2 and H2, and/or the cracking reactions. The catalyst coating can be placed directly on reaction tubes or on top of a previously applied adhesion promoter and/or auxiliary medium placed on the reaction tubes, in particular on a grid. Preferably, the catalyst coating is applied thermally, by cold-coating processes, in particular the slip process, by vapor deposition and/or,adhesion. The catalyst can promote, in particular, gasification of coke with water vapor after the water-gas reaction in CO, CO2 and H2 and make hydrogen, obtained during catalytic gasification, available for cracking hydrocarbons and/or as additional product.

Abstract: A two-step method and apparatus for controlling cracking severity in the effluent from a cracking furnace such as an ethylene cracker. The method includes two steps. The first step consists of determining the near infrared spectrum of effluent in-line. The second step consists of changing the temperature and/or residence time of the furnace according to the determination of the first step. The apparatus includes a light source mounted on a conduit for the effluent, a light detector mounted on the opposite side of the conduit from the light source to receive light emitted from the light source, means for sheltering the light source from the effluent, means for sheltering the lights detector from the effluent, means for flowing a fluid past the light source at a higher pressure than the pressure of the effluent; and means for flowing a fluid past the light detector at a higher pressure than the pressure of the effluent.

Abstract: The present invention refers to a crystalline material of zeolitic nature named ITQ-3 characterized by its characteristic X-ray diffraction pattern and its microporous properties, to the process of preparation thereof characterized by the use of one or several organic additives in a reaction mixture that is made to crystallize by heating and to the use thereof in processes of separation and transformation of organic compounds, which material has the empirical formula x(M1/nXO2):yYO2:SiO2 where x has a value lower than 0.15 and may be equal to zero; and y has a value lower than 0.1 and may be equal to zero; M is H+ or an inorganic cation of charge +n, X is a chemical element with oxidation state (Al, Ge, B and Cr), Y is a chemical element with oxidation state (Ti, Ge and V), and when x=0 and y=0 can be described as a new polymorphous of silica of microporous nature.

Abstract: A steam-cracking process with a very high degree of severity of a feedstock that comprises at least 20% by weight of hydrocarbons of the group that is formed by ethane and propane in which the feedstock that is diluted with water vapor is circulated in the radiation zone of a furnace, in at least one pipe with a length L≧14 m and a hydraulic diameter that is greater than or equal to 34 mm in the end portion of the pipe at least, is described under the following conditions of dwell time &tgr; and furnace output temperature COT: 120 ms≦&tgr;≦2800 ms and 858° C.≦COT≦1025° C. to obtain a conversion of at least 77% of ethane of the feedstock if the feedstock contains ethane and/or a conversion of at least 96% of the propane of the feedstock if the feedstock contains propane, and to maintain this conversion for a cycle time that is greater than or equal to about 8 days.

Abstract: A pyrolysis heater particularly for the cracking of hydrocarbons in the production of olefins has a burner arrangement in the firebox which directly heats the hearth of the firebox such that it becomes a radiant surface. This improves the heat flux in the lower portion of the firebox and produces a more uniform vertical heat flux profile over the firebox elevation. The base burners may fire horizontally across the hearth or may comprise porous ceramic burners as a part of the hearth. The base burners operate along with vertically firing hearth burners and optional wall burners in the upper portion of the firebox.

Abstract: An adsorptive separation process for preparing the separate feed streams charged to naphtha reforming unit and a steam cracking unit is presented. The feed stream to the overall unit is fractionated to yield a C5 stream and a second stream containing the rest of the feed, which is passed into the adsorptive separation unit. The C5 stream is utilized as the desorbent in the adsorptive separation. The adsorptive separation separates the C6-plus components of the feed stream into a normal paraffin stream, which is charged to the steam cracking process, and non-normal hydrocarbons which are passed into a reforming zone. The invention improves the yields from both downstream units.

Abstract: A improved hydrocarbon conversion process, comprising applying a plating, cladding, paint or other coating to at least a portion of a hydrocarbon conversion reactor system which is used to convert hydrocarbons to products in the presence of steam, said coating being effective to reduce the amount of undesirable by-products in said process; and operating the hydrocarbon conversion process at a steam to hydrocarbon ratio that is lower than the steam to hydrocarbon ratio at which said process was operated prior to applying said coating. Preferred hydrocarbon conversion process includes steam cracking of hydrocarbons to produce ethylene and dehydrogenation of ethylbenzene to styrene.

Abstract: A process and a device for separating ethane and ethylene from a hydrocarbon steam-cracking effluent is described. Effluent (1) is absorbed in an absorption column (7) by a cooled solvent (9). At the bottom of the column, liquid phase (12) that contains the solvent and the C2+ hydrocarbons is recovered and hydrogenated (15). The hydrogenation effluent that contains the solvent is introduced into a first distillation column (70) where the solvent is regenerated. The solvent is cooled and recycled at the top of absorption column (7). The C2+ hydrocarbons are collected at the top, and a condensed liquid phase is distilled in a second distillation column (77) to recover a C2 fraction that consists of ethane and ethylene.

Abstract: A process for separating ethane and ethylene from a hydrocarbon steam-cracking effluent is described. Effluent (1) is absorbed in an absorption column by a cooled solvent (9). At the bottom of the column, the liquid phase that contains the solvent and the C2+ hydrocarbons is recovered and hydrogenated (15). The hydrogenation effluent that contains the solvent is introduced into a first distillation column (16). Ethane-ethylene mixture (17) is drawn off laterally from the column, and a phase (19) that contains the solvent and hydrocarbons with at least 3 carbon atoms is drawn off at the bottom of the column. This phase (19) is separated in a second distillation column (22), and C3+ hydrocarbons and, at the bottom of the column, regenerated solvent (26) that is cooled and that is recycled (9, 52) in the absorption column are collected.

Abstract: The present invention includes an improvement to the existing method of steam reforming of hydrocarbon, wherein the improvement comprises: the flowing is at a rate providing a residence time less than about 0.1 sec resulting in obtaining product formation yield or amount that is the same or greater compared to product formation at a longer residence time. Another improvement of the present invention is operation at a steam to carbon ratio that is substantially stoichiometric and maintaining activity of the supported catalyst. The present invention also includes a catalyst structure for steam reforming of a hydrocarbon.

Abstract: A process for hydrocarbon conversion to prepare lower olefins such as ethylene, propylene, etc., and light aromatics by bringing hydrocarbons into contact with a solid granular catalyst. In order to optimize the reaction conditions and product structure and save the capital and operating costs, a piston flow reactor is used in this process and multiple groups of feed inlets, which allow hydrocarbons with different properties to enter the device from different feed inlets and proceed pyrolysis under different operation conditions, are set on the reactor. This process is usable for individual pyrolysis or co-feed pyrolysis of hydrocarbons from refinery gases, liquid hydrocarbons, to heavy residues.

Abstract: The invention relates to a process for converting cycle oils produced in catalytic cracking reactions into olefin and naphtha. More particularly, the invention relates to a process for hydroprocessing a catalytically cracked light cycle oil, and then re-cracking it in an upstream zone of the primary FCC riser reactor.

Abstract: The invention relates to a process for converting naphtha and cycle oils produced in catalytic cracking reactions into light olefins. More particularly, the invention relates to a process for hydroprocessing a catalytically cracked light cycle oil, and then re-cracking it along with naphtha in an upstream zone of the primary FCC riser reactor.

Abstract: The invention relates to a process for converting cycle oils produced in catalytic cracking reactions into light olefin and naphtha. More particularly, the invention relates to a process for hydroprocessing a catalytically cracked light cycle oil in order to form a hydroprocessed cycle oil containing a significant amount of tetralins. The hydroprocessed cycle oil is then re-cracked in an upstream zone of the primary FCC riser reactor.

Abstract: The present invention is a fluidized catalytic cracking process that incorporates a zoned riser reactor. The process provides an in-situ method for feed upgrading in a riser reactor. The process assists in the removal of undesirable contaminants, such as nitrogen, from FCC feedstocks.

Abstract: The present invention is a fluidized catalytic cracking process that incorporates a zoned riser reactor. The process provides an in-situ method for feed upgrading in a riser reactor. The process assists in the removal of undesirable contaminants, such as nitrogen, from FCC feedstocks.

Abstract: The present invention is a fluidized catalytic cracking process that incorporates a zoned riser reactor. The process provides an in-situ method for feed upgrading in a riser reactor. The process assists in the removal of undesirable contaminants, such as nitrogen, from FCC feedstocks.

Abstract: Olefins may be produced by thermally steam cracking residuum containing a short residuum having a boiling point range greater than 565° C. wherein at least 3 weight percent of the short residuum has a boiling point greater than or equal to 650° C. The residuum has pentane insolubles less than or equal to 1.2, ASTM 893. Further, the weight percent of hydrogen of the residuum is greater than or equal to 12.5. Such feedstocks are produced by hydrotreating, where necessary, a petroleum residuum having pentane insolubles less than 1.0, ASTM 893, until the weight percent of hydrogen of the petroleum residuum is 12.5. Where necessary, the petroleum residuum may be deasphalted prior to subjecting it to hydrotreatment.

Abstract: Olefins may be produced by thermally steam cracking a crude oil having pentane insolubles less than or equal to 1.2, ASTM D-893, and a weight percent of hydrogen greater than or equal to 12.5.

Abstract: A process for thermal pyrolysis of a feedstock containing at least 80% ethane to convert to ethylene at a conversion rate of at least equal 80% by feeding the feedstock into a reaction zone in which heating means are arranged approximately perpendicular to the direction of flow of the feedstock. The temperature of the outlet of the heating zone in the reaction zone is between 880 and 960° C. and the dwell time of the feedstock in the heating zone is between 1005 and 3000 milliseconds.

Abstract: A method for making an oil soluble coking process additive, includes the steps of: providing mixture of a metal salt in water wherein the metal salt contains a metal selected from the group consisting of alkali metals, alkaline earth metals and mixtures thereof; providing a heavy hydrocarbon; forming an emulsion of the mixture and the heavy hydrocarbon; heating the emulsion so as to react the metal salt with components of the heavy hydrocarbon so as to provide a treated hydrocarbon containing oil soluble organometallic compound, wherein the organometallic compound includes the metal and is stable at a temperature of at least about 300° C. The oil soluble additive and a process using same are also disclosed.

Abstract: A method and apparatus for decoking and suppressing coke formation during pyrolysis has been discovered that does not require complete shut down of the pyrolysis furnace. For the decoking step, the hydrocarbon feed is cut off to one or more coils for usually less than about three hours during which a decoking additive is added to the steam flow in that coil. This additive is comprised of an aqueous solution of a group IA metal salt and a group IIA metal salt and catalyzes the coke removal. The hydrocarbon feed continues in the other coils during this procedure. After decoking, a suppression additive also comprising group IA and IIA metals is added to the steam and hydrocarbon feed. This suppression additive will melt onto the inner surfaces of the pyrolysis furnace coils, coating the coils with a glass layer which inhibits coke formation.

Abstract: An integrated process for converting a hydrocarbon feedstock having components boiling above about 100° C. into steam cracked products is described. The process first involves passing the feedstock to a hydrotreating zone to effect substantially complete decomposition of organic sulfur and/or nitrogen compounds. The product from the hydrotreating zone is passed to an aromatics saturation zone. The product is then passed to a steam cracking zone. Hydrogen and C1-C4 hydrocarbons, steam cracked naphtha, steam cracked gas oils and steam cracked tar are recovered. The amount of steam cracked tar produced is reduced by at least about 30 percent, and the amount of steam cracked tar produced is reduced by at least about 40 percent, basis the starting hydrocarbon feedstock which has not been subject to hydrotreating and aromatics saturation.

Abstract: The present invention is a method for mitigating the fouling from thermally cracked oils by minimizing the residence time at the temperature when the fouling is highest.

Abstract: A method for making an oil soluble coking process additive, includes the steps of: providing mixture of a metal salt in water wherein the metal salt contains a metal selected from the group consisting of alkali metals, alkaline earth metals and mixtures thereof; providing a heavy hydrocarbon; forming an emulsion of the mixture and the heavy hydrocarbon; heating the emulsion so as to react the metal salt with components of the heavy hydrocarbon so as to provide a treated hydrocarbon containing oil soluble organometallic compound, wherein the organometallic compound includes the metal and is stable at a temperature of at least about 300° C. The oil soluble additive and a process using same are also disclosed.

Abstract: A steam-cracking process includes the injection, at at least one point upstream from a secondary quenching indirect exchanger (4b), of particles with a mean size of between 0.02 and 4 mm, at a velocity speed in the exchanger of 20 to 180 m/s, in sufficient quantity to limit the rise in the output temperature of the effluents from the exchanger to a value that is less than 100° C. per month. At least 70% by weight of the quantity of injected particles is introduced downstream from primary quenching exchangers (4a) and upstream from the inlet to the secondary quenching exchanger. At intervals, decoking of the pyrolysis pipes and primary quenching exchangers is carried out in the presence of air.

Abstract: A steam-cracking unit and a steam-cracking process with controlled injection of solid particles in a quenching exchanger (3) is described. The particles are injected through a single axial injection pipe that is arranged on the axis of input cone (2) of the quenching exchanger, just upstream from an impact separator-diffuser (6) that comprises solid surfaces that are arranged opposite the transfer pipe of the cracked gases toward the exchanger; this impact separator-distributor is located in input cone (2) of the exchanger and is gas-permeable along a number of passages and at least 70% opaque when viewed from the transfer pipe.

Abstract: The present invention is directed to 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.degree. C. to 490.degree. C. for a time sufficient to cause pyrolysis of said heavy hydrocarbons contained in the feed mixture, but insufficient to permit substantial undesired polymerization, oxidation and dehydrogenation reactions to take place in said feed mixture; cooling the resulting pyrolyzed waste oil mixture to a temperature in the range of 300.degree. C. to 425.degree. C.

Abstract: A lubricating base stock useful for forming lubricants such as a multigrade automotive oils, automatic transmission oils, greases and the like is prepared by hydroisomerizing a waxy hydrocarbon feed fraction having an initial boiling point in the 650-750.degree. F. range and an end point of at least 1050.degree. F., synthesized by a slurry Fischer-Tropsch hydrocarbon synthesis process. The hydroisomerization forms a hydroisomerate containing the desired base stock which is recovered, without dewaxing the hydroisomerate. The hydroisomerization is conducted at conditions effective to convert at least 67 wt. % of the 650-750.degree. F.+ waxy feed hydrocarbons to lower boiling hydrocarbons. When combined with a standard lubricant additive package, these base stocks have been formed into multigrade automotive crankcase oils, transmission oils and hydraulic oils meeting the specifications for these oils.

Abstract: A method for preparing an oil soluble catalytic precursor includes the steps of: providing a mixture of a catalytic metal salt in water, wherein the catalytic metal salt contains a catalytic metal selected from the group consisting of alkali metals, alkaline earth metals, transition metals, and mixtures thereof; providing a heavy hydrocarbon phase; forming a water in oil emulsion of the mixture in the heavy hydrocarbon phase; and heating the emulsion at a temperature sufficient to dehydrate the emulsion so as to provide a hydrocarbon containing an oil soluble compound containing the catalytic metal.

Abstract: A process for upgrading a heavy hydrocarbon feed includes the steps of: providing a hydrocarbon feedstock including a fraction having a boiling point greater than or equal to about 320.degree. C.; mixing the feedstock with steam so as to provide a reaction feedstock; providing a catalyst including a first metal selected from the group consisting of Group VIII non-noble metals and a second metal selected from the group consisting of alkali metals, the first and second metals being supported on a support selected from the group consisting of kaolin, alumina, silica, carbon, petroleum cokes and mixtures thereof; and contacting the reaction feedstock with the catalyst at steam conversion conditions so as to provide a reaction product including an upgraded hydrocarbon fraction.

Abstract: Sulphur-containing hydrocarbon feedstocks are desulphurized prior to being subjected to steam cracking in the presence of one or more thiohydrocarbons wherein the sulphur is part of aromatic heterocycles, preferably thiophene and/or benzothiophene. Optimum results are obtained in terms of the combination of reduced coking rate and reduced carbon monoxide formation.

Abstract: A feed mixture containing C.sub.4 -olefins to C.sub.7 -olefins is evaporated and mixed with steam in a weight ratio of H.sub.2 O:hydrocarbons in the range from 0.5:1 to 3:1. The steam containing feed mixture with an inlet temperature in the range from 380.degree. to 500.degree. C. is introduced into a reactor, which contains a bed of granular, form-selective zeolite catalyst. The zeolite is of the pentasil type and has an atomic ratio of Si:Al of 10:1 to 200:1. From the bed a product mixture is withdrawn whose temperature is 20.degree. to 80.degree. lower than the inlet temperature, and whose total content of propylene and butene isomers is at least 60 wt-% of the olefinic constituents of the feed mixture.

Abstract: A continuous pyrolysis and decoking process and apparatus is described for the production of acetylenic compounds, in which hydrocarbons and steam are circulated in at least one tube (31) of a steam cracking reactor (30) and steam is circulated in at least one tube (32) of that reactor. The hydrocarbon effluent and steam then circulate in at least one row (1) of a pyrolysis reactor (40) and the decoking effluent comprising steam circulate in at least one other row (2) of that reactor (4) to effect decoking. A set of valves V1, V2, V11, V12 is used to alternate the pyrolysis step path and the decoking step path. The temperature in the steam cracking furnaces is lower than that in the pyrolysis reactor.

Abstract: A flexible steam cracking process for hydrocarbon feeds comprises injection of particles with an average size of between 0.02 mm and 4 mm, at a circulation rate in indirect transfer line exchangers (4) of 20 to 180 m/s, and in a sufficient quantity to limit the increase in temperature at the outlet to the exchangers (4) to a value of less than 100.degree. C. per month, into at least one point upstream of an indirect transfer line exchanger (4), cracking zone (2) remaining in communication with downstream means (6) for the treatment of cooled effluents. At least 70% by weight of the quantity of injected particles is introduced between the outlet to the cracking zone (2) and the tubes of the indirect transfer line exchanger (4). Chemical decoking is carried out in the tubes of the cracking zone at time intervals of less than 4 months by establishing accelerated coke gasification conditions, for example by injecting compounds which catalyse gasification by steam, or by decoking in air and/or steam.

Abstract: A facility and a process for steam cracking include controlled injection of solid particles into a transfer line exchanger (3). The particles are injected via injection lines, numbering between 1 and 8, just upstream of an impact-diffuser (6) comprising solid surfaces disposed on either side of the line for transfer of the cracked gases to the exchanger; this impact-diffuser is located in the inlet cone (2) of the exchanger, is permeable to the gases via a plurality of passages and at least 70% opaque viewed from the transfer line.

Abstract: A process for producing normally gaseous olefins from two different process units sharing common downstream quench and fractionation facilities, wherein one of the process units is a short contact time mechanically fluidized vaporization unit for processing petroleum residual feedstocks and the other is a conventional steam cracking unit.

Abstract: A heat exchange surface in reactors and/or heat exchangers of installations for the conversion of hydrocarbons and other organic compounds at high temperatures in the gaseous phase. According to the invention, the metallic surfaces coming into contact with the organic substances are treated at a temperature of 300 to 1000.degree. C. over a period of 0.5 to 12 hours with a mixture of a silicon- and sulfur-containing product and a dry gas flow which is inert with respect to the silicon- and sulfur-containing product. The invention is further directed to a process for producing a catalytically inactivated metallic surface in chemical reactors and/or heat exchangers.

Abstract: A method for thermo-mechanical cracking and hydrogenation of chemical substances such as hydrocarbons in liquid or solid form, waxes, carbonates, lime, oil-shale, oil-sand, oily residue from refineries and crude tank bottoms, plast and the like. The cracking and the hydrogenating of the substances in the presence of hydrogen releasing chemicals as water is performed in a mechanical established fluidized bed (8) of fine grained solids where the mechanical action in the fluidized bed (8) generates the heat participating in the cracking in addition to the mechanical action to the substances whereby the cracking in the cavitating micro bubbles and the hydrogenation takes place in the reactor (1) with an overall temperature and pressure lower than by conventional cracking and/or hydrogenation processes.