Abstract: A process for upgrading petroleum residua to more valuable products by visbreaking or otherwise thermally cracking a petroleum residuum to produce a thermally cracked bottoms stream, vacuum distilling at least a portion of the thermally cracked bottoms stream to produce a vacuum distilled thermally cracked pitch, blending a portion of the pitch with a hydrocarbon residuum that is not a vacuum distilled thermally cracked pitch to produce a delayed coker feed component, producing a delayed coker heater charge having a recycle ratio, by weight, of less than about 1.27:1, and introducing the coker heater charge into a delayed coker.

Abstract: A thermosetting plastic foam solid formed from the reaction product of: (a) either polyisocyanate or isocyanate-based foam; (b) a polyol-based foam; (c) a catalyst which is capable of promoting the thermosetting reaction between the polyisocyanate or isocyanate-based foam and the polyol-based foam; and (d) a blowing agent which comprises a high purity cyclopentane product, wherein the high purity cyclopentane product is about 95% or greater pure cyclopentane, and, optionally, (e) water and/or (f) liquid flame retardant.

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 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: In a process and apparatus for visbreaking a heavy hydrocarbon feedstock in the liquid state, whereby the feedstock is brought to an appropriate temperature to cause cracking of at least part of the hydrocarbons present, and is then introduced into the bottom of a soaker (3) wherein it travels from bottom to top, and is then discharged from the top of said soaker (3) and directed to a fractionation unit, the improvement wherein a preferably inert gas is injected into the hydrocarbon feedstock inside the soaker (3), in the vicinity of the soaker side walls, at least at the bottom of the soaker (3) and the gas is injected upward along the side walls of the soaker (3) and flows from bottom to top along said walls co-currently with the hydrocarbon feedstock.

Abstract: High-vacuum oil refinery systems and process are disclosed in this invention. The systems and process enables to carry out vaporization and distillation of oils under the condition of 1-10.sup.-4 Torr of high vacuum and at the temperature of not higher than 360.degree. C. and thereby removing possibility of thermal cracking while heating to be vaporized and easily produces high quality oil. The vaporized gases are centrifugally separated and liquefied by specific gravity using high-vacuum gas specific gravity centrifugal separators and thereby producing high purity oil of uniform quality. The process also carries out vaporization and distillation of the oil at the temperature of not higher than 360.degree. C. so that the process prevents vaporization of sulfur components of the oil, but simply drains the sulfur components along with the concentrated sludge oil and thereby distilling and desulfurizing the crude or heavy oil at the same time without using expensive conventional desulfurizing process.

Abstract: A process for thermally cracking waste motor oil into a diesel fuel product is provided. The thermal cracking process uses low temperature cracking temperatures from 625.degree. F. to 725.degree. F. with ambient pressure to generate a column distilled fraction of diesel fuel mixed with light ends, the light ends being flashed off to produce a high quality #2 diesel fuel. The process further provides for removal from the cracking vessel an additional product stream which, when filtered, is suitable for use as a #3 fuel oil and that can be further blended with a bunker oil to yield a #5 fuel product.

Abstract: A two-stage process for obtaining a substantial amount of olefinic product from a residua feedstock. The first stage is comprised of a thermal process unit containing a reaction zone comprised of a horizontal moving bed of fluidized hot particles operated at temperatures from about 500.degree. to 600.degree. C. and having a short vapor residence time, and the second stage thermal conversion zone operated at a temperature of about 700.degree. C. to about 1100.degree. C., and also having a short vapor residence time.

Abstract: A two-stage process for obtaining a substantial amount of olefinic product from a residua feedstock. The first stage is comprised of a thermal process unit containing a reaction zone comprised of a horizontal moving bed of fluidized hot particles operated at temperatures from about 500.degree. to 600.degree. C. and having a short vapor residence time, and the second stage thermal conversion zone operated at a temperature of about 700.degree. C. to about 1100.degree. C., and also having a short vapor residence time.

Abstract: In a first embodiment of the invention, a method for determining the hydrogen-to-carbon ratio of a liquid hydrocarbon fraction is presented. A sample of the liquid fraction is subjected to an ultra-violet absorption analysis. The results of the analysis correlate directly to the hydrogen-to-carbon ratio of the hydrocarbon fraction and, with a knowledge of this correlation, the hydrogen-to-carbon ratio of the sample under analysis may be determined. Another embodiment provides a method for monitoring the performance of a process for the preparation of olefins by the thermal cracking of a hydrocarbon feedstock. A liquid fraction is recovered from the product of the thermal cracking and subjected to an ultra-violet absorption analysis. The result of the analysis correlates directly to the hydrogen-to-carbon ratio of the product, which in turn correlates to the cracking severity being applied in the thermal cracking process.

Abstract: Undermelted waste plastics which have not been completely melted from the exterior of a thermal cracking vessel is introduced into a container provided in an upper position within said thermal cracking vessel and having a net-like opening, allowing the plastics to melt within said container, allowing the resulting plastic melt to drop into the thermal cracking vessel through said net-like opening, the plastic melt is thermally cracked within the thermal cracking vessel.

Abstract: Disclosed is a process for converting olefinic hydrocarbons using spent FCC catalysts which comprises using spent FCC catalysts, optionally containing spent FCC additives, in the reactor/stripper part of the FCCU, instead of or in addition to a separate olefin upgrader, to upgrade C.sub.2 -C.sub.8 oligomerizable olefins, preferably propylene and ethylene, into C.sub.4 /C.sub.5 olefins and isoparaffins as well as gasoline, wherein feedstock can be product streams of the FCCU containing propylene/ethylene such as, for example, the absorber and depropanizer overheads.

Abstract: An improved fluidized bed coking process wherein a residuum feedstock is introduced into a first stage comprised of a short vapor contact time reactor containing a horizontal moving bed of fluidized hot particles. Carbonaceous material is deposited onto the hot particles on contact with the hot particles, and a vapor product is produced. The hot particles, containing the carbonaceous deposits, are fed to a second stage fluidized bed coking process.

Abstract: The invention relates to a process for the conversion of petroleum hydrocarbons in the presence of catalyst particles in a fluidized phase in an essentially upflow or downflow tubular reaction zone. The process includes at least one stage of steam cracking of at least one light hydrocarbon fraction and a stage of catalytic cracking of at least one heavy hydrocarbon fraction. The steam cracking is carried out by contacting the light hydrocarbons and a quantity of steam equal to at least 20 percent by weight in a fluidized bed of the catalyst particles, the resulting temperature ranging from 650.degree. to 850.degree. C. The catalytic cracking of the heavy hydrocarbons is carried out by injection of the effluents from the upstream section of the reaction zone into the catalyst suspension in such a way that the temperature of the mixture ranges from 500.degree. to 650.degree. C. and is then reduced to a temperature ranging 475.degree. to 550.degree. C.

Abstract: This invention relates to a process for cracking waste polymers in a fluidized bed reactor to produce vaporous products comprising primary products which can be further processed, eg in a steam cracker to produce olefins, characterized in that the vaporous products are treated to generate a primary product substantially free of a high molecular weight tail having molecular weights >700 prior to further processing. The removal of the high molecular weight tail minimizes fouling and prolongs the lifetime of the reactors used for further processing.

Abstract: Plastic wastes are thermally cracked to give primarily liquid products which are transformed into synthesis gas by partial oxidation.

Abstract: A process is provided for converting a heavy hydrocarbon oil into light hydrocarbon fuels by thermal cracking or hydrocracking, which comprises adding to about 100 parts by weight of the heavy hydrocarbon oil feedstock (A) about 0.1 to 50 parts by weight of a substance (B) which is a hydrogenated oil obtained by aromatic ring hydrogenation of about 430.degree.-600.degree. C. thermal-treated or cracked petroleum feedstock product oil boiling higher than about 200.degree. C. to hydrogenate abot 20 to 90% of the aromatic rings present.

Abstract: A process and apparatus for low cracking or recracking of liquid hydrocarbons with FCC catalyst containing 0.2 to 1.5 wt % coke is disclosed. FCC naphtha, or a thermally or hydrocracked naphtha, contacts spent FCC catalyst in a naphtha recracking reactor for limited conversion to lighter products and an increase in octane number. Spent catalyst from the recracking reactor can be recycled to the FCC reactor without stripping or regeneration. Naphtha recracking products are preferably cooled, then used as an absorbent to recover gasoline boiling range products from the FCC main column overhead vapor. Use of spent catalyst and controlled conversion conditions minimizes overcracking of the light liquid and minimizes formation of heavy ends.

Abstract: There is provided a process for dewaxing a hydrocarbon feedstock, wherein the effluent from a dewaxing reaction zone is passed over an oligomerization catalyst under conditions sufficient to oligomerize olefins in this effluent. The temperature of the oligomerization reaction is less than the temperature of the dewaxing reaction.

Abstract: Disclosed is a process wherein a two-stage hydroconversion process for converting a heavy hydrocarbonaceous feedstock to lower boiling products which process comprises: (a) reacting the feedstock in a first reaction stage at hydroconversion conditions which include temperature from about 650.degree. F. to 900.degree. F.

Abstract: The invention relates to a process for the conversion of petroleum hydrocarbons in the presence of catalyst particles in a fluidized phase in an essentially upflow or downflow tubular reaction zone, said process comprising at least one stage of steam cracking of at least one light hydrocarbon fraction and a stage of catalytic cracking of at least one heavy hydrocarbon fraction.The steam cracking is carried out by contacting the light hydrocarbons and a quantity of steam equal to at least 20 percent by weight in a fluidized bed of the catalyst particles, the resulting temperature ranging from 650.degree. to 850.degree. C.The catalytic cracking of the heavy hydrocarbons is carried out by contacting them with the effluents from the upstream section of the reaction zone and the catalyst suspension in such a way that the temperature of the mixture ranges from 500.degree. to 650.degree. C. and is then reduced to a temperature ranging from 475.degree. to 550.degree. C.

Abstract: An improvement in iso-olefin etherification is obtained in an integrated process combining a fluidized catalytic cracking reaction and a fluidized catalyst etherification reaction wherein zeolite catalyst particles are withdrawn in partially deactivated form from the ether reaction stage and added as part of the catalyst in the FCC reaction.

Abstract: A process and apparatus for fluidized catalytic cracking of heavy oils are disclosed. Quenching and cyclone separation are done in the transfer line to the main distillation column. Quenching hot vapor from the reactor, preferably with liquid recycled from the main column, improves yields, prevents coking in the transfer line and permits higher cracking reactor temperatures. Cyclone separation of quench and/or condensed liquid prevents slugging, or two phase flow, in the transfer line. Some rough-cut fractionation can be achieved in the cyclone separator. Steam stripping of cyclone liquid optimizes operation of the main column.

Abstract: The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compouns as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.

Abstract: An integrated process for the production of a hydrogenated distillable hydrocarbonaceous product from a temperature-sensitive hydrocarbonaceous stream containing a non-distillable component by the utilization of a hot hydrogen flash zone and a secondary separation zone to achieve a high yield of hydrogenated distillable hydrocarbonaceous product.

Abstract: A process for the production of olefins and aromatics from hydrocarbon feedstocks by catalytically cracking alone or cracking and dehydrogenating the hydrocarbons in the presence of an entrained stream of catalytic heat carrying solids at short residence times to preferentially produce olefins having three or more carbon atoms and/or to produce aromatics, especially benzene.

Abstract: An improvement in iso-olefin production without substantial decrease in overall yield is obtained in an integrated process combining a fluidized catalytic cracking reaction and a fluidized catalyst olefin interconversion reaction when crystalline medium pore shape selective zeolite catalyst particles are withdrawn in partially deactivated form from the interconversion reaction stage and added as part of the active catalyst in the FCC reaction.

Abstract: A method for upgrading paraffinic naphtha to high octane fuel by contacting a feedstock, such as C7-C22 fresh virgin naphtha, with porous acid cracking catalyst under low pressure selective cracking conditions effective to produce C4 -C5 isoalkenes and C4-C5 isoalkanes. The preferred feedstock is straight run naphtha containing C7+ alkanes, at least 15 wt % C7+ cycloaliphatic hydrocarbons and less than 20% aromatics, which can be converted with a fluidized zeolite catalyst in a vertical riser reactor during a short contact period.The isoalkane products of cracking are dehydrogenated and etherified to provide high octane fuel components.

Abstract: Methods for the fluidized catalytic cracking of plural hydrocarbon feedstocks in a riser reactor are disclosed. The processes generally comprises contacting a relatively light hydrocarbon feedstock in a first reaction zone with a first catalyst stream comprising spent catalyst, contacting a relatively heavy hydrocarbon feedstock in a second reaction zone with a second catalyst stream comprising freshly regenerated catalyst, and introducing at least a portion of the effluent from the first reaction zone into the second reaction zone. The first reaction zone and the second reaction zone preferably comprise first and second riser reaction zones, respectively.

Abstract: Process for producing gasolines having improved RON and MON which consists in subjecting the LCO, HCO and CLO obtained by catalytic cracking of a heavy hydrocarbon feedstock, to a hydrogenation treatment and subjecting the obtained products to a new catalytic cracking and then recovering hydrocarbons boiling in the range of gasolines.

Abstract: An improved process for upgrading paraffinic naphtha to high octane fuel by contacting a naphtha feedstock, such as virgin naphtha feedstock stream containing predominantly C.sub.7 -C.sub.12 alkanes and naphthenes, with solid medium pore acid zeolite cracking catalyst under low pressure selective cracking conditions effective to produce at least 10 wt % selectivity C.sub.4 -C.sub.5 isoalkene. Cracking effluent is separated to obtain a light olefinic fraction rich in C.sub.4 -C.sub.5 isoalkene and a C.sub.6 + liquid fraction of enhanced octane value containing less than 50 wt % aromatic hydrocarbons. In a multistage operation enhanced octane products are obtained by etherifying the isoalkene fraction and by contacting the C.sub.6 + normally liquid fraction with reforming catalyst under moderate reforming conditions at elevated temperature to obtain a reformate product of enhanced octane value.

Abstract: Process and apparatus for upgrading paraffinic naphtha to high octane fuel by contacting a fresh virgin naphtha feedstock stream medium pore acid cracking catalyst comprising MCM-22 zeolite under low pressure selective cracking conditions effective to produce increased yield of total C4-C5 branched aliphatic hydrocarbhons. The preferred feedstock is straight run naptha containing C7+ alkanes, at least 15 wt % C7+ cycloaliphatic hydrocarbons and less than 20% aromatics, which can be converted with a fluidized bed catalyst in a vertical riser reactor during a short contact period.The isoalkene products of cracking are etherified to provide high octane fuel components.

Abstract: A process is disclosed for reprocessing contaminated oils, such as used crankcase oil from automobile engines, by thermal treatment, such as visbreaking, in the presence of other hydrocarbon feedstocks, followed by fractional distillation for the recovery of a gasoline fraction, a carboxylic acid fraction, a gas oil fraction containing chlorinated hydrocarbons and a high boiling bottoms fraction. The gas oil fraction is subjected to catalytic hydrocracking with the simultaneous destruction of chlorinated hydrocarbons. The resulting hydrocracked oils, after separation of hydrogen chloride, are free from chlorine compounds and other contaminants.

Abstract: Heavy hydrocarbon oil, containing asphaltene, sulfur and metal contaminants, is hydrotreated in the presence of a hydrotreating catalyst having a small pore diameter in an initial process step to remove sulfur and metal contaminants. Removal of additional metal and sulfur contaminants is then accomplished in a second process step by solvent deasphalting, wherein the size of the pore diameter of the hydrotreating catalyst utilized in the initial hydrotreating step affects the metals rejection in the subsequent solvent deasphalting step. In a third process step the deasphalted oil is catalytically cracked substantially in the absence of added hydrogen to provide lower boiling hydrocarbon products.

Abstract: A multistep process is disclosed for the manufacture of synthetic lubricants from the C.sub.8 to C.sub.24 linear olefin components of below liquid fuel value petroleum distillate fractions derived via the high temperature thermal cracking of petroleum residua. Such feeds contain major amounts of 1-n-olefins, n-paraffins and greater than 0.1% concentration of sulfur mostly in the form aromatic, thiophene type sulfur compounds.In the first step of the present process such feeds are enriched in the straight chain aliphatic hydrocarbon components by one or more separation processes, preferably via urea adduction or by crystallization. In the second step, the olefin components are oligomerized to sulfur containing C.sub.30 to C.sub.60 polyolefins, preferably in the presence of BF.sub.3 complex catalysts. In the third step, the polyolefins are hydrogenated to novel isoparaffin lubricants in the presence of sulfur resistant catalysts, preferably transition metal sulfides.

Abstract: An improvement in gasoline octane without substantial decrease in overall yield is obtained in an integrated process combining a fluidized catalytic cracking reaction and a low severity fluidized catalyst olefin oligomerization reaction when crystalline medium pore shape selective zeolite catalyst particles are withdrawn in partially deactivated form from the oligomerization reaction stage and added as part of the active catalyst in the FCC reaction.

Abstract: The benzene concentration in the gasoline pool of a petroleum refinery is decreased by alkylation of the benzene in a catalytic dewaxing reactor using the olefinic by-products from the dewaxing reaction as alkylating agents. The catalytic dewaxing is preferably carried out in the presence of an intermediate pore size zeolite such as ZSM-5 using a distillate or lube boiling range dewaxing feed. The benzene rich feed preferably contains less than about 2% C.sub.7+ aromatics in order to reduce alkylation of non-objectionable species in the reformate.

Abstract: Process for the manufacture of kerosene and/or gas oil(s) wherein a hydrocarbon feedstock is catalytically treated in the presence of hydrogen at elevated temperature and pressure and wherein the material obtained is subjected to a distillation treatment, in which process a hydrocarbon feedstock is used containing flashed distillate produced via a catalytic residue conversion process.

Abstract: High octane gasoline and high quality distillate are co-produced by a hydrocracking light cycle oil from a catalytic cracking process under conditions of low to moderate hydrogen pressure and severity to produce a high octane, hydrocracked gasoline. The distillate fraction from the hydrocracker is separated to form a first fraction which boils immediately above the gasoline fraction and a second, higher boiling fraction which is withdrawn as product. The first distillate fraction is recycled, preferably to extinction, to the cracker to increase the paraffinic content of the higher boiling distillate product by removal of the hydroaromatic components in the recycled fraction. The recycled fraction may be mixed with fresh feed to the cracker or may be injected at a higher level in the cracking riser as a secondary feed injection. The paraffinic distillate product has a low sulfur content and a high cetane index and is useful as a road diesel fuel.

Abstract: A process for performing catalytic reactions with intensive heat of reaction, in which a reaction mixture is conducted through a catalyst bed, from which the reaction heat is removed or to which it is fed by indirect heat exchange with a heat exchange medium. The catalyst bed adjoins at least one bed of a catalytically inert material, which also is in indirect heat exchange with the heat exchange medium.

Abstract: Process and apparatus for upgrading paraffinic naphtha to high octane fuel by contacting a fresh virgin naphtha feedstock stream medium pore acid cracking catalyst under low pressure selective cracking conditions effective to produce at least 10 wt % C4-C5 isoalkene to obtain a light olefinic fraction rich in C4-C5 isoalkene and a C6+ liquid fraction of enhanced octane value. The preferred feedstock is straight run naphtha containing C7+ alkanes, at least 15 wt % C7+ cycloaliphatic hydrocarbons and less than 20% aromatics, which can be converted with a fluidized bed catalyst in a vertical riser reactor during a short contact period.The isoalkene products of cracking are etherified to provide high octane fuel components.

Abstract: Process for thermal cracking of residual hydrocarbon oils by(1) feeding the oil and a synthesis gas to a thermal cracking zone, the gas having a temperature sufficiently high to maintain the temperature in the cracking zone by direct heat exchange at 420.degree.-645.degree. C.;(2) separating the cracked products into (a) a gas, (b) at least one distillate fraction and (c) a cracked residue;(3) separating the cracked residue into a heavy hydrocarbon oil poor in asphaltenes and a heavy hydrocarbon oil rich in asphaltenes;(4) gasifying the oil rich in asphaltenes in the presence of oxygen and steam to produce synthesis gas; and(5) recycling synthesis gas from step 4 as feed to step 1.

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: Heavy hydrocarbon oils of high paraffin content are catalytically cracked using zeolite beta. The paraffin content of the oil is at least 20 weight percent or higher. The gasoline cracking products have a high octane rating and the higher boiling products a decreased pour point resulting from the dewaxing activity of the zeolite beta. The use of cracking temperatures above 500.degree. C., preferably above 550.degree. C., also improves iso-butene production.

Abstract: Waste oil is treated in a tubular reactor having a length of up to and in excess of 2 km in a plurality of stages each of which involves heating the product to a different temperature and maintaining the product at a different pressure. The released fractions are evacuated from the path for the flow of waste oil and are immediately condensed and distilled to yield a variety of products from oil having a low boiling point to coke. One or more withdrawn fractions can be treated (for example, hydrogenated) in one or more discrete tubular reactors. The heating can involve raising the temperature of waste oil to several times the critical cracking temperature, and the regulation of pressure can involve a reduction of pressure to less than 1 mbar. The last stage of the reactor can be cleaned by abrasive particles, by vibration at high frequencies and/or by acceleration of the conveyed stream to an elevated speed.

Abstract: A process for upgrading topped crude oils and residual portions comprising material boiling above 552.degree. C. (1025.degree. F.) by the combination of partial demetallizing and decarbonizing of the residual oil before effecting zeolite catalytic cracking thereof is described in conjunction with a product separation process, a combined hydrocarbon gas product concentration section and the use of parallel arranged CO boilers to produce sulfur free flue gas and steam. Steam generated by the combination operation effectively reduces the energy requirement of the combustion process.

Abstract: A catalytic cracking process is described featuring multiple risers in which a variety of hydrocarbon conversion reactions takes place, a stripping unit in which entrained hydrocarbon material is removed from catalyst and a regeneration zone in which spent cracking catalyst is regenerated, which comprises:(a) converting a relatively high boiling hydrocarbon charge material in a first riser in the presence of a catalyst mixture comprising, as a first catalyst component, an amorphous cracking catalyst and/or a large pore crystalline cracking catalyst and, as a second catalyst component, a shape selective medium pore crystalline silicate to provide lighter products including naphtha and C.sub.3 and/or C.sub.4 olefin;(b) converting an ethylene-rich charge material introduced to a second riser at a lower level thereof in the presence of said catalyst mixture to provide heavier products and to increase the temperature of the catalyst in said region; and,(c) converting C.sub.3 and/or C.sub.

Abstract: Plastic scrap, especially of polyolefin plastics, is converted to low pour point oils by thermal cracking in the liquid phase followed by catalytic conversion of the vaporous cracking products over an intermediate pore size zeolite such as ZSM-5.

Abstract: A process of thermally cracking a heavy petroleum oil wherein the heavy petroleum oil is treated successively in a cracking furnace and then in a perfect mixing type tank reactor. The thermal cracking in the cracking furnace is performed at a temperature at the outlet of the cracking furnace of 450.degree.-520.degree. C. with a conversion of at least 60-75% of the overall conversion rate while the thermal cracking in the tank reactor is performed at a temperature of 400.degree.-450.degree. C. a pressure of from ambient pressure to 1 kg/cm.sup.2 for a period of time of less than 30 minutes but not less than 10 minutes while feeding steam having a temperature of 435.degree.-700.degree. C. to the tank reactor in an amount of 8-20% by weight of the heavy petroleum oil fed to the cracking furnace.

Abstract: A catalytic cracking process is provided featuring multiple risers in which a variety of hydrocarbon conversion reactions take place, a stripping unit in which entrained hydrocarbon material is removed from catalyst and a regeneration zone in which spent cracking catalyst is regenerated, which comprises:(a) converting a relatively high boiling hydrocarbon charge material in a first riser in the presence of a first catalyst component which is an amorphous cracking catalyst and/or a large pore crystalline zeolite cracking catalyst to provide lighter products;(b) converting an ethylene-rich charge material introduced to a second riser at a lower level thereof in the presence of a second catalyst component which is a shape selective medium pore crystalline silicate zeolite catalyst to provide heavier products and to increase the temperature of the catalyst in said region; and,(c) converting a naphtha charge material introduced to the second riser at a higher level thereof in the presence of said second catalyst c