Abstract: The present invention provides an improved selective hydrogenation process for removing C10-C16 diolefins in the product from dehydrogenation of C10-C16 paraffins to mono-olefins, which process includes bringing the mixture stream of paraffins and olefins containing C10-C16 mono-olefins and C10-C16 diolefins into contact with a specific hydrogenation catalyst in a plurality of hydrogenation reactors connected in series under the reaction conditions for hydrogenation. Hydrogen is injected into each reactor respectively. To convert the diolefins in the mixture stream of paraffins and olefins into mono-olefins, &ggr;-alumina having a specific surface area of 50-300 m2/g and a pore volume of 0.2-2.0 cm3/g is used as the supporter of the hydrogenation catalyst, palladium is supported on the supporter as the main catalyst element and an element selected from silver, gold, tin, lead or potassium is supported on the supporter as the promoter.

Abstract: A process is provided for the selective hydrogenation of dienes from a mixed hydrocarbon stream. The catalyst contains nickel in an amount between approximately 5 and 15 weight percent and, alternatively, may contain nickel oxide and molybdenum oxide in an amount between approximately 3 to 6 and 12 to 25 weight percent, respectively. The catalyst metals are on an aluminum oxide support. The process does not require any activation or pre-treatment of the catalyst. No sulfur is added to the reaction zone and the catalyst is not adversely affected by the presence of up to 0.20% by weight of sulfur in the feed stream. According to the process, conjugated dienes are reduced by at least 80 to 90%.

Abstract: A solid acid-base catalyst contains vanadium pentoxide hydrate.

Abstract: A catalyst packing which can be produced by vapor deposition and/or sputtering of at least one substance active as catalyst and/or promotor onto woven or knitted fabrics or sheets as support material is used in a process for catalytic distillation in which a heterogeneously catalyzed reaction is combined with a simultaneous distillation or rectification over the catalyst packing.

Abstract: A novel catalyst comprises at least one support and at least one metal from group VIII or the periodic table e.g. palladium and is characterized in that the metal particles deposited on the support are not isolated from each other, e.g. at least 50% of the particles have a point of contact with one other particle.

Abstract: The use of the ligands and complexes of general formula I and II for catalytic, enantioselective hydrogenation.

Abstract: This invention relates to a layered catalyst composition, a process for preparing the composition and processes for using the composition. The catalyst composition comprises an inner core such as alpha-alumina, and an outer layer bonded to the inner core composed of an outer refractory inorganic oxide such as gamma-alumina. The outer layer has uniformly dispersed thereon a platinum group metal such as platinum and a promoter metal such as tin. The composition also contains a modifier metal such as lithium. The catalyst composition shows improved durability and selectivity for dehydrogenating hydrocarbons.

Abstract: A catalyst which contains, in its active composition, from 0.05 to 1.0% by weight of at least one metal or compound of a metal of the 10th group of the Periodic Table of the Elements and from 0.05 to 1.0% by weight of at least one metal or compound of a metal of the 11th group of the Periodic Table of the Elements, with the weight ratio of the metal of the 11th group to the metal of the 10th group being from 0.95 to 1.05, and, as support, an SiO2 -containing catalyst support having a BET surface area of from 2 to 400 m2/g, wherein at least 20% of the total pore volume of the catalyst is made up by pores having a diameter greater than 100 nanometers, can be used in processes for removing alkynes, dienes and/or monounsaturated hydrocarbons from streams of materials.

Abstract: The invention relates to catalyst packing and a production process for catalyst packing in which a fabricated woven or knitted fabric in the form of continuous web goods is shaped to give a package by stacking a plurality of layers, and segments (S) are cut out of the package and assembled to give one or more course(s) which completely fill the reactor cross section. A reactor containing catalyst packing of this type is particularly suitable for catalytic reactions, preferably for hydrogenations, selective hydrogenations, selective oxidations or isomerizations.

Abstract: A process for selective hydrogenation of unsaturated compounds such as acetylenic compounds or diolefins is carried out in the presence of a catalyst comprising at least one support, at least one metal from group VIII of the periodic table and at least one additional element M selected from the group formed by germanium, tin, lead, rhenium, gallium, indium, gold, silver and thallium. The process is characterized in that the catalyst is prepared using a process in which said metal M is introduced in an aqueous solvent, in the form of at least one organometallic compound comprising at least one carbon-M bond.

Abstract: A particulate selective hydrogenation catalyst for hydrogenating unsaturated diolefinic hydrocarbons to &agr;-olefinic hydrocarbons at rates which are at least 1.5 times higher than the rate of hydrogenation of &agr;-olefinic hydrocarbons to saturated compounds contains palladium distributed at the periphery of particles (spherules or extrudates), and at least one element selected from tin and lead. Further, the tin and/or lead is advantageously distributed at the periphery of the spherules or extrudates.

Abstract: A catalyst composition and process for preparing such catalyst composition which can be useful in contacting a hydrocarbon-containing fluid which contains a highly unsaturated hydrocarbon such as 1,3-butadiene, in the presence of hydrogen, with such catalyst composition in a hydrogenation zone under a hydrogenation condition effective to hydrogenate such highly unsaturated hydrocarbon to a less unsaturated hydrocarbon such as n-butene is disclosed. Such process for preparing a catalyst composition includes (1) combining a zeolite, a Group VIB metal, and an inorganic support to form a modified zeolite; (2) calcining such modified zeolite under a calcining condition to produce a calcined, modified zeolite; and (3) contacting such calcined, modified zeolite with a carburizing agent under a carburizing condition to provide such catalyst composition.

Abstract: A novel catalyst for transforming organic compounds is described. The catalyst is composed of a support selected from refractory oxides such as aluminas, silicas, silica-aluminas or magnesia, used alone or as a mixture, a group VIII metal such as palladium, associated or not associated with another metal, said catalyst being such that the volume of chemisorbed carbon monoxide is greater than or equal to 180 cm3 per gram of metal and has a programmed temperature reduction profile comprising a single hydrogen consumption peak.

Abstract: A process is provided for the selective hydrogenation of at least one organic compound having at least one unsaturated group, by bringing the at least one organic compound into contact with a hydrogen-containing gas in the presence of a catalyst, wherein the catalyst comprises an active material which is applied to a solid electrolyte to which, in turn, a metallic substrate is connected in such a way that a current flows through the solid electrolyte, so that the active material can be kept at a constant potential and a voltage is applied to

Abstract: A process and apparatus for treating raw gasoline from catalytic cracking to obtain gasoline with the qualities required for use as motor fuel comprises selective hydrogenation followed by stabilization and optional cooling of the effluent, then sweetening followed by degassing to obtain a dedienized, stabilized and sweetened gasoline. The hydrogenation catalyst preferably comprises 0.1-1% of palladium deposited on a support, sweetening is preferably carried out on a solid catalyst containing an aluminosilicate of an alkali metal (for example sodalite), a metal chelate and activated charcoal. The product from this process can be placed directly in the gasoline pool or, advantageously, fractionated to obtain one or more cuts which can be used as feeds for etherification.

Abstract: An environment-purifying material is obtained by immersing a carrier with a titanium oxide film coated on its surface or a substrate comprising titanium oxide particles, in a pseudo-body fluid containing an excessive amount of calcium phosphate, and then coating the surface of the substrate with a porous calcium phosphate film that easily adsorbs toxic substances and that is inactive as a photocatalyst.

Abstract: A process for the selective hydrogenation of the diolefins and acetylenic compounds in a olefin rich aliphatic hydrocarbon streams is disclosed wherein the selective hydrogenation is carried out at 40 to 300° F. under low hydrogen partial pressure in the range of about 0.1 psi to less than 70 psia at 0 to 350 psig in a distillation column reactor containing a hydrogenation catalyst which serves as a component of a distillation structure, such as supported PdO encased in tubular wire mesh. Essentially no hydrogenation of the olefins occurs.

Abstract: A supported hydrogenation catalyst composition is disclosed which comprises palladium, an inorganic support such as alumina, and a selectivity enhancer selected from the group consisting of silver, phosphorus, sulfur, and combinations of two or more thereof. Also disclosed is a selective hydrogenation process in which highly unsaturated hydrocarbons such as diolefins and/or alkynes are hydrogenated with hydrogen to less unsaturated hydrocarbons such as monoolefins.

Abstract: A process is disclosed for generating pure aromatic compounds from a reformed gasoline which contains aromatic compounds, olefins, diolefin, and triolefins, which comprises the steps of:(a) selectively hydrogenating the olefins, diolefins and triolefins in the reformed gasoline to obtain a mixture of hydrogenated, non-aromatic compounds and aromatic compounds; and(b) separating the aromatic compounds from the hydrogenated, non-aromatic compounds in the mixture formed during step (a) by either extractive distillation, liquid--liquid extraction or both to obtain the pure aromatic compounds.

Abstract: A supported hydrogenation catalyst composition is disclosed which comprises a palladium component, at least one alkali metal iodide such as, for example, potassium iodide, and an inorganic support material such as alumina. The palladium component is concentrated in an area within about 150 microns of the exterior surface of the composition. Also disclosed is a selective hydrogenation process in which diolefins and/or alkynes are hydrogenated with hydrogen to corresponding monoolefins.

Abstract: A palladium-base catalyst can selectively hydrogenate highly unsaturated hydrocarbon compounds contained in small amounts in an olefin compound prepared by steam cracking or the like of naphtha without causing hydrogenation of the olefin as a side reaction and the precipitation of a carbonaceous material. The catalyst comprises palladium and alumina, and the exposed face of each palladium crystallite is mainly accounted for by (100) and (110) faces. Further, in the desorption of absorbed hydrogen by heating, desorption peaks are observed in the temperature ranges of 40 to 90.degree. C. and of 120 to 170.degree. C. and the ratio of hydrogen desorption amount of the former to the latter is (4:6) to (3:7).

Abstract: A catalyst is described for selective gas phase hydrogenation of acetylenic compounds containing 2 or 3 carbon atoms to the corresponding ethylenic compounds. The catalyst, in the form of spherules or extrudates, comprises palladium, at least one metal from group IB, optionally at least one alkali or alkaline-earth metal, and alumina, in which at least 80% of the palladium and at least 80% of the element from group IB are present in a volume at the periphery of the catalyst defined between a spherical or cylindrical surface with radius r.sub.1 corresponding to the average radius of the spherules or extrudates of the catalyst and a spherical or cylindrical surface with radius r.sub.2 at least equal to 0.8 r.sub.1, the catalyst having a group IB metal/palladium ratio of 0.4 to 3 by weight. Further, it is advantageous for this catalyst that at least 30% of the metal particles contain both palladium and silver.

Abstract: A process for separating 1,3-butadiene from a crude C.sub.4 stream containing butanes, butenes, butadienes and acetylenes has been developed. The process begins with introducing hydrogen, a solvent, and the crude C.sub.4 stream to a catalytic extractive distillation unit having a reaction zone containing a catalyst capable of hydrogenating acetylenes. Butanes and butenes, being less soluble in the solvent, are distilled in an overhead stream from the catalytic extractive distillation unit. Butadienes and acetylenes, being more soluble in the solvent, are carried with the solvent to the reaction zone located within the catalytic extractive distillation unit. In the reaction zone the acetylenes are converted to hydrogenation products. The hydrogenation products other than butadiene are separated from the butadienes by the extractive distillation occurring in the unit. The solvent and butadiene mixture is removed from the catalytic extractive distillation unit in a distillate stream.

Abstract: In a process for the separation of p-xylene from a feed to be treated containing a mixture of xylenes and olefinic impurities, at least a portion of the feed is circulated in an enrichment zone (14) to enrich a first fraction (15) in p-xylene and provide a second fraction (18) which is depleted in p-xylene. The second fraction is circulated in an isomerisation zone (19) and an isomerate (20) is recovered which is recycled to the enrichment zone. At least a portion of the feed to be treated, the isomerate, or a mixture thereof is circulated in at least one selective hydrogenation zone (3) to partially remove the olefinic impurities and thereafter in at least one clay tretment zone (8) to remove additional olefinic impurities. An effluent is recovered which is sent to the enrichment zone.

Abstract: A process for the alkylation of benzene contained in a mixed refinery stream is disclosed wherein the refinery stream is first subjected to hydrogenation of higher olefins prior to alkylation of the benzene with selected types and quantities of lower olefins. Streams containing sulfur compounds may be pretreated by hydrodesulfurization. All of the process steps are advantageously carried out in distillation column reactors to take advantage of that mode of operation.

Abstract: In an olefins plant for the production and recovery of ethylene and propylene, the hydrogenation of the C.sub.2 acetylenes, the C.sub.3 acetylenes and dienes and the C.sub.4 and heavier acetylenes, dienes and olefins and the selective separation of the resulting products is carried out by the use of various arrangements of one or more reaction distillation columns. These columns contain a hydrogenation catalyst in enriching and stripping sections and concurrently perform a catalytic hydrogenation reaction and a distillation function.

Abstract: A process for the selective hydrogenation in the gas phase of acetylene compounds containing 2 or 3 carbon atoms to the corresponding ethylene compounds is described. The process uses a catalyst in the form of spherules or extrudates containing palladium, at least one group IB metal, optionally at least one alkaline or alkaline-earth metal and alumina, in which at least 80% of the palladium and at least 80% of the group IB element are present in a volume at the periphery of the catalyst defined between a spherical or cylindrical surface of radius r.sub.1 corresponding to the average spherule or extrudate diameter and a spherical or cylindrical surface of radius r.sub.2 at least equal to 0.8r.sub.1. More particularly, the catalyst comprises an alumina, palladium in a proportion of 0.01% to 0.5% by weight, and group IB metal in a proportion of 0.001 to 0.02% by weight, with a weight ratio of group IB metal/palladium of 0.05 to 0.25.

Abstract: A process for the removal of vinylacetylene, ethylacetylene and 1,2-butadiene from C.sub.4 aliphatic hydrocarbon streams comprising, concurrently: (1) feeding hydrogen and a hydrocarbon stream comprising C.sub.4 hydrocarbons including butanes, butenes, butadienes and vinylacetylene to a distillation column reactor containing a bed comprising a hydrogenation catalyst of the type characterized by platinum, palladium or rhodium which is prepared as a distillation structure to selectively hydrogenate a portion of the vinylacetylene and the 1,2-butadiene and (2) fractionally distilling the reaction mixture to remove a heavier fraction and removing a fraction overhead comprising substantially all of the C.sub.4.

Abstract: In a process for the hydrogenation of multiply unsaturated C.sub.2 -C.sub.8 hydrocarbons, in particular C.sub.2 -C.sub.8 -alkynes and/or C.sub.4 -C.sub.8 -alkynenes and/or C.sub.4 -C.sub.8 -alkadienes in fluids comprising these by contact with a catalyst packing in the presence of free hydrogen, the catalyst packing can be produced by applying at least one substance which is active as catalyst and/or promoter to woven or knitted meshes or foils as support material.

Abstract: A supported hydrogenation catalyst composition is disclosed which comprises a palladium component, at least one alkali metal iodide such as, for example, potassium iodide and an inorganic support material such as alumina. Also disclosed is selective hydrogenation process in which diolefins and/or alkynes are hydrogenated with hydrogen to this corresponding monoolefins.

Abstract: A light hydrocarbon stream, such as a C.sub.3 -C.sub.5 stream recovered from an FCC unit, is catalytically treated for the selective hydrogenation of dienes and for the removal of mercaptans by thioetherification. The effluent of the reaction zone is fractionated to remove light ends and thioethers in a dual section fractionation zone, with the interconnection of the sections facilitating a reduction in capital and operating costs.

Abstract: A silica-supported catalyst suitable for the selective hydrogenation of acetylene in hydrocarbonaceous streams, comprising from 0.001 to 1% by weight, based on the supported catalyst, of palladium and from 0.005 to 5% by weight, based on the supported catalyst, of at least one promoter metal of groups 1 and 2 of the periodic table, obtainable by impregnating a silica support with a solution comprising at least one promoter metal, drying the impregnated support, impregnating with a palladium-including solution, drying and calcining.

Abstract: High space velocity catalysts useful in the substantial elimination of chloroprene and trichloroethylene from an industrial product stream of ethane dichloride; the last is useful in the production of vinyl chloride.

Abstract: A process is described for the high-efficiency selective hydrogenation of an aromatic hydrocarbon cut which also contains monoolefinic hydrocarbons and polyolefinic and/or acetylenic hydrocarbons with a bromine number of 10000 to 100 mg per 100 g of product with an aromatic degree of conversion which is limited to a maximum of 0.15% by weight, the process being characterized in that the cut, which is at least partially in the liquid phase, is passed with hydrogen into a hydrogenation zone in contact with a catalyst containing 0.1% to 1% by weight (with respect to the support) of palladium, the catalyst having been treated before activation with at least one organic sulphur-containing compound to introduce 0.05% to 1% of sulphur (by weight with respect to the weight of the catalyst), the process being carried out at a temperature in the range 20.degree. C. to 25.degree. C., at a pressure of 4-50 bar, a GHSV of 0.2-25 h.sup.-1 and with a H.sub.2 /monoolefin +polyolefin and/or acetylenes ratio in the range 0.

Abstract: A process for treating a light cracked naphtha to be used as an etherification or alkylation feedstock in which the mercaptans and diolefins reacted in a single pass fixed bed reactor and are removed in a distillation column reactor which hydrogenate the unreacted diolefins. The mercaptans are reacted with the diolefins to form sulfides which are higher boiling than that portion of the naphtha which is used as feed to the etherification or alkylation unit. The higher boiling sulfides are removed as bottoms along with any C.sub.6 and heavier materials. Any diolefins not converted to sulfides are selectively hydrogenated to mono-olefins for use in the etherification process. Certain C.sub.5 olefins, for example pentene-1 and 3-methyl butene-1 are isomerized during the process to more beneficial isomers.

Abstract: A light hydrocarbon stream, such as a C.sub.3 -C.sub.5 stream recovered from an FCC unit, is catalytically treated for the selective hydrogenation of dienes and for the removal of mercaptans by thioetherification. The effluent of the reaction zone is fractionated to remove light ends and thioethers in a dual section fractionation zone, with the interconnection of the sections facilitating a reduction in capital and operating costs.

Abstract: A selective hydrogenation of an alkyne in an olefin-containing fluid is provided which comprises contacting the fluid and hydrogen gas with a catalyst in the presence of at least one sulfur compound, under reaction conditions effective to produce at least one alkene wherein the catalyst comprises at least one alkali metal, fluorine and an inorganic support material.

Abstract: The C.sub.2 to C.sub.5 and heavier acetylenes and dienes in a thermally cracked feed stream are hydrogenated without significantly hydrogenating the C.sub.2 and C.sub.3 olefins. Additionally, the C.sub.4 and heavier olefins may be hydrogenated. Specifically, the cracked gas feed in an olefin plant is hydrogenated in a distillation reaction column containing a hydrogenation catalyst without the necessity of separating the hydrogen out of the feed and without any significant hydrogenation of the ethylene and propylene. A combined reaction-fractionation step known as catalytic distillation hydrogenation is used to simultaneously carry out the reactions and separations while maintaining the hydrogenation conditions such that the ethylene and propylene remain substantially un-hydrogenated and essentially all of the other C.sub.2 and heavier unsaturated hydrocarbons are hydrogenated. Any unreacted hydrogen can be separated by a membrane and then reacted with separated C.sub.

Abstract: The present invention relates to a process for the catalytic selective hydrogenation of a polyunsaturated organic compound, wherein the hydrogenation is carried out in a plurality of two or more series-connected loops, wherein each loop involves the use of one reactor, which comprises:(a) feeding the polyunsaturated organic compound and hydrogen to an upper part of a reactor to catalytically hydrogenate said the polyunsaturated organic compound to produce a hydrogenation product,(b) recycling a portion of said hydrogenation product back into said upper part of said reactor,(c) feeding the remainder of said hydrogenation product from said reactor to an upper part of a subsequent reactor wherein the polyunsaturated organic compound is catalytically hydrogenated to produce a subsequent hydrogenation product, and wherein a portion of said subsequent hydrogenation product has been recycled and is fed with said remainder of said hydrogenation product to said upper part of said subsequent reactor,(d) repeating step

Abstract: A process for the selective hydrogenation in the gas phase of acetylene compounds containing 2 or 3 carbon atoms to the corresponding ethylene compounds in the presence of a catalyst in the form of spherules or extradates containing an alumina support, 0.01-0.5% by weight palladium, 0.001 to 0.5% by weight of at least one group IB metal, preferably silver, and optionally at least one alkaline or alkaline-earth metal, the weight ratio of the group IB metal to palladium being 0.05:1 to 0.25:1, in which catalyst at least 80% of the palladium and at least 80% of the group IB element are present in a volume at a periphery of the catalyst defined between a spherical or cylindrical surface of radius r.sub.1 corresponding to the average spherule or extradate diameter and a spherical or cylindrical surface of radius r.sub.2 at least equal to 0.8r.sub.1.

Abstract: A process for producing a branched chain olefin which comprises isomerising and transhydrogenating a hydrocarbon stream containing at least one straight chain paraffin of 4 or more carbon atoms by contacting the same at elevated temperature with a stream containing a hydrogen acceptor that is more highly unsaturated than a mono-olefin to produce a stream containing at least one branched chain olefin product. The product is separated to give a stream depleted of the product. The thus depleted stream is recycled to the isomerising and transhydrogenating stages. The hydrogen acceptor stream may comprise a diene and/or acetylene.

Abstract: A process for treating C.sub.3 to C.sub.12 petroleum fractions, such as a light cracked naphtha to be used as an etherification feed stock in which H.sub.2 S is removed by distillation of at least the C.sub.3 fraction and mercaptans and diolefins are removed simultaneously in a distillation column reactor using a dual catalyst bed. The mercaptans and H.sub.2 S are reacted with the diolefins in the presence of a reduced nickel catalyst to form sulfides which are higher boiling than the portion of the feed which is fractionated to an upper hydrogenation catalyst bed of palladium for hydrogenating diolefins and acetylenes. The higher boiling sulfides are removed as bottoms along with heavier materials. Any diolefins not converted to sulfides and acetylenes are selectively hydrogenated to mono-olefins in the presence of a palladium oxide catalyst in an upper bed, producing overheads, substantially free of sulfur compounds, diolefins and acetylenes.

Abstract: The invention concerns a process for reducing the benzene content of petrol fractions and isomerizing paraffins in the presence of an isomerization catalyst comprising 4 to 15% of at least one halogen and at least one metal from group VIII deposited on a support composed of a mixture of specific proportions of eta alumina and gamma alumina, in which isomerization is carried out on a mixture of a) a feed with the following composition by weight: 40% to 80% of paraffins, 0.5% to 7% of cyclic hydrocarbons and 6% to 45% of aromatics, and with a maximum distillation temperature of between 70.degree. C. and 90.degree. C., b) a C.sub.5 -C.sub.6 cut which is generally a straight run cut, and c) a chlorine-containing compound providing a concentration of 50-5000 ppm of chlorine in the mixture.

Abstract: A catalyst composition comprising palladium, silver and a support material (preferably alumina) is contacted at a relatively low temperature (of up to about 60.degree. C.) with a liquid composition comprising an effective reducing agent (preferably an alkali metal borohydride, hydrazinc, formaldehyde, formic acid, ascorbic acid, dextrose, aluminum powder). Preferably, at least one alkali metal compound (more preferably KOH, RbOH, CsOH, KF) is also present in the liquid composition. An improved process for selectively hydrogenating acetylene (to ethylene) employs this wet-reduced catalyst composition.

Abstract: A supported catalyst composition, which is effective as a diolefin hydrogenation catalyst, comprises palladium, silver and alkali metal fluoride. This catalyst composition is employed in the selective hydrogenation of C.sub.4 -C.sub.10 diolefins (preferably 1,3-butadiene) with hydrogen gas to the corresponding monoolefins.

Abstract: A naphtha or a middle distillate hydrocarbon is dehydroaromatized by hydrotreating in the presence of a catalyst containing non-noble Group VIII metal and Group VI-B metal on carbon.

Abstract: The invention relates to a process for the selective hydrogenation of diolefins in steam cracking petrol in the presence of a nickel catalyst and is characterized in that prior to the use of the catalyst, a suphur-containing organic compound is incorporated into the catalyst outside of the reactor.

Abstract: A method for conversion of linear C5 olefins in the presence of contaminant diolefins to corresponding iso-olefins of the same carbon number which comprises contacting a linear C5 olefin-containing organic feedstock with a catalyst comprising material having the structure of ZSM-35 under skeletal isomerization conditions, wherein said conversion is carried out at temperatures between about 100.degree. and 750.degree. C., weight hourly space velocities (WHSV) based on linear C5 olefins in said feedstock between 0.1 and 500 WHSV, C5 linear olefin partial pressures between 2 and 2000 kPa, and in the presence of hydrogen added in an amount sufficient to enhance linear C5 olefin conversion activity and extend the catalyst life of the catalyst relative to operation without any hydrogen added.

Abstract: An improved method for regenerating acetylene hydrogenation catalysts which does not require an oxygenation step is provided. The method may be used to regenerate any acetylene hydrogenation catalyst; however, the method is particularly advantageous when used with a palladium based catalyst which has been used to remove acetylenic contaminants from ethylene.

Abstract: A process for the selective hydrogenation and simultaneous isomerization of hydrocarbons in a feed stream (12) containing a mixture of hydrocarbons of varying degrees of unsaturation and having 4 or more carbon atoms. The process comprises contacting the mixture with hydrogen gas under hydrogenating and isomerizing conditions in the presence of a suitable catalyst (2, 3, and 4) in a multistage packed bed catalytic reactor (1). The process comprises supplying the hydrogen gas (20) in increasing molar ratio amounts relative to the remaining unreacted diolefin concentration in at least three points (24, 26 and 28) spaced apart along the flow direction of the feed stream through the reactor.