摘要:
In the process for the conversion of maleic acid to gamma-butyrolactone, 1.4-butanediol and/or tetrahydrofuran, a feedstream comprising maleic acid is hydrogenated in a first hydrogenation zone to produce a reaction product comprising succinic acid and unreacted hydrogen which is then supplied to a second hydrogenation zone, where succinic acid is converted to 1,4-butanediol, the temperatures of the feedstream comprising maleic acid and the first hydrogenation zone are controlled such that the temperature of maleic acid in the feedstream and the first hydrogenation zone does not exceed about 130° C., thereby minimizing the corrosive effects of the maleic acid and prolonging reactor life and improving overall process economics.
摘要:
Maleic acid, maleic anhydride or other hydrogenatable precursor are catalytically hydrogenated to 1,4-butanediol and tetrahydrofuran. It has been discovered that high yields of 1,4-butanediol are achieved when the hydrogenation catalyst comprises at least one noble metal of Group VIII of the Periodic Table and at least one of rhenium, tungsten or molybdenum on a carbon support wherein the carbon support has been contacted with an oxidizing agent prior to the deposition of the metals. This hydrogenation catalyst is prepared by the steps of (i) oxidizing the carbon support by contacting the carbon support with an oxidizing agent, (ii) impregnating in one or more impregnation steps comprising contacting the carbon support with a source of Group VIII metal and at least one metal selected from the group consisting of rhenium, tungsten and molybdenum being in at least one solution, (iii) after each impregnation step, drying at a temperature under about 150.degree. C. the impregnated carbon support to remove solvent, (iv) heating the impregnated carbon support at a temperature of about 100.degree. C. to about 350.degree. C. under reducing conditions.
摘要:
Tetrahydrofuran and optionally gamma-butyrolactone are prepared from at least one of maleic anhydride or succinic anhydride in the absence of alcohols by catalytically hydrogenating vaporous maleic anhydride or vaporous succinic anhydride in the presence of hydrogen and a catalyst comprising the mixed oxides of copper, zinc and aluminum.
摘要:
Maleic anhydride is hydrogenated to produce 1,4-butanediol in a two-stage process. In the first stage maleic anhydride and/or maleic acid contacted with hydrogen at a temperature of about 100.degree. C. to about 350.degree. C. in the presence of a suitable hydrogenation catalyst to produce succinic anhydride and/or gamma-butyrolactone. In the second stage, the succinic anhydride and/or gamma-butyrolactone and hydrogen are contacted at a temperature of about 180.degree. C. to about 350.degree. C. in the presence of a ruthenium-containing hydrogenation catalyst to produce 1,4-butanediol.
摘要:
Maleic acid, maleic anhydride or other hydrogenatable precursor are catalytically hydrogenated to 1,4-butanediol and tetrahydrofuran. It has been discovered that high yields of 1,4-butanediol are achieved when the hydrogenation catalyst comprises palladium, silver and rhenium on a carbon support and is prepared by the steps of(i) impregnating a carbon support with a source of palladium, silver and rhenium, wherein the source of palladium, silver and rhenium is at least one solution,(ii) after each impregnation step, drying the impregnated carbon support to remove solvent,(iii) heating the impregnated carbon support at a temperature of about 120.degree. C. to about 350.degree. C. under reducing conditions.The palladium in the catalyst is present in the form of crystallites having a particle size of less than 10 nm.
摘要:
Tetrahydrofuran and optionally gamma-butyrolactone are prepared from at least one of maleic anhydride or succinic anhydride by catalytically hydrogenating vaporous maleic anhydride or vaporous succinic anhydride in the presence of hydrogen and a catalyst comprising the mixed oxides of copper, zinc and aluminum.
摘要:
The ammoxidation of n-butane to acrylonitrile and hydrogen cyanide by a process comprising reacting a gaseous mixture containing n-butane, ammonia and oxygen in the presence of a metal promoted highly siliceous zeolite catalyst, where the zeolite is one comprising ZSM-5, ZSM-5-type aluminosilicate zeolites, or aluminum-free ZSM-5-type zeolites, is disclosed.
摘要:
Disclosed is the hydrogenation of maleic acid in the presence of a solid iron-containing ruthenium catalyst containing the elements and the ratios indicated by the empirical formula,RuFe.sub.a M.sub.b O.sub.xwhereM is one or more of Pd and Rh,a is 0.1-5,b is zero-3, andx is a number sufficient to satisfy the valency requirements of the cations present in the catalyst,said process being effected by contacting in a reaction zone an excess of hydrogen with an aqueous solution of maleic acid in admixture with said catalyst.
摘要:
A catalyst is disclosed which comprises a ruthenium-copper-containing complex of the formulaM.sub.a A.sub.b RuCu.sub.c N.sub.z O.sub.xwhereinM is selected from the group consisting of Ce, Cr, Fe, Mn, and mixtures thereof,A is an alkali metal, alkaline earth metal or mixture thereof,a is from 0 to about 1,b is from about 0.002 to about 10,c is from about 0.2 to about 20,z is from 0 to about 1% by weight,x is the number of oxygens needed to fulfill the valence requirements of the other elements, said complex being supported by an activated carbon support having a surface area of at least about 300 square meters per gram. A process for converting mixtures of hydrogen and carbon monoxide, particularly synthesis gas, to alcohol with minimal levels of hydrocarbon by-products being formed is also disclosed.