摘要:
Phthalic anhydride is prepared by catalytic gas-phase oxidation of xylene and/or naphthalene by a gas comprising molecular oxygen in a fixed bed at elevated temperature and using at least three coated catalysts arranged in superposed zones, which catalysts have a layer of catalytically active metal oxides applied to a core of support material. In the process described, the catalyst activity rises from zone to zone from the gas inlet end to the gas outlet end and the activity of the catalysts of the individual zones is set such that the least active catalyst comprises a lower amount of active composition and, if desired, additionally more alkali metal selected from the group consisting of potassium, rubidium and cesium as dopant than the catalyst of the next zone and the subsequent even more active catalyst comprises the same amount of active composition and even less alkali metal as dopant or a greater amount of active composition and, if desired, less alkali metal as dopant than the catalyst of the second zone, with further conditions.
摘要:
In a process for preparing phthalic anhydride by catalytic gas-phase oxidation of o-xylene/naphthalene mixtures by molecular oxygen, use is made of a catalyst I in a first zone on the gas inlet side which makes up from 25 to 75 percent by volume of the total catalyst volume, comprising, in each case based on the catalytically active composition, from 1 to 10% by weight of vanadium oxide (calculated as V205), from 1 to 10% by weight of antimony oxide (calculated as Sb203) and from 80 to 98% by weight of titanium dioxide of the anatase type having a BET surface area of from 13 to 28 m2/g and also from 0.05 to 1% by weight of cesium (calculated as Cs) applied to a steatite support and a catalyst II in a second zone which makes up the remaining 75 to 25 percent by volume of the total catalyst volume, comprising, in each case based on the catalytically active composition, from 1 to 10% by weight of vanadium oxide (calculated as V205), from 1 to 10% by weight of antimony oxide (calculated as Sb203) and from 80 to 98% by weight of titanium dioxide of the anatase type having a BET surface area of from 13 to 28 m2/g and from 0.01 to 1% by weight of phosphorus oxide (calculated as P) and also from 0.01 to 0.2% by weight of cesium (calculated as Cs) applied to a steatite support, wherein the cesium content of the catalyst II is less than 15% by weight of the cesium content of the catalyst I and the catalyst I and the catalyst II have been prepared without addition of compounds of niobium.
摘要翻译:在通过分子氧的邻二甲苯/萘混合物的催化气相氧化制备邻苯二甲酸酐的方法中,使用在气体入口侧的第一区中的催化剂I,其占25-75体积% 的总催化剂体积,包括在每种情况下基于催化活性组合物,1-10重量%的氧化钒(按V205计算),1-10重量%的氧化锑(以Sb 2 O 3计)和 80至98重量%的具有13至28平方米/克的BET表面积为13至28平方米/克的锐钛矿型二氧化钛和0.05至1重量%的应用于滑石支撑的铯(以Cs计算) 催化剂II在构成总催化剂体积的剩余75至25体积%的第二区域中,在每种情况下基于催化活性组合物,包含1-10重量%的氧化钒(以V205计算) ,1至10重量%的氧化锑(计算为 Sb 2 O 3)和80〜98重量%的BET表面积为13〜28m 2 / g,0.01〜1重量%的氧化磷(P计算)的锐钛矿型二氧化钛,0.01 至0.2重量%的铯(以Cs计算),其中催化剂II的铯含量小于催化剂I的铯含量的15重量%,催化剂I和催化剂II具有 在不添加铌化合物的情况下制备。
摘要:
The invention relates to a process for preparing aromatic amines by catalytically hydrogenating the corresponding aromatic nitro compound, which comprises using a copper catalyst with a support comprising SiO2, the SiO2 having been prepared by wet grinding and subsequent spray drying.
摘要:
The invention relates to a process for the electrochemical separation of hydrogen from a hydrogen-comprising reaction mixture R by means of a gastight membrane-electrode assembly comprising at least one selectively proton-conducting membrane and at least one electrode catalyst on each side of the membrane, where at least part of the hydrogen present in the reaction mixture R is oxidized to protons over the anode catalyst on the retentate side of the membrane and the protons are, after passing through the membrane to the permeate side, I reduced to hydrogen over the cathode catalyst and/or II reacted with oxygen over the cathode catalyst to form water, with the oxygen originating from an oxygen-comprising stream O which is brought into contact with the permeate side of the membrane, and also a reactor equipped with at least one membrane-electrode assembly.
摘要:
The present invention relates to a hydroamination catalyst comprising boron beta zeolites, wherein the hydroamination catalyst is doped with lithium, and also a process for producing it. The present patent application further relates to a process for preparing amines by reaction of ammonia or primary or secondary amines with olefins at elevated temperatures and pressures in the presence of the hydroamination catalyst of the invention.
摘要:
Process for the direct amination of hydrocarbons to aminohydrocarbons, which comprises the steps: a) reaction of a feed stream E comprising at least one hydrocarbon and at least one aminating reagent to form a reaction mixture R comprising aminohydrocarbons and hydrogen and b) electrochemical separation of at least part of the hydrogen formed in the reaction from the reaction mixture R by means of a gastight membrane-electrode assembly having at least one selectively proton-conducting membrane and at least one electrode catalyst on each side of the membrane, where at least part of the hydrogen is oxidized to protons over the anode catalyst on the retentate side of the membrane and the protons are, after passing through the membrane, b1) reduced to hydrogen and/or b2) reacted with oxygen from an oxygen-comprising stream O which is brought into contact with the permeate side of the membrane to form water over the cathode catalyst on the permeate side.
摘要:
The invention relates to a process for preparing aromatic amines by catalytically hydrogenating the corresponding aromatic nitro compound, which comprises using a copper catalyst with a support comprising SiO2, the SiO2 having been prepared by wet grinding and subsequent spray drying.
摘要:
Olefins are oligomerized by bringing at least one C2 to C8-olefin into contact with a nickel-containing heterogeneous catalyst. The catalyst is conditioned before contact with the olefin by passing an inert gas flow over the same, until the inert gas flow has a water content of less than 1000 ppm. Selectivity for the production of higher oligomers, in particular trimers relative to the formation of dimers is increased by the pretreatment.
摘要:
A process for preparing an amine by reacting a primary or secondary alcohol, aldehyde and/or ketone with hydrogen and a nitrogen compound selected from the group of ammonia and primary and secondary amines, in the presence of a supported copper-, nickel- and cobalt-containing catalyst, wherein the catalytically active material of the catalyst, before the reduction thereof with hydrogen, comprises oxygen compounds of aluminum, of copper, of nickel and of cobalt, and in the range from 0.2 to 5.0% by weight of oxygen compounds of tin, calculated as SnO, and catalysts as defined above.
摘要:
The present invention relates to a process for the pretreatment of hydroamination catalysts, wherein the hydroamination catalyst is brought into contact with an ammonia-comprising mixture before the reaction of olefins with ammonia, a primary or secondary amine, with the ammonia-comprising mixture comprising less than 40% by weight of olefinThe invention further relates to a process for preparing alkylamines by reaction of olefins with ammonia, primary or secondary amines over a hydroamination catalyst, wherein the hydroamination catalyst is pretreated according to the invention before the reaction of the olefins by bringing the hydroamination catalyst into contact with an ammonia-comprising mixture comprising less than 40% by weight of olefin.