摘要:
A process for preparing 1,4-butanediol by continuous catalytic hydrogenation of 1,4-butynediol comprises reacting 1,4-butynediol with hydrogen in the liquid continuous phase in the presence of a heterogeneous hydrogenation catalyst at from 20 to 300° C., a pressure of from 1 to 200 bar and values of the liquid-side volumetric mass transfer coefficient kLa of from 0.1 s−1 to 1 s−1 a) using a catalyst suspended in the reaction medium, where if a packed bubble column is employed this is operated in the upflow mode and at a ratio of gas leaving the reaction vessel to gas fed to the reaction vessel of from 0.99:1 to 0.4:1, or b) passing the liquid and gas in cocurrent in an upward direction through a fixed-bed reactor operated in the gas-circulation mode while maintaining a ratio of the gas fed to the reaction vessel to gas leaving the reaction vessel of from 0.99:1 to 0.4:1.
摘要:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated. It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
摘要:
In a process for preparing alcohols containing cycloaliphatic groups by hydrogenation of carboxylic acids containing aromatic nuclei, or anhydrides or esters thereof, in the presence of a catalyst, the hydrogenation is carried out in one stage, and the catalyst contains at least one element from groups 8 to 10 and at least one element from group 7 of the Periodic Table of the Elements, in the form of the metal or an oxide in each case.
摘要:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
摘要:
In a process for the preparation of alcohols by catalytic hydrogenation of carbonyl compounds, the catalyst used is 0.01 to 50% by weight of rhenium and 0 to 20% by weight, in each case based on the total weight of the catalyst, of at least one further metal chosen from Zn, Cu, Ag, Au, Ni, Fe, Cr, V on oxidatively pretreated activated carbon as support.
摘要:
A process for the hydrogenation of an organic compound containing at least one carbonyl group comprises bringing the organic compound in the presence of hydrogen into contact with a shaped body which can be produced by a process in which (i) an oxidic material comprising copper oxide, zinc oxide and aluminum oxide is made available, (ii) pulverulent metallic copper or pulverulent cement or a mixture thereof is added to the oxidic material, and (iii) the mixture resulting from (ii) is shaped to form a shaped body.
摘要:
In a process for preparing aliphatic alcohols by hydrogenating aliphatic carboxylic acids or anhydrides or esters thereof or lactones in the presence of a catalyst comprising Pt and Re, in the form of the metal or an oxide in each case, the catalyst further comprises at least one further element from the groups 5 to 12 and 14 and the lanthanides of the Periodic Table of the Elements in the form of the metal or an oxide.
摘要:
Novel supported, titanized chromium catalysts can be used for the homopolymerization of ethylene and the copolymerization of ethylene with α-olefins.
摘要:
A process for preparing cyclopentanone by reacting adipic esters of the formula R1OOC—(CH2)4—COOR2 I where R1 and R2 are each alkyl having from 1 to 12 carbon atoms, cycloalkyl having 5 or 6 carbon atoms, aralkyl or aryl and R2 may additionally be hydrogen, in the presence of oxidic catalysts comprises reacting adipic esters of the formula I having less than 5% by weight of by-products other than adipic esters in the gas phase in the presence of water, a carrier gas and a) from 0.01 to 10% by weight of at least one metal oxide selected from the first or second main group of the periodic table or from the group of the rare earth metals on titanium dioxide or zirconium dioxide as catalyst support, or b) from 0.01 to 50% by weight of at least one metal oxide selected from the second main group of the periodic table on zink oxide as catalyst support.
摘要:
A catalyst solid for olefin polymerization comprising A) at least one magnesium halide, B) at least one metallocene complex and C) at least one compound capable of forming metallocenium ions, is prepared by i) firstly preparing finely divided support particles consisting of the magnesium halide A) and an C1-C8-alcohol having a mean particle diameter of from 1 to 200 μm from an adduct of the magnesium halide A) and a C1-C8-alcohol, where the adduct contains from 1.5 to 5 mol of the C1-C8-alcohol per mole of magnesium halide, ii) then depositing the compound C) capable of forming metallocenium ions on the finely divided support particles and iii) subsequently bringing the reaction product hereby obtained into contact with the metallocene complex B). This catalyst solid can be used for the polymerization or copolymerization of olefins.