摘要:
Catalytic reactions are carried out in a reactor which contains a liquid phase in which at least one catalyst is suspended, and which may additionally contain a gas phase, by a process in which the liquid phase and, if present, also the gas phase are fed, at least partly, through an apparatus having orifices or channels in the reactor, the hydraulic diameter of which orifices or channels is from 0.5 to 20 mm, preferably from 1 to 10 mm, particularly preferably from 1 to 3 mm.
摘要:
The invention relates to a process for the selective liquid-phase hydrogenation of .alpha.,.beta.-unsaturated carbonyl compounds of the formula I, ##STR1## where R.sub.1 is hydrogen or an organic radical, and R.sub.2, R.sub.3 and R.sub.4, independently of one another, are hydrogen or a C.sub.1 -- to C.sub.4 --alkyl group, to saturated carbonyl compounds of the formula II ##STR2## using hydrogen in the presence of a pulverulent palladium and/or rhodium catalyst and in the presence of an organic base. The process is carried out in a packed bubble column reactor (1, 2) with product recycling (11, 17) and circulating hydrogen gas (4, 15, 16). It is particularly suitable for the selective hydrogenation of citral to citronellal.
摘要:
Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase over palladium catalysts by a process which comprises A. using a fixed-bed catalyst which is obtainable by heating the preferably metallic carrier in the air, cooling, coating under reduced pressure with metallic palladium, suitable molding and processing to a monolithic catalyst elements and B. adding from 10 to 180 ppm of CO to the hydrogen used for the hydrogenation.
摘要:
In a process for the catalytic hydrogenation of 2,5- and 2,3-dihydrofuran with hydrogen to give tetrahydrofuran, use is made of a catalyst in which a metal or a plurality of metals have been deposited by vapor deposition or sputtering on a metal wire mesh or a metal foil as support.
摘要:
The present invention relates to a gauze catalyst based on titanium or vanadium zeolites and inert gauze fabrics which is suitable for accelerating oxidation reactions such as epoxidation of olefins, hydrogen peroxide production or hydroxylamine synthesis.
摘要:
Monomodal or polymodal catalyst supports or catalysts having a BET specific surface area of from 0.01 to 250 m.sup.2 /g and a monomodal or polymodal pore size distribution having a mean pore diameter of from 50 to 300,000 nm measured by the mercury pressure porosimetry method, whereina) from 10 to 95% of the pore volume is at from 0.2 to 100 times the mean pore diameter and/orb) from 10 to 80% of the pore volume is at from 0.8 to 100 times the mean pore diameter and/orc) from 50 to 95% of the pore volume is at from 0.2 to 1 times the mean pore diameter and/ord) from 50 to 80% of the pore volume is at from 0.8 to 1 times the mean pore diameter ande) the width at half height of the pore size distribution is less than 0.6 times the mean pore diameter, whichare useful for the preparation of chlorine from hydrogen chloride in a non-steady-state Deacon process, for the reaction of ethylbenzene to give styrene in a non-steady-state oxydehydrogenation, for preparing aziridine from ethanolamine, in reductions, hydrogenations, oxidations, dehydrogenations, acid- or base-catalyzed reactions or reactions in a fluidized bed, for removing combustion residues from diesel exhaust gases and for removing NO.sub.x from waste gases, in bioreactors together with bacteria and as biocatalyst supports with immobilized enzymes or microbes, and a process for producing said monomodal or polymodal catalyst support or catalyst.
摘要:
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.
摘要:
A process for the preparation of alkylphenols of the formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 stand for hydrogen or C.sub.1 -C.sub.8 alkyl, by reaction of an alkylcyclohex-2-en-1-one of the formula II ##STR2## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 have the aforementioned meanings, at temperatures of from 200.degree. to 400.degree. C. and pressures ranging from 0.01 to 50 bar in the presence of palladium-on-.alpha.-Al.sub.2 O.sub.3 catalysts, wherein the catalyst used has a specific surface area (BET) of from 1 to 10 m.sup.2 /g, a pore diameter of from 5 nm to 300 .mu.m and a pore volume of from 0.1 to 0.5 cm.sup.3 /g, from 80 to 100% of the pores having a diameter of from 40 to 400 nm, and also novel palladium-on-.alpha.-Al.sub.2 O.sub.3 catalysts as obtained from a fine-grained alumina powder by steps of molding, pyrolysis and calcination.
摘要:
A process for reacting an organic compound in the presence of a catalyst, wherein the catalyst comprises a homogeneous ruthenium compound or a mixture of two or more thereof deposited in situ on a support.
摘要:
Catalyst and process for the preparation of butene-2-diol-1,4 by the hydrogenation of butyne-2-diol-1,4 in aqueous solution over a palladium-containing fixed-bed catalyst, which is doped with lead or cadmium, in which a catalyst is used which has been made by applying Pd and Pb or Pd and Cd successively, by vapor deposition or sputtering, to a metal gauze or a metal foil acting as support material followed by forming the catalyst at an elevated temperature in air.