Abstract:
A process for autothermal catalytic steam reforming of hydrocarbons by passing a reactant mixture of hydrocarbons, oxygen and water or water vapor, heated to a preheating temperature, over a catalyst. The process is operated adiabatically and the catalyst has a coating of a catalyst material on a support structure, the catalyst material containing at least one platinum group metal on an oxidic support material which can be aluminum oxide, silicon dioxide, titanium dioxide or mixed oxides thereof and zeolites.
Abstract:
The invention provides a supported metal membrane which contains a metal membrane on a support surface of a porous membrane support. The supported metal membrane is obtainable by applying the metal membrane to the support surface of the membrane support, wherein the pores in the membrane support are sealed, at least in the region of the support surface, prior to applying the metal membrane and are opened by removing the auxiliary substance only after applying the metal membrane.
Abstract:
A continuous method of producing .gamma.-aminopropyltrialkoxysilanes as well as mixtures of primary and secondary aminosilanes by reacting .gamma.-chloropropyltrialkoxysilane with ammonia is disclosed. The steps are: a) .gamma.-chloropropyltrialkoxysilane and ammonia are first mixed in the desired amount ratio, b) this mixture is heated to the reaction temperature, c) allowed to run through a pressure reactor with a dwell time sufficient for the complete reaction, during which the mixture can run through several temperature zones, d) the reaction mixture is subsequently cooled off, e) the product (.gamma.-aminopropyltrialkoxysilanes or the mixtures) is separated out of a two-phase mixture and f) the ammoniacal phase returned into the reactor.
Abstract:
A process for the production of 2,2'-bis(4-hydroxyphenyl)propanes by reacting the corresponding phenols and carbonyl compounds in the presence of organopolysiloxanes containing sulphonate and mercapto groups and acting as a catalyst, consisting of units of the formula �O.sub.3/2 --Si--R.sup.1 --SO.sub.3 --!.sub.x M.sup.x+ (I), wherein R.sup.1 is a linear or branched alkylene group having 1 to 12 C atoms, a cycloalkylene group having 5 to 8 C atoms or a unit of the formulae ##STR1## and units of the formula O.sub.3/2 --Si--R.sup.2 --SH (III)
Abstract:
A process is disclosed for continuously hydrogenating unsaturated fats, fatty acids or fatty acid esters on a shaped catalyst in a solid bed. The reactants flow over the catalyst in the presence of a medium or solvent mixture in supercritical conditions. This leads to considerably improved activity and selectivity of the hydrogenation reaction compared with conventional trickle bed hydrogenation processes.
Abstract:
A process for the impregnating and priming treatment of mineral building materials of synthetic or natural origin using aqueous suspensions or solutions which contain at least one silicon-containing ion exchanger of the formula �(YO).sub.3 Si(CH.sub.2).sub.x !.sub.n EX (I) or an oligomer of this compound, wherein x signifies an integer of 1 to 12, n signifies an integer of 1 to 3, depending on E Y signifies H, Na, K, Mg, Ca, Ba E signifies a cation-exchanging or anion-exchanging group, and X signifies H.sup.+ or an alkali cation or alkaline earth cation or OH.sup.- or an anion, in a quantity of from 0.1 to 70% by weight, particularly from 10 to 30% by weight, based on the total quantity of the solution or suspension, with the treatment being carried out in a single stage or in multiple stages, optionally combined with a treatment with aqueous or organic emulsions or solutions containing hydrolyzable silanes and/or siloxanes.
Abstract:
Metal-containing, shaped, polymeric, tertiary and/or secondary organosiloxane amine compounds are introduced which contain the metals Pd, Pt, Ru, Rh individually or in combination as well as optional promotors and/or moderators. The organosiloxane amine functioning as carrier for the metals contains the units ##STR1## and/or units ##STR2## in which R.sup.1 to R.sup.5 are a group ##STR3## with R.sup.6 as a double-bonded group bound to N and Si (e.g. an alkylene group) and X is an amine group such as The carrier substance can be cross-linked with cross-linking agents containing Si, Ti, Zr or Al. The metal-containing product is spherical in form and is defined by the parameters of sphere diameter, specific surface and pore volume as well as bulk density. A method of production is disclosed which can be carried out in several variants as well as the use of the metal-containing product as catalyst for hydrogenation reactions and oxidation reactions.
Abstract:
Organosiloxane copolycondensates which are optionally cross-linked by means of cross-linking agents containing Si, Ti, Zr and/or Al and comprised of the units ##STR1## and X--R.sup.4, wherein ##STR2## wherein R.sup.5 =alkylene with C.sub.1 -C.sub.10 bound directly to N or X, or cycloalkylene with C.sub.5 -C.sub.8 or ##STR3## X=--NH.sub.2, --NH--(CH.sub.2).sub.2 --NH.sub.2, --N(CH.sub.3).sub.2, --N(C.sub.2 H.sub.5).sub.2 --NH--(CH.sub.2).sub.2 --NH--(CH.sub.2).sub.2 --NH.sub.2, --Cl, --Br, --I, --SH, --P(C.sub.6 H.sub.5).sub.2, ##STR4## wherein R"=H or alkyl with C1-C5 in the form of spherical particles with a diameter of 0.01 to 3.0 mm, a specific surface of up to 1000 m.sup.2 /g, a specific pore volume of up to 6.0 ml/g and a bulk density of 50 to 1000 g/l. The formed copolycondensates can be used for removing metals from solutions and/or for the adsorption of gaseous organic compounds and/or of water vapor.
Abstract:
Process for the selective hydrogenation of alphatic or aromatic substrates under supercritical or near critical conditions. Hydrogenation is effected using a heterogeneous catalyst in a continuous flow reactor containing a supercritical or near critical reaction medium and selectively of product formation is achieved by varying one or more of the temperature, pressure, catalyst and flow rate.
Abstract:
A process for producing carboxylic acid esters by the following steps:a) preparation of a reaction mixture containing an alcohol and a carboxylic acid and/or a carboxylic anhydride and/or a carboxylic acid ester and or a partially esterified carboxylic acid,b) heating of this mixture to the suitable reaction temperature in the presence of a solid polysiloxane insoluble in the reaction medium and having sulphonic acid groups with intensive thorough mixing accompanied by continuous separation of the reaction water which forms, wherein the polysiloxane used as the catalyst in modified by treatment with a soluble aluminum, titanium or zirconium compound, and the spherical particles thereof have a diameter of 0.01 to 3 mm, a specific surface of 0.1 to 1200 m.sup.2 /g, a specific pore volume of 0.01 to 6.0 ml/g and a bulk density of 50 to 1000 g/l.