摘要:
A process is disclosed for preparing coated catalysts, inter alia, for gas phase oxidations in organic chemistry, comprised of an inert support and a coating of catalyst material enclosing this support, wherein a suspension of the starting material for the coating is sprayed onto an agitated bed of the support, while the suspending medium is being partially removed by a gas stream, and the raw material is then dried and heat-treated. For this purpose, the support bed is mechanically agitated and loosened by a gas stream blown in from below. The catalyst precursor containing a binder and, if appropriate, a pore-former is sprayed in an increasing amount from above onto the bed, the ratio between suspending medium sprayed on and drawn off remaining about constant. The thermal expansion coefficient of the precursor as a dry powder must not deviate by more than 15% from that of the support. The applied coating is densified by continuing the mechanical and fluidizing mixing motion, the material is then dried in a continuing gas stream and heat-treated, if appropriate after decomposition of an added pore-former.
摘要:
A process is disclosed for preparing coated catalysts, inter alia, for gas phase oxidations in organic chemistry, comprised of an inert support and a coating of catalyst material enclosing this support, wherein a suspension of the starting material for the coating is sprayed onto an agitated bed of the support, while the suspending medium is being partially removed by a gas stream, and the raw material is then dried and heat-treated. For this purpose, the support bed is mechanically agitated and loosened by a gas stream blown in from below. The catalyst precursor containing a binder and, if appropriate, a pore-former is sprayed in an increasing amount from above onto the bed, the ratio between suspending medium sprayed on and drawn off remaining about constant. The thermal expansion coefficient of the precursor as a dry powder must not deviate by more than 15% from that of the support. The applied coating is densified by continuing the mechanical and fluidizing mixture motion, the material is then dried in a continuing gas stream and heat-treated, if appropriate after decomposition of an added pore-former.
摘要:
A process is disclosed for preparing coated catalysts, inter alia, for gas phase oxidations in organic chemistry, comprised of an inert support and a coating of catalyst material enclosing this support, wherein a suspension of the starting material for the coating is sprayed onto an agitated bed of the support, while the suspending medium is being partially removed by a gas stream, and the raw material is then dried and heat-treated. For this purpose, the support bed is mechanically agitated and loosened by a gas stream blown in from below. The catalyst precursor containing a binder and, if appropriate, a pore-former is sprayed in an increasing amount from above onto the bed, the ratio between suspending medium sprayed on and drawn off remaining about constant. The thermal expansion coefficient of the precursor as a dry powder must not deviate by more than 15% from that of the support. The applied coating is densified by continuing the mechanical and fluidizing mixing motion, the material is then dried in a continuing gas stream and heat-treated, if appropriate after decomposition of an added pore-former.
摘要:
A process is disclosed for preparing acrolein from propylene and methacrolein from isobutylene or tertiary butanol, by oxidation in oxygen-containing gas mixtures on specially prepared coated catalysts comprised of an inert support and a coating, enclosing this support, of an oxidic catalyst material containing the elements nickel, cobalt, iron, bismuth, phosphorus, molybdenum and tantalum or samarium and, if appropriate, also alkali metal or alkaline earth metal in certain atomic ratios. This coated catalyst is obtained by spraying a suspension of the starting material for the coating, which suspension contains a binder and, if appropriate, a pore-former, from above in an increasing amount onto a bed of the support, which bed is mechanically agitated and loosened up by a gas stream blow in from below, the ratio between suspending medium sprayed on and removed again by the gas stream remaining approximately constant. The thermal expansion coefficient of the precursor as a dry powder must not deviate by more than 15% from the coefficient of the support. The coating is densified by further agitation, and the material is dried in the continuing gas stream and heat-treated, if appropriate after decomposition of an added pore-former.
摘要:
A method of preparation for acetals utilizing saturated or unsaturated aldehydes, in particular, the preparation of dimethylacetals of acetaldehyde, acrolein and methacrolein. The production of the acetal takes place in a liquid phase in the presence of a solid acid catalyst, such as a strongly acidic ion exchange resin or zeolite. The conversion mixture is extracted by means of water and by means of water insoluble organic solvents. There is obtained not only the desired acetals, but in addition also the unconverted initial quantities of the starting materials by a simple method and with very good yields.
摘要:
The present invention relates to a process for the production of acrolein by catalytic gas-phase oxidation of propene with air in the presence of steam and an inert gas or waste gas from the reaction, the starting materials being passed in defined quantitative ratios at 300.degree. to 380.degree. C. under 1.4 to 2.2 bar pressure over a catalyst containing the combination of elements MoFeCoNiBiP(As)K(Rb,Cs)SmSiO in the form of a bed of individual elements, the catalyst elements fulfilling certain geometric conditions and a number of critical physico-chemical parameters and a specific load of 2 to 8 mol propene/dm.sup.3 catalyst bed/h being adjusted.
摘要:
A catalyst for the synthesis of methyl mercaptan from hydrogen sulfide and methanol, as well as a process for preparing the catalyst. The catalyst contains active aluminum oxide on which 15% to 40% by weight cesium tungstate is deposited as the activator. The activator, cesium tungstate, gives an unexpected increase in activity and selectivity as compared with potassium tungstate, which is used exclusively at the present state of the art.
摘要:
A catalyst is described for the production of unsaturated aldehydes by means of oxidation with a oxygen-containing gas where an active mass, containing at least the elements Mo, Bi, P and O, as well as Si-containing carrier material, is used in the form of a catalyst body with a certain ratio between the outer surface and the volume and with a defined extent in terms of space, porosity, density, specific surface, breaking strength, abrasion, and gas through-flow capability. Also described is a method of making the catalyst.
摘要:
A reactor for performing endothermic catalytic reactions is disclosed formed of a monolithic counterflow reactor with parallel heating and reaction channels. The internal walls of the reaction channels are coated with a catalyst for the catalytic reaction to be performed, while the internal walls of the heating channels have a catalyst for the catalytic combustion of a fuel gas/air mixture.
摘要:
A process for preparing 3-hydroxyalkanals having 3 to 12 carbon atoms by hydration of 2-alkenals with homogeneous catalysis, by using as catalyst a compound corresponding to the formula ##STR1## wherein: z denotes H, C.sub.1 - to C.sub.6 -alkyl, --CH.sub.2 --CH(CH.sub.3) --Y' or --(CH.sub.2).sub.o --Y'R denotes H, C.sub.1 - to C.sub.6 -alkyl, benzyl, phenyl, .omega.-hydroxy --C.sub.1 - to C.sub.6 -alkyl, --CH.sub.2 --CH(CH.sub.3)--Y' or --(CH.sub.2).sub.o --Y'Y and Y' are identical or different and denote --COOH, --P(O) (OH).sub.2, --OH, pyridyl, or --P(O) (CH.sub.2 OH)OH, wherein the acid functional group may be present partly in the form of its alkali metal salt, alkaline-earth salt or ammonium saltn denotes 1, 2, 3, 4, 5 or 6 where Y is --COOH, --P(O) (OH).sub.2, pyridyl or --P(O) (CH.sub.2 OH) OH; 2 or 3 where Y is --OHo denotes 1, 2, 3, 4, 5 or 6 where Y' is --COOH, --P(O) (OH).sub.2, pyridyl or --P(O) (CH.sub.2 OH)OH; 0, 2 or 3 where Y' is --OH.