摘要:
A process for preparing dicarboxylic acids by oxidizing cycloaliphatic alcohols, cycloaliphatic ketones or mixtures thereof with nitric acid, by performing the reaction and separation of the components in a fractionating column or rectification column.
摘要:
A process is proposed for reprocessing the exhaust gas from a plant for producing hydroxylamine or hydroxylammonium salts by catalytic reduction of nitrogen monoxide with hydrogen for the purpose of utilization of at least a part of the nitrogen monoxide and if appropriate hydrogen present in the exhaust gas for producing hydroxylamine or hydroxylammonium salts, which comprises, in a first separation stage, selectively separating off nitrogen monoxide from the exhaust gas of the plant for producing hydroxylamine or hydroxylammonium salts.
摘要:
A process is proposed for reprocessing the exhaust gas from a plant for producing hydroxylamine or hydroxylammonium salts by catalytic reduction of nitrogen monoxide with hydrogen for the purpose of utilization of at least a part of the nitrogen monoxide and if appropriate hydrogen present in the exhaust gas for producing hydroxylamine or hydroxylammonium salts, which comprises, in a first separation stage, selectively separating off nitrogen monoxide from the exhaust gas of the plant for producing hydroxylamine or hydroxylammonium salts.
摘要:
A process for oxidizing a starting material with an oxidizing agent to obtain a product, which comprises carrying out the oxidation in a reaction apparatus which has a bottom region at the lower end, a top region at the upper end and a reaction zone between the top region and the bottom region, maintaining the reaction mixture in the boiling state in the reaction zone, and introducing oxidizing agent into the reaction zone in at least two substreams.
摘要:
Process for the continuous preparation of unsaturated ketones of the formula I where the dashed line can be an additional C—C bond, R1 is an alkyl, and R2 is an aliphatic hydrocarbon having from 1 to 37 carbons, a cycloalkyl or a cycloalkylalkyl, by reacting an unsaturated alcohol of the formula II with an alkyl acetoacetate of the formula III where R3 is an alkyl having from 1 to 5 carbons, in the presence or organic aluminum compounds as catalyst.
摘要:
A process for producing solids by precipitation in a mixer to form a mixture of solid and liquid, where the starting materials are fed into a mixing apparatus which has essentially a rotationally symmetrical mixing chamber which has a rotor disposed therein and is formed by a peripheral wall and two end walls, and where a) the starting materials are each fed to at least one inlet opening in the peripheral wall of the mixing chamber, and b) the solid-containing mixture which is formed is removed from at least one outlet opening in the peripheral wall of the mixing chamber.
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:
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:
A process for preparing at least one unsaturated alcohol (B) comprises the steps (I) to (III) below: (I) reaction of at least one alkali metal hydroxide or alkaline earth metal hydroxide with at least one alcohol (A) in at least one organic solvent (L) to give a mixture (G-I) comprising at least the alcohol (A), the solvent (L) and an alkoxide (AL); (II) reaction of at least one carbonyl compound of the formula R—CO—R′ with at least one alkyne of the formula R″—C≡C—H and the mixture (G-I) obtained in step (I) to give a mixture (G-II) comprising at least the alcohol (A), the solvent (L) and an unsaturated alcohol (B); (III) distillation of the mixture (G-II) obtained in step (II) to give the alcohol or alcohols (B) and a mixture (G-III) comprising the solvent (L) and the alcohol (A), wherein the solvent (L) obtained in step (III) and the alcohol (A) obtained in step (III) are recycled as a mixture to step (I).
摘要:
A structured packing for heat exchange and mass transfer between a liquid and a gas in a column having at least one packing layer with a first, lower end and a second, upper end is described, the packing layer having an internal geometry which varies over its height so that by suitably setting the liquid and gas flow rates in a first, in particular lower, region of the packing layer a bubbling layer having a predominantly disperse gas phase forms in a targeted manner and simultaneously in a second, in particular upper, region of the packing layer a film flow of the liquid having a predominantly continuous gas phase forms in a targeted manner.