Abstract: The present invention relates to a process for separating off CO2 from a gas stream, wherein in a second step the CO2 is removed from the CO2-absorbing agent by means of phase separation.

Abstract: The present invention relates to a process for separating off CO2 from a gas stream, wherein in a second step the CO2 is removed from the CO2-absorbing agent by means of phase separation.

Abstract: A ceramic microreactor for carrying out reactions having a large heat of reaction which has at least three interior spaces, with at least one interior space having internal buffers whose shape, number and positioning ensure homogeneous flow, is described. The microreactor is built up as a monolith from at least seven plate-shaped layers of inert ceramic material, preferably aluminium oxide, which form an upper heating/cooling space, a central reaction space and a lower heating/cooling space. One interior space has a coating of a catalyst comprising noble metal. The shape, number and positioning of the internal buffers is determined by means of flow simulation calculations; the internal buffers preferably have a lozenge shape. The microreactor displays very good selectivity in reactions having a large heat of reaction, in particular in heterogeneous gas-phase reactions, and is used in particular for hydrogen production and/or hydrogen purification in fuel cell technology.

Abstract: Recuperative heat exchangers or regenerative heat exchangers are used for the thermal decomposition of N2O in N2O-containing gases. The process for the thermal decomposition of N2O in N2O-containing gases at from 800 to 1200° C. comprises passing the N2O-containing gas through one or more recuperative heat exchangers or regenerative heat exchangers in such a way that when the gas to be reacted is passed through a charge of heat transfer material it is heated to a temperature in the range from 800 to 1200° C. and the N2O present is decomposed thermally, and cooling the reacted gas by heat exchange so as to heat the charge of heat transfer material and the gas to be reacted.

Abstract: (Cyclo)aliphatic polyisocyanate compositions which have a long shelf life, are obtainable by phosgene-free methods, preferably by thermal cleavage of (cyclo)aliphatic polycarbamates, and, for stabilization, contain at least one primary stabilizer (2a), preferably a sterically hindered phenol and/or an aromatic amine, or at least one secondary stabilizer (2b), preferably an organic phosphite and/or a thioether, or at least one acidic stabilizer (2c), preferably a carboxylic acid, an acyl chloride, an inorganic acid, an inorganic acid chloride and/or a diester of phosphoric acid, or a stabilizer system comprising at least 2 of the stabilizers (2a) to (2c), a process for the preparation of the (cyclo)aliphatic polyisocyanate compositions and their preferred use for the preparation of isocyanurate-containing polyisocyanates.

Abstract: The invention relates to a method of reacting alkyl carboxylate chlorides and/or carboxylic dichlorides dissolved in corresponding diaikyl carboxylates with the corresponding alkanol at temperatures ranging from 60.degree. to 300.degree. C., in which the resultant hydrogen chloride remains in the reaction mixture.

Abstract: The preparation of cyclohexene oxide, cyclohexanol and cyclohexanone involvesa) oxidizing cyclohexane using a gas containing molecular oxygen to form cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone,b) jointly separating the mixture from a) and c) by distillation, andc) reaction of the cyclohexyl hydroperoxide fraction from b) with cyclohexene in the presence of a transition-metal compound from group 4 to 6, forming cyclohexene oxide, and separating the product mixture in b).

Abstract: Caprolactam is purified continuously by passing a 75-95% strength by weight aqueous caprolactam solution together with hydrogen at 50.degree.-95.degree. C. and 1.5-100 bar upward through a fixed-bed supported palladium or nickel catalyst in a tubular zone while maintaining a residence time of from 10 to 100 min.

Abstract: Hydroxylammonium salts are eliminated from wastewaters containing such salts by a process which comprises treating a wastewater containing such salts with not less than 0.5 mole of manganese (IV) oxides per mole of hydroxylamine in the form of hydroxylammonium salts at a pH of from 1 to 4 and at from 10.degree. to 100.degree. C.