Abstract:
A process for preparing isocyanoatoorganosilanes by thermolysis of carbamatoorganosilanes in the presence of microwave radiation, optionally employing homogeneous or heterogeneous catalysis, provides isocyanatoorganosilane product in higher yield than prior art thermolyses, and with fewer byproducts. A continuous process is thus possible.
Abstract:
Isocyanatosilanes are prepared by themolyzing carbamatosilanes in a fluidized bed reactor containing fluidized solid particles. The process substantially avoids the deposition of solid reaction by products in the reactor.
Abstract:
A method for the separation and purification of an aqueous mixture of main components, namely acetic acid and formic acid and non-volatiles by extraction, uses a solvent in a circulatory system. A raffinate stream is mixed with the larger proportion of water from a solvent stripper column (11) for the removal of water. The extraction stream is introduced into a solvent distillation column (8), from which in a first step involving the use of a mixture (A) containing a larger proportion of the solvent is separated out via a header and a mixture (B) of formic acid, water and solvent is separated out via a side offtake and a mixture (C) of acetic acid and non-volatiles is also separated out. A mixture (B) is introduced into a formic acid distillation column (4) for further processing, and a mixture (C) is introduced into an acetic acid distillation column (5), and purified acetic acid is subsequently isolated in the acetic acid distillation column (5) from the header. Pure formic acid is isolated at the settling basin of the formic acid distillation column (4).
Abstract:
The invention relates to supported catalysts consisting of an active material on an inert support in the shape of rings, wherein the rings have one or more notches in the upper and/or lower flat side of the ring.
Abstract:
A process for preparing saturated carboxylic acids having from one to four carbon atoms by gas-phase oxidation, includes reacting 2-butanone with oxygen over a coated catalyst which is an inert nonporous support body and a catalytically active mixed oxide composition comprising (a) one or more oxides selected from the group consisting of titanium dioxide, zirconium dioxide, tin dioxide and aluminum oxide, and (b) from 0.1% to 1.5% by weight, based on the weight of the component (a) and per m2/g of specific surface area of the component (a), of vanadium pentoxide, applied to the external surface of the support body.
Abstract:
The invention relates to a method for separating and purifying an aqueous mixture that mainly consists of acetic acid, formic acid and high-boiling substances by extraction with a solvent in a cyclic process. The inventive method is characterized in that the flow of raffinate is fed to a solvent stripping column (11) with the major part of the water in order to remove the water from the cycle. The flow of extract is fed to a solvent recovery distillation column (8). In a first step, a mixture (A) that consists of water and solvent, is separated by overhead distillation. A mixture (B) that consists of acetic acid, formic acid and high-boiling substances is separated via a sump. Once the formic acid is removed in a column (29), mixture (B) is separated in an acetic acid distillation column to give pure acetic acid and high-boiling substances. Mixture (A) is fed to a phase separator and the aqueous phase is returned to the solvent stripping column (11) together with any residual portions of the solvent while the organic phase is returned to the extractor (8).