Abstract: Cyclopentane and/or cyclopentene and, if desired, isopentane can be obtained by distillative separation from a pre-benzene fraction or a C5 fraction which has in each case being partially hydrogenated to remove acetylene compounds and diolefins, wherein a) in a first fractional distillation, low boilers are removed as first top product and, either b1) the first bottom product is fed to a second fractional distillation and there cyclopentene is taken off as second top product and cyclopentane and higher-boiling hydrocarbons are taken off as second bottom product and this second bottom product is separated into cyclopentene and higher boilers in a third fractional distillation, or b2) the first bottom product is subjected to a catalytic hydrogenation and subsequently, in a fractional distillation, separated into cyclopentane as top product and higher boilers as bottom product, or b3) the first bottom product is subjected to a fractional distillation to separate off the relatively high boilers as bottom prod

Abstract: Cyclopentane and/or cyclopentene and, if desired, isopentane can be obtained by distillative separation from a pre-benzene fraction or a C5 fraction which has in each case being partially hydrogenated to remove acetylene compounds and diolefins, wherein

Abstract: Cyclopentane and/or cyclopentene and, if desired, isopentane can be obtained by distillative separation from a pre-benzene fraction or a C5 fraction which has in each case being partially hydrogenated to remove acetylene compounds and diolefins, wherein a) in a first fractional distillation, low boilers are removed as first top product and, either b1) the first bottom product is fed to a second fractional distillation and there cyclopentene is taken off as second top product and cyclopentane and higher-boiling hydrocarbons are taken off as second bottom product and this second bottom product is separated into cyclopentene and higher boilers in a third fractional distillation, or b2) the first bottom product is subjected to a catalytic hydrogenation and subsequently, in a fractional distillation, separated into cyclopentane as top product and higher boilers as bottom product, or b3) the first bottom product is subjected to a fractional distillation to separate off the relatively high boilers as bottom prod

Abstract: The production of 1,2-butadiene in purities of at least 85% becomes possible by means of a process in which a polymerization-inhibitor-containing C4 hydrocarbon fraction is subjected to at least one fractional distillation.

Abstract: The i-butene present in a C.sub.4 raffinate I is subjected in a first step to a first hydroisomerization. The hydroisomerization product is subjected to fractional distillation, with essentially 2-butene and n-butane being obtained as bottom product and i-butene and i-butane being obtained as overhead product. The overhead product is condensed and the condensate is divided into two parts. One part is subjected to a second hydroisomerization and the second hydroisomerate is recycled to the upper third of the fractionation column. The other part of the condensed overhead product is fed to the oligomerization. The condensed overhead-product of the fractionation column is divided in such a manner that, based on 1 part by volume of condensate conducted to the oligomerization, 1-5 parts by volume are fed to the second hydroisomerization.

Abstract: Molybdenum/bismuth-based fluid-bed catalysts which are used for the ammoxidation of olefins can be reactivated by addition of a mixed oxide of formulaMo.sub.20 (P, Cr).sub.0.3-2.0 (Bi, Ni, Fe, Co).sub.1.33-4.0 O.sub.xwherein, besides Mo, one element from component group (P, Cr) and one or more metals from component group (Bi, Ni, Fe, Co) are present, andx results from the valency requirements,the mixed oxide being applied to SiO.sub.2 as support.

Abstract: The ammonium sulphate contained in tar-rich waste streams from the production of (meth)acrylonitrile can be precipitated out by adding 1 to 30 times the amount by weight of methanol, relative to the water content of the waste stream, and additionally 0.05 to 10% the amount by weight of ammonia, relative to methanol, to such a waste stream at 10.degree.-60.degree. C. and separating off the ammonium sulphate which precipitates out. The waste stream remaining after separating off the ammonium sulphate can, for example, be disposed of as low-sulphur waste-fuel in a combustion chamber.

Abstract: The effluent arising in the production of acrylonitrile can be purified by adjusting it to a pH value from 4 to 9 and then subjecting it to reverse osmosis at a membrane at a temperature from 10.degree. to 50.degree. C. and a differential pressure of 10 to 80 bar. The flow velocity at the membrane is adjusted to a value from 0.5 to 4 m/second. The concentrate is recycled into the acrylonitrile production process.

Abstract: Ethylene/acrylonitrile high pressure solvent-free polymers with reduced tackiness may be obtained by the copolymerisation of small quantities of acryloyl or methacryloyl compounds.

Abstract: A paint resin for powder coating is described which consists of modified high-pressure polyethylene (LDPE) and is characterized by(a) a content from 0.1 to 1 mol %, based on the total number of moles of all monomers, of unsaturated carboxylic acids present as copolymerized units, and/or the equivalent content of carboxylic anhydrides,(b) a neutralization degree of the carboxyl groups, which can also originate from anhydride groups, from 0 to less than 50%,(c) a termonomer content from 0 to 5 mol %, based on the total number of moles of all monomers,(d) a melt flow index from 20 to 200 g/10 minutes (190.degree. C.; 2.16 kp) and(e) a particle size from 1 to 600 .mu.m,as well as the use thereof in a process for powder coating.

Abstract: An ionomer-modified polyethylene, that is, an ethylene/carboxylic acid copolymer in which at least some of the acidic groups are neutralized, is preparable by a one-stage procedure by reacting ethylene with unsaturated carboxylic acids and salts of such unsaturated carboxylic acids in the presence of a free radical polymerization initiator, under the conditions employed in the production of high pressure polyethylene (LDPE). The concentration of salt which is incorporated in the polymer is kept at no more than 1 mol %, relative to converted ethylene and other comonomers respectively. Advantageously, the unsaturated carboxylic acids and their salts are added to the copolymerization reaction as a homogeneous solution in a suitable solvent.The ionomer-modified polyethylenes based on low density polyethylene (LDPE), in which 30-95% of the carboxyl groups are neutralized and the neutralized carboxyl groups represent 0.1-0.

Abstract: The present invention relates to copolymers containing ethylene monomer units and .alpha.-cyanacrylate monomer units and processes for their production.

Abstract: A device for emission-free sampling of volatile liquids comprises a 4-way tap from which lead two lines, which can be connected together, from and to the container holding the liquid to be tested and two other lines, which can also be connected together, lead to a sample bottle which can be sealed and which can be connected to the device. The device further comprises a supply line for an inert flushing medium, which joins the line leading into the sample bottle in the region of the sample bottle, and a discharge line for the inert flushing medium, which leads from the line coming out of the sample bottle in the region of the sample bottle and proceeds to a disposal system.

Abstract: A process for the preparation of pure alkyl tertiary alkyl ethers and hydrocarbon raffinates which are substantially free from tertiary olefins and alkanols. An alkanol and a hydrocarbon mixture containing at least one tertiary olefin are contacted with the alkanol being present in a stoichiometric excess. The reaction product is removed from the reaction zone and excess alkanol in the reaction product or a partial stream thereof is absorbed on a synthetic ion exchanger containing groups which exchange cations or anions or mixtures of such ion exchangers. After absorption of at least a portion of the alkanol on the synthetic ion exchanger, the alkanol is desorbed by contacting the same with a hydrocarbon mixture containing at least one tertiary olefin.

Abstract: Pure tert.-olefins are prepared from mixtures of hydrocarbons, which contain at least one such tert.-olefin, by reaction with an alkanol to give the corresponding alkyl tert.-alkyl ethers, and subsequent cleavage of these ethers back to the corresponding pure tert.-olefins and the alkanol, and the separation of the pure tert.-olefin from the alkanol. For this, the alkanol present after the cleavage of the ether is separated from the tert.-olefin to the extent of 60 to 99% by weight by distillation, and the residual amount of alcohol in the olefin fraction is removed by adsorption from this fraction onto a synthetic ion exchanger as an absorber resin. The admixture of the alkanol to the mixture of hydrocarbons with at least one tert.-olefin is carried out partly by using the alkanol fraction arising from the separating off of the pure tert.-olefin, and partly by desorption of the alkanol from the absorber resin with the aid of the mixture of hydrocarbons containing at least 1 tert.-olefin.

Abstract: Process for the preparation of tertiary olefins by catalytic cleavage of their n-alkyl ethers at elevated temperature and with simultaneously recovery of the corresponding n-alkanols, characterized in that the cleavage is carried out in the presence of acidic molecular sieves, which have been activated, if necessary, by a treatment with hydrogen, at temperatures of from 100.degree. to 300.degree. C.