Abstract: Process for isolating one or more organic substances from a gas mixture in which these organic substances are present, in which the gas mixture is subjected to a quenching in a column, characterized in that quenching is carried out in the upper part of the column and the quenching liquid is subjected to stripping in the lower part of the column.

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: Process for isolating one or more organic substances from a gas mixture in which these organic substances are present, in which the gas mixture is subjected to a quenching in a column, characterized in that quenching is carried out in the upper part of the column and the quenching liquid is subjected to stripping in the lower part of the column.

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: A catalytic agent for etherifying, hydrogenating and isomerizing crude C.sub.4 -C.sub.8 -- hydrocarbon mixtures having a sulfur content, comprising a macroporous or gel cation exchanger having SO.sub.3 H groups and being charged with a mixture of a metal selected from the group consisting of Pd, Ru, Rh and Pt with a metal selected from the group consisting of Fe, Co, Ni, Cu, Ag and W.

Abstract: C.sub.4 -C.sub.6 -alkenes having an internal double bond can be produced by hydroisomerization of C.sub.4 -C.sub.6 -alkenes having a terminal double bond in the presence of H.sub.2 on a catalyst having a content of a noble metal of group VIII of the Periodic Table of the Elements (Mendeleev), if C.sub.4 -C.sub.6 -alkenes having a terminal double bond are fed into a hydroisomerization reactor after preheating, as such or in a mixture with other hydrocarbons, and the reaction product is divided into a work-up stream and a recycle stream. The recycle stream is recycled to the inlet of the hydroisomerization reactor and is used there as feed together with the C.sub.4 -C.sub.6 -alkenes having a terminal double bond or with the hydrocarbon stream comprising the C.sub.4 -C.sub.6 -alkenes having a terminal double bond and with the H.sub.2.

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: High-octane, low-olefin motor fuels and motor fuel components having a content of alkyl tert.-alkyl ethers can be produced by reacting a crude hydrocarbon stream, which contains tertiary C.sub.5 -C.sub.8 -olefins in addition to saturated and olefinically, diolefinically and acetylenically unsaturated hydrocarbons in the same boiling range, simultaneously with one or more C.sub.1 -C.sub.4 -alkanols in a quantity from 0.5 to 5 mol per mol of the tertiary olefin(s) and with excess hydrogen relative to the total unsaturation under a pressure from 12 to 80 bar and at a temperature from 60.degree. to 180.degree. C. on a catalyst known per se or a mixture of catalysts known per se, which effect(s) both the etherification and the olefin hydrogenation.

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: The invention concerns new sulfonation products of naphthalene, process for their preparation according to which naphthalene is sulfonated under special reaction conditions by sulfur trioxide in inert organic solvents. The new sulfonation products are used as intermediates e.g. for the production of naphthalene-1,5-disulfonic acid.

Abstract: The present invention relates to a process for the preparation of 2,4,6-trifluoro-1,3,5-triazine (TFT) from 2,4,6-trichloro-1,3,5-triazine (TCT) or from mixed chlorinated/fluorinated 1,3,5-triazines by fluorination with sodium fluoride in dipolar aprotic solvents.The process is characterized in that TCT or mixed chlorinated/fluorinated 1,3,5-triazines or mixtures thereof are metered into a suspension of sodium fluoride in a dipolar, aprotic solvent, which is warmed to a temperature of between 120.degree. C. and 220.degree. C. and optionally contains a further solvent.

Abstract: A process for purifying organically polluted salts comprising forming a melt of said salts at a temperature of from about 600.degree.to 1000.degree. C., and contacting salt melt with an oxygen-containing gas. Acidic or basic fluxes may be present. The heat to maintain the mass molten may be supplied by electrodes which dip into the melt and which may be hollow so oxygen can be introduced therethrough. A suitable apparatus is also described.