Abstract: The reaction between methanol, carbon monoxide and oxygen for preparing dimethyl carbonate, in the presence of cuprous chloride as the catalyst, is carried out in a special reactor constituted by two parallel, vertical tubes, at the base of one of which the fresh gas and the recycle gas are fed; the reaction products are separated by partially condensing the recirculate vapors.

Abstract: A processing cycle for separating C.sub.8 aromatics (mixtures of ortho-, para-, meta-xylene and ethylbenzene) is disclosed, in which a first subdivision of the mixture is preformed into two streams respectively comprising: para-xylene and ethylbenzene as the first stream; and meta- and ortho-xylene as the second stream followed by a separation of the first stream by rectification, during which ethylbenzene within specifications is obtained as the overhead fraction, with the second stream also being sent to a separation by rectification, with ortho-xylene within specifications being obtained as the bottom fraction. The possible content of C.sub.9 species can be furthermore removed by subsequent distillation.

Abstract: A process for preparing tertiary alkyl ethers from isoolefins and aliphatic alcohols in the presence of a catalyst in the form of sulphonated styrene-divinylbenzene resins, characterized in that both the reaction leading to the formation of the tert-alkyl ether and the separation of the tert-alkyl ether from the hydrocarbons and compounds which accompany it take place in a single plate fractionating apparatus, in which some of the plates are provided with beds of catalyst in the form of spherules suitable for preparing said tert-alkyl ether, the ether obtained being withdrawn as a substantially pure bottom product.

Abstract: A method for separating benzene, toluene, xylenes and higher aromatics from admixtures containing them is disclosed, said method being based on the use of a solvent which is a 5-atom cyclic derivative of urea in which at least one of the nitrogen atoms is bound to an alkyl.Representative of this class of selective solvents is N,N'-dimethyl ethylene urea.Procedure details and examples are given.

Abstract: A multi-stage process for the solvent extraction of isoprene or cyclopentadiene from a mixed feed stock containing the same, piperylene and C-5 saturated and olefinic hydrocarbons is disclosed wherein the feed stock is contacted with N-formyl morpholine and C-5 saturated and olefinic hydrocarbons are separated therefrom in a first stage, the solvent, piperylene and cyclopentadiene present in the feed stock are separated from the isoprene in a second stage, and the solvent is recovered and recycled to the second stage.

Abstract: A multi-stage process for the solvent extraction of butadiene from a mixed feed stock containing butadiene, C-4 saturated and olefinic hydrocarbons and acetylenic compounds is disclosed wherein the feed stock is contacted with N-formyl morpholine and C-4 saturated and olefinic hydrocarbons are separated therefrom in a first stage and, in a second stage, the solvent and acetylenic compounds present in the feed stock are respectively separated from one another.