摘要:
A process for the preparation of olefins from methanol and/or dimethyl ether by conversion in the presence of a zeolite catalyst, in particular a borosilicate zeolite, at elevated temperature, with the addition of a small amount of an electron donor.
摘要:
A process for the preparation of lower olefins from methanol or dimethyl ether by catalytic conversion at from 300.degree. to 550.degree. C. in two stages over borosilicate zeolites, wherein C.sub.2 -C.sub.4 -olefins and C.sub.1 -C.sub.4 -paraffins are removed after the first reaction stage, the C.sub.5.sup.+ hydrocarbons are passed to the second reaction stage, the aromatics are removed from the reaction product of the second stage and the remaining reaction products are recycled. The advantage of this process is an improvement in the yield of olefins.
摘要:
The process for the preparation of olefins by converting methanol and/or dimethyl ether in the presence of a zeolite catalyst is improved by treating the catalyst with hydrogen fluoride. Aluminosilicate zeolites and borosilicate zeolites, especially those of the pentasil type, are chiefly used.
摘要:
But-2-enes are obtained from C.sub.4 -hydrocarbon mixtures which contain but-1-ene and may or may not contain but-2-enes by catalytic isomerization of the but-1-ene to but-2-enes in an isomerization zone at elevated temperatures by a process in which the isomerization is carried out in combination with a distillative separation zone, the said hydrocarbon mixture being fed to the isomerization zone and/or distillative separation zone, the isomerization mixture obtained from the isomerization zone is passed into the distillative separation zone, a but-1-ene-containing fraction is removed above the lower third of the distillative separation zone and passed into the isomerization zone, and the but-2-enes or a fraction containing these are or is removed in the lower third of the distillative separation zone.
摘要:
Alkylbenzenes are prepared by converting an alkyl-, alkylidene- or alkenylcyclohexene or an alkyl- or alkenylcyclohexadiene in the presence of an acidic zeolite catalyst of the pentasil type, in the gas phase or liquid phase.
摘要:
2-Methylalk-2-enals of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl or an aromatic radical, are prepared by isomerization of an acrolein derivative of the formula ##STR2## with a zeolite catalyst, an aluminum silicate and/or an aluminum phosphate.
摘要:
Novel crystalline ZBH borosilicate zeolites of the pentasil type are prepared by hydrothermal crystallization of silicon dioxide and boric acid in the presence of alkali metal salts, at from 80.degree. to 140.degree. C. in an ethereal or aqueous-ethereal mixture.
摘要:
C.sub.2 -C.sub.4 -olefins are prepared by catalytic conversion of methanol and/or dimethyl ether in the presence of a zeolite catalyst at elevated temperatures by a process wherein the catalyst used is a borosilicate zeolite which is treated with hydrogen fluoride, molded together with an amorphous aluminosilicate as a binder and then treated with hydrochloric acid.
摘要:
Ketones of the general formula (I) ##STR1## where R.sup.1 and R.sup.2 independently of one another are each alkyl, cycyloalkyl, arylalkyl, aryl or hetaryl, and one or more of the radicals R.sup.1 and R.sup.2 carry one or more hydrogen atoms on the .alpha.-carbon atom, are prepared by reacting two carboxylic acids of the general formulae (IIa/IIb), R.sup.1 --COOH (IIa) and R.sup.2 --COOH (IIb) or by reacting a carboxylic acid R.sup.1 --COOH (IIa) and a ketone ##STR2## or by reacting a mixture of IIa, IIb and Ib, in the gas phase in the presence of a catalyst, by a process in which a catalyst is used whose active material contains at least 50% by weight of titanium dioxide having a specific surface area greater than 10 m.sup.2 /g.0.