A method for selective recovery of the isobutyl narrow fit from in addition to the isobutylene more other hydrocarbons having 4 carbon atoms, in particular n - butene and / or n - butane and / or butadiene, and / or hydrocarbons having 1 to 3 carbon atoms in the form of mixtures containing (methyl) - (tert-butyl) - ether

摘要

1532477 Separating isobutylene by selective reaction MAGYAR ASVANYOLAJ ES FOLDGAZ KISERLETI INTEZET 7 Oct 1976 [29 Oct 1975] 41688/76 Heading C5E [Also in Division C2] Isobutylene is removed as methly t-butyl ether from mixtures containing predominantly isobutylene and other C 4 hydrocarbons by reacting with a stoichiometric excess of the required quantity of methanol in the presence of sulphuric acid catalyst in a homogeneous liquid phase at 50-120‹ C.; after the reaction the mixture is cooled to between -25 and +40‹ C. and a quantity of reaction product from which methanol has been removed and/or a quantity of a C 4 fraction free ofisobutene obtained in the process is added; the sulphuric acid phase which then separates is recirculated to the reaction, and methanol and methyl t-butyl ether are isolated by aqueous washing and distilling the residual mixture which contains sulphuric acid in a reduced quantity. The C 4 hydrocarbon mixtures may be a fraction derived from a catalytic cracking process or from the pyrolysis of gasoline, and may contain butadiene as well as butanes and butenes.