isolation process of pure 1,3-butadiene from a crude c4 fraction

摘要

the present invention relates to the process to isolate the pure 1,3-butadiene from a crude c4 fraction, which produces the pure 1,3-butadiene which has the maximum prescribed content of at least one low boiler and maximum content 1,2-butadiene, in each case based on 1,3-butadiene, in which (a) a low boiler fraction and a high boiler fraction are separated by distillation of the crude c4 fraction, providing a c4 fraction purified water whose content of at least one low boiler, based on 1,3-butadiene, is equal to or less than the maximum prescribed content of at least one low boiler and whose content of 1,2-butadiene, based on 1,3-butadiene, is equal to or less than the maximum prescribed amount of 1,2-butadiene; (b) the purified c4 fraction is subjected to at least one extractive distillation using a selective solvent, providing at least a fraction comprising butanes and butenes and a fraction of pure 1,3-butadiene. the process makes a pure distillation column unnecessary.