The invention relates to a method for producing butylene-1 from C4 light
hydrocarbon, and belongs to the field of C4 light
hydrocarbon processing and application. The method solves the technical problems of
high energy consumption and poor economical efficiency during separation and preparation of
butene-1 after catalytic
cracking of mixed C4 with high
alkane content and low olefin content in the prior art. The method for producing
butene-1 comprises the following steps: feeding etherified C4 into a precise rectifying
tower, carrying out rectification separation on light and heavy C4, carrying out selective hydrogenation to remove butadiene from a fraction rich in
butene-1 and iso-
butane, feeding the fraction into an
extractive distillation tower, carrying out
alkane-olefin separation, carrying out
water washing on
raffinate to remove an entrained extractant, and carrying out
distillation to obtain the butene-1, wherein the fraction is extracted from a side line of the
tower and is rich in butene-1 and iso-
butane; and refining in a butene-1 refining tower, and extracting a butene-1 product from the tower top. According to the method, the process can be shortened, the
energy consumption can be reduced, impurities in the raw materials can be removed, the method has the characteristics of high
operability and high butylene-1 yield, and a high-purity
isobutane product can be obtained.