The invention discloses a method for separating
isoprene by front-end hydrogenation one-section extraction, which belongs to the C5 fraction separation technical field. The invention aims to solve the problems that: during the prior C5 separation flow, a second extraction unit has
high energy consumption, complicated operation and strict operation requirement, and large loss of extracting
solvent and so on, and provides a method for separating
isoprene fractions by one-section extraction rectification. The method removes
cyclopentadiene by a rectification method and removes
acetylene hydrocarbon by an azeotropic rectification method, can obtain a
polymerization grade
isoprene product without secondary extraction, and save the second extraction unit and a
solvent refining column. The method has simple and easy operation, and reduces production cost. Under the same
raw material treatment load, the
heat energy consumption of a
polymerization grade isoprene unit is about 20 percent of the prior second extraction unit, m-pentadien is extracted from a pre-deheavy fractionator without entering an extraction rectification unit, the treatment capacity of an extraction rectification column, an absorption
tower and a de-heavy fractionator is reduced by 50 percent, and the
energy consumption is correspondingly reduced by 50 percent, so the construction cost and the production cost are greatly reduced.