Purification of isoprene from renewable resources

Abstract

Methods and apparatus for the purification of isoprene, such as the purification of a bioisoprene composition from fermentor off-gas. The apparatus includes two columns that process the fermentor off-gas, which includes isoprene and various impurities. A solvent is added to the off-gas in the first column, and the isoprene is stripped from the solvent in the second column. Also provided is a downstream further purification process. Also provided are the resulting purified isoprene compositions.

1 . A method of purifying isoprene from a fermentor off-gas comprising:
 contacting a fermentor off-gas comprising isoprene, volatile impurity, and bio-byproduct impurity, with a solvent in a first column to form:   an isoprene-rich solution comprising the solvent, a major portion of the isoprene and a major portion of the bio-byproduct impurity present in the off-gas; and   a vapor comprising a portion of the volatile impurity present in the off-gas;   transferring the isoprene-rich solution from the first column to a second column; and   stripping isoprene from the isoprene-rich solution in the second column to form:   an isoprene-lean solution comprising a portion of the bio-byproduct impurity present in the off-gas; and   a purified isoprene composition.   
     
     
         2 - 84 . (canceled)