Purification of isoprene from renewable resources

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;
• further comprising extracting at least one of methanol, acetone, or methyl acetate from the isoprene-lean solution.