Published April 1971
There was interest in polyisoprene, and consequently isoprene manufacture, at the time our initial report was issued on isoprene (September 1967) and interest in these products has increased in the past few years. In the initial report five isoprene process routes were evaluated. This interim report presents evaluations of two relatively new process routes that may have certain advantages over some of the processes evaluated earlier. The first of these is a route proposed by the Marathon Oil Company for producing isoprene from isobutylene and formaldehyde; the method differs considerably from other routes that have been proposed using these two raw materials. The estimated capital and production costs indicate the process could be competitive with other synthesis routes for isoprene. The second process that is evaluated in this report is based on patents to the Japanese Geon Company to recover the isoprene contained in the C5 fraction from an ethylene plant (naphtha or heavier feed). This route (and similar extraction methods) is a relatively inexpensive way of obtaining isoprene if a sufficient supply of feed is available.
