A lot of research is going on in the area of biofuels and biochemicals and a blog is not a great vehicle to capture all of the important developments. I will cover this subject from time to time as particularly interesting topics catch my eye. An interesting trend is that some R&D firms that originally worked on producing biofuels (e.g. biodiesel, alohols) realized that biochemicals would fetch a higher price. So, I was interested to learn that automobile tires will within five years or so be partly made from synthetic isoprene based on microbial fermentation of different sugars. Isoprene is the five carbon molecule that is the key component of natural rubber.
A brief history: Natural rubber comes from a type of tree that is indigenous to countries like Malaysia and Brazil. The tree sap, known as latex, is converted to “natural” rubber. The first bicycle tire was produced in 1830 and in 1895 Michelin in France adapted the tire to the automobile. Today, tires are made in a complex process that includes both natural and several types of synthetic rubber, the latter made from petrochemical molecules such as styrene, butadiene, butylenes, etc.
Biotechnology companies such as Genencor, Amyris and others are well along in developing fermentation techniques to make the isoprene and butylene molecules from sugars. In this they are supported by tire producers like Goodyear and Michelin and by synthetic rubber firms like Lanxess (a spinoff from Bayer, the large German chemical/pharmaceutical firm). Their interest was spurred by the fact that natural and synthetic rubber prices have been rising, as rapidly increasing demand for cars (e,g, in China and India) and high crude oil pricing have substantially increased the cost of these key raw materials. Natural rubber prices have increaed from 70 cents to two dollars a pound over the last several years. ( M. Bomgardner, Chemical& Engineering News, December 12, 2011, Pp. 18-19)
Now, another development has made this research even more important. With natural gas liquids (e.g. ethane, propane) now a preferred feedstock for ethylene production, much less naphtha and gas oil are cracked and much less butadiene, butylene and isoprene are accordingly recovered as byproducts. Tire manufacturers are therefore keen to have another supply source for rubber.
According to the cited article, Goodyear has made concept tires from sugar-based isoprene. Lanxess, working with Gevo, has converted sugar-based isobutyl alcoho into isobutylene which can be polymerized to butyl rubber. Michelin is working with Amyris to make renewable isoprene. With the large tire companies, who spend billions of dollars buying rubber, behind this effort, it appears that sugar-based tires are not that far off.