Researchers at Goodyear Tire & Rubber Co. and Genencor are working to create "renewable feedstocks" that would replace petroleum in tires, effectively resulting in a completely "green" tire. And that could happen within five years, they said.

The technology was presented at the 239th National Meeting of the American Chemical Society, held recently in San Francisco.

The new tires will be an advance toward greener, more sustainable transportation in a quite literal sense, according to Dr. Joseph McAuliffe, who reported on the technology. The process can use sugars derived from sugar cane, corn, corn cobs, switchgrass or other biomass to produce the ingredient, a biochemical called isoprene, derived from renewable raw materials.

The resulting product – called BioIsoprene – would replace the seven gallons of crude oil required to produce a single passenger tire.

“An intensive search has been underway for years for alternative sources of isoprene, in particular those from renewable resources such as biomass,” said McAuliffe. “One technical challenge has been the development of an efficient process for converting sugars into isoprene. One means by which we’re addressing this challenge is by using a fermentation process based on a modified bacterial strain that is designed to convert carbohydrate feedstocks into BioIsoprene product.”

McAuliffe is a staff scientist at Genencor, an industrial biotechnology company in Palo Alto, Calif.

Goodyear and Genencor established a research collaboration to develop an integrated fermentation, recovery and purification system for producing BioIsoprene, which Genencor intends to commercialize the technology within the next five years.

In his ACS presentation, McAuliffe described how Genencor engineered bacteria to efficiently convert sugars to isoprene and how the smooth integration of fermentation and recovery processes promises to deliver a new route to this strategically important ingredient used to make synthetic rubber.

Tiremakers use isoprene to produce synthetic rubber to supplement use of natural rubber in tires, and the oil-based synthetic is also used in a wide range of other products. Worldwide production of high purity isoprene derived from petroleum-based feedstocks totals about 1.7 billion pounds.

“This is an enormous market,” McAuliffe said. “BioIsoprene will serve as a renewable and cost-competitive alternative to isoprene. It’s a material that can drive new markets, so I believe those numbers highlighting global consumption would grow if new material became available.”