Car tires are generally considered environmentally unfriendly because they are predominantly made from fossil fuels. Natural rubber is generally not used anymore; most tires are made from isoprene, which is chemically very like rubber but is produced by thermally breaking apart molecules in petroleum in a process called cracking. The isoprene is separated out and purified and then reacted to form the artificial rubber that is the major component in car tires. The tires eventually end up discarded in giant piles that represent one of our biggest waste disposal problems.
For decades, tire companies have had initiatives to try to develop isoprene derived from biomass instead of petroleum. However, isoprene turns out to be a difficult molecule to generate from microbes and efforts to make it from entirely biological processes have not been successful.
In a new study published in the journal ACS Catalysis, a team led by the University of Minnesota and including researchers from University of Massachusetts Amherst and the Center of Sustainable Polymers at U Minnesota has announced the development of a new technology to produce isoprene from natural products like trees, grasses or corn. They use a three-step process that combines biological fermentation with catalytic refining. The breakthrough was the discovery of a new catalyst that is the third step of the process that turns the intermediate substance methyl-THF into isoprene. Their newly-discovered catalyst demonstrated an efficiency of 90% for turning the biomass into isoprene.
Economically, bio-source isoprene has the potential to allow production of tires from renewable, readily-available resources instead of fossil fuels. The discovery could also impact many other technologically advanced rubber-based products.
Photo, posted September 10, 2014, courtesy of Flickr.