Using paraxylene (PX) derived from ethanol-based isobutanol, Gevo Inc. (Englewood, CO) and Toray Industries collaborated on fully biobased polyethylene terephthalate (PET). In addition to Gevo's PX monomer, Toray and Gevo used a commercially available renewable mono ethylene glycol (MEG) to polymerize the fully renewable PET.
In April 2010, the two companies signed a non-binding letter of interest for the future supply of renewable PX derived from Gevo's isobutanol sometime in 2012 or thereafter. Gevo is hoping to tap into what it calculates at PET's 50-million ton annual market PET, including its conversion into films and bottles for packaging; fibers for non-wovens and textiles; and resins for automotive applications.
Toray's current PET offerings include Tetoron fiber and Axtar nonwoven fabric. On the resin side, its polyester-based materials include Toraycon polybutylene perephthalate (PBT), Siveras liquid crystal polyester; and Hytrel, polymer elastomer, which is manufactured and sold in Japan by DuPont-Toray Co. Ltd.
Gevo says the heart of its technology is a proprietary fermentation method that relies on a biocatalyst and the efficient separation of isobutanol, a platform it calls Gevo's Integrated Fermentation Technology (GIFT). The company currently uses ethanol as a feedstock but has said that once cellulosic biomass processing technology is ready for commercialization, it plans to deploy cellulosic butanol technology. Gevo's fermentation method uses a proprietary yeast biocatalyst, which converts sugars derived from multiple renewable feedstocks into isobutanol. Its proprietary separation unit is designed to bolt onto existing ethanol facilities. This production technology is similar to ethanol production, except that Gevo replaces the ethanol-producing biocatalyst with its isobutanol-producing biocatalyst and then adds a separation unit.
As it enters the market, Gevo's plan is to retrofit existing ethanol facilities, tapping into the approximately 20 billion gallons per year of operating ethanol production capacity worldwide. In September 2010, Gevo acquired its first production facility in Luverne, MN, with commercial production expected there in the first half of 2012. The company has said it plans to expand its production capacity and sell more than 350 million gallons per year of isobutanol by 2015. Once it's up and running in the first half of 2012, the Minnesota site will have an annual ethanol production capacity of 22 million gallons, with 18 million gallons/yr of isobutanol capacity.
At this time, in addition to its work with Toray on plastics and fibers, Gevo is collaborating with Lanxess for synthetic rubber, Total for gasoline blend stock, and Sasol for solvents. Patrick Gruber, Gevo's CEO, co-founded bioplastics supplier NatureWorks LLC (formerly Cargill Dow LLC) in 1997, and served as that company's VP of technology and operations and chief technology officer until 2005.
