|Gevo’s production process. Click to enlarge.|
Gevo, a privately held renewable chemicals and advanced biofuels company (earlier post), has successfully produced isobutanol from fermentable sugars derived from cellulosic biomass. The company also successfully converted the cellulosic isobutanol into isobutylene and paraffinic kerosene (jet fuel).
The production of isobutanol from cellulosic biomass is the subject of a previously announced $1.8 million award from the US Department of Energy and Agriculture’s Biomass R&D Program. The grant supports the ongoing development of a cellulosic biocatalyst that Gevo exclusively licensed from Cargill.
Gevo uses synthetic biology and metabolic engineering to develop biocatalysts (fermentation organisms) to make only isobutanol via fermentation at high concentrations—i.e., without the typical expression co-products. The initial generation biocatalyst operates on fermentable sugars from grain crops, sugar cane and sugar beets. Gevo has already produced renewable gasoline and jet fuel that meet or exceed all ASTM specifications.
The company is now developing a new generation of biocatalysts that can use the mixed sugars from biomass to produce cellulosic isobutanol.
To operate its fermentation at optimum conditions for the organism, and within the process conditions found in ethanol plants, Gevo developed a novel separation technology. The solution uses a process innovation for continuous separation of the isobutanol—which in high concentrations inhibits the growth of microorganisms—as it is produced.
Today’s announcement demonstrates Gevo’s progress in making its biocatalyst viable for use in cellulosic biorefineries. As the cellulosic ethanol industry becomes operational, companies could have the option to produce isobutanol instead of ethanol.—Dr. Patrick Gruber, CEO of Gevo
Isobutanol is a four-carbon alcohol that can function as a “drop-in” platform chemical with broad applications in the product of approximately 40% of petrochemicals and 100% of hydrocarbon fuels. It can be used directly for a solvent and can be dehydrated with known processes into isobutylene, a raw material for plastics and fiber. Gevo believes its isobutanol will provide a route to the renewable production of rubber, polypropylene, polystyrene, and PET.
|High-level process schematic for hydrocarbons from isobutanol. Source: Gevo. Click to enlarge.|
Hydrocarbon fuels from biomass via isobutanol. The chemistry to convert isobutanol to a variety of hydrocarbon fuels molecules is simple and well known—the dehydration of isobutanol to isobutylene and the subsequent oligomerization of isobutylene to hydrocarbon fuels. Isobutylene oligomerization is practiced in refineries today on a mixed olefin stream. The process technology for converting isobutanol to hydrocarbons is low-energy input and reduces greenhouse gas emissions by 85.%
|Fuels from isobutanol. Source: Gevo. Click to enlarge.|
What’s new is the cost-effective production and purification of isobutanol from biomass. Gevo projects that the cash operating cost for its hydrocarbon fuel is competitive with $65 per barrel crude oil (without incentives).
Isobutanol can also be used directly as a gasoline blendstock and as a building block in the production of hydrocarbons found in petroleum-derived gasoline, jet and diesel fuels.
Gevo was founded in 2005 by Drs. Frances Arnold, Matthew Peters and Peter Meinhold of the California Institute of Technology. The company is focused on the development of advanced biofuels and renewable chemicals based on isobutanol and its derivatives using engineered microbes.
In 2009, oil and gas major Total has invested an undisclosed amount in Gevo’s series D financing round. (Earlier post.)
Hydrocarbon Fuels from Plant Biomass (Gevo, 2009)