Goldman Sachs’ investment gives it a minority stake in Iogen, the only company to be operating a demonstration facility that converts agriculture materials like straw, corn stalks, and switchgrass to ethanol. Goldman Sachs joins the Royal Dutch/Shell Group as a major investor. (Earlier post.) The funds will be used to accelerate Iogen’s commercialization program.
Iogen’s process uses a combination of thermal, chemical and biochemical techniques to convert fibrous biomass (wheat straw) into fuel ethanol with a yield of more than 340 liters per tonne of fiber. The lignin in the plant fibre powers the process by generating steam and electricity, thus eliminating the need for fossil CO2 sources such as coal or natural gas.
Iogen’ technology innovations fall into five categories:
Pretreatment. A modified steam explosion process prepares the feedstock for the enzymatic hyrdolysis stage that converts the cellulose to sugar for fermentation. The steam explosion increases the surface area of the plant accessible to enzymes.
Enzyme production. New, efficient cellulase enzyme systems specific to the feedstock.
Enzymatic hydrolysis. A multi-stage hydrolysis process separates hydrolysis and fermentation, resulting in a high conversion rate.
Fermentation. Tailored microorganisms and fermentation systems convert both C6 and C5 sugars into ethanol.
Process integration. Energy efficient heat integration, water recycling, and co-product production that make the overall process efficient and economical.
A joint study by the US Departments of Agriculture and Energy (USDA and DOE) has concluded that the land resources of the US could produce a sustainable supply of biomass sufficient to displace 30% (60 billion gallons of renewable fuel per year) of the country’s present petroleum consumption.