FROM STRAW TO HORSEPOWER

BIOETHANOL: Risø National Laboratory has incorporated export opportunities and sustainability in a major research programme on the production of second generation bioethanol

Erik Steen Jensen

Second generation bioethanol, produced from waste products such as straw and wood chips, is not yet economically competitive with first generation bioethanol which is made from carbohydrate-rich crops such as sugar beet. But at Risø National Laboratory, now part of the Technical University of Denmark (DTU), they are working flat out to make second generation bioethanol as cheaply as petrol. Professor Erik Steen Jensen, who heads the programme at Risø, expects that bioethanol will be cheaper to produce in the long term, with excellent opportunities to export biofuel technologies.

Multiple biomass sources
“We are working on a biorefinery concept at Risø,” says Erik Steen Jensen . “In the long term it might be possible to use many different kinds of biomass depending on the global location of the refinery. The world needs both renewables and reliable energy supplies, and in this connection straw and waste could play an important role. Under all circumstances, we have to do something to reduce CO₂ emissions.”

Risø has been working on producing bioethanol for car engines since the early 1990s, and is currently developing new technologies for preprocessing biomass for second generation technologies. Together with DTU, Risø has patented a process to convert straw into ethanol.

More environmentally friendly
“The process involves subjecting straw to a high pressure treatment, using methods that have been continuously refined since the early 1990s,” says Erik Steen Jensen. “In collaboration with Dong Energy and Copenhagen University we have recently built a plant in Skærbæk, Jutland, which can process 1 ton of straw per hour. Our objective is to rapidly increase this to 25 tons per hour by optimising both the technology and production processes.”

“Our biorefinery concept is designed to exploit most of the many different substances in plant tissue,” says Erik Steen Jensen. “Besides producing bioethanol, other plant components can be used to manufacture industrial source materials and  products such as drugs, bioplastics and biocomposites for the transportation sector and for lubricating oil. Straw makes the entire process a lot more environmentally friendly because it is a waste product, and the unconverted portion can be used as animal feed or for electricity and heat production in a power station.”

In Denmark, cars can now use petrol containing 5% ethanol. In January 2007, Risø acquired three specially engineered cars which can run on fuel containing up to 85% ethanol. “It seems right to use them in the light of the work we are doing. It takes the project to its natural end point,” says Erik Steen Jensen.

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