Evaluation proves Taurus Energy yeast

By | November 15, 2010
News release posted Nov. 22, 2010

SEKAB E-Technology and Taurus Energy AB have successfully carried out a three-week long industrial demo scale evaluation of Taurus Energy's yeast. The yeast has been specially developed, and, in contrast to ordinary yeast, it can ferment pentose as well as hexose. Taurus Energy and SEKAB see this as a crucial step on the way towards commercializing a process for producing ethanol from cellulose-based raw materials.

The production of ethanol from cellulose-based raw materials from forestry and agriculture is a technology which has the potential to revolutionize the bioenergy sector, since the raw material is virtually unlimited. The ability to produce ethanol from renewable raw materials which are available in large quantities and which do not compete with food production is an important stage in breaking the dependence of the transport sector on oil.

SEKAB E-Technology has demonstrated that it can achieve the same ethanol yield on an industrial scale as in laboratory experiments. From the cellulose, it has succeeded in fermenting 90 percent of the available pentose, which is an excellent result, said Sune Wännström, research manager. It also means that the company now confident that it can transfer the results from optimization on a laboratory scale to full-scale production.

The conversion of cellulose-based raw materials to fermentable sugars is a complex process, and utilizing the sugars efficiently has long been a challenge. SEKAB and the Swedish company, Taurus Energy, can now demonstrate a process which has been verified on an industrial demo scale with a very high yield from pentose (xylose), a sugar which is extracted from hemicellulose, and which ordinary yeast strains cannot convert to ethanol. This means that the raw material can be utilized much more efficiently than in the industrial fermentation processes currently in use.

SEKAB is responsible for the process of using dilute acid and enzymes to convert hemicellulose and cellulose from a range of forestry and agricultural raw materials to pentose (a sugar with five carbon atoms) and hexose (with six carbon atoms). Taurus Energy has developed selective yeast strains which can ferment these and can survive the hostile environment of the process liquid.

The cultivation of yeast is a challenge in itself, since laboratory cultivation is considerably easier to control, and has none of the problems that can arise in large-scale cultivation. SEKAB has successfully demonstrated that the Taurus yeast can be cultivated in large volumes.

The company is delighted that we have confirmation that our yeast strain is robust enough to perform on an industrial scale, and that the yield is the same as we achieved on a laboratory scale, said Lars Welin, CEO of Taurus Energy. The two essential requirements have now been met.

The trial, which was co-financed by the Swedish Energy Agency, also proves that the process developed by SEKAB and Taurus Energy in collaboration with researchers from Chalmers University of Technology and the Faculty of Engineering at Lund University, is now capable of producing commercially-viable ethanol yields. The successful trial achieved an ethanol yield of four percent by weight, which is the level required for profitable industrial production.

Taurus position among the world leaders in the fermentation of pentoses from lignocellulose-based raw materials has been confirmed by the results achieved, said Professor Lisbeth Olsson, director of research at Taurus. The results of the demo scale trial are the fruits of many years of research and development in the lab.