Biofuels

In 2007, we started an exclusive cooperation with Süd-Chemie AG to develop and market plants for the production of second generation (2G) biofuels.

As a matter of priority, Linde is determined to push bioethanol production technologies that avoid any conflict with food production, especially in emerging economies. In contrast to 1G biofuels, 2G biofuels safeguard food supplies by exclusively using plant waste from food production.

Existing infrastructures and technologies can nonetheless be used to obtain liquid biofuels such as ethanol. This not only ensures acceptance of this process among the general public, but also eases market introduction. Experts are forecasting a promising future for this technology.

The process itself involves thermal-mechanical pretreatment of the biomass, saccharification, fermentation to obtain ethanol, and subsequent purification.

Saccharification and lignocellulosic biomass

In biotechnology, ethanol is obtained through the fermentation of monosaccharides. Since sugar only occurs as polymers in lignocellulosic biomass, these must be converted to monosaccharides using suitable enzymes (biocatalysts) before ethanol fermentation takes place.

In the resulting sugar solution, lignin is the only solid residue present. The lignin can be separated from the monosaccharide solution and used to produce energy or other materials. The sugar solution is then fermented to obtain ethanol.

Lignocellulosic biomass is the generic term for plant biomass comprising a mixture of sugar polymers (cellulose and hemicellulose) and the aromatic polymer lignin. Cellulose is made up of the C6 sugar glucose, while hemicellulose consists of a mix of different C6 and C5 sugars.