There is no doubt that combustion of fossil fuel in motor vehicles releases huge amounts of gases that can have a negative impact on human health and will change global climate drastically. Bioethanol as a fuel has the potential to lower emissions of harmful substances. The CO2 emissions from the combustion of bioethanol from biomass will be consumed by plants during photosynthesis and the net introduction of C O2 to atmosphere will be zero in the long term, while fossil fuels gives a net increase. Life cycle analyses (LCA) of bioethanol as a fuel have shown that emissions of CO2 and other greenhouse gases are lower than when just using gasoline as a fuel in transport systems (Niven, 2005). Especially ethanol produced from lignocellulosic feedstock is reducing the emissions of fossil CO2 by up to 90%.

9.7 Flow chart of different steps in bioethanol pilot plant in O-Vik, Sweden.

(1) Intake feedstock, (2) steaming step, (3) pre-treatment step,

(4) reactor steps, (5) membrane filter press to remove lignin,

(6) detoxification step, (7) fermentation step, (8) yeast separator stage, (9) distillation system, (10) evaporation step, and (11) storage tank (with permission from Swedish Energy Agency and SEKAB for reproduction).