The freezing pre-treatment of lignocellulosic material: A cheap alternative for Nordic countries

The highest hydrolysis efficiency figure was 19.42%, which was achieved in laboratory tests where the biomass was frozen and thawed a total of four times. The best result from a field test was 10.28% from straw which had been stored in a swathe and which has been gathered in March. Fermentation yields ranged up to 88.80 g per kilogramme of biomass. Field tests showed that in the bale the temperature never fell below freezing and therefore the pre-treatment was not effective. When in the swathe the straw does freeze through, but the winter in Estonia was too changeable for this method to work effectively.