Preparation of ethanol by fermentation from mechanical grinding washing waters in laboratory scale

Abstract

The purpose of this thesis was to produce ethanol from the black liquor of woodchips by fermentation in laboratory scale. Hemicellulose, the second most common polysaccharide in nature, represents about 20%-35% of lignocellulosic biomass. The hemicelluloses were extracted from woodchips by pressurized hot water extraction. The extract contains polysaccharides and also lignins, the polysaccharides could be hydrolyzed into monosaccharides by using sulphuric acid. The sodium hydroxide was used to neutralize the hydrolysate. The monosaccharides were fermented by saccharomyces cerevisiae yeasts.

Biofuel is a type of energy whose energy comes from biological carbon fixation. Biofuels are derived from biomass conversion, such as solid biomass, liquid fuels and various biogases. Cellulosic biomass comes from non-food sources such as trees and grasses. It is also being researched as a raw material for ethanol production. The choice of feedstock depends on climate, for example sugar cane is used in tropical zones, wheat is popular in Europe and corn is typical for North America. Bioethanol facilities often are linked to sugar or starch factories and use the by-products from that industry as substrates (in the form of molasses, starch hydrolysate a.s.o.).