Pretreatment of lignocellulosic wastes to improve ethanol and biogas production : A review

• Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX), supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute- and concentrated-acid hydrolyses, and biological pretreatments.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Annan industriell bioteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Other Industrial Biotechnology (hsv//eng)

Keyword

chitin

glucosamine

ethanol

biomass

biogas

lignocelluloses

baker's yeast

saccharomyces

cerevisiae

encapsulation

flocculation

superabsorbents

chitosan

zygomycetes

mucor

rhizopus

rhizomucor

MTBE

biopolymers

furfural

acetic acid

HMF

fed-batch

continuous cultivation

immobilization

denitrification

activated sludge

bread

orange peels

citrus

waste

keratin

methyl tertiary butyl ether

superabsorbents

chitosan

Energi och material

Publication and Content Type

ref (subject category)

art (subject category)