Page 45 - Biofuels Refining and Performance

28 Chapter One

TABLE 1.4 Yield of Some Important Crops and Their Biomass Utilization
Approximate composition (%)
Organic matter Organic matter
Latex Moisture Water sol. high MW Low MW
Heve 65 3 31 1
Euphorbia 63 9 27 1
Ideal yield of some crops
Crop MT/ Ha/ Yr

Sugarcane 30
Sugar beet 33
Algae 87
Sorghum 36
Corn 13
Eucalyptus 54
Rubber (Malaysia) 2
Example of chemical diversification of biomass
Sugar cane ⎯⎯⎯⎯→ Cane Juice ⎯⎯⎯→ Ethanol
↓ ↓ ↓
Bagasse Butanol Ethylene
(Cellulose Lignin) Glycerol Chemicals
Fodder Citric Acid Ethyl chloride, etc.
Energy Aconitic Acid

species of Euphorbia—particularly on the rocky, arid, or laterite belts,
which are rather unproductive for forestry or cultivation. It is worth-
while to take a glance at some information already available on these
products [6].

1.12 Biogas
Age-old phenomena of spontaneous combustion of natural gas, continuously
or intermittently, were called “will-o-wisp” or “fool’s fire.” Later, these phe-
nomena were assigned to “marsh gas” and mainly methane by H. Tappeiner
(1882) [7]. Almost a century passed, through which different postulates had
to be verified in order to unveil the mechanism behind this natural
methanogenesis or biogas formation. First, one-step microbial degradation
of cellulose to methane was proposed. This was replaced by a two-step con-
cept, where lower-molecular-weight organic acids are produced as interme-
diates, which further undergo conversion to methane. Finally, the three-step
concept has been prevailing (the entire process is anoxic):

Hydrolytic Acetogenic stage Methane, organic
S S
fermentive stage sMesophilicd sThermophilicd