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CHAPTER 8

FUELS FROM BIOMASS

Fossil fuels are finite energy resources (Pimentel and Pimentel, 2006). Therefore, reduc-
ing national dependence of any country on imported crude oil is of critical importance for
long-term security and continued economic growth. Supplementing petroleum consump-
tion with renewable biomass resources is a first step toward this goal. The realignment
of the chemical industry from one of petrochemical refining to a biorefinery concept is,
given time, feasible has become a national goal of many oil-importing countries. However,
clearly defined goals are necessary for increasing the use of biomass-derived feedstocks in
industrial chemical production and it is important to keep the goal in perspective.
In this context, the increased use of biofuels should be viewed as one of a range of pos-
sible measures for achieving self sufficiency in energy, rather than a panacea (Crocker and
Crofcheck, 2006; Worldwatch Institute, 2006; Freeman, 2007; Nersesian, 2007).
Biomass, a source of energy has been used since ancient times (Xiaohua and Zhenmin,
2004), is the collective name for renewable materials which includes: (a) energy crops grown
specifically to be used as fuel, such as wood or various grasses, (b) agricultural residues and
by-products, such as straw, sugarcane fiber, rice hulls animal waste, and (c) residues from for-
estry, construction, and other wood-processing industries (Brown, 2003; NREL 2003; Wright
et al., 2006).
Biomass is a renewable resource, whose utilization has received great attention due to
environmental considerations and the increasing demands of energy worldwide (Tsai et al.,
2007). Biomass is clean for it has negligible content of sulfur, nitrogen, and ash-forming
constituents, which give lower emissions of sulfur dioxide, nitrogen oxides, and soot than
conventional fossil fuels. The main biomass resources include the following: forest and
mill residues, agricultural crops and wastes, wood and wood wastes, animal wastes, live-
stock operation residues, aquatic plants, fast-growing trees and plants, and municipal and
industrial wastes. The role of wood and forestry residues in terms of energy production is
as old as fire itself and in many societies wood is still the major source of energy. In gen-
eral, biomass can include anything that is not a fossil fuel and is bioorganic-based (Lucia
et al., 2006).
There are many types of biomass resources that can be used and replaced without irre-
versibly depleting reserves and the use of biomass will continue to grow in importance as
replacements for fossil materials are used as fuels and as feedstocks for a range of products
(Narayan, 2007). Some biomass materials also have particular unique and beneficial prop-
erties which can be exploited in a range of products including pharmaceuticals and certain
lubricants.
Following from this, a biofuel is any fuel that is derived from biomass, that is, recently
living organisms or their metabolic by-products. Biofuel has also been defined as any fuel
with an 80 percent minimum content by volume of materials derived from living organisms
harvested within the 10 years preceding its manufacture.
However, for many staple food crops, a potentially large economic resource is effec-
tively being thrown away. For example, the straw associated with the wheat crop in often
ploughed back into the soil, even though only a small proportion is needed to maintain the

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