Page 235 - Biosystems Engineering

CHAPTER 7

Biomass Pyrolysis

and Bio-Oil

Refineries

Manuel Garcia-Pérez
Department of Biological Systems Engineering
Washington State University
Pullman, Washington

7.1 Introduction
Replacing petroleum-based industrial chemicals and fuels with those
from renewable sources is a very worthy and alluring objective. The
reduction of greenhouse emissions, the lessening of dependence on
nonrenewable resources, the increase in markets for farm products,
and the potential for new industries in widely distributed geographi-
cal locations are outcomes that are attractive to any country. Biomass
is virtually the only renewable, “carbon neutral” widely distributed
natural resource capable of supplying carbon-based transportation
fuels as well as some chemicals presently obtained from nonrenew-
able sources such as coal and petroleum. Today, nearly 2 million tons
of fuelwood are consumed daily by almost half the world population
for cooking and heating homes. Although this energy represents less
than 10 percent of the total energy consumed worldwide daily, it
accounts for as much as 95 percent of the energy supply in some of
the poorest nations (Wood and Baldwin 1985).
The pyrolysis of biomass (cellulose, hemicelluloses, lignin, extrac-
tives, triglycerides, etc.) results in the formation of crude bio-oil, char,
and gases (Moses 1994; Czernik and Bridgwater 2004; Bridgwater
et al. 2001; Roy et al. 2001; Meier and Faix 1999). It is certainly not a
new technology in that pyrolysis has been used for centuries to produce
charcoal. Charcoal was the first synthetic material produced by humans.

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