Page 25 - Biomass Gasification, Pyrolysis And Torrefaction Practical Design and Theory

4 Biomass Gasification, Pyrolysis, and Torrefaction

These biomass products find use in following four major types of
industries:

1. Chemical industries for production of methanol, fertilizer, synthetic fiber,
and other chemicals.
2. Energy industries for generation of heat and electricity.
3. Transportation industries for production of gasoline and diesel.
4. Environmental industries for capture of CO 2 and other pollutants.
The use of ethanol and biodiesel as transport fuels reduces the emission
of CO 2 per unit of energy production. It also lessens our dependence on fos-
sil fuels. Thus, biomass-based energy is not only renewable but also clean
from the standpoint of greenhouse gas (GHG) emission, and so it can take
the center stage on the global energy scene. However, this move is not new.
Civilization began its energy use by burning biomass. Fossil fuels came
much later, around AD 1600. Before the nineteenth century, wood (a biomass)
was the primary source of the world’s energy supply. Its large-scale use dur-
ing the early Industrial Revolution caused so much deforestation in England
that it affected industrial growth. As a result, from AD 1620 to AD 1720, iron
production decreased from 180,000 to 80,000 tons per year (Higman and van
der Burgt, 2008, p. 2). This situation changed with the discovery of coal,
which began displacing wood for energy as well as for metallurgy.

1.1.1.1 Chemicals Industries
Theoretically, most chemicals produced from petroleum or natural gas can
be produced from biomass as well. The two principal platforms for chemical
production are sugar-based and syngas-based. The former involves sugars
like glucose, fructose, xylose, arabinose, lactose, sucrose, and starch, while
the latter involves CO and H 2 .
The syngas platform synthesizes the hydrogen and carbon monoxide con-
stituents of syngas into chemical building blocks (Chapter 11). Intermediate
building blocks for different chemicals are numerous in this route. They
include hydrogen, methanol, glycerol (C3), fumaric acid (C4), xylitol (C5),
glucaric acid (C6), and gallic acid (Ar), to name a few (Werpy and Petersen,
2004). These intermediates are synthesized into a large number of chemicals
for industries involving transportation, textiles, food, the environment, com-
munications, health, housing, and recreation. Werpy and Petersen (2004)
identified 12 intermediate chemical building blocks having the highest poten-
tial for commercial products.

1.1.1.2 Energy Industries
Biomass was probably the first on-demand source of energy that humans
exploited. However, less than 22% of our primary energy demand is cur-
rently met by biomass or biomass-derived fuels. The position of biomass as