Environmental Engineering Reference
In-Depth Information
15.6.2 Chemical Pretreatment of Forest Biomass .......................................................... 385
15.6.2.1 Acid-Catalyzed Steam Explosion ......................................................... 386
15.6.2.2 Organosolv Pretreatment ...................................................................... 386
15.6.2.3 Sulfite Pretreatment—SPORL .............................................................. 387
15.7 Conclusions ......................................................................................................................... 389
Acknowledgments .......................................................................................................................... 389
References ...................................................................................................................................... 390
15.1 IntroductIon
Interest in renewable biomass for fuel, chemicals, and materials is high (e.g., Rocha et al. 2002), as
many products currently derived from petrochemicals can be produced from biomass (Sims et al.
2006). Biomass can be converted into many energy products and chemicals: e.g., alcohol by fer-
menting cellulose, charcoal, bio-oil, and gases by biomass pyrolysis (Khesghi et al. 2000). Biomass
and biofuels technologies with the most potential in the United States include co-firing in coal-fired
power plants, integrated gasification combined-cycle units in forestry, and ethanol from hydrolysis
of lignocellulosics (Sims 2003). A wide range of products from woody biomass has been demon-
strated in New Zealand: “value-added” chemicals, hardboards, activated carbon, animal feed, and
bioenergy feedstock (Sims 2003). Using harvested biomass to replace fossil fuels has long-term
significance in using forest lands to prevent carbon emissions, and bioenergy projects can contribute
to slowing global climate change (Swisher 1997). The potential importance and cost-effectiveness
of bioenergy measures in climate change mitigation require evaluation of cost and performance in
increasing terrestrial carbon storage.
Biomass-based heat, electricity, and liquid fuels are about 14% of the world's primary energy
supply (IEA 1998), with about 25% of that in developed countries and 75% in developing countries
(Parikka 2004). From an estimated 3.87 billion ha of forest worldwide, global production and use
of wood fuel was about 1.753 billion m
3
in 1999 (Table 15.1), 90% of which was produced and con-
sumed in developing countries.
The total sustainable worldwide annual bioenergy potential is about 100 EJ (Table 15.1), about
30% of total current global energy consumption (Parikka 2004). Annual woody biomass potential
is 41.6 EJ, or 12.5% of total global energy consumption. Worldwide, less than 40% of the existing
bioenergy potential is used. In all regions except Asia, current biomass use is less than the available
taBle 15.1
Plantation and total Forest areas (10
6
ha), total Woody Biomass
(10
9
t), Wood Fuel Produced annually (10
6
m
3
), and Bioenergy
Potential Per year (10
18
eJ) from Wood, all Biomass, and currently
used (%) by World region
Forest area
Bioenergy Potential
Woody
Biomass
Wood
Fuel
region
Plantation
total
Wood
all
used
North America
2
549
61
133
12.8
19.9
16
South America
10
885
179
168
5.9
21.5
12
Asia
115
547
44
883
7.7
21.4
108
Africa
8
649
70
463
5.4
21.4
39
Europe
32
1039
61
95
4.0
8.9
22
World
171
3869
421
1753
41.6
103.8
38
Source:
Parikka, M.,
Biomass and Bioenergy
, 27, 613-620, 2004.
