Forest Trees - Bioenergy Crop Plants - page 363

These EG and EA genotypes are desirable for SRWC systems in Florida and similar regions for
many bioenergy applications. On suitable sites and/or with intensive culture, EG and EA may reach
harvestable size in as few as three years (Rockwood 1997, Langholtz et al. 2007). Whole-tree chips
of 9-year-old EG produced 70% char and oil and 21% noncondensed volatile oil and low-energy
gas (Purdy et al. 1978). EA and EG SRWCs are promising for cofiring in coal-based power plants
in central Florida (Segrest et al. 2004), but little is known about their suitability for a wider range of
value-added products. Even when used for dendroremediation (Rockwood et al. 1995, 2004, 2005)
and windbreaks (Rockwood et al. 2005), EG and EA may be bioenergy resources.
SRWC opportunities for renewable bioenergy have recently gained momentum in the State's pub-
lic policy and in research and media coverage. By combining superior clones (Meskimen et al. 1987,
Rockwood 1991), suitable culture (Rockwood et al. 2006, 2008), innovative harvesting (Rockwood
et al. 2008), and efficient conversion, EG and EA are poised to meet bioenergy needs in Florida.
As in other SRWC development situations, research and development on genetic material, spacing,
fertilization, planting, control of pests and diseases, forest management, etc., will be essential for
achieving high SRWC productivity.
Biomass-derived electricity and liquid fuels may compete with fossil fuels in the short-term,
most likely by using integrated gasifier/gas turbines to convert biomass to electricity (Sims et al.
2003). Biomass production and conversion into modern energy carriers must be more fully devel-
oped, and favorable policy options such as subsidies and carbon taxes are also needed to support
bioenergy expansion.

15.2.1.7 summary
Overall, bioenergy could be the highest contributor to global renewable energy in the short to
medium term with SRWC Eucalyptus providing a large portion of the biomass (Sims et al. 2006).
Eucalyptus species can be widely planted to produce abundant biomass (Table 15.3). Several conver-
sion technologies are operational, and more are being developed. Biomass characteristics, difficulty
in securing adequate and cost effective supplies early in project development, and planning con-
straints currently constrain Eucalyptus bioenergy development. However, increased biomass pro-
ductivity and quality, carbon trading, distributed energy systems, multiple high-value products from
biorefining, and government incentives should foster Eucalyptus use for bioenergy. Opportunities
for energy crops include development of biorefineries, carbon sequestration, and small, distributed
energy systems.
Many other Eucalyptus species may be grown for bioenergy (NAS 1980, 1982). By broad cli-
matic region, these include E. brassiana , E. deglupta , and E. pellita for humid tropics, E. globulus ,
E. robusta , and E. tereticornis for tropical highlands, and E. citriodora , E. gomphocephala ,
E. microtheca , and E. occidentalis for arid and semiarid regions.
Brazilian experience suggests that Eucalyptus bioenergy can be produced sustainably at low
cost. With reduced production costs, bioenergy could be commercialized widely and reduce carbon

taBle 15.3
Biomass energy consumption and share and srWc
Base for some large countries that Grow eucalyptus
country Biomass (eJ) Biomass (%) srWc base (ha)

China 7.5 16.4 7-10 million

United States 2.9 2.8 50,000

Brazil 2.0 27.2 3 million

Australia 0.2 3.8 ~6000

Source: Wright, L., Biomass Bioenergy , 30, 706-714, 2006.