Forest Trees - Bioenergy Crop Plants - page 355

SRWCs are benefitting from decades of research and development of forest management prac-
tices including genetic improvement, spacing, fertilization, planting techniques, control of pests and
diseases, and coppicing. Mean yields of Eucalyptus SRWCs went from 14 m 3 ha per year during the
1970s to the current approximately 40 m 3 /ha per year through breeding and silvicultural practices.
Up to three harvests are possible from one planting of Eucalyptus. In comparison to its own aver-
age productivity of 450 GJ/ha per year, one Brazilian company's highest Eucalyptus productivity is
1000 GJ/ha per year, whereas in the United States, commercial forests average less than 100 GJ/ha
per year and switchgrass may achieve 430 GJ/ha per year. Stumpage prices for Eucalyptus in Brazil
were just 0.5-0.6 U.S.$/GJ (ABRACAVE 2003).
Vegetative propagation of superior clones has enhanced Eucalyptus productivity. Starting in
the 1960s, rooted cuttings provided local site adaptation with cost and wood property advantages.
Optimized and efficient transformation and recovery procedures exist for some Eucalyptus geno-
types. Various transgenic Eucalyptus plantlets have been regenerated from stem or leaf segments.
Micropropagation and transformation have combined with efforts to engineer novel or alter existing
traits. Elite hybrid clones with superior wood quality, rapid growth, and disease resistance are also
used extensively in tropical and subtropical regions of South Africa, Congo, and China.
Under Brazil's Code of Best Practices for Planted Forests, several desirable SRWC practices
are encouraged (Piketty et al. 2008). No-tillage or reduced tillage is the usual method of planting.
Reduced input of chemicals is recommended. For SRWC licensing, general BMPs must be followed.
Small farmers have incentives for reforesting marginal lands. In an “integrated system,” industry
provides clones (seedlings) and all other agricultural materials; farmers provide land and labor.
A transition is taking place from “conventional” biomass (e.g., firewood used for cooking) to
“modern” biomass (industrial heat and electricity and biofuels). In Brazil's advanced programs for
bioenergy (Lora and Andrade 2008), biomass gasification is widely applied and encouraged. At
11.3%, “modern” biomass in the Brazilian energy matrix is practically the same as traditional bio-
mass (12.5%). On a global scale, modern biomass is only 1.73% of the whole energy consumption.
In Brazil, bioenergy is implemented at three levels: (1) low, 1-25 kWs (small communities); (2) up
to 5 MWs (small communities, sawmills, furniture factories, and rice treatment plants), and (3) over
5-10 MW (sugar and alcohol plants, pulp and paper mills, and biomass thermal power plants).
Brazil ranked first in a global assessment of land potentially available to supply charcoal to the
steel industry (Piketty et al. 2008). Increasing charcoal making efficiency from 330 to 450 kg/tons
of wood (+36%), using 100% SRWCs by 2010, cleaner carbonization techniques, and by-products
such as liquid fuels and chemicals through gases and liquids recovery will insure the continued
use of charcoal (Rosillo-Calle and Bezzon 2000). A simple upgrade of traditional charcoal produc-
tion can significantly increase liquid fuel output. Slow pyrolysis bio-oil can be an excellent, cost-
effective and renewable liquid fuel (Stamatov and Rocha 2007). A biochar-refinery for production
of charcoal, activated carbon, liquid fuel and variety of chemicals presents a possible approach for
the development of biomass-based industry. Under the current levels of best practices in Eucalyptus
SRWCs, carbonization and charcoal use, 50 million tons of steel would require 6.5 million ha of
SRWCs.
When new plantations and reforestation resulting mainly from the National Programs are ready
to be harvested, Brazil will have forest biomass for export. A least three big energy and pulp com-
panies have their own ports.
Estimates of the total installed potential for electricity generation from biomass range from 2680
to 4740 MW. The total installed power is 96.63 GW of which 4.74 GW (4.9%) is from biomass.
Several cogeneration plants have been built in the sugar/alcohol sector. The pulp and paper indus-
try had potential in 2003 for 1740 MW and had excellent prospects for electric self-sustainability
through cogeneration using renewable energy (wood residue, bark and black liquor). Six thermal
power plants using biomass totaling 80.35 MW are being built, and 42 other units with a total power
of 673.6 MW have been authorized. About 5% of SRWC Eucalyptus could be used to generate elec-
tricity, increasing potential output from 4000 to 8000 MW.