Environmental Engineering Reference
In-Depth Information
be able to receive carbon incentives to help make poplar biomass plantations more economically
feasible (Yemshanov and McKenney 2008).
Another encouraging development is the recent sequencing of the poplar genome by molec-
ular biologists (Tuskan et al. 2006). This new development should allow geneticists to improve
growth, disease resistance and chemical composition of poplars in the future (Taylor 2002, 2008;
Wullschleger et al. 2005). There now may be opportunities for genetic engineering of herbicide
resistance into poplars (i.e., Roundup Ready poplars) and improved cellulosic biosynthesis needed
to make cellulosic ethanol more economical (Joshi et al. 2004; Sims et al. 2009).
There are some possible policy decisions that could make cellulosic ethanol more competitive,
but they are not yet available (Carling 2009). But there are still other limitations that include produc-
tion and transportation costs as well as access to land in populated areas (Alexander and Gordon
2009). Notably, Greenwood Resources, Inc., and ZeaChem are currently building the first poplar
demonstration biorefinery to produce cellulosic ethanol in Boardman, OR. It is scheduled to open
in 2010 (Eaton 2008a).
Europe is ahead of the rest of the world in development of poplar biomass crops for power
production, probably because of incentives. In Italy, four power plants of the energy company
Power Crop that will use poplar biomass as a feedstock are under construction. These facilities
will require 30,000 ha of land dedicated to short rotation poplar coppice plantations to feed
them. The commercial plantations were scheduled to become operational in 2009. Another
power company near Milano, Italy, is constructing a small power plant that will utilize poplar
biomass from 3000 ha of poplar plantations nearby. Another European power company, RWE,
is planting 10,000 ha of short rotation poplar coppice to feed a co-fired coal power plant in
Germany. RWE has plans to develop other facilities in Romania and Spain that will utilize
poplar biomass. A French power company also has plans to use 1000 ha of short rotation poplar
coppice for a co-fired power plant in Hungary. And, in the United Kingdom, the Drax power
company is planning on building three power plants that will utilize local poplar biomass. They
presently have a power plant that utilizes imported wood pellets for fuel. These power plants
are able to economically use poplar biomass because of the EU tax policies aimed at reducing
CO2 emissions to the atmosphere. There have already been several successful biomass fired
power plants in Northern Ireland and Sweden using willow biomass. The short rotation willow
coppice system was developed by a research group at the Swedish University of Agricultural
Science in Uppsala, Sweden (Perttu 1989).
Poplar biomass will likely be used for fuel in developing countries for years to come. However,
there is a worldwide increase in the use of poplar wood residues for energy production in small forest
products industries and businesses in developing countries, especially China and India. Moreover,
there is a trend toward co-firing poplar biomass with coal for electricity generation in some coun-
tries to decrease costs and improve air quality (De and Assadi 2009). This trend will likely continue
to increase in the future because of the shrinking world economy.
The cellulose ethanol industry in Europe is still undergoing development as in North America
(Slade et al. 2009). Poplars are one of the several preferred biomass feedstocks under study, and
North America companies may build or acquire poplar based cellulosic ethanol plants in Europe
once this technology has been commercialized. Thus, the successes in the next few years will likely
determine the future success of commercialization of poplar bioenergy throughout the industrial-
ized world.
There are also encouraging developments for the use of poplars for their environmental benefits.
Short rotation woody crops can provide ways of cleaning up (i.e., phytoremediation) polluted water
and soils (Perttu 1989; Licht and Isebrands 2004). There are many intangible benefits that short
rotation poplars for biomass production provide including soil erosion control, protection, wildlife
benefits, air quality improvement, carbon sequestration, aesthetics and psychological benefits (Licht
and Isebrands 2004; Isebrands 2007). All of the aforementioned developments point toward a prom-
ising future for the use of poplars as a bioenergy source.
