Perspectives on Bioenergy and Biofuels - Sustainable Biotechnology: Sources of Renewable Energy - page 192

7000

6000

5000

4000

Coal Dow

3000

FT (2 mln tonnes per annum)

Naphtha Dow

Dow

2000

Dow

Ethane (Middle East) Dow

1000

200 300 400 500 600 700 800 900 1000

Variable costs $/tonne

Starch (corn) to ethanol to
C 2 H 4
Lignocellulose to ethanol
to C 2 H 4

Fossil to C 2 H 4

Sugarcane (Brazil) to
ethanol to C 2 H 4

Fig. 3 Return on investment as a function of capital and variable costs (based on 1 million tonnes
per annum production)

exists (to a large extent) and is on the brink for successful commercial application.
Perhaps the most complex issue surrounding the production of biofuels lies with the
renewable raw materials itself. Ethical, social and ecological issues surrounding the
biomass with respect to competition with food production and prices, land conver-
sion and carbon debt are complex and so strategies that address these sufficiently
are perhaps the most rate determining step for acceptance and success in biofuel
production.

References

1. www.iea.org (IEA Energy stastistics -Energy Balance for Netherlands 2005)
2. http://ec.europa.eu/energy/res/legislation/doc/biofuels/en_final.pdf
3. Searchinger, T., Heimlich, R., Houghton, R.A., Dong, F., Elobeid, A., Fabiosa, J., Tokgoz, S.,
Hayes, D., and Yu, T.H. (2008) Use of US croplands for biofuels increases greenhouse gases
through emissions from land-use change. Science 319 (5867), 1238-1240.