Agrofuels are sometimes referred to as biofuels. The term biofuels is used widely for any fuel derived from biological material in contrast to fossil fuels (coal, oil, gas). It includes for example biogas production from landfill sites. Where plants are cultivated in agricultural systems for the purpose of fuel production, the term agrofuel is more appropriate to include the specific context and problems such as monoculture plantations and the competition with land for food production.
Myths and realities
First generation agrofuels are liquid fuels made from the reproductive parts (seeds) of crop plants. Two examples of the main types are ethanol produced from the starch of maize kernels and biodiesel from the oil of soya beans. They were strongly promoted as a means to address climate change, to improve energy security and to regenerate rural areas, without reducing the use of internal combustion engines (e.g. cars, tractors, planes, generators) or even modifying those engines too radically.
But contradictions soon emerged, as shown by the report Towards a Reality Check in Nine Key Areas. Agrofuels threaten biodiversity and food security without actually being a solution for climate change. They also need large areas of land and plenty of water. The suggestion that they should be grown on millions of hectares of 'marginal land' ignores the fact that such land may well be vital to local communities and the resilience of ecosystems, their function and services. If such land is genuinely degraded, as often claimed, it is unlikely that it would support the production of crops at industrial scale without massive inputs.
Second generation agrofuels are now promoted as a solution to the problems of the first generation. These 'advanced' agrofuels are meant to utilise the whole plant or tree to produce fuel and other commercially valuable products that are currently derived from fossil fuels, such as plastics. Producing these next (or second) generation agrofuels is energy intensive and involves breaking down the complex, resilient lignin and the different celluloses in tree and plant biomass, using heat, pressure and chemicals. Microbiological processes are also required and are being further developed for these purposes, including the use of genetically modified microorganisms. At the same time researchers are trying to produce fast-growing genetically modified (GM) trees with reduced or less resilient lignin.