1 Institute of Chemical Engineering, Biotechnology and Environmental Technology, Faculty of Engineering, SDU2 Technical University of Denmark3 Copenhagen Energy4 IFEU - Institute for Energy and Environmental Research, Heidelberg, Germany5 Institute of Chemical Engineering, Biotechnology and Environmental Technology, Faculty of Engineering, SDU
Throughout the world, nations are seeking ways to decrease CO2 emissions and to reduce their dependency on fossil fuels, especially oil, for environmental as well as geopolitical reasons. Being a renewable, CO2-reducing and easily storable energy carrier, biomass is a priority resource for fossil fuel substitution, and biomass is increasingly used for both the transport and the heat and power sectors, with increasing interest in using it for chemicals production as well. For the transport sector, the conversion of biomass to the liquid biofuels of bio-diesel and bioethanol is at present a technological pathway promoted by governments in many countries. With the increasing interest in our biomass resource, however, the issue of competition for the biomass and the need for prioritising it has become evident. For several decades ahead, we still depend heavily on fossil fuels, and we can only replace them to the extent and with the speed that alternatives become available. As the magnitude of biomass that is or can be made available for energy purposes is small compared to the magnitude of the new potential customers for it, any long-term and large-scale prioritisation of biomass for one purpose will imply a loss of alternative uses of the same biomass. If the lost alternatives are, then, significantly more efficient as well as economically more attractive in fossil fuels substitution and CO2 reduction, we lose more than we win. It is our claim that this is the case for most liquid biofuels, including first-generation bio-diesels (plant bio-diesels) as well as first- and second-generation bioethanols produced in Europe and the USA. When we prioritise biomass for these biofuels, we deprive ourselves the better alternative of using the same limited biomass for heat and power and running our cars on the fuels saved there.
Treatise on Sustainability Science and Engineering, 2013, p. 259-266