Life Cycle Assessment of Second Generation Biofuels Production Using High-Gravity Hydrolysis and Fermentation

Conference poster, 2012

The search for sustainable production of 2nd generation biofuels is an ongoing effort. This production is not only aiming at substituting fossil-based transportation fuels with their renewable counterparts. It is also aiming at using renewable resources that will not affect food production, an issue that the 1st generation biofuels (e.g. ethanol from corn) have been criticized for. As well, 1st generation biofuels have been shown to be not as advantageous from an environmental perspective as was first expected, for instance due to the increased use of fertilizer. Lignocellulosic materials such as wood and straw are resources that can be used for the production of these 2nd generation biofuels. However, it has been particularly difficult to develop economically feasible processes for the production of these fuels. High gravity processes, i.e. processes with high raw material concentration, have the potential of meet the economic requirements. In order to assess the environmental impact of such a process, Life Cycle Assessment (LCA) is applied in order to account for these impacts along the value chain of these fuels. This process technology development project focuses on the production of ethanol and 1-butanol using high gravity hydrolysis and fermentation. However, parts of this technology are still in the early stage of development and have not even reached the pilot scale stage. Therefore, lab scale data and information are used to assess the technology under development and process simulation is needed to generate data about the industrial-scale process. This implies that scale-up issues need to be taken into account in the LCA. Issues specific to biofuel production such as land use and land use change, and water use need to be addressed as well. The outcomes of the LCA can then be used to identify the weak and strong points of the process and this information can then be used in the development of the technology. This poster presents a short review of the literature on the relevant issues regarding biofuel production and the use of LCA in technology development. Furthermore, a project plan for the environmental assessment of the technology under study and the use of these assessments in the technology development process is presented. LCA will thus be used during the technology development and will potentially have a significant influence on this development, and therefore on the sustainability of 2nd generation biofuels that are produced with a high gravity production process.