Combustion and Emission Characteristics of Biofuels Used for Transportation

Project Objective:
The use of biofuels, as an alternative to using petroleum-derived fuels, has been promoted recently by authorities at the local, state, and federal level as well by the engineering and scientific communities. While attractive, given the current fuel/energy crisis and the phenomenon of global warming, it is essential that the overall impact of using such fuels be evaluated by appropriate and well-thought investigations. Only then rigorous insight can be provided into the effect of using new and untested fuels on engine performance, the environment, and health.

Despite of all the hype, at present there is minimum amount of information on how biofuels burn and what types of emissions they produce. Such evaluations can only be performed in simplified and well-controlled experiments. Engine results, absent of fundamental knowledge and understanding, can be of limited value, as the simultaneous presence of turbulent fluid mechanics and various loss mechanisms could mask the underlying processes that control the fuel oxidation process.

The proposed research will provide the first systematic experimental data on both the burning and emission characteristics of biofuels to compare to those of conventional petroleum-derived fuels currently used in engines. In addition to those comparisons, the research will be used to advance chemical kinetic models of biofuels, of great value to engine modeling. This has clearly both practical and intellectual value. While the practical value related to combustion efficiency and environment is rather obvious, the intellectual value stems from the fact that the new parameter space that will be investigated will require notable advances in the scientific knowledge of the physics and chemistry of oxidation of oxygenated compounds that chiefly control the composition of biofuels.

The project described here is, in our opinion, important and relevant to two METRANS Themes, namely Area 1, Commercial Goods Movement and International Trade, as well as Area 3, Highway Infrastructure. Biofuels and biofuel additives (e.g., ethanol) are rapidly becoming ubiquitous and key components of the fuel infrastructure of our State (and in the Nation), but as noted above key unanswered questions still remain about them, including the economics of their production, as well as about safety and environmental aspects of their use. The results that will be obtained within the 12-month period of the project will be the first of their kind and will be used to demonstrate to various government agencies as well as fuel and engine manufacturers the advantages and disadvantages of using biofuels. It is rather certain, that within the current political environment, with crude oil consistently averaging in excess of $70/bbl, additional and hopefully multi-year funding will be generated, once some preliminary data have been generated.

The PIs have already formed a consortium with Reaction Design, the Chevron Corporation, and the National Laboratories to pursue such endeavors with the Department of Energy and NASA, among others. Additionally the PIs believe that long-term, biofuels represent an excellent opportunity as the focus point of a larger multidisciplinary activity within USC, dealing with many of the other technical and non-technical aspects that will critically determine the eventual adaptation of this important renewable resource. They include economic and business aspects, efficient policies to promote their use, including market incentives for early adaptation, and efficient technologies for their distributed production and distribution. The PIs of this proposal are willing to spearhead an effort in this direction.