Application and evaluation of 2nd generation biofuels

Project name

Application and evaluation of 2nd generation biofuels

Project duration

01.06.2006 - 30.11.2007

Brief description

The aim of this project is to investigate and evaluate the influence of different types of fuel and their properties on the overall diesel engine process in a targeted manner. Due to the increasingly restrictive regulations regarding exhaust emissions from diesel vehicles in the future, it is necessary to realize improvements in many areas of the engine development process in order to achieve a more efficient utilization of the energy chemically bound in the fuel. Measures that can effectively optimize the mixture formation and ignition of the fuel-air mixture and thus effectively reduce emissions already within the engine offer the advantage of avoiding cost-intensive exhaust gas aftertreatment concepts in connection with the numerous disadvantages, such as increased fuel consumption and extensive control and regulation strategies. One suitable measure that has great potential for reducing emissions within the engine is the use of synthetic fuels or biofuels in a targeted manner in the combustion engine. With a defined composition of the fuel and the absence of aromatics as far as possible as a result of the manufacturing process, particulate emissions can be reduced considerably without additional measures. In addition to a drastic reduction in emissions (particulates, nitrogen oxides) when using 2nd generation biofuels, these fuels contribute to a largely CO2-free transportation policy due to their production from biomass.
Influencing the fuel properties during the operation of the combustion engine is also very important. By increasing the fuel temperature, for example, the evaporation conditions of the fuel droplets can be achieved more quickly after injection in the combustion chamber, resulting in an increasing homogenization of the fuel-air mixture. By simultaneously avoiding fuel wall build-up due to the reduction in the average penetration depth of the liquid fuel, considerable reductions in the exhaust gases emitted can be achieved depending on the operating point. Furthermore, an increase in the fuel temperature and the associated improved evaporation opens up the possibility of achieving a pressure reduction in the injection system at selected operating points, which can significantly increase the efficiency of the overall process. Due to the lower pressure level in the injection system and the resulting reduced abrasive effect during operation, individual components are protected. There would be increased long-term stability, e.g. for the inlet edges of the injection holes and the associated stable combustion quality, including the exhaust gases emitted.
In addition to the emission-reducing potential of these fuels, possible adverse effects of using the latest fuels must also be investigated as part of such a project. First-generation biofuels, especially those based on rapeseed methyl ester (RME), sometimes cause considerable damage to pumps due to their reduced viscosity. Furthermore, these fuels have poorer cold-start properties than commercially available diesel fuels and therefore lead to reduced customer acceptance. Together with the project partner, solutions are to be proposed.
The task of the TUD Dresden University of Technology in this project is to investigate and evaluate the potential of 2nd generation biofuels and other synthetic fuels in conjunction with currently used combustion processes with regard to their efficiency and exhaust emissions compared to conventional diesel fuels using the measurement carriers available at the Chair of Internal Combustion Engines and the resulting closed measurement chain. The results can be used in conjunction with the project partner, CHOREN GmbH, to determine future fuels and their composition for series use in road traffic and to prepare an optimal large-scale production process.

Cooperation partner

• UET Umwelt- und Energietechnik Freiberg GmbH, - (Germany)

contact