The 2nd Dessau Gas Engine Conference took place in Dessau on 7-8 June 2001. It was organized by WTZ Roßlau which is a non-profit R&D center for the development of diesel and gas engines. 130 participants from all over the world discussed the papers presented in the five main sessions of the conference:
The most recent engine already uses a common rail system to inject the diesel fuel, a feature which was also implemented in the demonstration engine FEV Motorentechnik used to realize their high efficient low NOx gas engine.
The amount of pilot diesel fuel injected in the Wärtsilä engines is below 1 % of the total fuel consumption at full load. Stephen Dexter from AVL pointed out that this amount of diesel fuel can further be reduced when renouncing on the 100 % diesel mode operation capability.
Titus Tschalamoff from WTZ Roßlau showed how it is possible merely by optimizing the combustion process to reach more than 42 % efficiency in a pre-chamber gas engine simultaneously fulfilling the NOx limit of ½ TA Luft.
To meet the even more stringent requirements for NOx required in Zürich, Switzerland the concept of ETH Zürich is to operate the gas engine stoichiometrically with cooled EGR. Carefully optimizing the combustion process and using a three-way catalyst an efficiency of 41 % with NOx emissions of only 1 mg/Nm3 can be reached.
Two papers in the first conference section dealt with a novel concept to initiate combustion in gas engines, the so called Homogeneous Charge Compression Ignition, whereas the new engine of CATERPILLAR Motoren (G-CM34) uses spark-ignition in a pre-chamber.
Topics of the thursday afternoon session were different gas engine accessories, such as spark plugs, explosion relief valves and cylinder pressure indicators. In the gas engine oils session special emphasis was placed on the need to develop engine oils for gases containing sulphur, chlorine, fluorine or silicon compounds. Oils with high TBN can be profitable to use when engines are powered by acid gases. Used lubricating oil analysis indicating high silicon contents do not necessarily correlate with high wear of engine components despite the fact that in recent years organic silicon compounds were clearly identified as the reason for increased wear when silicon oxide deposits were found in engines operated with sewage or landfill gas. A way to tackle this problem was demonstrated in the gas purification concepts session by Wolfgang Doczyck from Siloxa Engineering and Ulrich Prochaska from Menag Energy.
Combining different cleaning methods a siloxane contamination of more than 1000 mg/m3 can be reduced down to less than 1 mg/m3 allowing highly contaminated gases to be used economically in gas engines. In the papers presented by representatives of Johnson Matthey and HUG Engineering the state-of-the-art of exhaust catalysts for gas engines was discussed.
Finally three papers dealt with the application of gas engines in the cogeneration market and in shunting locomotives, respectively. In his closing remarks Mr Häntsche, managing director of WTZ Rosslau, pointed out that the gas engine conference now is an established forum for the gas engine community. Encouraged by the positive response of many participants the next one will be organized in 2003. The conference proceedings of the 2nd Dessau Gas Engine Conference are available on CD ROM.