Emissions of particles from gas engine powered CHP plants

A recently performed PSO project has shown that gas engine fired CHP plants can emit very high numbers of fine and ultrafine particles. Some of these particles contain metal oxides that arise from additives in the lubrication oil, and these particles are known to pose a threat to human health. This project will identify why particles appear in large numbers in emissions CHP plants using gas engines. Methodologies include data collection of key parameters (engine type and operational conditions, lubrication oil type etc.) from existing Danish CHP plants, and measurements on gas engine plants during different operational conditions. A number of chemical and physical parameters will be analyzed. Particle size, distribution and composition will be measured together with a number of stack gas parameters through field experiments at 7 gas engine powered CHP plants. In these experiments, parameters will be varied such as engine type, operating conditions such as stoichiometry (fuel/air ratio), lubrication oil type, composition and amount of lubrication oil added to the engine, oil temperature, and temperature profile in the stack gas. Furthermore, the project will investigate whether the emissions can be reduced through altered engine design/operation and/or through a change of lubrication oil types. This will be done on the basis of the findings of the field experiments. The project will be performed by FORCE Technology in close co-operation with DGC, manufacturers of gas engines (Rolls Royce and Wärtsilä) and lubrication oil for gas engines (Statoil Lubricants), and the Danish Association for Combined Heat and Power Plants (Dansk Fjernvarme).