Emission Reduction in Small SI Engine Generator Sets

Emission regulations for portable generator sets have been enforced in India from June 2000 and more stringent standards since 2001. Studies on application of catalytic converters on two-stroke gasoline and 4-stroke kerosene fuelled SI engine generator sets were carried out in addition to lean tuning of the engines for making these compliant with the emission standards currently in force and likely to be implemented in the coming years. The kerosene fuelled generator sets are set for very rich operation to obtain smooth combustion and hence an air blower had to be employed for injection of the high amount of required secondary air for functioning of oxidation catalysts resulting in 77 to 88% reduction in HC (hydrocarbons) and CO (carbon monoxide) emissions By lean tuning and catalytic converter optimization 74 to 89% reductions in HC and CO emissions were obtained on the 2-stroke generators even without secondary air. Emissions obtained by these control measures are well below the present standards with good margin of safety for production compliance.