Emission Results from the New Development of A Dedicated Hydrogen - Enriched Natural Gas Heavy Duty Engine

Steady state emissions testing on a dynamometer with an 11-liter heavy-duty engine have shown the ability to obtain tail pipe oxides of nitrogen (NO_x) emissions of 0.15 g/bhp and below. Equivalence ratios of 0.53 have been achieved over the operating range. The development of a dedicated hydrogen-enriched natural gas (HCNG) engine utilizes a mechanical means to extend the lean limit of combustion through a quiescent intake path. Hydrogen blend ratios of 30-40% have been employed.

Current manufactured natural gas heavy-duty engines use intake swirl as a means of extending the lean limit of combustion for reducing NO_x emissions. These engines have shown reductions in NO_x emissions with HCNG and lean burn however, are unable to meet 2007 goals. Principals at Collier Technologies, Inc (CTI) have been developing and operating HCNG engines for the past eleven years with dramatic results in NO_x and CO emissions. CTI, Hess Microgen and Daewoo Heavy Industries are cooperatively developing the next generation of HCNG heavy-duty engines to meet the stringent 2007 emission requirements.

Transit authorities are researching all possible methods to meet the pending 2007 EPA emissions standards for heavy-duty transportation. Including HCNG, hybrids, pure hydrogen ICE's and fuel cells.