Hydrogen Enriched Compressed Natural Gas (HCNG) as an Alternative Fuel for Conventional IC Engines. A Review
Keywords:
NG/CNG, H2, HCNG, Dynamic mixing system, Ignition System, HCNG engineAbstract
With the continuous increasing demand of alternative energy and various stringent emission norms forces engine researchers toput on strategic plans to appropriate usage of available energy and reduce the carbon emission of fuels. Moving ahead with these plans hydrogen emerged as best energy carrier amongst gaseous fuels but technical limitations restrict its uses. On theother hand, Hydrogen enriched compressed natural gas (HCNG) also called Hythane proved to be better energy carrier for internalcombustion engines. Worldwide many countries are endeavoring hard to lower down the emission level by promoting HCNG-fueled gasoline vehicles. It was observed that under precise circumstances the indicated thermal efficiency of the HCNG engine is much better compared to CNG engines with identical emissions. In spite of that the H2 enrichment to NG/CNG provides increased NOx, however, it can be reduced with the application of lean burn combustion concept and also using three-way catalytic (TWC) converter. This review is an overview of HCNG engines. This review provides a detailed discussion on fundamentals of characteristics of HCNG mixture, engine combustion and emissions. For covering the prospects of the HCNG engines various approaches are discussed along with methods to increase the power output, thermal efficiency, and emissions reduction along with gaseous fuel induction strategy.