Development of a CNG Injection Engine Compliant to Euro-IV Norms and Development Strategy for HCNG Operation

The rising demand for cleaner vehicles considering the upcoming stringent emission norms like Euro-IV has promoted development of CNG vehicles. The need for expensive after treatment technologies has imposed constraints on Euro-IV Gasoline and Diesel engine development. On the contrary CNG engines have easily met Euro-III norms with Carburetion technology and Euro-IV and beyond norms with Injection technology. CNG has proved to be a clean and environmentally friendly fuel, significantly improving the ambient air quality of cities. The addition of Hydrogen to CNG has potential to even lower the CNG emissions and is considered to be the first step towards promotion of a Hydrogen economy.

Worldwide experts have described Hydrogen as the cleanliest fuel for IC Engines [1, 2 and 3]. Hythane is the patented blend of 15% of Hydrogen in CNG by Energy content. HCNG is the blend of Hydrogen and CNG in varying proportions. From the literature [4-5] it has been observed that HCNG reduces NOx emissions by 50%, non-methane hydrocarbons by 58%, and total hydrocarbons by 23% and CO₂ by 7% as compared to CNG. This paper presents the results obtained during the optimization of a dedicated CNG Injection 6-Cylinder naturally aspirated engine and optimization strategy for further up gradation to run on HCNG. The original carbureted CNG Euro-III compliant engine was upgraded to meet Euro-IV norms by replacing the carburetion kit with a injection kit. Work is in progress to further upgrade this engine to run on HCNG.