Effect of Compression Ratio on Emission of CI Engine using Neat Karanja Oil and Karanja Oil Methyl ester Blends

The standard design parameters of a compression ignition engine fail to give specified performance with strait vegetable oil (SVO) from different origins. This study is performed to find the effect of compression ratio on emission characteristics such as carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), nitrogen oxides (NOx) and smoke opacity with all the tested fuels in a single cylinder, four stroke VCR engine fueled with neat Karanja oil blends (10 and 20%) with diesel (on volume basis) and Karanja oil methyl ester (KOME) blends (20, 40 and 60%) and compare the results with diesel. Experiments haves been conducted at compression ratios of 16:1, 17:1, 18:1. At higher CR, minimum value of CO is recorded as being 0.04 for 20% blend of KOME (B20), while maximum CO2 is4.45%. Lowest HC and NOx emission recorded are 22 ppm and 552 ppm respectively for 40% blend of KOME (B40). Emissions are marginally higher for K10 and K20 than for diesel. Overall observation shows that B40 has the lowest emissions among other blends of KOME at higher compression ratios.