Performance and Emissions of Ci Engine Operated with Linseed Oil Biodiesel-Diesel Blends under Varied Compression Ratio

This paper shows the effects of changing fuel blend ratio and compression ratio on performance and emissions of a CI engine operated with blends of linseed oil biodiesel with diesel. Linseed oil biodiesel was prepared by transesterification process of raw linseed oil. The test engine was a single cylinder, four stroke, variable compression ratio (VCR), direct injection diesel engine with necessary instruments and computer interface to measure and record the performance and exhaust emission variables. During the experiments, percentage of linseed oil biodiesel in the blends was varied from 0% to 100% by volume, while the compression ratio was varied from 15 to 20. Injection variables were not changed from manufacturer's settings (injection pressure 220 bars and injection timing 23º BTDC). The results revealed improvement in brake thermal efficiency and lowered emissions of carbon monoxide (CO), hydrocarbons (HC) when fuel blends were enriched with biodiesel. Increasing the compression ratio also improves engine performance and reduces emissions of CO and HC. However, nitrogen oxides (NOx) increased with increase in biodiesel content of the blend as well as with increase in compression ratio. Further, it was concluded that linseed oil biodiesel has potential to replace conventional diesel.