Study of Biodiesel as a Fuel for Ci Engines and Its Environmental Effects: a Research Review

Biodiesel will play an increasing role in fulfilling the world’s energy requirement. The world has experienced negative effect from the fossil fuel such as global warming and acid rain etc. With the increase in consumption of biodiesel, its impact on environment has raised a discussion around the world. Energy requirement of the world will increase in coming future and is projected to increase by 50% from 2005 to 2030. The paper presents the results of biodiesel combustion emission on the environment. A review of literature available in the field of vegetable oil usage has identified many advantages. Vegetable oil is produced domestically which helps to reduce costly petroleum imports, it is biodegradable, nontoxic, contains low aromatics and sulphur and hence, is environment friendly. The biodiesel shows no obvious NOx emission difference from the pure diesel fuel at low and medium engine loads. Biodiesel blend ratios have little effect on the NO/NOx ratio at medium and high engine loads. The CO emission of biodiesel increases at low engine loads. The HC emissions show a continuous reduction with increasing biodiesel blend ratios. There is a good correlation between smoke reduction and the ratio of the biodiesel blends. The addition of biodiesel fuel increases formaldehyde emission. A series of engine tests, with and without preheating have been conducted using each of the above fuel blends for comparative performance evaluation. The results of the experiment in each case were compared with baseline data of diesel fuel. Significant improvements have been observed in the performance parameters of the engine as well as exhaust emissions, when lower blends of karanja oil were used with preheating and also without preheating. Karanja oil blends with diesel (up to K50) without preheating as well as with preheating, can replace diesel for operating the CI engines.