Abstract
Farm based waste digestion plants return higher profit if the emanating methane (CH4) rich biogas is purified and used in agricultural vehicles, as it is used to generate heat and electricity. For this reason, ignition process of diesel engines, the prime movers in farms, was thoroughly reviewed because it directly influences the resulting toxic emissions. Methane, coming from natural gas or biogas, when fed into these engines along with diesel, was found to reduce nitrogen oxides and particulate matter but increased knocking at high loads and misfire at light loads. Several solutions have been studied all over the world and some reached the market stage; however many challenges still face the advance of this technology.
