Abstract
The production of biofuel from olive mill wastewater (OMWW) may be one of the promising techniques for use in diesel engines. In this study, biofuel was produced from the hydrothermal liquefaction of OMWW using a methanol-water co-solvent. Biofuel blends of 10% (B10), 20% (B20) and 30% (B30) by volume of biofuel, were prepared. The chemical and physical properties of biofuel blends are mostly similar to those of conventional diesel fuel. The engine speed was kept constant (1500 rpm) throughout the tests under different engine loads (25, 50, 75 and 100%). The effects of biofuel-diesel blends on exhaust emissions and engine performance were investigated. The results show that the in-cylinder pressure follows almost the same trend for all fuels. However, at high loads, with increasing biofuel blend, the combustion duration tends to become longer. The B10 blend provided close results to diesel fuel in terms of performance and polluting emissions. Moreover, the use of B10 resulted in reduced emission levels, with 11% of unburned hydrocarbons, 12% of particles and 26% of carbon dioxide compared to the other blends.