PRELIMINARY STUDY ON TRIBOLOGICAL PERFORMANCE OF STRAW BASED BIO-FUEL

摘要

More and more attention has been paid to alternative fuel in internal combustion engine. One of alternative fuels is to convert straw biomass to biomass fuel. Various methods and apparatuses used for converting straw biomass to bio-fuel were invented and developed. However, alternative fuel from biomass can not be used well in internal combustion engine. The reason is complicated and relative with the separation technology of bio-fuel and corrosion, wear, lubrication and combustion chemical reaction between bio-fuel and the surface of combustion room. It is necessary to study the tribological properties of bio-fuel in order to instead the current gasoline or diesel oil in internal combustion engine in the future. In the present study, the straw based bio-oil obtained by liquidizing process was chosen to evaluate its lubrication by MQ-800 four-ball tribometer, in which extreme pressure and friction coefficient and wear resistance were measured respectively. The experimental results showed that the extreme pressure of the bio-fuel was up to 392 N, and the extreme pressure of diesel oil was 333 N. The frictional coefficient of bio-fuel varies between 0.08 and 0.11. The wear scar diameter increased with load slowly in 30 min. SEM images indicate that lots of thin and dense belt-like ploughs were presented on the rubbed ball surface. The chemical compositions of the worn zone on the ball surface were analyzed by XPS, the thermal property and variation of chemical compositions of bio-fuel before and after friction and wear tests were studied by TGA and GC-MS, respectively. It was shown that the rubbing surface film was composed of FeS, FeSO{sub}4 and organic compounds with C-C, -COH and -COOH groups.