Improvement of combustion and emission characteristics of a diesel engine working with diesel/jojoba oil blends and butanol additive

Abstract

The main concerns of exploiting Jojoba oil in CI engines is that it has a high viscosity, low volatility, and high NOx formation. Therefore, this article purposes in endeavoring to improve the combustion and emission parameters of a CI engine working with diesel-jojoba oil blends and n-butanol additives under various engine loads. A 10% by volume of n-butanol is combined with 5%, 10%, 15%, 20%, 25, 30 and 35% of jojoba oil, and they are designated as DBJ5, DBJ10, DBJ15, DBJ20, DBJ25, DBJ30, and DBJ35, respectively. The experiments are divided into two steps, firstly, the viscosity of the fuel mixture is measured according to ASTM standards, and it is compared to ASTM D6751– 12 standers limits. Secondly, the jojoba oil with volume fraction up to 15% is tested in a CI engine to evaluate the combustion and emission developments. The results indicate that the addition of n-butanol with diesel-jojoba oil lowers the mixture viscosities by up to 85% compared to pure raw jojoba oil. The findings display that there is an increase in pmax. and HRR for DBJ5, DBJ10, and DBJ15 blends compared to pure diesel fuel, whereas the combustion duration and ignition delay are slightly reduced. The brake specific fuel consumption is enlarged. The NOx, CO, and UHC formations are reduced by 50%, 30%, and 40% respectively for diesel-jojoba oil-n-butanol mixtures. It can be deduced that combining high fractions of jojoba oil with n-butanol (DBJ15) have the feasible to accomplish low emission formations in the interim having high thermal efficiency level.