Numerical Investigation of n-Butanol Addition on the Performance and Emission Characteristics of CI Diesel Engine

Abstract

The demand for higher output efficiencies, greater specific power output, increased reliability, and ever reduced emissions has been rising. Due to its availability one promising alternative is the use of butanol in internal combustion engines. In this study, the effects of n-butanol addition (5%, 15% and 25% by volume) to diesel fuel on the performance and exhaust emissions of a 6 cylinder four stroke turbocharged direct injection CI Diesel engine were investigated using GT-Power computational simulation tool. The simulations were performed by varying the engine speed between 1000 and 2000 rpm at four different loads of brake mean effective pressure (bmep) (4.5, 8.5, 10.5 and 12.75 bar). The performance and exhaust emissions of the engine when working with the three butanol-diesel blends were compared with neat diesel fuel. The results showed that the butanol-diesel blends reduced carbon monoxide (CO) and nitrogen oxide (NO_X) by about 40% and 70% respectively, However carbon dioxide (CO₂) and unburned hydrocarbon (HC) emissions increased. It was also found that the brake thermal efficiency (BTE) improved by more than 20% for butanol diesel blends when compared with the corresponding diesel fuel. Due to its optimum values in terms of emission and performance parameters 15% butanol-diesel blend was found to be the best choice.