Performance and emission characteristics of a CI engine operated with n-Butane blended DME fuel

In this study, a compression ignition (CI) engine operated with n-Butane blended di-methyl ether (DME) fuel was experimentally investigated. Specifically, the performance, emissions characteristics, and combustion stability of a CI engine fueled with n-Butane blended DME fuel were examined at 1500 rpm. All the experimental results were compared to the results of diesel fuel with the same experimental conditions. The percentage of n-Butane in the fuel blend ranged from 0 to 40% by mass. The results showed that stable engine operation was possible for a wide range of engine loads up to 30% n-Butane by mass. The engine power output and fuel consumption were improved with the blended fuel since the energy content of n-Butane is much higher than that of DME. Exhaust emission measurements showed that when the blended fuels at low engine loads were used, hydrocarbon and CO emissions increased due to partial burn from over-mixing. Soot and NOx emissions were comparable for all blends. Our results on engine power output and exhaust emissions demonstrate that blended fuels up to 30% n-Butane by mass can be used as an alternative to diesel in a CI engine, and n-Butane blended DME fuel has the potential to enlarge the DME market.