Effects of isopropanol-butanol-ethanol on the performance, combustion and emission characteristics of a diesel-methanol dual-fuel engine

Both diesel-methanol dual-fuel (DMDF) combustion and the addition of isopropanol-butanol-methanol (IBE) into diesel are capable of reducing the fossil fuel usage and soot emissions of diesel engines, but few of studies focused on combining the advantages of these two methods. Thereby, diesel containing 10 %, 20 % and 30 % of IBE by volume were utilized as pilot fuel in this study to investigate how the addition of IBE into diesel affects the performance, combustion and emissions of the DMDF engine. Experiments were performed at the engine load of 20 %, 40 % and 60 % with the engine speed fixed at 1400r/min. The results show that at most test conditions, the brake thermal efficiency of the DMDF engine only suffers a slightly drop while the soot emissions greatly reduce when IBE is blended into the pilot fuel diesel. Moreover, the deterioration of CO, HC and NOx emissions of DMDF engine can be significantly improved by blending no more than 20 % vol. IBE into the pilot fuel diesel. Additionally, with the volume ratio of IBE into the pilot fuel diesel increases to 30 %, the soot emissions of the DMDF engine can be further reduced at the costs of engine performance deteriorates and CO, HC, NOx emissions increase. Although the deterioration of the engine performance caused by the addition of IBE into the pilot fuel diesel can be mitigated by increasing the methanol flow rate, NOx emissions increase significantly.