A Comparative Study on the Effect of Alcohol Induction and Addition on Performance Behavior of a CI Engine Fueled with “Madhuca Indica” as Fuel 2015-01-0853

The effect of methanol addition (by blending) and methanol induction (by carburetion) on performance of a vegetable oil (Madhuca Indica called as Mahua oil) based diesel engine was studied experimentally. A single cylinder, water cooled, DI, diesel engine was used. Baseline data was generated with neat diesel and neat Mahua oil as fuels. Subsequently methanol was blended with Mahua oil in different proportions such as 5, 10, 15 and 20% by mass and tested for engine's performance. Finally the engine was operated in dual fuel mode of operation with methanol induction and Mahua oil injection. Engine performance, emission and combustion characteristics of ND (neat diesel), NMO (neat Mahua oil), MOMB (Mahua oil+15% methanol blend by mass) and MOMDFE (Mahua oil dual fuel engine at 15% mass share) were compared and analyzed at 100% and 40% loads.

NMO resulted in inferior performance and increased emissions at both power outputs as compared to ND. MOMB and MOMDFE resulted in improvement in performance and reduction in smoke emissions. MOMDFE resulted in better improvement in brake thermal efficiency as compared to MOMB at 100% load. The brake thermal efficiency at 100% load was found as 30.5%, 26.8%, 27.8% and 29.5% respectively with ND, NMO, MOMB and MOMDFE respectively. Smoke was reduced considerably with MOMB and MOMDFE. MOMDFE showed drastic reduction as compared to MOMB at both loads. MOMB and MOMDFE indicated considerable reduction in NOx at both power outputs. MOMDFE showed more reduction than MOMB at both power outputs. HC and CO were found to be higher for MOMDFE as compared to NMO whereas MOMB resulted in reduced HC and CO emissions.

Ignition delay of NMO was higher as compared to ND at both loads. MOMB and MOMDFE further increased the ignition delay. Energy release rate indicated inferior combustion at the initial stage with NMO. However it was improved with MOMB and MOMDFE (except at 40% load). It was concluded that methanol addition and induction techniques can be adopted for improving performance of a diesel engine using Mahua oil as main fuel. If drastic reduction in smoke and NOx is aimed with superior thermal efficiency at peak power output, then methanol induction can be preferred. If no engine modification is required to operate the engine with moderate improvement in performance and reduction in all emissions at all power outputs then methanol addition can be preferred.