Experimental Study on Combustion and Performance of a Stationary CIDI Engine Fueled with 1-Heptanol-Diesel Mixtures

Abstract

1-Heptanol is a renewable higher alcohol for compression ignition direct injection (CIDI) engines because of its distinctive physicochemical properties. The developed renewable production approaches of 1-heptanol promote its application in CIDI engines. The present study investigates the combustion of 1-heptanol/diesel blends with up to 50vol% 1-heptanol substitution ratio on CIDI engine. The substitution ratios of 1-heptanol/diesel are 10/90, 20/80, 30/70, 40/60, and 50/50 (v/v%), denoted as Hep10, Hep20, Hep30, Hep40, and Hep50. This work utilized a one-cylinder natural aspiration air cooling CIDI engine research facility. The steady-state test was performed at various loads ranged between 10% to 100% and engine speeds of 900 and 1500 rpm. The findings reveal that under the same conditions of the TGA experiment, the 1-heptanol/diesel mixture evaporates faster than diesel. 1-Heptanol/diesel mixtures showed longer ignition delay and tend to burn under premixed combustion mode than diesel. Also, Hep10-50 blends released more heat under fast burn mode compared to regular diesel. Hep10-50 mixtures showed higher cyclic variation (COVimep), higher BSFC, lower BTE, lower combustion efficiency, with no significant variations in cylinder pressure, THR, and IMEP compared to regular diesel. Soot and NOx emissions were demoted by 70% and 25% for Hep50 at 100% compared to diesel.