Experimental investigation on the combustion and exhaust emission characteristics of biogas–biodiesel dual-fuel combustion in a CI engine

• Published in: Fuel processing technology Vol. 92; no. 5; pp. 992 - 1000
• Main Authors: Yoon, Seung Hyun, Lee, Chang Sik
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2011; Elsevier
• Subjects: Alternative fuel; Applied sciences; aromatic compounds; Biodiesel; Biogas; Biomass; combustion; Compression ignition engine; diesel engines; Dual-fuel combustion; emissions; Energy; energy use and consumption; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exhaust emissions; Fuels; heat; injectors; Natural energy; oxygen; soot; sulfur; temperature; Alternative fuel; Biogas; Compression ignition engine; Exhaust emissions; Biodiesel; Dual-fuel combustion; Desulfurization; Gaseous fuel; Diesel fuel; Engine test; Pollution control; Soot; Biofuel; Combustion; Oxygen content; Pollutant emission; Heat liberation; Combustion gas; Injector; Exhaust gas; Fuel gas; Diesel engine; Experimental study; Case study; Sulfur content; Dual fuel engine; Cetane number; Ignition delay; Performance
• ISSN: 0378-3820; 1873-7188
• DOI: 10.1016/j.fuproc.2010.12.021

An experimental investigation was performed to study the influence of dual-fuel combustion characteristics on the exhaust emissions and combustion performance in a diesel engine fueled with biogas–biodiesel dual-fuel. In this work, the combustion pressure and the rate of heat release were evaluated under various conditions in order to analyze the combustion and emission characteristics for single-fuel (diesel and biodiesel) and dual-fuel (biogas–diesel and biogas–biodiesel) combustion modes in a diesel engine. In addition, to compare the engine performances and exhaust emission characteristics with combustion mode, fuel consumption, exhaust gas temperature, efficiency, and exhaust emissions were also investigated under various test conditions. For the dual-fuel system, the intake system of the test engine was modified to convert into biogas and biodiesel of a dual-fueled combustion engine. Biogas was injected during the intake process by two electronically controlled gas injectors, which were installed in the intake pipe. The results of this study showed that the combustion characteristics of single-fuel combustion for biodiesel and diesel indicated the similar patterns at various engine loads. In dual-fuel mode, the peak pressure and heat release for biogas–biodiesel were slightly lower compared to biogas–diesel at low load. At 60% load, biogas–biodiesel combustion exhibited the slightly higher peak pressure, rate of heat release (ROHR) and indicated mean effective pressure (IMEP) than those of diesel. Also, the ignition delay for biogas–biodiesel indicated shortened trends compared to ULSD dual-fueling due to the higher cetane number (CN) of biodiesel. Significantly lower NOx emissions were emitted under dual-fuel operation for both cases of pilot fuels compared to single-fuel mode at all engine load conditions. Also, biogas–biodiesel provided superior performance in reductions of soot emissions due to the absence of aromatics, the low sulfur, and oxygen contents for biodiesel.