Effects of Methanol/Gasoline Blends on a Spark Ignition Engine Performance and Emissions

Abstract

Three typical methanol-gasoline blends M10, M20, and M85 containing 10%, 20%, and 85% of methanol by volume, respectively, were used to investigate the effects of different methanol/gasoline ratios on engine power, thermal efficiency, and emissions, especially the exhaust methanol emission. A three-cylinder, port fuel injection engine was applied. Experimental results show that the engine power/torque ratio under the wide open throttle condition mainly depends on the amount of heat delivered to the engine. The addition of methanol significantly improves the brake thermal efficiency, while the methanol/gasoline ratio has a slight effect on it. Engine out CO and NO x emissions decrease with the increase of the methanol/gasoline ratio. The use of M85 leads to a reduction of CO and NO x by about 25% and 80%, respectively. A gas chromatograph is calibrated and used to measure the methanol emission. Measurement indicates that the addition of methanol in gasoline results in an increase of the unburnt CH 3 OH emission. And its concentration is nearly logarithmically proportional to the cyclically injected quantity. Because the response of the flame ionization detector to methanol is 40% that of hydrocarbon, the total hydrocarbon emission of the engine is revised. The nonmethanol hydrocarbons that resulted from gasoline are less affected by methanol addition, while the methanol emission is controlled independently by the cyclic quantity of fuel methanol injection.

Experimental Investigation on the Use LPG-Methanol Blends as a Fuel in Si Engine and Emissions Characteristics

“…Methanol gives higher engine efficiency and is less flammable than gasoline but the range of the methanol-fueled vehicle is as much as half less because of lower density and calorific value, so larger fuel tank is required. The organic emissions (ozone precursors) from methanol combustion will have lower reactivity than gasoline fuels hence lower ozone forming potential [14,15,16]. If pure methanol is used then the emission of benzene and PAHs is very low.…”

“…Methanol boiling point at 65°C, ethanol boils at 78°C and LPG has a low boiling point of -6°C. Compared with LPG, the higher boiling point, faster flame propagation speed, high oxygen content (50 wt %), and simple chemical structure of methanol all help to reduce the CO and hydrocarbon (HC) emissions but NOx emissions an increase by 5-10% [14,16,17]. Fig.…”

“…The experiments were conducted on a four cylinder, four stroke spark ignition engine (type fiat 149A4) for this study. The engine has swept volume of 1585 cc 3 , compression ratio of 9.7/1 and its maximum torque is 3800 rpm. The tail pipe of the vehicle exhaust was attached to blower pipes forming the primary segment of the sampling line.…”

“…With ever increasing concerns on environmental pollution, energy security, and future oil supplies, the global community has been seeking nonpetroleum based environment friendly alternative fuels. Alternative fuels for internal combustion engines (SI and CI) have become very important owing to increased environmental protection concern, the need to reduce dependency on petroleum and even socioeconomic aspects [1,2,3,4].…”

Unregulated emissions from a gasohol (E5, E15, M5, and M15) fuelled spark ignition engine

“…Ethanol contains 44% (w/w) carbon (gasoline contains 86%), which gets converted directly into CO upon incomplete combustion. Lower carbon fuel would therefore emit lesser CO emission [46]. UHC emissions are important in order to estimate fuel energy lost in this unburnt form in the exhaust.…”