Performance and emission characteristics of butanol and gasoline mixtures in a spark ignition engine

Petrol and petroleum based fuels resources are declining and their productioncosts are increasing rapidly. In addition, these fuels cause several environmentalpollutions. For this reason, researches about alternative fuels are increasing in orderto reduce production cost, decrease environmental pollution and increase efficiency.LPG, natural gas, biodiesel and some derivatives of alcohol like ethanol andmethanol are good examples for alternative fuels. Some of these fuels can be used aspure or as blends with derivatives of petrol.In this experimental study, affects of fuel blends that are prepared by mixingbutanol with gasoline at volumetric rate of 5%, 10% and 15% to performance andexhaust emissions of a petrol engine were investigated. Firstly, pure unleadedgasoline and pure butanol were tested according to ASTM standards, after those fuelproperties of fuel blends that are prepared by mixing butanol with gasoline atvolumetric rate of 5%, 10% and 15% were measured similarly. By using acommercial 4 stroke, 4 cylinder petrol engines, performance values like torque andpower were measured with a computer controlled hydraulic dynamometer, fuelconsumption values were measured with computer controlled volumetric flow meterand emission values were measured by the help of exhaust gas analyzer. Accordingto experimental results it was determined that addition of butanol to gasolinedecreased engine performance values due to its lower heating value; however, sincebutanol contains oxygen, it increased combustion efficiency and as a result causedreduction of exhaust emission values at important rates.Key Words: Butanol, Torque, Power, Fuel Consumption, Emissions.