Operation of a Spark-ignition Engine on Mixtures of Petrol and N-butanol

The Article analyses the use of n-butanol (biobutanol) in mixtures with petrol in spark-ignition (SI) internal combustion engines (ICE). Analysis of the scientific literature allowed determining that n-butanol content had a different effect on the same engine parameters in different tests, thus a decision was made to conduct additional research, where, having assembled the necessary equipment and conducted experimental planning, experimental studies of n-butanol (with its volumetric content being 0%, 20% and 40%) and petrol blends in a SI engine were carried out. Regression analysis of research results was conducted and regression dependences were formed allowing evaluating the impact of the key variables (δ and θ) on engine parameters (Me, Pe and be). The research results have shown that without changing the ignition advance angle θ, petrol blend with 10% n-butanol has essentially no adverse effect on engine power Pe, engine torque Me and specific fuel consumption be. Increasing n-butanol concentration δ, the maximum engine torque Me and effective power Pe decrease, while the specific fuel consumption be increases. Energy engine indicators decline as a result of a lower calorific capacity of n-butanol compared to that of petrol and lower combustion rate of n-butanol. Increasing n-butanol concentration δ in fuel mixture, engine parameters can be improved by advancing the ignition angle θ.