The optimisation of bio-diesel production from Sunflower oil using RSM and its effect on engine performance and emissions

Bio-fuel production provides an alternative non-fossil fuel without the need to redesign current engine technology. This study presents an experimental investigation into the effects of using bio-diesel blends on diesel engine performance and its emissions. The bio-diesel fuels were produced from Sunflower oil using the transesterification process with low molecular weight alcohols and sodium hydroxide then tested on a steady state engine test rig using a Euro 4 four cylinder Compression Ignition (CI) engine. This study also shows how by blending bio-diesel with diesel fuel at intervals of B5, B10, B15, and B20 can decrease harmful gas emissions significantly while maintaining similar performance output and efficiency. Production optimization was achieved by changing the variables which included methanol/oil molar ratio, NaOH catalyst concentration, reaction time, reaction temperature, and rate of mixing to maximize bio-diesel yield. The technique used was the response surface methodology (RSM). In addition, a second-order model was developed to predict the bio-diesel yield if the production criteria is known. The model was validated using additional experimental testing. It was determined that the catalyst concentration and molar ratio of methanol to sunflower oil were the most influential variables affecting percentage conversion to fuel and percentage initial absorbance.