Sunflower biodiesel: efficiency and emissions

Abstract

With economic development, energy needs grew, utilizing natural resources such as wood, fossil fuels, and nuclear energy in the preceding century. However, rising concerns on energy security and climate change in recent years have focused attention on using alternative sources of energy such as bio-fuels. Biofuels are produced from renewable resources, particularly plant-derived materials, and its production provides an alternative nonfossil 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 four cylinder Compression Ignition (CI) engine. The paper also shows how by blending bio-diesel with diesel fuel harmful gas emissions can be reduced 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. In addition, a second-order model was developed to predict the bio-diesel yield if the production criteria is known. 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.