A Review on the Influence of Additive Blended Biodiesel to the Performance and Emission Characteristics of Heavy-Duty Diesel Engines

Modern industrial society is heavily dependent on energy. The amount of energy needed to sustain a society increases as the world's population grows and transportation systems improve. However, the stringent emissions regulations enacted to control the number of harmful exhaust pollutants from heavy-duty diesel engines are likely to gradually phase out internal combustion engines that run solely on petrochemical fuels. This challenge puts constant pressure on researchers to seek improved fuel technologies that meet emission standards while reducing costs and emissions. In this paper, the impact of biodiesel blends, with or without additives was found to have both positive and negative effects on heavy-duty diesel engines. Biodiesel blends with additives such as 50% biodiesel 400mg/l additive and 100 % biodiesel 500mg/l additive have the potential to reduce emissions of harmful pollutants such as particulate matter (PM), carbon monoxide (CO), and hydrocarbons (HC). However, the impact on nitrogen oxide emissions is less clear and may depend on engine type and operating conditions. Regarding engine performance, additive biodiesel blends exhibited lower power and torque output and slightly lower fuel consumption than conventional diesel. On the other hand, non-additive biodiesel blends such as 5%, 10%, and 20% biodiesel in conventional diesel showed higher nitrogen oxide emissions and fuel consumption, but a reduction in HC and CO emissions. Overall, the use of additives in biodiesel blends can improve certain properties, such as cold weather performance and oxidation stability but the effect largely depends on engine design, operating conditions, and the percentage of additives used. Hence, more research is needed to fully understand the effect of biodiesel blends and additives on heavy-duty diesel engines and optimize their use for maximum benefits.