Performance and Emission Characteristics of VCR Diesel Engine using Biodiesel Derived from Waste Cooking Oil: A Review

Abstract

This literature review explores the topic of biodiesel production, including its combustion, performance and impact on emissions. The depletion of fossil fuels is a growing concern as the world becomes more reliant on finite resources such as oil, coal and natural gases which have limited resources that will eventually run out. Their extraction also contributes to environmental degradation and climate change. The demand for alternative energy is on the rise, combined with the limited supply of fossil fuels and driving up prices making alternative sources of energy more attractive. To meet this demand there are many oil-bearing crops that can be used as feed stocks for biodiesel production. There are several commonly oil-bearing crops include soybean, rapeseed (canola), palm oil, jatropha, sunflower among which some were considered as potential alternative fuels for diesel engines. The use of vegetable oil in an engine can lead to several problems, including viscosity issues. Vegetable oil has a higher viscosity than diesel or gasoline, which can clog fuel filters and cause poor fuel flow. Engine damage: vegetable oil can also cause damage the engine components such as injectors and seals. To overcome these issues linked with using vegetable oil as fuel in an engine is either chemically alter or blend with diesel to reduce its viscosity and improve performance. It was reported that the biodiesel has distinct combustion characteristics compared to conventional diesel fuel like lower emissions, higher cetane number, higher lubricity, lower flash point. The biodiesel power output is to be equivalent to that of diesel fuel. In addition, the use of alternative fuels has the potential to mitigate the impact of greenhouse gas emissions, increase energy security and reduce dependence on finite fossil fuels. In VCR engine, compression ratio can be changed in real-time, based on operating conditions such as engine load and speed, allowing the engine to be optimized for different operating conditions. The ability to adjust the compression ratio in a VCR engine offers several advantages over conventional engines, including improved fuel efficiency and lower emissions.