Comparative study of gas-to-liquid fuel, B5 diesel and their blends with respect to fuel properties, engine performance and exhaust emissions

Gas-to-liquid (GTL) fuel is regarded as a promising alternative diesel fuel. It can be used either directly as a diesel fuel or in blends with petroleum-derived diesel or biodiesel. This study investigated the fuel properties, engine performance and exhaust emissions of B5 diesel, GTL fuel and their blends. The main fuel properties of the blended fuels showed a linear variation with the fraction of GTL fuel in the blend. The density and viscosity of the blends decreased with the addition of GTL fuel, but the flash point, cetane number and calorific value increased. The engine performance test results showed an average increase in power of 1.15–5.18%, but a lower brake-specific fuel consumption (1.11–5.58%) for GTL fuel and its blends compared with B5 diesel alone. The emission analysis results showed that the GTL fuel and its blends had a slight reduction in NOx emissions (2.33–11.3%) and a significant reduction in CO (6.92–21.52%), hydrocarbon (8.62–31.76%) and smoke (12.2–48.88%) emissions compared with B5 diesel. These indicate the potential for the application of B5 diesel–GTL blends.