Influence of gas-to-liquid (GTL) fuel in the blends of Calophyllum inophyllum biodiesel and diesel: An analysis of combustion-performance-emission characteristics

This study investigates of the production of calophyllum biodiesel (CIBD) from its crude oil and provides a comparative analysis of the blends of CIBD (CI20) and GTL fuel (G20) with diesel, including a combined blend (DCIG20) of CIBD, GTL and diesel, in the context of fuel properties, combustion, engine performance and emission characteristics. This combined blend was selected to aggregate the promising properties of the two alternative fuels, which is a pioneer investigation that involves GTL fuel. All of the blends were investigated in a four cylinder compression ignition engine. CIBD and CI20 showed improved fuel properties than their crude oil, and DCIG20 and G20 showed promising properties compared with the biodiesel blend. Combustion analysis showed that the peaks of both in-cylinder pressure and heat release rate (HRR) of G20 were slightly lower and occurred at later crank angles than those of diesel. Unlike G20, the other two blends demonstrated higher peak values of in-cylinder pressure and HRR than diesel, and DCIG20 showed lower peak values than CI20 in both cases. The peak locations of CI20 and DCIG20 were slightly advanced compared to those of diesel. The engine performance test results revealed an increase in brake thermal efficiency (BTE), and low Brake Specific Fuel Consumption (BSFC) and Brake Specific Energy Consumption (BSEC) in G20. The two other blends showed a decrease in BTE, but an increase in both BSFC and BSEC, when compared with diesel. Emission analysis results showed that all fuel blends exhibited a reduction in CO, HC and smoke emissions compared with diesel. In the case of NOx emission, both CI20 and DCIG20 showed high values, but G20 showed a significant decrease, when compared with diesel. DCIG20 exhibited an improvement in all of the performance-emission test parameters compared with CI20. (C) 2015 Elsevier Ltd. All rights reserved.