An overview: Energy saving and pollution reduction by using green fuel blends in diesel engines

Green microalga Scenedesmus acutus grown on municipal wastewater to couple nutrient removal with lipid accumulation for biodiesel production.

Performance and emission characteristics of variable compression ratio CI engine fueled with dual biodiesel blends of Rapeseed and Mahua

This work investigated the optimization of biodiesel production from neem (Azadirachta indica) oil using a two-step transesterification process and determination of the qualities of the neem oil biodiesel. This was with a view to establish its production and viability potentials. Biodiesel production was carried using a two-step transesterification process. The first step was carried out using 0.60 w/w methanol-to-oil ratio in the presence of 1% w/w H2SO4 as an acid catalyst in 1 h at 50°C. The second step was base (NaOH) transesterification of the product from the first step using conditions specified in the optimization design. The central composite design optimization conditions for the second step were temperature (45°C to 65°C), catalyst amount (0.45% to 1.45% w/w), reaction time (45 to 65 min), and methanol/oil molar ratio (1.5 to 7.5). The physicochemical properties of the neem biodiesel were carried out using standard methods, while the fatty acid profile was determined using gas chromatography. Optimized biodiesel yield of 89.69% was produced at reaction time of 65 min, catalyst amount of 0.95 g, temperature of 55°C, and methanol/oil molar ratio of 4.5:1. The values for the physicochemical properties are 0.05% moisture content, 0.9 specific gravity at 25°C, 5.5 mm2/S kinematic viscosity, 207 mg KOH/g, 70.7 g I2/100 g iodine value, 55.31 cetane number, 39.85 MJ/Kg calorific value, 4 pour point, 8 cloud point, and 110 flash point. These values conform to international standards, in particular, American Society Testing Materials (ASTM).

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Optimization of two-step transesterification production of biodiesel from neem (Azadirachta indica) oil

Engine performance improvement and exhaust emissions reduction are the two most important issues to develop a more efficient engine with less environmental impact. For a diesel engine, injection timing is one of the major parameters that affect the engine performance and emissions. Now-a-days, alternative fuels for internal combustion engines have created interest among the researchers around the world due to the limited reserve and rapid depletion of petroleum based fuels. In this paper, studies focused on characterizing influence of injection timing on engine performance and exhaust emissions have been critically reviewed where diesel, biodiesel, alcohol and other alternative fuels are used. In case of diesel fuel, advancement in injection timing results in lower carbon monoxide (CO) and hydrocarbon (HC) emission; though it increases nitrogen oxides (NOX) emission. Advance injection timing increases brake thermal efficiency (BTE) and decreases brake specific fuel consumption (BSFC). Biodiesel–diesel blends produce more HC and CO emission, but reduce NOX emission when injection timing is retarded. Advancement in injection timing results in higher exhaust gas temperature with increase of biodiesel percentage in the blends.

Assessment of emission and performance of compression ignition engine with varying injection timing

A 10.3-kW single-cylinder water-cooled direct-injection diesel engine was evaluated using blends of biodiesel (B10 and B20) obtained from a mixture of mahua and simarouba oils (50:50) with high-speed diesel (HSD) in terms of brake specific fuel consumption, brake thermal efficiency, and exhaust gas temperature and emissions such as CO, HC, and NOx. Based on performance and emissions, blend B10 was selected for long-term use. Experiments were also conducted to assess soot deposits on engine components, such as cylinder head, piston crown, and fuel injector tip, and addition of wear metal in the lubricating oil of diesel engine when operated with the biodiesel blend (B10) for 100 h. The amount of soot deposits on the engine components was found to be, on average, 21% lesser for B10-fueled engine as compared with HSD-fueled engine due to better combustion. The addition of wear metals such as copper, zinc, iron, nickel, lead, magnesium, and aluminum, except for manganese, in the lubricating oil of B10-fueled engine after 100 h of engine operation was found to be 11% to 50% lesser than those of the HSD-fueled engine due to additional lubricity.

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Snehal S Jadav

Papers

Performance of a diesel engine with blends of biodiesel (from a mixture of oils) and high-speed diesel