Study of Biodiesel Blends on Emission and Performance Characterization of a Variable Compression Ratio Engine

Abstract

This study explores the emission of different pollutants using different blends in a variable compression ratio (VCR) engine. Biodiesel synthesized from Jatropha oil using a heterogeneous catalyst was investigated for emission analysis on a single-cylinder VCR engine with various blending ratios as well as load. Blends (biodiesel + diesel) of JB00, JB10, JB20, JB30, and JB100 were prepared at 40°C. The emission parameters, such as nitrogen oxides (NO x ), carbon monoxide (CO), and hydrocarbon (HC), were studied and compared to diesel fuel. Results showed that, among the blends prepared from methyl ester of Jatropha, JB30 shows reduction in emissions of CO and HC up to 43 and 50%, respectively, with an increment of NO x emission up to 20% at the lowest load and compression ratio (CR) of 15. The optimum parameter for the lowest pollutant emission for JB30 was found with a load of 6 kg at CR of 15. ■ INTRODUCTIONThe fossil fuels, such as diesel, gasoline, liquefied petroleum gas (LPG), etc., are diminishing sources of energy, but the demand for energy is increasing day by day. In this regard, biodiesel is a sustainable option 1,2 because it is a nontoxic, biodegradable, renewable, oxygenated, and sulfur-free fuel 3,4 and can be obtained by treating various kinds of vegetable oils and fats. 5,6 Biodiesel production is 82% of the total biofuel production in the European Union, and its global production is estimated to be over 35 billion liters. 7 The comparative higher heating values of biodiesel (39−41 MJ/kg) make it competitive to gasoline (46 MJ/kg), petrodiesel (43 MJ/kg), petroleum (42 MJ/kg), and coal (32−37 MJ/kg) for use in transportation fuel. 8 Therefore, it can be used as a blend or stabilizer 9 at a particular proportion with diesel fuel without any modification to the diesel engine. 10,11 Diesel engines produce a large amount of polluting gases, such as carbon monoxide (CO), unburnt hydrocarbons (HCs), and nitrogen oxides (NO x ), which pose a threat to the environment and, hence, living beings. Emissions of these harmful gases and particles, also result in the greenhouse effect. These gases and particles if inhaled by the humans and animals can cause various detrimental diseases. Hence, to prolong the air excellence, the European emission standard restricted the pollutant emissions for light-duty vehicles as well as heavy-duty vehicles, as mentioned in Table 1.Therefore, the study of blending of a renewable source of fuel, such as ethanol 12 or biodiesel, 13 with diesel on the emissions of polluting gases is very significant for many purposes, such as transportation, pollution, energy generation, etc. Several studies 3,14−17 have explored performance and emission features of biodiesel engines at various engine speeds, loads, and biodiesel ratios. These results showed that the engine performance is affected by the percentage of biodiesel present in the fuel. 18−20 The numerous works on blending of diesel with soybean, 21 Ceiba pentandra, 22 and Eruca sativa gars 23 derived biodiesel were reported for dire...

A Comparative Study of Engine Performance and Exhaust Emissions of Biodiesel and Its Blends Produced from Waste Cooking Oil and Neutralized Waste Cooking Oil

“…The changes of exhaust gas temperature values depending on the engine speed of ED, biodiesels and fuel blends are shown in Figure 6. Biodiesel usage usually improves CO emissions and increases CO2 and NOx emissions due to higher combustion temperature and extra oxygen content in the chemical composition [17]. As a result of the performed tests, it was found that maximum CO emissions occurred at low engine speeds and CO emissions decreased depending on the engine speed rises (Figure 7).…”

Fuel properties, performance and emission characterization of waste cooking oil (WCO) in a variable compression ratio (VCR) diesel engine

“…Higher compression ratios enhance the combustion and thus nitrogen oxides emissions significantly elevates due to higher in-cylinder temperature and higher flame velocity. Biodiesel usage usually improves CO emissions and increases CO 2 and NO x emissions due to higher combustion temperature and extra oxygen content in the chemical composition [26].…”

Influence of the compression ratio on the performance and emission characteristics of a vcr diesel engine fuelled with alcohol blended fuels

“…For biodiesel-alcohol blends, the maximum increment was observed with B95E5 fuel as 7,94% compared to biodiesel at 16:1 CR. The main reason of these trends may be due to improved combustion of diesel-alcohol and biodiesel-alcohol blends [19].…”