STUDY ON USE OF RENEWABLE FUELS IN A COMPRESSION IGNITION ENGINE

Abstract

In the backdrop of rising transportation and Industrial air pollution, air quality is a major concern for human health and environmental degradation. The air quality level in India has also reached the critical stage, particularly in the winter season. To mitigate both concerns, the Government of India has adopted the BS-VI emission and fuel from 1st April 2020. In these standard norms,sulphur containsin petroleum diesel is going to reduce which affects the lubrication property of fuel. Furthermore, HC and NOx emission is also reduced. The implementation of BS-VI norms is a major challenge in the diesel engine manufacturing sector and huge investment is required to modification of engine to achieve the BS-VI. After reviewing the number of significant research articles of this area it was found that the problem of lower sulphur content (low lubricity) in fuel and higher HC emissions can be addressed by the use of biodiesel instead of engine modification. However, the use of biodiesel or blend of biodiesel with diesel was improved the lubricity and HC emission but increased the NOx emission which negating the BS-VI emissions. Therefore, to reduce the NOX emissions and kinematic viscosity and density of biodiesel, many researchers use the blend of alcohol with biodiesel, Moreover NOx reduction was achieved but the performance of the engine was compromised. From the last two decades, a lot of work was carried out on biodiesel particularly on jatropha biodiesel but the use of available jatropha biodiesel was underutilized, due to higher viscosity and higher NOx emission. Because biodiesel, still used as an extender fuel in the CI engine. However, the potential substitute for mineral diesel is still undetermined. Hence, in this research, a small capacity diesel engine is used that is widely used in the agriculture sector. An effort is made to explore the effective utilize of jatropha Study on use of Renewable Fuels in a Compression Ignition Engine vii biodiesel with a blend of n-butanol and n-octanol which can completely replace the petroleum diesel without compromising the performance and emissions characteristics of an unmodified diesel engine. Jatropha is the most versatile inedible oil for easily manufacturing of biodiesel, which is supported by GOI biofuel policy. Recently trial of JME as an aviation fuel also boost its presence as an alternative fuel. Butanol is biomass-derived renewable alcohol such as ethanol while the n-octanol is synthesized by the petrochemical process of ethylene and n-heptane. It can also be produced from biomass. The jatropha oil was extracted from the jatropha seeds. The four variable parameters were used for a reduction in FAA from 7.1% to 1.7 %, during the esterification process. The value of that parameter was the catalytic concentration of 1.13, reaction temperature 58⁰C reaction time 67 minutes, and molar ratio 6.35. The transesterification for biodiesel production was also optimized through design expert software and RSM was adopted for reduction of production cost and maximizes the production yield up to 96.63 %. The value of optimised parameters was molar ratio 7.52, the catalytic concentration of 0.83, reaction temperature 48⁰C reaction time 72 minutes. The JOME produced by using the optimized parameters and analytical grade n-butanol and n-octanol was purchased from standard chemical suppliers. The blend of n-butanol and n-octanol with JOME was prepared in 10% and 20% by volume. The characterization of fuel and blend was measured as per ASTM standard and compared with diesel. The viscosity of samples was slightly higher than diesel, however, it suitably conformed to ASTM D6751. The test rig was developed with Kirloskar make engine model TV-1 having rated power of 5.2 kW and experimental work emission, performance, and combustion analysis was carried out with a blend of JOME90B10, JOME80B20, JOME90O10, JOME80O20 and JOME100 and compare with base fuel D100. Study on use of Renewable Fuels in a Compression Ignition Engine viii The maximum brake thermal efficiency of 29.75 % was obtained by JOME80O20 at 80% load which is 18.34 % higher than BTE of JOME100. The HC and CO emissions of all tested fuels are much lower compared to conventional diesel fuel for all loading conditions. The addition of alcohol leads to HC emissions as compare to JOME100 but this change is marginal. The JOME80O20 emits 17.11% lower HC emission and 54.76% CO emission as compared to a conventional diesel engine. The NOX emissions of JOME80O20 is 9.54% lower than JOME100 but comparable to a conventional diesel engine. A notable observation of blend of n-butanol and n-octanol with JOME was a notice in combustion analysis. The blend of JOME80O20 achieved the highest in-cylinder pressure 72.68 bar among all blend including diesel and JOME and also shown highest HRR 60.95 J/⁰CA and RPRs 6.38 bar/⁰CA but rather than diesel. Higher CHRR was observed for JOME80O20 while the lowest was for JOME100. The blend of n-octanol, shown more CHRR compare to the blend of n-butanol. The blend of n-butanol and n-octanol increased the mass fraction burn rate in the diffusion state and also increase the ignition delay of JOME from 9.9⁰CA to 11.7⁰CA. However the overall outcome of engine trial and subsequent analysis of result it may be stated that the blend JOME80O20 is a better biofuel that may be used in an unmodified diesel engine. The blends of JOME and n-octanol have better performance than a blend of n-butanol and JOME while tested on unmodified diesel engine and this performance improves with increasing the percentage n-octanol up to 20 %.