UTILIZATION OF ORGANIC WASTE GENERATED BIO METHANE FOR TRANSPORTATION APPLICATION

Abstract

Municipal waste management has been a persistent issue in India for decades, with the increasing urbanization and population leading to an alarming rise in daily waste generation. Unfortunately, most of this waste is not segregated, leading to environmental and health hazards as the organic waste gets mixed with non-biodegradable waste. This also makes recycling and reusing waste materials challenging, leading to natural resource depletion and environmental degradation. Therefore, immediate action is required to address this issue. In present work a case study was conducted at Delhi Technological University to tackle the problem, where organic waste was collected from the university campus. For easy segregation, 750 dustbins labeled organic and inorganic waste were distributed across the canteen, mess, and all residential apartments, with a holding capacity of up to 13 kg of garbage. Over 12 months, 24 sample sets of household organic waste were studied, with a sample size of 1620 waste bags. The study found 73 types of organic waste, with raw vegetable waste (RVW), fruit waste (FW), and mixed cooked waste (MCW) being the most common, weighing 518.53 kg, 263.57 kg, and 249.94 kg, respectively. The relationship between these waste types was analyzed using the regression method. The result suggested that the coefficient of determination (R2 ) of RVW and FW, RVW and MCW, and FW and MCW were 0.90, respectively 0.91, and 0.94, respectively, with p < 0.05. Firstly, it analyzes the relationship between different types of organic waste, and then experiments are conducted to optimize biogas production. The Taguchi method is used, which involved nine experimental anaerobic digesters (ADs) with a total capacity of 10 liters. The design of experiment data tumbling and without tumbling processes was used to determine the best combination of parameters for optimal biogas production. It investigated FW, RVW, and MCW at different proportions (1:1, 1:1.5, and 1:2) with varying v temperatures (35°C, 40°C, and 45°C) and multiple feeds. It evaluated the tumbling effect for 0,10, and 20 minutes at 15 rpm. The Taguchi method gave coefficient of determination (R2 ) values of 94.76% and 98.48% for experiments without tumbling and with tumbling, respectively. At 40°C and a 1:1.5 ratio, the average optimum CH4 gas generation in FW without the tumbling effect was 37.12%. The ratios of 1:1.5 and 1:2 in RVW and MCW and the value of CH4 at 35°C were estimated to be 26.7% and 26.68%, respectively. Our findings indicate that tumbling can enhance the amount of CH4 gas produced. Specifically, CH4 gas production in FW increased by 11% and 6% after 10- and 20-min tumbling, respectively, compared to without tumbling. Tumbling resulted in 31.1% and 47.9% more CH4 gas production after 10 and 20 minutes in RVW, and 25.7% and 12.2% more were produced after 10 and 20 minutes in MCW, respectively. Overall, the Taguchi method was an effective tool for determining the optimal parameters for biogas production, and our study highlights the importance of tumbling in enhancing biogas production. To explore the potential of alternative fuels in spark-ignition (SI) engines, pure biogas is compressed and blended with gasoline, ethanol, methanol, and methyl acetate alcohol. It measured the engine performance parameters (BTE, ITE, BP, BSFC, BSEC), combustion phenomenon (Cylinder pressure, Crank angle, Cylinder volume, Mass fraction burned, Mean gas temperature, Rate of pressure rise), and emission characteristics (HC, CO, CO2, NOx). The study included using 10%, 20% (Ethanol, Methanol, Methyl Acetate), and 100% Compressed Biogas (CBG) as alternative fuels. CBG produced the highest BTE of 23.33% compared to all other fuels. The minimum fuel consumption rate of 1.72 kg/h at maximum rpm achieved a BSFC value of 0.44 kg/kWh and an ISFC value of 0.261 kg/kWh. The G90M10, with a cylinder volume of 48.58 cc, achieved the highest cylinder pressure of 67.9 bar. The G80E20 had the highest mean gas temperature (MGT) of 390.20°C. The G90M10 achieved a maximum rate of pressure rise of 0.14 bar/degree at a crank angle of 374°. CBG had the lowest vi emission gases at both minimum and maximum RPM, indicating its potential for producing the best emission results with engine performance compared to all other alternative fuels. Installing biogas plants in urban societies and university campuses can play a vital role in reducing the amount of solid waste produced by utilizing household organic waste to produce green energy. Biogas plants can convert organic waste into eco-friendly green energy, which helps solve the problem of solid waste. CBG fuel is the most effective solution for solid organic waste and a better alternative to gasoline fuel, as it burns cleaner and produces fewer harmful emissions. Waste-to-energy technologies, such as biogas plants, give a reliable renewable energy source and contribute to achieving carbon neutrality goals. CBG fuel can play a key role in reducing dependence on fossil fuels and mitigating climate change. The findings of this study have significant implications for policymakers and waste management authorities as it promotes sustainable waste management practices and the use of renewable energy sources. Governments and industries can collaborate to encourage the development and deploy biogas and CBG technologies to promote sustainable energy practices.