Scrupulous analysis of the carbon footprint of sustainable electricity produced from raw bagasse, torrefied bagasse, and filter cake pellets in Thailand

Abstract

This study evaluates the carbon footprint of a 25 MW biomass power plant in a sugar factory, focusing on its 8 MW grid supply. Six key activities were assessed: fuel preparation, combustion, power generation, particulate removal, and water production (soft and cooling). The research compares greenhouse gas (GHG) emission from three scenarios: 100 % raw bagasse (RB), RB mixed with torrefied bagasse (TB), and RB with filter cake pellets (FP) at ratios of 95:5, 97:3, and 99:1. Data collected throughout 2023 revealed that the plant consumed 119,769.89 tons of RB (51 % moisture, 7740.40 kJ/kg heating value), generating 31,552,711.00 kWh annually. Emissions were calculated in kg CO2eq/kWh using the 2006 IPCC Guideline (The Intergovernmental Panel on Climate Change). Results showed that 100 % RB emitted (0.184+0.006, −0.005) kg CO2eq/kWh. Incorporating TB reduced emissions to 5 % = (0.178±0.005), 3 % = (0.178+0.006, −0.005) and 1 % = (0.178+0.006, −0.005) kg CO2eq/kWh due to decreased diesel oil, electricity, and steam usage in fuel preparation. Remarkably, using FP further decreased emissions, with 5 % FP resulting in negative total GHG emissions of (-0.225+0.015, −0.017) kg CO2eq/kWh, primarily due to the FP preparation process (-15,096,234.40±56,716.07 kg CO2eq/year). The study concludes that combining RB with TB or FP significantly reduces emissions and increases electricity production 5 % torrefied bagasse decreased 0.30 %, 3 % torrefied bagasse decreased 1.34 % and 1 % torrefied bagasse decreased 2.41 %, 5 % pelletized filter cake decreased 229.95 %, 3 % pelletized filter cake decreased 139.77 % and 1 % pelletized filter cake decreased 48.77 % by compare raw bagasse 100 %, promoting sustainable energy generation. These findings encourage the use of biomass for sustainable and environmentally advantageous power production.