Sustainable bio-oil production from municipal solid waste: Optimising pyrolysis parameters for superior yield and quality

Utilising municipal solid waste (MSW) as a dry feedstock for bio-oil production significantly enhances the pyrolysis process, optimising both the yield and quality of the bio-oil. The study aims to determine pyrolysis conditions that would lead to a high heating value (HHV) and a low oxygen concentration. These features are essential for bio-oil to be a viable renewable fuel. This study aims to fill this knowledge gap by methodically optimising the pyrolysis parameters, therefore enhancing the efficiency and quantity of bio-oil production from MSW. This study investigated the effects of temperature, residence time, and particle size on bio-oil generation from MSW using the pyrolysis process. The MSW could be refined by comparing the traditional drying procedure at 100°C for 24 hours to an accelerated drying approach at 160°C for 6 hours. The dry basis Municipal solid waste feedstock with particle sizes between 1.5 mm and 6 mm is utilised to generate bio-oil. A response surface methodology (RSM) experimental design, as a comprehensive experimental approach, can systematically modify the selected parameters. MSW samples consist of diapers, paper, plastic, and organic waste. The odour was detected at 170°C during the pretreatment of MSW. Bio-oil yield was monitored and assessed at temperatures (405°C-645°C), residence lengths (5-55 minutes), particle sizes (0.5-7.0 mm), and heat increase rates of 10°C per minute. A maximum bio-oil yield of 44% was achieved from the three parameters with the 500 ml/min nitrogen gas flow rate. The bomb calorimeter measured 35.526 MJ/kg of bio-oil. The CHNS equation predicted an HHV of 38.46 MJ/kg. The CHNS data showed that bio-oil has 75.25% carbon, 0.2% nitrogen, 0% sulphur, 12.34% hydrogen, and 12.21% oxygen. The FTIR results indicated that the bio-oil comprises various chemicals and functional groups, including alkanes, alkenes, ethers, alcohols, and aromatics.