Food and Market Waste–A Pathway to Sustainable Fuels and Waste Valorization

Food and market waste (FMW) is one of the most abundant unrecycled products which poses waste management issues and negative environmental impacts. Thermo-catalytic reforming (TCR) is a pyrolysis based technology which can convert a wide range of biomass wastes into energy vectors bio-oil, syngas, and char. This paper investigates the conversion potential of FMW into sustainable biofuels. The FMW was processed using a laboratory scale 2 kg/h TCR reactor. The process produced 7 wt % organic bio-oil, 53 wt % permanent gas, and 22 wt % char. The bio-oil higher heating value (HHV) was found to be 36.72 MJ/kg, comparable to biodiesel, and contained a low oxygen content (<5%) due to cracking of higher molecular weight organics. Naphthalene was detected to be the most abundant aromatic compound within the oil, with relative abundance of 12.95% measured by GC-MS. The total acid number of the oil (TAN) and viscosity were 11.7 mg KOH/g and 6.3 cSt, respectively. The gross calorific value of the produced biochar was 23.64 MJ/kg, while the permanent gas showed a higher heating value of approximately 17 MJ/Nm3. Methane (CH4) was found to be the largest fraction in the permanent gases reaching over 23%. This resulted either due to the partial methanation of biosyngas over the catalytically active FMW biochar or the hydrogenation of coke deposited on the biochar in the post reforming stage.