Recovery of biogas from food waste using treated and untreated anaerobic digestion

Abstract

Biogas is an environmentally friendly, clean, and low-cost renewable energy source. This alternate sustainable source can be used for heat, power, or fuel and making it a good alternative for renewable energy. Biogas can be produced through anaerobic digestion of biodegradable organic materials without oxygen and can be improved by performing thermal treatment. In this study, biogas was recovered using treated and untreated food waste. The characterisation of food waste for its suitability for an anaerobic digestion process was studied by its total solids, volatile solids, pH value, and C/N ratio, following the APHA standard. The anaerobic digestion was treated in a water bath at a temperature of 70 °C for 45 minutes. The Biochemical Methane Potential method was conducted to determine the biogas production from treated and untreated anaerobic digestion. The treated and untreated anaerobic digestion were anaerobically digested at a mesophilic temperature of 37 °C and at a speed of 100 rpm for 15 days. The biogas produced was measured daily by using water displacement method. The total production of biogas for treated anaerobic digestion was 198.70 mL, meanwhile for untreated anaerobic digestion was 185.50 mL. Treated anaerobic digestion showed a slightly higher production of biogas in 15 days by 13.2 mL. The biogas yield obtained for treated and untreated anaerobic digestion was 51.21 mL/g and 47.80 mL/g for every 1 g of total wet sample. This study found that thermal treatment of anaerobic digestion helps in the degradation of organic content in food waste for anaerobic digestion, which leads to higher biogas recovery.