(619f) Biogas Production Trend at Various Temperature Conditions and Methane Enrichment Using Solvent Absorption Method

Depletion of the fossil fuels and their prices are going up therefore it is the need of the hour to find out alternative renewable energy resources. At the same time the garbage production is increasing and creating serious environmental and health risks. This waste requires safer treatment to maintain human health and natural environment. Nowadays, main focus is on transformation of waste into value added products as well as energy production. This work investigates the biogas production considering the effect of pH and temperature. Methane enrichment process by removal of CO₂ & H₂S was also the part of this study. Fruit and vegetable waste (FVW) of banana, apple, orange, potato, poes peels and cabbage were used as raw material for biogas production. Lab scale batch anaerobic digestion (AD) is conducted at mesophilic temperature (MT) 35^oC and thermophilic temperature (TT) 55^oC. The raw biogas is pebbled through water, NaOH, Ca(OH)₂ and triethanolamine (TEA) for purification.

The experimental results show that mixed fruit waste (MFW) provides 10% more biogas yield than mixed fruit vegetable waste (MFVW). The maximum biogas yield was 0.030 (g/g volatile solids) at TT. The optimum pH range is found between 8 -8.5. The use of chemical solutions like NaOH, Ca(OH)₂ and TEA instead of water increases methane enrichment upto 5%, 9% and 7%  respectively. The impurities CO₂ and H₂S decreased upto 28% and 150 ppm respectively by using Ca(OH)₂. Process is effective to enhance the gas production with change of process conditions and enrichment of biogas by removing carbon dioxides and hydrogen sulfide.