การผลิตก๊าซชีวภาพจากขยะชุมชนและเศษไม้โดยใช้เทคนิคการย่อยสลายแบบแห้ง

Abstract

This study investigates biogas production from municipal solid waste and wood chip using dry-digestion technique. The experiments compare biogas produced efficiency at differences of mixture ratio of municipal solid waste (MSW) to wood chip. The ratio of MSW to wood chip are1:0, 2:1, 5:1 and 10:1. Each experiment was prepared by using 24 kg of MSW mixed with 6 kg of cow manure and 6 liters of water. Then, let the primary fermentation is closed tank for 14 days. The mixed is then added wood chip with the controlled ratio of MSW to wood chip. Fermentation tank size is 150 liters. Leachate is down-flow to 150 liters leachate tank connected to the bottom of fermentation tank. Daily leachate circulation is 50% by using a circulation pump. Gas production is stored in sampling gas bag, while daily gas production is measured. Fermentation period is 60 days. The results show that the ratio of MSW to wood chip of 5:1 produces maximum accumulative biogas, which is 339.7 liters. The ratio of 2:1, 1:0 and 10:1 produces 280.3, 244.95 and 236.2 liters respectively. The maximum percentage of methane is 57% at the ratio of MSW to wood chip of 2:1 and 5:1. The maximum heating value of methane is 6369.19 kJ. The ratio of 2:1, 1:0 and 10:1 heating value is 5304.38, 4431.12 and 4047.72 kJ respectively. At the ratio of 5:1, solid removal efficiency is 66%, COD removal efficiency is 78% and VFA/COD ratio is 0.372. Sludge remaining in ferment tank is then analyzed for N-P-K. The result show then N and K compositions meet the standard of organic fertilizer. P composition of the ration 10:1 meets the standard of organic fertilizer.