FABRICATION OF BIOGAS DIGESTER AND PRODUCTION OF FUEL FROM ANIMAL DROPPINGS USING HIGH-DENSITY POLYETHYLENE AND POLYVINYL CHLORIDE

Abstract

A portable biogas digester was fabricated to obtain combustible methane gas from livestock waste using HDPE plastics and PVC pipes. The structure was made airtight, and fitted with an inlet channel, gas outlet channel, waste outlet channel, and emergency pressure outlet channel. A domestic water purification filter with filtration elements of activated charcoal, iron filings, and local potash was modified for biogas upgrading. All filter composite materials were dried, and mixed with charcoal, potash, and iron filings in the ratio of 4:3:l. Leak proofing was done using PVC gum, silicon bonds, and rubber gaskets to ensure gas-tight seals. HDPE thread tape was also used as screw-able elements. Upon fabrication completion, a leak test was carried out using one (1) liter of water, and no leakages were observed. The animal droppings of poultry (three bags of 50 kg) were - filled into the digester, mixed, and allowed to generate uniform mass for appropriate environmental conditions for microbial processes of anaerobic digestion, involving the breakdown of microorganisms in the absence of oxygen, for the emission of the gas (methane). Gas collection was achieved through the outlet pipe (connected from the filter) which is the flexible hose connected to the gas cylinder valve, allowing direct capture of upgraded methane in the metal cylinder. The bill of engineering measurement and evaluation (BEME) for the fabrication was made. The obtained methane gas produced was purified - able to biomethane, which is burnable to obtain electricity and heat using combined heat and power (CHP) plants, usable as fuel, and inject - able to the natural gas.