Development of Two-Stage Anaerobic Digesters for Biogas Production from Biodegradable Waste of Phitsanulok Municipal, Thailand

Abstract

The purpose of this research is to get more efficiency from a methane producing system using municipal biodegradable waste. This research built a pilot plant in a Phitsanulok municipal slaughter house with a treating capacity of 100 kilogram per day for biodegradable wastes from Phitsanulok city. For more improved efficiency, the pilot plant built a grinding machine, conveyor, added acid tank, twostage anaerobic digesters with pillows in each digester for promotion of methane productions. Data collection such as Temperature, pH, TDS, Con., salt by data logger and COD, BOD, TS, TSS, TVS, TKN were tested by chemical lab. Gas volume was by a gas meter and methane content by gas chromatography. The result showed that the performance of the system Anaerobic Sequencing Batch Tank (ASBT) was high. The average biodegradable loading rate was 54.45 kg/d., the organic loading Rate 3.5 kgTCOD/(m³.d) in acid tank and 0.47 kgTCOD/(m³.d) in two-stage anaerobic digesters. The biogas generation rate average 0.13 m³/kgTCOD.d and methane production average was 49.1-56.0 %. From these results, the two-stage anaerobic digesters showed high efficiency of methane producing about two times of the general fresh waste biogas system could produce about 20-30 % in general. This fundamental data was showed that, it is reasonable to expand to a large scale for municipal biodegradable waste treatment and is useful for the development of high methane producing system.