DESIGN OF DOMESTIC SCALE BIO-DIGESTER ASSEMBLY, EXPERIMENTATION FOR BIOGAS PRODUCTION AND COMPARISON OF RESULTS WITH CONVENTIONAL DIGESTER

Abstract

The work explored various digesters that are currently under implementation, explored their pros and cons and designed a digestion gas collection mechanism suitable for small scale applications. Internal mixing being uneconomical in the domestic and individual scale, it is not being practiced which has to be compensated with large hydraulic retention time to prevent sludge accumulation and scum formation. This in turn reduces the plant capacity for gas production. Our design configuration incorporates automatic and controlled pressure swing mechanisms incorporated by the gas production which acts as the driving force for slurry circulation in the digester and promotes gas recovery as well as improve digestion efficiency. The configuration was run  in 20 l and 50 L scales  and observed for the physical constraints encountered during  operation, recorded for change in digestion parameters with changes in substrate and organic loading rates and also recorded the gas production which was compared with the results in the literature as well as conventionally operated domestic  scale digesters.