Performance of 200 Liter of Continuous Anaerobic Digester for Processing Animal Waste of Cattle Dung

Abstract

This study aims to explore continuous anaerobic digesters that normally use cattle dung as a substrate. In this work, a 200-liter continues anaerobic digester was established to conduct the research. The digester was filled with mixture of cattle dung and water (50%:50%). The digester was operated in the batch system for about 1 month at the beginning. The digester was then operated by continuously feeding every day with 5 liter mixture of cattle dung and water (50%:50%) for 1 month observation. The digester was stirred during feeding time for easy flow of the substrate inside the anaerobic digester and also avoid the formation of scum. The biogas production was measured, methane and carbon dioxide composition were detected, and temperature inside digester as well as ambient temperature outside the digester was recorded. The pH inside the digester were measured to recognize the process that was involved. Biogas production is found to almost linearly increase with a rate around 15 liter/day. The average methane concentration is around 65.4 %. The average CO₂ content is found around 30.8%. The average temperature inside the digester is 33.6^oc and average ambient temperature outside digester is 30.1^oC.  The average pH is found to be at a value of  6.7. The 200 liter continuous anaerobic digester is found sophisticated by feeding with 5 liter slurry of cattle dung every day.