PERFORMANCE ANALYSIS OF FLEX BAG ANAEROBIC DIGESTER

Abstract

This study is aimed to assess the performance of flex bag digester according using different performance parameters; the capacity of the digester was 2000 Liters with working volume of 1500 Liters. The performance parameters assessed were technical performance parameters include temperature fluctuation, pH levels and gas production per kg of feedstock, operational performance parameters include cleanliness of the site and ease of use, economic performance parameters include investment cost, operational cost , and social, environmental parameters include stove and lamp use, and firewood saving. Two kinds of feedstocks were used in the study Cow dung feedstock and food waste feedstock with a dry matter of 20 percent and 50 percent respectively, the average feeding of cow dung feedstock was about 19kg per day, and 10 kg per day for the food waste feedstock. The retention time of the feedstocks was found to be 40 days and 30 days respectively, with potential gas production of 32 Liters per kg of cow dung and 194 Liters per kg of food waste. The absence of an inlet mixing tank at the inlet makes feeding it more cumbersome and also increases the likelihood of spillage of the mixture around the inlet of the biodigester. The produced biogas was used in cooking stove for cooking different types of food. It found that the consumption of biogas is proportionally changes with change of cooking time and the pressure inside the digester.