Co-digestion of Cattle Manure and Tea Waste for Biogas Production

Abstract

The increase of world population brings energy and food requirements. Increasing energy demand drives humanity towards new energy sources and work towards energy efficiency developments. Concordantly, due to population growth, the amount of waste is also increasing and causing environmental -issues. Biogas production by co-digestion of wastes -could be a common solution to both issues. Animal manures are typically used as a main substrate in co-digestion applications. Tea waste is used as a co-substrate in this -work due to having large production and consumption volume in Turkey. The aim of this study is to emerge new methods for disposal and reuse of household tea waste. For this purpose, co-digestion method was carried out to determine the biogas potential of household tea waste. Laboratory scale batch type co-digestion is carried out for 80 days under mesophilic (37±2 o C) conditions. All reactors fed with different mixing ratio of wastes and operated with different stirring speeds. The results showed that co-digestion of the wastes have positive impact on biogas and methane yield. Optimum biogas yield is 296.89 mL/gVS and 77.10% methane content are obtained from A2 which consist of 75% cattle manure and 25% tea waste with 100 rpm stirring speed. According to the results, co-digestion of cattle manure and household tea waste both have a positive effect on biogas production and methane content of biogas.