DEVELOPMENT OF CO-DIGESTER WITH ADSORPTION CHAMBER FOR CONVERSION OF CASHEW APPLE RESIDUE, COW DUNGS AND CORN LEAVE TO COMBUSTIBLE BIOGAS

Biogas production is a crucial aspect of renewable energy development, providing an alternative to fossil fuels and contributing to environmental sustainability. Despite the availability of large organic waste, especially in rural areas, many are yet to adopt the use of biogas due to the high cost of installation of sophisticated biodigester. This research aimed to design and fabricate a co-digester for the conversion of waste cashew apple residue, corn leaves, and cow dung into biogas for domestic uses.  A 64.3 Litre with a purification unit of 28.86 Liter stainless steel biodigester was fabricated. A biochar adsorbent was prepared from a waste shear butter shell and characterised using Fourier Transform Infrared (FTIR) and Scanning Electron Micrography (SEM). A substrate composition of cashew apple residue, cow dung, and corn leave mixing ratio of 10:6:2 was used for the biogas production. The choice of the mixed composite was to provide a suitable carbon-to-nitrogen ratio for biogas production The biogas composition was determined using GC-MS, while the bomb calorimeter was used for the determination of the heating value. The biogas produced had 66.18% methane content but slightly dropped to 65.22% due to loss on purification. The adsorption process caused an alteration in the FTIR spectra and SEM morphology of the developed adsorbent after treatment. The developed biodigester can be recommended for the conversion of different blends of organic waste to biogas, the purification units can also accommodate different adsorbents in biogas upgrade for both domestic cooking and power generation.