PROSPECTS OF DRY ANAEROBIC DIGESTION OF ORGANIC SOLID WASTES FOR BIOGAS PRODUCTION IN NEPAL

As wet methane fermentation process has only been utilized till now for the treatment of cattle manure to produce biogas in Nepal, the further dissemination of biogas can be fueled by providing solutions to the technical problems including unavailability of water source, scarcity of the space near to house, flow of liquid digestate and handling of slurry to the farm. Dry methane fermentation process is a prosperous and future technology for efficient biogas production with remarkable benefits including stabilization of the organic solid wastes in its produced form, no requirement of liquid source, high organic loading rate, smaller fermenter, no liquid effluent, and no requirement of purification of the effluent. Although it has not been used so far in Nepal, it would be a promising excellent alternative to the conventional wet methane fermentation process to treat cattle manure and other biodegradable materials. The existing technology (Fixed dome type biogas fermenter) can also be used for the dry methane fermentation process in Nepal with minor modifications by increasing the diameter of inlet feeding pipe and enlarging outlet chamber.