Biogas Purification, Compression and Storage

Abstract

Municipal solid waste in the Kathmandu Valley and emerging cities has been a burden for the government of Nepal for over a decade. Nepal, these days, is notorious in illegal dumping of solid waste on riverbanks and crossroads at urban cities creating a serious environmental and public health problem besides destroying the city's beauty and hindering cultural and religious activities. Time and again, conflict of poorly managed landfill sites have arisen which led to halt of solid waste collection in Kathmandu valley for several days in a place where daily solid waste generation is about 500 tones of which 69 percent is of organic materials and 24 percent recyclable materials (plastics, paper, metal, glass). In order to solve the solid waste management problem in urban cities, the country failed to introduce any reliable and sustainable technology. However, among several waste management technologies available, biogas production may prove to be viable and sustainable waste to energy conversion technology. But biogas can supply energy only near to the plant, which limits its wide spread application and, therefore, bottling of biogas is a must to supply it in and around the cities and villages. In this paper we evaluate the model used in bio-based energy laboratory, Kathmandu University to upgrade and bottle biogas in a cylinder. It is found that the biogas purification, compression and storage system of Kathmandu University has net energy output 180 kWh th per cycle.