Possibilities and challenges for converting waste biomass into fuel, feed, and fertilizer in Nepal

Waste biomass is mainly used conventionally, without being converted into valuable products in developing countries, e.g., Nepal, mainly due to a lack of proper conversion knowledge, infrastructure, and resource data. We assessed the amount of biomass at sub-national (geography, province, and district) levels in Nepal to explore its conversion possibilities and challenges. Our assessment includes waste biomass such as agriculture crop residues, municipal waste, livestock, and human waste. We identified their current utilization practices and discussed their conversion possibilities, focusing on fuel, feed, and fertilizers. We estimated that about 1.7–5.0 million tonnes (Mt) of pellet/briquette and biochar, 1.7–5.1 Mt of feed block, 129–387 million m3 of biogas, and 0.6–1.9 Mt of fertilizer can be produced in Nepal. The conversion of the waste biomass into valuable products can have significant environmental and economic benefits. Our findings can help authorities formulate appropriate policies and entrepreneurs to develop business plans for proper biomass utilization in Nepal at national and subnational levels.