ECONOMIC AND ENVIRONMENTAL IMPACTS OF BIOMASS UTILIZATION IN LOCAL COMMUNITIES: A CASE STUDY OF MINAMISANRIKU TOWN

Anaerobic digestion (AD), also known as biogas technology, is an optimal alternative for municipal organic waste (MOW) treatment due to its capability to recover both material and energy from waste. This study focuses on Minamisanriku Town, where public-private partnerships have promoted the utilization of MOW (kitchen/food waste and surplus sludge from human waste and sewage treatment) as local biomass resources since 2012. We quantified the economic and environmental impacts of MOW utilization by integrating a site-specific Life Cycle Assessment (LCA) based on stakeholder interviews and scenario analysis. This analysis considered the pre- and post-operation of the BIO facility, the use and non-use of digestate as liquid fertilizer, and the facility's 100% operational efficiency. Over the first ten years of the BIO facility's operation, there has been a reduction in waste incineration, increased regional cooperation on local resource recycling, and promotion of sustainable agricultural production. Despite these benefits, kitchen/food waste collection rates remain low (less than 10% of total waste), the facility's utilization rate is suboptimal (50-60%), and several challenges remain unresolved. Scenario analyses indicate that full operation of the BIO facility and marketing of value-added products, such as branded rice grown using liquid fertilizer, could significantly reduce GHG emissions and the integrated environmental load, improve the regional economy, and increase net income. The results underscore the importance of maximizing the benefits of biomass utilization by enhancing stakeholder collaboration to develop value-added uses.