Techno-Economic Optimization and Environmental Impact Analysis for a Mixed-Mode Upstream and Midstream Forest Biomass to Bio-Products Supply Chain

Book excerpt: Growing awareness and concern within society over the use of and reliance on fossil fuels has stimulated research efforts in identifying, developing, and selecting alternative energy sources and energy technologies. Bioenergy represents a promising replacement for conventional energy, due to reduced environmental impacts and broad applicability. Sustainable energy challenges, however, require innovative manufacturing technologies and practices to mitigate energy and material consumption. This research aims to facilitate sustainable production of bioenergy from forest biomass and to promote deployment of novel processing equipment such as transportable biorefineries. The study integrates knowledge from the renewable energy production and supply chain management disciplines to evaluate economic and environmental targets of bioenergy production with the use of the multi-criteria decision making approach. The presented approach herein includes qualitative and quantitative methods to address the existing challenges and gaps in the bioenergy manufacturing system. The qualitative method employs decision tree analysis to classify the potential biomass harvesting sites, considering biomass quality and availability. The quantitative method proposes mathematical models to optimize the upstream and midstream biomass-tobioenergy supply chain cost, using mixed bio-refinery modes (transportable and fixed) and transportation pathways (traditional and new). The supply chain environmental impacts are assessed by considering the carbon footprint of the harvesting, collection, size reduction, transportation activities, and bio-refinery processing. While transportable bio-refineries are shown to reduce biomass-to-bioenergy supply chain costs, production and deployment of transportable bio-refineries are limited due to operational challenges associated with undeveloped mixed-mode bioenergy supply chains, as well as supply uncertainty. A case study for northwest Oregon, USA is undertaken using actual data to verify the proposed approach.