Production of bulk chemicals from lignocellulosic biomass via thermochemical conversion and syngas fermentation: a comparative techno-economic and environmental assessment of different site-specific supply chain configurations

This study presents the design and assessment of site-specific supply chains and related manufacturing processes for the production of bio-based chemicals from the syngas platform and via gasification of lignocellulosic biomass followed by syngas fermentation. The supply chains include feedstocks production and collection, biomass gasification, syngas fermentation, and downstream processing. For each of these stages, different alternatives were considered: four feedstocks (pine, corn stover, sugarcane bagasse, and eucalyptus), three products (ethanol, 2,3-butanediol and hexanoic acid), and three geographical locations (the Netherlands, the USA, and Brazil). Conceptual development and analysis of the supply chains were done through the combination of different design and assessment tools, namely biomass supply chains design, fermentation process design (based on thermodynamics and transport), process simulation, and economic and environmental assessments. The minimum selling price (MSP) and two environmental impact categories, i.e., global warming potential (GWP) and non-renewable energy use (NREU), were used as performance indicators. These were compared to data reported in scientific literature and commercial sources for similar processes and ­products. The best overall performance was obtained for the production of 2,3-butanediol from pine sourced in the USA. In the cases of ethanol and hexanoic acid, the syngas fermentation stage had significant contributions to MSP, GWP, and NREU, due mainly to its high energy requirements. Regarding the geographical location, the best economic performance was obtained for the USA followed by the Netherlands and Brazil respectively. Furthermore, operation in Brazil led to the lowest environmental impacts, followed by the Netherlands and the USA.