(778b) Sustainability Analysis of the Supply Chain of Bio-Syngas Production and Its Potential As Chemical Platform for Syngas Fermentation

This study discusses the potential of bio-syngas as a renewable chemical platform for the production of bulk-chemicals considering a hybrid process, i.e. thermochemical and biochemical processes. The focus of this study is on the upstream section of the value chain, from biomass production, collection, distribution, and processing into syngas and its subsequent purification. In addition, further syngas fermentation into ethanol is included as a case-study to represent the production of bulk chemicals from syngas.

Here, conceptual designs of the whole value chain were developed through the combination of different tools for supply chain design and for (bio)chemical process design. The whole value chain includes the feedstockâ??s supply chain and the thermochemical conversion from biomass into syngas via gasification. Development of the supply chain was done using a tool obtained from literature and an Aspen plus model was conducted to simulate the conversion process.

Four different case studies were considered, based on the selected feedstocks: Pine, Corn stover, Sugarcane bagasse, and Eucalyptus. Feedstocks were selected based on availability, price and properties. The considered gasification technology is the indirectly heated circulating fluidized bed (CFB) gasifier and is selected based on syngas quality, tar yield, scale, size tolerance and mixing. Hence, two different geographical feedstock production locations are compared, Pine and Corn stover are located in the USA while Sugarcane bagasse and Eucalyptus are considered to be produced in Brazil. These four different cases were assessed by a techno-economic evaluation and a life cycle assessment (LCA) accounting for syngas production in three different regions (the EU, the USA and Brazil). A sensitivity analysis was performed to investigate the influence of the biomassâ?? moisture content, gasification temperature, tar reformer, co-generation of electricity and steam on the syngas production costs and the environmental impact.

Results confirmed that bio-syngas could be a feasible and sustainable platform. Comparing costs related to the production of the lignocellulosic sugar platform, syngas can be produced for less than half of the production costs of the sugar platform, saving $130/t of platform produced. In addition, the production of bio-syngas compared with production of coal derived gas, the global warming potential (GWP) and the non-renewable energy use (NREU) could be reduced by 54.6% and 72.6%, respectively. In addition, minimal 0.071 kg CO₂-eq/MJ and 3.04 MJ/MJ energy content of the gas could be saved by the production of bio-syngas. Although data confirms the potential of a modest and sustainable platform, this study provides the first data available considering production costs and environmental impact of the production of bio-syngas specifically for fermentation. Therefore additional research is recommended. Results from this work provide direction, focus and recommendations for development towards potential commercialization of the biomass conversion route for the production of bulk-chemicals.