Sustainability assessment of the biomass gasification process for production of ammonia

Any technology needs to be environmentally sustainable to be successful. The biomass gasification technology is often perceived to be carbon neutral. However, these perceptions need to be confirmed using a rigorous life-cycle assessment (LCA). This chapter presents a sustainability assessment of the biomass gasification technology for the production of ammonia. Conventional ammonia production that is based on hydrocarbon feedstock is known to be energy-intensive and tends to make a substantial contribution to the global greenhouse gas emissions. Therefore, an environmentally benign feedstock in the form of biomass is proposed as an alternative. Biomass, when used as a feedstock for ammonia production, is expected to yield a considerable reduction in environmental impacts. This chapter undertakes a cradle-to-gate life-cycle assessment (LCA) for ammonia production from biomass through the gasification route. Three different biomass feedstocks, namely wood, straw, and bagasse, are compared for their environmental sustainability by using different environmental indicators. Furthermore, these feedstocks are modeled for cultivation in three different geographical regions. The results suggest that different biomass feedstocks and geographical regions have their own niche environmental advantages. The global warming potential (GWP) for the straw-based ammonia production was found to be close to natural gas-based ammonia production. Contrariwise, 78% reduction in GWP compared to natural gas-based ammonia production is noticed when bagasse is used as a feedstock for ammonia production.