Life Cycle Assessment and Economic Analysis of Sustainable Ammonia Production from Biomass

This work investigates a sustainable ammonia production process from life cycle and economic aspects. Coal and coal/biomass feedstocks are adopted for ammonia production. A comprehensive economic analysis is conducted by using several key evaluation indexes. Cash flows of both pure coal and coal/biomass processes have been acquired at several discounted interest rates. Various environmental impact indicators of the Eco-indicator 99 index have been utilized to evaluate the life cycle performance of the production process. The results show that this project is profitable in a short period of time. Both the economic and environmental performances are improved by adding biomass into the feedstock with a mass fraction of 5% or higher. With the addition of biomass, the payback time can be shortened. By adding 15 wt % biomass into the feedstock, the net present value can be increased by around 5.66%. Discounted interest rate is one of the key factors that influences the process economics considering the time value of cash flow. Life cycle assessment provides detailed environmental analysis results from a life cycle point of view. The construction and recycling stages are important for alleviating environmental effects. Human health damage is the most significant category; hence, measures that alleviate the damage to human health have the priority. This work provides pragmatic results and an in-depth knowledge of the biomass-based green ammonia production process.