Sustainable renewable ammonia production via solar-driven biomass gasification: a techno-economic perspective

Ammonia (NH3) has emerged as a promising zero‑carbon fuel alternative for decarbonizing long-distance maritime transport, owing to its high energy density, carbon-free combustion, and ease of storage and distribution. To enable its sustainable production, this study develops and evaluates a solar-driven dual fluidized bed gasification (SDFBG) process for converting biomass into NH3, using Aspen Plus simulations. The process achieved an NH3 yield of 2663.4 kg/h from a biomass input of 6250 kg/h, corresponding to 2.35 kg of biomass and 1.01 kg of water per kilogram of NH3 produced. Energy analysis showed overall system efficiencies of 43.32 % (day mode) and 43.28 % (night mode), with normalized energy consumption of 45.12 and 44.62 GJ/t NH3, respectively. CO2 emissions were estimated at 0.81 t CO2/t NH3 during daytime operation and 0.75 t CO2/t NH3 at night. The economic assessment yielded a normalized production cost of 871.70 USD/t NH3 and a payback period of 16.50 years, demonstrating competitiveness for small-scale, low-carbon NH3 production. Sensitivity analysis identified the NH3 selling price as the most influential factor in economic viability. With improved heat integration and favorable policy incentives, the SDFBG system offers a scalable and sustainable pathway for renewable NH3 production.