Process Design and Kinetic-Based Simulation of a Coupled Biomass Gasification and Chemical Looping Ammonia Generation System

Conventional ammonia production via the Haber–Bosch process is energy-intensive and carbon-heavy. Emerging biomass-based approaches offer a sustainable alternative but often lack rigorous system-level analysis based on actual reaction kinetics. This study presents a novel integrated process coupling biomass pyrolysis/gasification with Chemical Looping Ammonia Generation (CLAG) and waste heat recovery. Unlike previous models relying on simplified assumptions, this simulation incorporates experimental kinetic data for both N-absorption and N-desorption stages to ensure high fidelity. The system’s energy and mass flows were rigorously evaluated using Aspen Plus. Results indicate that the gasification stage is optimal at an O2/biomass molar ratio of 0.2 and 750 °C. In the CLAG unit, a higher N-absorption temperature (1600 °C) and α-Al2O3/C ratio (3:3) significantly enhance ammonia yield. Under these optimal conditions, the system achieves a remarkably low energy consumption of 10.12 GJ/t-NH3 and specific CO2 emissions of 3.2 t/t-NH3—a reduction of over 60% compared to traditional coal-based routes. The integration of waste heat recovery is identified as a critical factor in minimizing net energy input. This work validates the feasibility of the biomass-based CLAG process as a low-carbon, energy-efficient pathway for sustainable ammonia synthesis.