Abstract: This study addresses the challenges of analytical solution for equilibrium calculation of complex chemical reactions with high stoichiometric coefficients in chemical equilibrium teaching. Focusing on the equilibrium conversion rate of ammonia synthesis, we integrate the Gibbs function criterion, Van't Hoff equation, and Le Chatelier's principle to elucidate both qualitative and quantitative effects of temperature and pressure on reaction equilibrium. To overcome traditional teaching limitations in calculating the conversion rates for multi-molecular reactions, we employ Aspen HYSYS software's Gibbs Reactor module to establish a digital simulation platform. Using the PR-Twu property package with real gas fugacity corrections, we simulate hydrogen conversion rates under operational conditions of 450-550 ℃ and 20-30 MPa, comparing results with theoretical values derived from ideal gas assumptions. Our findings demonstrate significant fugacity effects under high pressure (e.g., 49.3% simulated conversion vs. 62.9% theoretical maximum at 30 MPa/450 ℃), confirming the inadequacy of ideal models for high-pressure systems. Furthermore, results show that increased temperature reduces ammonia synthesis conversion while elevated pressure enhances it. This work provides visual verification of thermodynamic principles through digital simulation, offering a data-driven pedagogical approach for chemical equilibrium education.

Key words: Asepn HYSYS, Chemical equilibrium, Ammonia synthesis, Conversion rate