The Potential of Work Integration to Improve Energy Efficiency and Reduce Carbon Emissions in Urea Synthesis Processes

Improving energy efficiency and reducing carbon emissions have become critical challenges in urea production, motivating increased interest in recovering mechanical energy within the process. This study develops a superstructure-based work exchange network with direct work exchangers to analyze mechanical energy recovery in urea synthesis. The work integration (WI) method is evaluated for single-, double-, and triple-stage configurations across different production capacities and compared with a conventional HPRT-based system. Results show that WI consistently outperforms HPRT in both energy recovery and CO2 reduction. The single-stage configuration achieves the highest energy recovery, reaching 8448 MWh/year at 3710.83 t/day, an 18.8% improvement over HPRT. Wind power has the lowest carbon intensity, and emission reduction increases with production capacity. The largest absolute CO2 reduction occurs in the single-stage case, while the greatest relative improvement (up to 41.1%) is observed in the three-stage configuration. Overall, WI significantly enhances energy efficiency and environmental performance in urea production.