(390k) SmartCO2 Ptu: A Novel Integrated Process for Sustainable Urea Production

The Smart Carbon Power-to-Urea (SmartCO2 PtU) process is introduced as an innovative approach to urea production, integrating renewable energy sources with advanced carbon capture and utilization strategies. This novel method addresses the challenges of conventional urea synthesis by reducing capital and operating expenses while enhancing sustainability. The process leverages electrolysis to produce green hydrogen, pressure swing adsorption for air separation, and post-combustion carbon capture (PCC) using aqueous ammonia. The captured CO₂ and renewable ammonia form a reactive stream that feeds directly into the urea synthesis loop, eliminating the need for CO₂ compression and solvent regeneration. Comparative process simulations demonstrate a 49.2% reduction in capital expenditures and a 38.8% decrease in operational costs compared to conventional urea production.

The AsPyCC tool is a Python-based automation framework developed to support the design and optimization of post-combustion carbon capture (PCC) units within the SmartCO₂ PtU framework. Integrated with Aspen Plus®, it streamlines PCC process design by applying built-in design heuristics like CO₂ loading targets, capture rates, and equipment constraints. This significantly reduces engineering effort across diverse industrial applications. AsPyCC also supports scenario analysis and clustering to identify feasible and cost-effective capture opportunities, helping prioritize plant types and flue gas conditions for efficient PCC implementation.

To optimize the downstream utilization of captured CO₂ in urea production, an integrated Aspen Plus-Python framework has been implemented, focusing on kinetic parameter optimization and process conditions fine-tuning. A Sobol sensitivity analysis was conducted to refine the kinetic parameters of the urea pool reactor, achieving an overall error of 9.72% when compared to industrial data. Additionally, a parallelized particle swarm optimization algorithm was employed to determine optimal operating conditions, leading to a 53% reduction in computational time relative to non-parallelized approaches.

By uniting advancements in PCC technology, process automation, and green urea synthesis, the SmartCO2 PtU framework presents a transformative pathway for sustainable fertilizer production. The integration of renewable hydrogen, carbon capture, and ammonia-based CO₂ utilization significantly lowers the carbon footprint of urea manufacturing while enhancing cost-effectiveness.