This study proposes a methodology for High-Value-Added Byproduct Resource Recycling Feedback Network (HBRRFN) to enhance intersystem synergy in chemical processes. The HBRRFN employs feedback units to coordinate the allocation of multiple mass and energy resources for efficient utilization. A mixed-integer nonlinear programming (MINLP) model is developed to obtain the optimal system portfolio through feedback path selection and system scale adjustment. An industrial case involving propane dehydrogenation, ethane cracking, coal-to-methanol, and gas-to-urea is used to demonstrate the effects of recycling feedback of hydrogen, light hydrocarbons, fuel gas, and multigrade waste heat. The best economic and environmental portfolios are determined, and the urea system is specifically identified as a crucial system for reinforcing synergy for overall efficiency improvement. Multiobjective optimization guides the Pareto-optimal solution, achieving a 6.62% environmental gain at 0.01% economic loss, with 20.0% byproduct recovery and 25.4% waste heat utilization. Overall, the HBRRFN provides a generalizable superstructure that supports system-level restructuring and primary-resource substitution beyond conventional secondary-resource allocation.
Li et al. (Sun,) studied this question.