Abstract
The integration of industrial symbiosis (IS) and carbon capture utilization (CCU) is recognized as a key strategy for achieving net-zero emissions in industrial parks (IPs). However, the optimization of these processes in combination remains an undeveloped research area. This work presents a multi-objective optimization framework implemented in Pyomo and linked with OpenLCA to simultaneously maximize material exchanges and minimize operational costs while evaluating CCU deployment. Applied to Portugal's largest industrial park, the model identified 26 feasible symbiotic exchange routes involving 14 enterprises and 7 potential CCU technologies. Maximum material exchange optimization yields 3,042,107 ton/year across 26 symbiotic routes and 7 CCU units, achieving 89.8 % reduction in climate change impact (from 13.5 to 1.76 million CO2eq/year); Cost minimization achieves 2,223,298 ton/year with 27 % fewer exchanges, delivering 87.0 % environmental reduction and net revenue of €65.5M/year via carbon tax avoidance. The proposed trade-off configuration deploys 2 CCU units (both for methanol production), establishes 12 symbiotic routes, exchanges 2,925,556 ton/year, and generates €65.5M/year net benefit. Decision variables encompassed inter-enterprise flows, binary decisions to select exchanges, and CCU unit selection informed by technology readiness level (TRL). The epsilon-constraint method generated a Pareto front revealing the cost-benefit trade-offs of the symbiotic network. IS with CCU integration can reduce IP climate impact by 87-90 % while generating substantial economic returns. Methanol emerges as the critical CCU pathway for replacing fossil-imported feedstocks. This framework provides decision-makers with actionable optimization strategies for achieving near net-zero industrial parks by 2050, not only through CCU but also through IS.