Unraveling economic-environmental coupling in China's petrochemical industry towards carbon peaking

• A FLIP model is developed to decarbonize the petrochemical industry. • The model differentiates flexible industries from lock-in infrastructure. • Structure upgrading and efficiency improvement should be coordinated. • Decoupling of economic growth and carbon emission is gained via model optimization. The petrochemical industry is a (key pillar) of chemical production and has relatively stable product demand in a long term, but it faces great decarbonization challenges due to the high energy consumption and complex industrial structure. To tackle this, a flow-land-infrastructure-petrochemical (FLIP) multi-factor model is developed with integration of material and energy flow analysis and decoupling assessment, targeting industrial carbon peaking via industrial structure upgrading and production efficiency improvement of four-digit level petrochemical sub-sectors. A nationally leading petrochemical industrial park was then selected to validate the model's effectiveness and robustness. Through the model optimization, the park could achieve 19 % and 30 % of CO 2 e emission reductions in 2025 and 2030 respectively, compared with emissions in the scenario without intervention. The overall carbon productivity could rise by 89 % with a decoupling index of -0.15 between economic growth and carbon emissions during 2020–2030, showing a feasible carbon peaking pathway. Infrastructure with lock-in emissions needs energy system transformation and adjacent industrial symbiosis from a regional perspective, while promotion targets and entry thresholds of carbon productivity should be individually tailored for each stock and incremental manufacturing sub-industry. The model could be extended to other petrochemical clusters and emission-intensive industries, synergistically addressing the effects of structure upgrading and efficiency progress to support practical and economically sustainable carbon peaking pathway formulation.