Spatially Explicit Optimal Decarbonization Pathways for China’s Cement Industry

Abstract

Cement production contributes about 8% of global CO2 emissions, but conventional assessments often overlook spatiotemporal heterogeneity in demand, energy resources, infrastructure, and policy constraints. This study develops a high-resolution whole-system optimization framework to evaluate deep decarbonization pathways for China’s cement industry across 31 mainland provinces from 2025 to 2060. The model compares a methane-reforming-based cement process, carbon capture and storage (CCS), and hydrogen-based carbon capture and utilization (CCU) under regional renewable-energy constraints, inter-provincial clinker and CO2 logistics, and dynamic policy and market conditions. Results show that the cost-effective pathway is not a uniform technology replacement but a heterogeneous three-phase transition in which CCS serves as a bridging option before hydrogen-based CCU becomes competitive after 2052. An interim 2040 emission level of approximately 400 Mt CO2 is identified as a critical transition benchmark. Inter-provincial clinker and CO2 flows allow renewable-rich regions to transfer low-carbon production advantages to demand-intensive regions, alleviating spatial mismatches between renewable supply and cement demand. Regional archetypes further show that natural gas prices shape the competitiveness of methane-reforming-based routes. Policy analysis identifies two key thresholds: an annual carbon-price increase exceeding 25 CNY/ton (3.5 USD/ton) CO2 accelerates mitigation, while a methanol price above 2750 CNY/ton (382 USD/ton) supports hydrogen-based CCU adoption. These findings frame cement decarbonization as a coupled energy-industrial system planning problem and provide transferable insights for hard-to-abate sectors facing spatial resource constraints.