China's petrochemical plants' CO₂ emissions and high-impact contributors for carbon-neutrality production

The petrochemical sector accounted for 15% of global industrial direct CO₂ emissions in 2021, with China contributing 43% of global chemical output and therefore being central to climate-change mitigation efforts. However, the lack of China-specific, process-based assessments has constrained targeted strategies. Here, we present a comprehensive CO₂ emissions analysis of 3119 petrochemical plants in China, capturing variations across 123 products, 185 processes, feedstocks, energy use, and product relationships within production chains. We estimate annual emissions at 813.7 million tonnes (Mt) CO₂ (±25%) in 2021, offering refined region-specific details beyond previous global or national assessments. We identify distinct emission hotspots at specific processes and product-chain stages, where low-carbon substitutions in feedstocks and reactions can reduce carbon intensity by up to 2.9 tonnes of CO₂ per tonne of product, while key stages in integrated complexes can account for up to 50% of chain emissions. These findings highlight the need for coordinated, chain-wide interventions to enable decarbonization.