Sustainable Transition Pathways of Green Methanol Production in China: Provincial Cost Evolution Under Carbon Neutrality Goals

Achieving sustainable industrial transformation under carbon neutrality constraints requires breaking the high-carbon lock-in of the chemical sector through renewable-based production pathways. Green methanol, produced via CO2 hydrogenation using green hydrogen and captured industrial CO2, represents a critical technological option for decarbonizing methanol production while enabling circular utilization of industrial carbon emissions. Existing research on green methanol cost generally treats the CO2 feedstock cost as a uniform national constant, thereby obscuring the economic heterogeneity of different industrial CO2 sources and their spatial coupling with provincial renewable resource endowments, which limits the granularity of decision support for regionally differentiated green methanol deployment. This study constructs an integrated sustainability assessment framework for green methanol in China, systematically differentiating four typical post-combustion industrial CO2 source scenarios—steel, cement, coal-fired power and coal–chemical industries. By integrating the levelized cost of electricity (LCOE) model, green hydrogen production cost accounting, and provincial-level CO2 capture cost trajectories, the framework forecasts the provincial green methanol production cost across 29 Chinese provinces from 2030 to 2060. The results show that (1) under the four industrial CO2 source scenarios, China’s provincial green methanol cost declines persistently between 2030 and 2060, with the coal–chemical source achieving the lowest cost (2032–3434 CNY/t) and the coal-fired power source the highest (2168–3565 CNY/t) in 2060. (2) The spatial pattern shows a stable “low costs in the Three-North region and high costs in southeastern and central China” differentiation, with Qinghai, Gansu, Inner Mongolia and Xinjiang positioned below 2500 CNY/t in 2060, reflecting the resource–environment coupling mechanism governing sustainable deployment of renewable-based chemical production. (3) Green hydrogen accounts for 76.4–80.9% of total cost while CO2 capture accounts for 4.1–10.1%, so that inter-provincial cost spread within any scenario is governed almost entirely by green hydrogen cost, whereas the choice of industrial CO2 source shifts the cost level of a given province. (4) Traditional industrial provinces such as Hebei and Jilin attain near-term cost competitiveness comparable to northwestern resource-rich provinces by combining locally available low-cost CO2 sources with a favorable renewable generation mix, though this advantage narrows towards 2060. These findings provide scientifically grounded pathways for China’s sustainable chemical industry transition, supporting the coordinated achievement of industrial decarbonization (SDG 9), climate action (SDG 13), and responsible consumption and production (SDG 12), while offering actionable guidance for spatially differentiated sustainable development policies that maximize economic and environmental co-benefits.