Direct air capture (DAC) removes CO₂ directly from air and achieves net CO₂ removal when coupled with transport and geological storage, thus becoming indispensable in global net-zero emissions pathways. This study proposes to identify demonstration regions and methods for cost reduction and performance improvement of direct air carbon capture and storage (DACCS) in China. We coupled life-cycle assessment (LCA) with DAC learning curves to evaluate and project the net removal efficiency and cost of liquid-solvent absorption and solid-sorbent adsorption. The results show that the national average net removal efficiencies for liquid-based DACCS vary across scenarios, ranging from 17.0% to 69.8%, whereas solid-based technology demonstrates relative stability (77.9% ~89.0%). National average net removal costs of DACCS decline with higher learning rates and larger deployment scales. By 2060, the costs are projected to be 1336~1970 RMB/t for liquid-based technology and 394~1184 RMB/t for solid-based route. There are significant provincial disparities in net removal efficiency for liquid-based technology in 2035, with only Sichuan and Yunnan provinces exceeding 70%, theoretically qualifying them as pilot demonstration. The solid-based technology, in contrast, maintains a steady efficiency of 78.6% ~84.1% across all provinces. Declining energy-related carbon emissions improve the net removal efficiency of DACCS. From 2035 to 2060, the proportion of energy-related carbon emissions drops from 77.3% to 45.7% for the liquid-based technology, and from 68.3% to 22.9% for the solid-based route, indicating that the dominant contribution of the energy supply stage to full-chain carbon emissions gradually weakens. The cost structure of the liquid route is generally energy-dominated, whereas the dominant cost component of the solid route shifts from capture-side capital expenditure to CO₂ transport and storage. This study thus suggests that DACCS demonstration projects be implemented in provinces with abundant non-fossil energy supply, and deployment should be expanded through scale effects and technological improvements to steadily reduce costs and expand adoption.

Against the background of addressing global climate change, hydrogen has attracted much attention because of its characteristics of being clean, carbon-free and efficient.In view of China's resource endowment, hydrogen demand and emission reduction demand, the integrated application of coal-to-hydrogen and carbon capture, utilization and storage(CCUS)technology is of great significance to China's low-carbon energy transformation.The development status, opportunities and challenges of integrated application of coal-to-hydrogen and CCUS technology in China were analyzed systematically in this study to provide relevant suggestions for the development of coal-to-hydrogen with low-carbon emission in China.The results showed that: ①Compared with other hydrogen production technologies, coal-to-hydrogen with CCUS has significant cost advantages; ②Compared with hydrogen production from renewable energy, carbon footprint is the weakness of coal-to-hydrogen, even though CCUS technology can reduce carbon emissions by about 90 %; ③Xinjiang, Shanxi, Shaanxi and Inner Mongolia can be the first areas to deploy coal-to-hydrogen with CCUS technology; ④The challenges of coal-to-hydrogen with CCUS mainly include lack of public recognition and the competition with renewable energy.In the future, China should strengthen the top-level design and publicity of coal-to-hydrogen with CCUS technology, actively promote the research, development and demonstration of coal-to-hydrogen with CCUS, so as to ensure the development of China's hydrogen industry.