Fuel from air: A techno-economic assessment of e-fuels for low-carbon aviation in China

• Techno-economic analysis of DAC-based efuels for aviation decarbonization in China. • China could meet 84% aviation fuel demand by 2050 with 102 MT of e-fuels. • E-fuel costs drop from $3100 to $900/ton with high DAC learning & low energy costs. • Solid absorbent DACs are ideal for high-demand regions like Beijing and Shanghai. • DACCS pathway offers 70% lower abatement costs and lower energy use than e-fuels. Aviation remains one of the most challenging sectors to achieve low carbon emissions due to its heavy reliance on fossil fuels and the lack of cost-competitive alternatives. This study evaluates the potential of Direct Air Capture (DAC)-based e-fuels to meet China’s aviation fuel demand by 2050. The research assesses e-fuel production costs and resource requirements under diverse scenarios, incorporating spatio-temporal variations in electricity, water, transportation, and policies. Results show that DAC capital costs and the energy market are the primary determinants. Liquid absorbent DAC (L-DAC), with lower capital costs but higher resource demands, is suitable for resource-abundant regions, while solid absorbent DAC (S-DAC), benefiting from higher learning rates and lower resource requirements, is optimal for water-scarce, high-demand regions like Beijing and Shanghai. By 2050, China could produce 102 Mt of e-fuels, meeting 84% of its demand, requiring 3457 TWh of renewable electricity and 597 billion liters of water, 78% of which would come from desalination. E-fuel costs range from $3176/ton (S-DAC) to $3208/ton (L-DAC), remaining 2.5–4 times higher than fossil jet fuels. Achieving cost parity requires low electricity prices (∼$5/GJ), high DAC learning rates ($80–50/ton), and strong policy incentives. This could reduce e-fuel costs to $900–1000/ton. The study also evaluates an alternative pathway involving Direct Air Capture with Carbon Storage paired with fossil fuel utilization. While this route offers cost and energy efficiency, it may raise long-term sustainability concerns. These findings underscore the potential of e-fuels for net-zero aviation targets, highlighting the urgency of supportive policies to scale their deployment effectively.