The race to decarbonize our energy systems has led to significant advancement in technologies for harvesting renewable energy, carbon capture and conversion. Future scenarios are being envisioned where CO₂ is captured from air and converted to valuable fuels and chemicals, with methanol (MeOH) being the most coveted product. Here we assess transition pathways for the sustainable production of MeOH using CO₂ via direct air capture (DAC) and hybrid power via renewable photovoltaic (PV) and grid electricity. Specifically, we perform techno-economic and life-cycle analysis on technologically mature 1^st generation (water electrolysis coupled to CO₂ hydrogenation) and emerging 2^nd generation air-to-MeOH (direct CO₂-to-MeOH electrolysis) routes. Our results indicate that the two transition pathways would be economically compelling only in jurisdictions where low-cost ($0.02 per kWh) grid electricity is available. Furthermore, the economic feasibility of the 1^st generation route will also depend on a drastic reduction in Si-PV ($300 per kW) and DAC ($280 per ton-CO₂ per year) capital costs. On the other hand, the 2^nd generation route will additionally need drastic performance improvement to be economically competitive, with required CO₂ electrolysis current densities >300 mA cm⁻², energy efficiency >50% and stack stability >2 years. The envisioned air-to-MeOH routes could lead to zero or negative CO₂ emissions in jurisdictions with clean grid electricity (<50 kg-CO₂ per MWh). We hope this study will garner key stakeholders to advance discussions about the cost and potential of this envisioned air-to-fuel technology.

中文翻译：

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迈向净零排放甲醇生产的过渡途径

使我们的能源系统脱碳的竞赛导致了可再生能源收集、碳捕获和转化技术的重大进步。正在设想从空气中捕获CO ₂并将其转化为有价值的燃料和化学品的未来场景，其中甲醇 (MeOH) 是最令人垂涎​​的产品。在这里，我们评估了通过直接空气捕获 (DAC)使用 CO ₂ 以及通过可再生光伏 (PV) 和电网电力的混合动力可持续生产甲醇的过渡途径。具体来说，我们执行技术经济和生命周期分析技术成熟1^第一代（水的电解耦合于CO ₂氢化）和新出现的2^次生成空气到甲醇（直接 CO ₂到甲醇电解）路线。我们的结果表明，只有在可以使用低成本（每千瓦时 0.02 美元）电网电力的司法管辖区，这两种过渡途径才会在经济上具有吸引力。此外，1条的经济可行性^ST代路线也将依赖于Si的PV（每kW $ 300）和DAC（$ 280元吨-CO的显着降低₂每年）的资本成本。另一方面，^第二代路线还需要大幅提高性能才能在经济上具有竞争力，所需的 CO ₂电解电流密度 >300 mA cm ^-2, 能效 >50% 和堆稳定性 >2 年。在使用清洁电网电力（<50 kg-CO ₂每兆瓦时）的司法管辖区，设想的空气到甲醇路线可能导致 CO ₂排放为零或负值。我们希望这项研究将吸引主要利益相关者推进有关这种设想的空燃技术的成本和潜力的讨论。