Medrano-García Juan D, Chagas Marina T, Guillén-Gosálbez Gonzalo
Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir Prelog Weg 1, Zurich 8093, Switzerland.
NCCR Catalysis, Zurich 8093, Switzerland.
ACS Sustain Chem Eng. 2025 May 8;13(19):7088-7097. doi: 10.1021/acssuschemeng.5c01021. eCollection 2025 May 19.
Green methanol is an important renewable platform chemical that could be used to produce a wide range of sustainable products and fuels. However, it is currently economically unappealing. This high cost is mainly driven by the CO hydrogenation process, which requires 50% more H consumption than the classic fossil-based CO-rich syngas to methanol. To overcome this limitation, here we evaluate the economic and environmental implications of producing green methanol from electrolytic H and captured CO integrated with the reverse Boudouard (RB) reaction. We designed an integrated process based on a standard green methanol plant, adding an RB reactor to reduce CO to CO using biochar prior to the methanol synthesis loop. Combining process simulation with life cycle assessment, we find that integrating both technologies leads to an economic and environmental win-win scenario compared with the base green methanol case. More specifically, production costs are decreased by 5% in an expanded system that assumes the simultaneous production of methanol, biogenic hydrogen, and industrial high-temperature heating under both scenarios. Furthermore, this alternative synthesis shows a reduced carbon footprint of 5% and a 4 to 10% improvement in human health, ecosystems quality, and resource scarcity, revealing no significant probability of associated burden shifting when expanding the system. Finally, when compared with fossil-based methanol, the RB integration makes green methanol competitive when H is available at 3.5-2.0 $/kg, compared to the 2.3-1.3 $/kg required for the standard green methanol configuration. Our results highlight a potentially better alternative to direct CO hydrogenation for green methanol synthesis and, in a broader context, demonstrate the benefits of integrating processes to exploit their synergies.
绿色甲醇是一种重要的可再生平台化学品，可用于生产多种可持续产品和燃料。然而，目前其在经济上缺乏吸引力。这种高成本主要是由一氧化碳加氢过程驱动的，该过程比传统的基于化石的富含一氧化碳的合成气制甲醇多消耗50%的氢气。为了克服这一限制，我们在此评估了由电解氢气和捕获的二氧化碳与逆布多阿尔德（RB）反应相结合来生产绿色甲醇的经济和环境影响。我们基于一个标准的绿色甲醇工厂设计了一个集成工艺，在甲醇合成回路之前增加一个RB反应器，使用生物炭将一氧化碳还原为一氧化碳。将过程模拟与生命周期评估相结合，我们发现与基础绿色甲醇案例相比，整合这两种技术会带来经济和环境双赢的局面。更具体地说，在一个扩大的系统中，假设在两种情景下同时生产甲醇、生物制氢和工业高温供热，生产成本降低了5%。此外，这种替代合成方法的碳足迹减少了5%，对人类健康、生态系统质量和资源稀缺性的改善幅度为4%至10%，这表明在扩大系统时不存在相关负担转移的显著可能性。最后，与基于化石的甲醇相比，当氢气价格为3.5 - 2.0美元/千克时，RB集成使绿色甲醇具有竞争力，而标准绿色甲醇配置所需的氢气价格为2.3 - 1.3美元/千克。我们的结果突出了一种可能比直接一氧化碳加氢合成绿色甲醇更好的替代方法，并且在更广泛的背景下，证明了整合工艺以利用其协同效应的好处。
