Abstract This study proposes an innovative methanol production process from landfill gas (LFG) through direct CO2 hydrogenation and methane (CH4) reforming. The integration of two methanol production routes from CO2 and CH4 enables the full upcycling of carbon sources in the LFG into methanol, as compared to conventional processes that utilize only CH4 as a carbon source. The optimal process configurations and operating conditions of two LFG-to-methanol processes (L2M), stand-alone (L2M-SA) and with hydrogen supply (L2M−HS), are proposed by developing rigorous process models with the aid of sequential quadratic programming optimization. The capability of the processes is analyzed using four evaluation metrics: carbon and energy efficiencies, net CO2 emission, and unit production cost (UPC). It was observed that the carbon and energy efficiencies of both the L2M processes could reach up to 92% and 69%, respectively. The methanol UPC is estimated in the range of 392–440 USD/ton, which is competitive against other renewable and conventional methanol production options. In addition, the CO2 emission (0.83 and 1.29 kg of CO2 per kg of MeOH of the L2M−HS and -SA, respectively) implies that the full upcycling of LFG to methanol is not only economically viable but also an environmentally clean strategy.

中文翻译：

---

将 CO2 加氢和甲烷重整相结合，将垃圾填埋气完全碳升级为甲醇：工艺开发和技术经济分析

摘要 本研究提出了一种通过直接 CO2 加氢和甲烷 (CH4) 重整从垃圾填埋气 (LFG) 中生产甲醇的创新工艺。与仅使用 CH4 作为碳源的传统工艺相比，CO2 和 CH4 两条甲醇生产路线的整合能够将填埋气中的碳源完全升级为甲醇。通过在顺序二次方程的帮助下开发严格的过程模型，提出了两种 LFG 制甲醇过程 (L2M)、独立 (L2M-SA) 和氢气供应 (L2M-HS) 的最佳工艺配置和操作条件程序优化。使用四个评估指标来分析流程的能力：碳和能源效率、净二氧化碳排放量和单位生产成本 (UPC)。据观察，两种 L2M 工艺的碳效率和能源效率分别可达到 92% 和 69%。甲醇 UPC 估计在 392-440 美元/吨的范围内，与其他可再生和传统甲醇生产方案相比具有竞争力。此外，二氧化碳排放量（每公斤 L2M-HS 和 -SA 的甲醇分别产生 0.83 和 1.29 公斤二氧化碳）意味着将填埋气完全升级为甲醇不仅在经济上可行，而且还是一种环境清洁策略。