The process design and life cycle assessment (LCA) of various methanol production processes, including the conventional natural gas reforming process and alternative CO₂ utilization-based pathways, are performed in this work. Three main technologies are considered for the CO₂ conversion to methanol: direct CO₂ hydrogenation, dry reforming and tri-reforming of methane. For each pathway, a process simulation that includes the CO₂ capture from typical flue gas of a cement kiln, the methanol synthesis and purification steps, is performed using the Aspen engineering suite. In addition, for each process, several heat integration measures are considered to maximize thermal efficiency. According to the simulation results, the thermal efficiency of the direct CO₂ hydrogenation process (47.8 % LHV) is higher than the dry reforming (40.6 % LHV) while it is lower than the conventional (68.4 % LHV) and tri-reforming (57.9 % LHV) processes. The LCA results showed that the direct CO₂ hydrogenation pathway is an environmentally friendly option, only when the electricity GHG intensity is lower than 0.17 kg CO₂ equivalent per kWh of electricity. As a result, in the context of Canada, the CO₂ hydrogenation options can be recommended only for the provinces where low-carbon electricity is available, such as Quebec, British Columbia, Manitoba and Ontario.

在这项工作中进行了各种甲醇生产工艺的工艺设计和生命周期评估 (LCA)，包括传统的天然气重整工艺和基于CO _{2 的}替代途径。CO ₂转化为甲醇考虑了三种主要技术：直接CO ₂加氢、干法重整和甲烷三重重整。对于每个途径，包括 CO ₂从水泥窑的典型烟气中捕获甲醇合成和纯化步骤是使用 Aspen 工程套件进行的。此外，对于每个过程，都考虑了几种热集成措施，以最大限度地提高热效率。根据模拟结果，CO ₂直接加氢工艺的热效率（47.8 % LHV）高于干法重整（40.6 % LHV），而低于常规（68.4 % LHV）和三重重整（57.9 % LHV) 过程。LCA 结果表明，直接 CO ₂加氢途径是一种环保选择，仅当电力 GHG 强度低于每千瓦时电力0.17 kg CO ₂当量时。因此，就加拿大而言，CO₂加氢选项只能推荐用于低碳电力可用的省份，如魁北克、不列颠哥伦比亚、曼尼托巴和安大略。