Abstract:

In response to the high carbon emissions, high energy consumption, and low utilization efficiency of coal resources in traditional coal to methanol processes, two new green hydrogen efficient coupling processes (process Ⅰ and Ⅱ) were proposed, which introduced carbon dioxide hydrogenation technology and dry reforming of methane technology, respectively. Taking the traditional coal to methanol route with an annual production capacity of 3×10⁵t as a case study, the material changes and energy consumption of the green hydrogen coupling processes were systematically analyzed through theoretical analysis and Aspen simulation. A comprehensive techno-economic analysis was conducted, comparing the new processes with the traditional coal to methanol process from multiple dimensions, including energy consumption, carbon emission intensity, carbon utilization efficiency, investment costs, and production costs. The results showed that compared with the traditional coal to methanol process, the carbon element utilization rate of the new process Ⅰ and new process Ⅱ had increased from 38.74% to 84.56% and 67.60%, the coal consumption per ton of methanol had decreased from 1.42t to 0.65t, and the carbon emission intensity per unit of methanol had decreased by 62.84% and 56.42%, respectively. Through the analysis of investment and production costs, it was found that due to the influence of hydrogen production scale, the investment of new process Ⅰ was relatively high, while the total investment of new process Ⅱ was comparable to that of the traditional process. Presently, owing to the high cost of hydrogen, the unit production costs of methanol for the two new processes were 1.84 times and 1.51 times of the traditional process, respectively. However, with the implementation of increasing carbon taxes and decreasing hydrogen production costs, the economic advantages of the new processes would become increasingly apparent. Both processes significantly reduced carbon emissions while increasing methanol production capacity, offering advantages in terms of energy efficiency and economic performance, and demonstrating promising application prospects.

Key words: coal to methanol, carbon dioxide hydrogenation, dry reforming of methane (DRM), green hydrogen, technio-economic analysis

摘要：

针对传统煤制甲醇工艺的高碳排放、高能耗、低煤炭资源利用效率等问题，本文提出了分别引入二氧化碳加氢技术和甲烷二氧化碳干重整技术的绿氢高效耦合新工艺Ⅰ和新工艺Ⅱ，以年产3×10⁵t的传统煤制甲醇工艺路线为案例，通过对全流程的理论分析和Aspen仿真模拟，系统地研究了绿氢高效耦合新工艺的物料变化和能耗情况，并从能耗、碳排放强度、碳元素利用率、投资成本和生产成本等多维度进行了技术经济分析和对比。结果表明，相比于传统煤制甲醇工艺，新工艺Ⅰ和新工艺Ⅱ的碳元素利用率从38.74%分别提高到了84.56%和67.60%，生产每吨甲醇煤耗从1.42t均降低到了0.65t，单位甲醇碳排放强度分别下降了62.84%和56.42%，通过分析投资和生产成本发现，受制氢规模影响，新工艺Ⅰ投资较高，新工艺Ⅱ与传统工艺总投资相当。由于氢气成本较高，当前两种新工艺的单位甲醇生产成本分别是传统工艺的1.84倍和1.51倍，随着碳税的增加和制氢成本下降，新工艺将逐渐凸显经济性优势。两种新工艺在实现甲醇扩能增产的同时极大地减少了碳排放，且在能耗和经济性上都更具优势，具有良好的应用前景。

关键词: 煤制甲醇, 二氧化碳加氢, 甲烷干重整, 绿氢, 技术经济分析