Abstract The scope of this work is to explore the viability of the direct synthesis of dimethyl ether (DME) over bifunctional catalysts, such as mixtures of CuO/ZnO/Al2O3 and γ-Al2O3 at industrial scale. To accomplish this purpose, the process is simulated using a phenomenological mathematical model considering momentum, mass and energy balances, applied to both the catalyst particles and reactor bed, which is solved in 2D axisymmetric coordinates. This constitutes a step beyond most of the available studies for the modelling of the DME synthesis reaction, based on simple 1D isothermal models. The use of this detailed model revealed the importance of intraparticle mass and heat transfer, with effectiveness factors within the range 0.5–1.1. At the reactor scale, radial phenomena were found to be relevant. A design-sensitivity analysis of mass flux, catalyst fraction, pressure, feed temperature, cooling potential and tube diameter on the reactor performance was carried out. An optimized reactor design that provides 80% CO conversion operating at inlet temperature and pressure 245 °C and 40 bar, corresponds to 0.02 m diameter, 8.50 m length and 3600 h−1 gas-hourly space velocity with a yield of dimethyl ether of 0.53.

中文翻译：

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多管固定床反应器直接合成二甲醚：二维多尺度建模与优化设计

摘要 这项工作的范围是探索在双功能催化剂上直接合成二甲醚 (DME) 的可行性，例如工业规模的 CuO/ZnO/Al2O3 和 γ-Al2O3 混合物。为了实现这一目的，该过程使用考虑动量、质量和能量平衡的现象学数学模型进行模拟，该模型应用于催化剂颗粒和反应器床，并在 2D 轴对称坐标中求解。这构成了基于简单的一维等温模型的 DME 合成反应建模的大多数可用研究之外的一步。这个详细模型的使用揭示了粒子内质量和传热的重要性，其有效性因子在 0.5-1.1 的范围内。在反应堆规模上，发现径向现象是相关的。质量通量的设计敏感性分析，催化剂分数、压力、进料温度、冷却潜力和管径对反应器性能进行了研究。优化的反应器设计可在入口温度和压力 245 °C 和 40 bar 下运行，提供 80% 的 CO 转化率，对应于 0.02 m 直径、8.50 m 长和 3600 h-1 气时空速，二甲醚产量为 0.53 .