Abstract

Reactive distillation is a strengthening process, which is widely used for the transesterification of propylene carbonate and methanol to synthesize dimethyl carbonate. In this paper, suitable catalysts of ZrO₂–Al₂O₃ solid solutions were prepared for distillation column. The structure–property correlations were characterized by XRD, XPS, N₂ adsorption–desorption, CO₂-TPD, and NH₃-TPD. The introduction of Al³⁺ replaced Zr⁴⁺ in zirconia forming a homogeneous solid solution, which generated strong basic sites and increased weak acid sites of the catalyst. It has shown excellent catalytic performance for the synthesis of dimethyl carbonate due to the synergistic effects of the acid–base sites. At the same time, the key parameters of the reactive distillation process were studied, and under optimized reaction conditions (feed alcohol ester ratio = 4, reflux ratio = 5:1, height of reaction section = 0.25 m, liquid space velocity of propylene carbonate = 0.26 h⁻¹), the propylene carbonate conversion and selectivity to dimethyl carbonate were 98.14% and 99.96%, respectively.

Graphic abstract

中文翻译：

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高选择性和稳定的ZrO 2 -Al 2 O 3用于反应蒸馏法合成碳酸二甲酯

摘要

反应蒸馏是一种强化过程，广泛用于碳酸亚丙酯和甲醇的酯交换反应以合成碳酸二甲酯。本文为蒸馏塔制备了合适的ZrO ₂ -Al ₂ O ₃固溶催化剂。通过XRD，XPS，N ₂吸附-解吸，CO ₂ -TPD和NH ₃ -TPD表征了结构与性质的相关性。Al ³⁺的引入取代了Zr ⁴⁺在氧化锆中形成均匀的固溶体，该固溶体产生强碱性位点并增加了催化剂的弱酸性位点。由于酸碱位点的协同作用，它在合成碳酸二甲酯方面显示出出色的催化性能。同时，研究了反应精馏过程的关键参数，并在优化的反应条件下（进料醇酯比= 4，回流比= 5：1，反应段高度= 0.25 m，碳酸亚丙酯的液体空速） ＝ 0.26h ^-1），碳酸亚丙酯的转化率和对碳酸二甲酯的选择性分别为98.14％和99.96％。

图形摘要