Abstract

This work presents a comparative study of two continuous flow reaction systems for the synthesis of propylene carbonate (PC) from CO₂ and propylene oxide (PO). The reaction systems in continuous flow consist of a flow tubular reactor and a Robinson-Mahoney (RM) isothermal packed bed reactor in homogeneous regime. The formulation of the synthesized catalyst had KI as the active phase on a support of aluminum oxy-hydroxide, activated carbon, sodium dihydrogen sulfate, nitric acid and poly (vinyl alcohol); the mixture of materials was spheronized to improve its mechanical and workability properties. The results revealed that the reaction followed a catalyst deactivation pattern, since the yield under heterogeneous regime dropped for both reaction systems after the first 4 h of operation; however, the overall performance of the RM reactor, determined by Total Dynamic Performance (TDP) measurements, turned out to be 5 times higher than that of the tubular reactor. The RM reactor was then used in a mixed heterogeneous/homogeneous operation, thus keeping a sustained yield and selectivity of about 90 and 84%, respectively, for the total evaluation time (50 h) after adjusting to homogeneous regime. The mixed operation proposal using the RM reactor ensured the correct distribution of reagents and catalyst, along with the additional benefits of using a three-phase reactor system. In addition, the continuous flow operation allowed to maintain high performance and selectivity rates, enabling to continue the next stages of the scaling-up process.

摘要

_{这项工作对用于从 CO 2}合成碳酸亚丙酯 (PC) 的两种连续流动反应系统进行了比较研究和环氧丙烷 (PO)。连续流动的反应系统由流动管式反应器和均相状态下的 Robinson-Mahoney (RM) 等温填充床反应器组成。合成催化剂的配方以KI为活性相，负载于氢氧化铝、活性炭、硫酸二氢钠、硝酸和聚(乙烯醇)；材料混合物被球化以提高其机械和可加工性。结果表明，反应遵循催化剂失活模式，因为在第一个 4 小时操作后，两个反应系统在非均相状态下的产率均下降；然而，通过总动态性能 (TDP) 测量确定的 RM 反应器的整体性能比管式反应器高 5 倍。然后将 RM 反应器用于混合的多相/均相操作，从而在调整为均相状态后的总评估时间（50 小时）内分别保持约 90% 和 84% 的持续产率和选择性。使用 RM 反应器的混合操作方案确保了试剂和催化剂的正确分配，以及使用三相反应器系统的额外好处。此外，连续流动操作允许保持高性能和选择性率，从而能够继续放大过程的下一阶段。使用 RM 反应器的混合操作方案确保了试剂和催化剂的正确分配，以及使用三相反应器系统的额外好处。此外，连续流动操作允许保持高性能和选择性率，从而能够继续放大过程的下一阶段。使用 RM 反应器的混合操作方案确保了试剂和催化剂的正确分配，以及使用三相反应器系统的额外好处。此外，连续流动操作允许保持高性能和选择性率，从而能够继续放大过程的下一阶段。