Analysis of Dynamic\nCharacteristics of Reconfigurable\nModular Reactor Systems for Renewable Methanol Synthesis

A modular production system for renewable methanol synthesis\nis\none viable way for simultaneously realizing scalable storage of renewable\nenergy and carbon dioxide utilization. It is crucial to improve the\ndynamic performances of the modular reactor systems to rapidly adapt\nto fluctuations of renewable energy and increase the methanol yield.\nIn this work, four configurations and their dynamic characteristics\nof reactors in series and parallel were investigated to elucidate\nthe impacts of reactor configurations on the performances of reconfigurable\nmodular reactors, in which a 2-D transient model of fixed-bed reactors\nfor methanol synthesis was established. The dynamic characteristics\nof the reactor systems during startup, shutdown, disturbance, and\nswitching were explored. The results indicated that modular reactors\nin series are preferred when the feed rate is less than two times\nthe rated flow rate in a single reactor, whereas modular reactors\nin parallel are favorable when the feed rate exceeds six times the\nrated flow rate. The modular reactors in series and parallel are much\nmore favorable for the feed rates in between. The startup and shutdown\ntimes of the reactor systems are significantly affected by the stage\nnumbers of the reactors and the feed flow rate in a single reactor.\nIn general, the startup and shutdown times increase with the increase\nof stage number and the decrease of flow rates of the reactors. The\nresponse time to flow rate fluctuations of the reactor system is mainly\ndetermined by the stage number of the reactor and the flow rate of\na single reactor. Fewer stage numbers and higher flow rates lead to\na rapid response. The mode switching time between different configurations\nis also intimately related to the flow rates. Larger flow rates result\nin a relatively short residence time and a rapid switching process.\nThese results provide insights into the optimal design and operation\nof modular reactor systems for renewable methanol production.