Analysis and estimation of gas-liquid flow pattern in packed bed compact tubular reactors

One of the factors that influence the performance of packed bed reactors is the flow pattern, and many flow pattern maps have been reported so far. In this study, a gas-liquid flow pattern map of a packed bed compact reactor, which is being increasingly used in the flow synthesis of functional chemicals, was constructed, and two types of flow patterns, trickle flow and pulse flow, were identified. In addition, an estimation method was developed to distinguish the trickle flow and pulse flow from differential pressure or voltage when the flow inside the reactor cannot be visually recognized from the outside. The effects of the liquid flow rate and the slug formation frequency at the mixer on the pulsation frequency, which is a parameter in reaction optimization, were examined. As a result, it was shown that the pulsation frequency increases as the liquid flow rate increases under a fixed gas flow rate and that the pulsation frequency and the slug formation frequency do not always match due to the possibility of coalescence of the gas and liquid slugs at the reactor inlet. (C) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.