Gas-Liquid and Gas-Liquid-Solid Microstructured Reactors: Contacting Principles and Applications

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• 作者：Volker Hessel ; Panagiota Angeli ; Asterios Gavriilidis ; and Holger Lö ; we
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2005
• 出版时间：December 7, 2005
• 年：2005
• 卷：44
• 期：25
• 页码：9750 - 9769
• 全文大小：1617K
• 年卷期：v.44,no.25(December 7, 2005)
• ISSN：1520-5045

文摘

A variety of gas-liquid microchannel reactors have been developed so far, using differentcontacting principles. Some devices utilize continuous-phase contacting (i.e., nondispersedseparate phases with large specific interfaces). Among these are microstructured falling film,overlapping channel, and mesh reactors. Dispersed-phase contacting is obtained when one ofthe phases is interdispersed into the other phase. Regular flow patterns are provided by thesegmented (Taylor) flow in a single microchannel or numbered-up versions such as themicrobubble column; other flow patterns such as annular flow may be achieved as well. Foammicroreactors utilize a moving rigid 3-D bubble network at high gas content. Miniaturized packed-bed microreactors follow the paths of classical engineering by enabling trickle-bed operation.Because of the often highly regular flow pattern, not obtained in conventional gas-liquidcontactors, an understanding of the underlying hydrodynamics and heat and mass transfer iscrucial for optimal performance of all types of gas-liquid microstructural reactors. Severalexamples are given, including film-thickness measurements, flow-pattern maps, determinationof mass-transfer coefficients, residence-time distributions, scale-out issues, etc. Numerousapplications demonstrate the improved performance of gas-liquid microreactors. Among theseare fluorinations, chlorinations, hydrogenations, sulfonations, photo-oxidations, etc. Recently,the scope of reactions has been widened, since there is now the possibility to carry out gas-liquid-solid processes in the same microreactors as used for noncatalytic reactions because ofthe development of catalyst washcoats and other materials deposited onto microchannels. Somerelevant examples are given for illustration.