Microrreator: diferenças entre revisões
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[[Image:LLNL-microreactor.jpg|right|frame|Microrreator desenvolvido no [[Laboratório Nacional de Lawrence Livermore|LLNL]] utiliza técnicas de micromaquinaria para miniaturizar o design do mesmo. Aplicações incluem processamento de combustíveis para geração de [[Hidrogênio molecular|hidrogênio]], [[Síntese química|síntese]] e estudos de biorreatores.]]
Um '''microrreator''' ou '''reator microestrutrurado''' ou '''reator microcanalizado''' é um dispositivo em que reações químicas ocorrem em um espaço de dimensões abaixo de 1 milímetro; a forma típica de tal confinamento são microcanais.<ref name=Watts>''Recent advances in synthetic micro reaction technology'' Paul Watts and Charlotte Wiles [[Chem. Commun.]], '''2007''', 443 - 467, {{DOI|10.1039/b609428g}}</ref> Microrreatores são estudados no campo da engenharia de microprocessos, juntamente com outros dispositivos — como micropermutadores de calor — em que processos físicos ocorrem. Um microrreator é, geralmente, um [[Reator químico|reator]] de fluxo contínuo (em contraste com um reator em batelada).<ref>{{
==História==
Microrreatores de [[Gás|fase gasosa]] têm uma longa história de estudo contudo aqueles de [[Líquido|fase líquida]] começaram a surgir no final da década de 1990.<ref name=Watts/> Um dos primeiros microrreatores com [[Trocador de energia térmica|permutadores de calor]] de alta performance foi confeccionado no início da década de 1990 pelo Departamento Central de Experimentação — ''Hauptabteilung Versuchstechnik'', HVT — do [[Forschungszentrum Karlsruhe]],<ref name=schubi01>{{
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==Benefícios==
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==Problemas==
* Although there have been reactors made for handling particles, microreactors generally do not tolerate particulates well, often clogging. Clogging has been identified by a number of researchers as the biggest hurdle for microreactors being widely accepted as a beneficial alternative to batch reactors. So far, the so-called microjetreactor<ref>{{
* Mechanical pumping may generate a pulsating flow which can be disadvantageous. Much work has been devoted to development of pumps with low pulsation. A continuous flow solution is [[electroosmotic flow]] (EOF).
*Typically, reactions performing very well in a microreactor encounter many problems in vessels, especially when scaling up. Often, the high area to volume ratio and the uniform residence time cannot easily be scaled.
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In microreactor studies a [[Knoevenagel condensation]]<ref>''Knoevenagel condensation reaction in a membrane microreactor'' Sau Man Lai, Rosa Martin-Aranda and King Lun Yeung [[Chem. Commun.]], '''2003''', 218 - 219, {{DOI|10.1039/b209297b}}</ref> was performed with the channel coated with a [[zeolite]] catalyst layer which also serves to remove water generated in the reaction. The same reaction was performed in a microreactor covered by polymer brushes.<ref>F. Costantini, W. P. Bula, R. Salvio, J. Huskens, H. J. G. E. Gardeniers, D. N. Reinhoudt and W. Verboom [[J. Am. Chem. Soc.]], '''2009''',131, 1650, {{DOI|10.1021/Ja807616z}}</ref>
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A [[Suzuki reaction]] was examined in another study<ref>''Instantaneous Carbon-Carbon Bond Formation Using a Microchannel Reactor with a Catalytic Membrane'' Yasuhiro Uozumi, Yoichi M. A. Yamada, Tomohiko Beppu, Naoshi Fukuyama, Masaharu Ueno, and Takehiko Kitamori [[J. Am. Chem. Soc.]]; '''2006'''; 128(50) pp 15994 - 15995; (Communication) {{DOI|10.1021/ja066697r}}</ref> with a palladium catalyst confined in a [[polymer network]] of [[polyacrylamide]] and a [[triphenylphosphine|triarylphosphine]] formed by [[interfacial polymerization]]:
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The [[combustion]] of [[propane]] was demonstrated to occur at temperatures as low as 300 °C in a microchannel setup filled up with an [[aluminum oxide]] lattice coated with a [[platinum]] / [[molybdenum]] catalyst:<ref>''Low temperature catalytic combustion of propane over Pt-based catalyst with inverse opal microstructure in a microchannel reactor'' Guoqing Guan, Ralf Zapf, Gunther Kolb, Yong Men, Volker Hessel, Holger Loewe, Jianhui Ye and Rudolf Zentel [[Chem. Commun.]], '''2007''', 260 - 262, {{DOI|10.1039/b609599b}}</ref>
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=== Enzyme catalyzed polymer synthesis ===
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Enzymes immobilized on solid supports are increasingly used for greener, more sustainable chemical transformation processes. Microreactors are used to study enzyme-catalyzed ring-opening polymerization of ε-caprolactone to polycaprolactone. A novel microreactor design developed by Bhangale et al.<ref>{{
===Análise===
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====Infrared spectroscopy====
Mettler Toledo and [[Bruker Optics]] offer dedicated equipment for monitoring, with [[attenuated total reflectance]] spectrometry (ATR spectrometry) in microreaction setups. The former has been demonstrated for reaction monitoring.<ref>{{
==Pesquisa acadêmica==
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<li>Dedicated developments. Manufacturer of microstructured components are mostly commercial development partners to scientists in search of novel synthesis technologies. Such development partners typically excel in the set-up of comprehensive investigation and supply schemes, to model a desired contacting pattern or spatial arrangement of matter. To do so they predominantly offer information from proprietary integrated modeling systems that combine computational fluid dynamics with thermokinetic modelling. Moreover, as a rule, such development partners establish the overall application analytics to the point where the critical initial hypothesis can be validated and further confined.</li></ol>
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==Referências==
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