Controlled multiphase oxidations for continuous manufacturing of fine chemicals
Controlled multiphase oxidations for continuous manufacturing of fine chemicals
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用于连续生产精细化学品的受控多相氧化
DOI：
10.1016/j.cej.2017.05.017
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发表时间：
2017
影响因子：
15.1
通讯作者：
Loponov K
中科院分区：
文献类型：
--
作者：
Loponov K
一个集成的连续两相氧化过程的可行性进行了研究，包括（i）电化学生成的氧化剂，（ii）膜乳化和振荡流反应器（OFR），以促进在两相反应系统中的传质和（iii）产品提取，使再生的氧化剂。研究了两相、无有机溶剂的过硫酸铵溶液（包括电化学生成的过硫酸铵）对苯乙烯的二羟基化反应，作为一个模型反应，在间歇和OFR中进行了研究。在强酸性溶液中加热过氧二硫酸盐被证明是产生活性氧化剂（卡罗酸）所必需的。膜乳化允许传质限制被克服，减少苯乙烯氧化的时间尺度从几个小时在传统的搅拌釜反应器中的分散单元中小于50分钟。采用快速图像采集技术，详细研究了液滴尺寸对乳液中总反应速率的影响。在OFR氧化过程中也证明了不稳定乳液的产生，并且获得了>70%的产物产率。然而，高频/高位移振荡所需的生成细液滴违反活塞流制度。成功地将膜乳化与OFR集成以进行两相氧化。在某些振荡条件下，OFR/错流膜组件可以在活塞流状态下操作，具有可比的总氧化速率。对于小于60 μm的液滴，没有观察到传质限制。最后，在单个OFR萃取单元中证明了连续反应后分离，以实现氧化剂的连续再生。
The feasibility of an integrated continuous biphasic oxidation process was studied, incorporating (i) electrochemical generation of an oxidant, (ii) membrane emulsification and an Oscillatory Flow Reactor (OFR) to facilitate mass-transfer in a biphasic reaction system and (iii) product extraction to enable regeneration of the oxidant. The biphasic, organic solvent-free dihydroxylation of styrene by ammonium peroxodisulfate solutions (including electrochemically generated peroxodisulfate) was investigated as a model reaction, both in batch and in an OFR. Heating of peroxodisulfate in a strongly acidic solution was demonstrated to be essential to generate the active oxidant (Caro’s acid). Membrane emulsification allowed mass-transfer limitations to be overcome, reducing the time scale of styrene oxidation from several hours in a conventional stirred tank reactor to less than 50 min in a dispersion cell. The influence of droplet size on overall reaction rate in emulsions was studied in detail using fast image capturing technology. Generation of unstable emulsions was also demonstrated during the oxidation in OFR and product yields >70% were obtained. However, the high-frequency/high-displacement oscillations necessary for generation of fine droplets violated the plug flow regime. Membrane emulsification was successfully integrated with the OFR to perform biphasic oxidations. It was possible to operate the OFR/cross-flow membrane assembly in plug flow regime at some oscillatory conditions with comparable overall oxidation rates. No mass-transfer limitations were observed for droplets <60 μm. Finally, the continuous post-reaction separation was demonstrated in a single OFR extraction unit to enable continuous regeneration of the oxidant.
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DOI：
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发表时间：
--
期刊：
影响因子：
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作者：
Nuno Albuquerque Matos
通讯作者：
Nuno Albuquerque Matos
DOI：
10.1201/9780203913291.ch1
发表时间：
2019-10
期刊：
--
影响因子：
--
作者：
A. Citterio
通讯作者：
A. Citterio
影响因子：
3.4
作者：
Heider, Patrick L.;Born, Stephen C.;Jensen, Klavs F.
通讯作者：
Jensen, Klavs F.
影响因子：
4.2
作者：
Kosvintsev, SR;Gasparini, G;Stillwell, MT
通讯作者：
Stillwell, MT
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
P. S. Silva;M. Dragosavac;G. Vladisavljević;H. Bandulasena;R. Holdich;M. Stillwell;Bruce Williams
通讯作者：
Bruce Williams