Understanding the effects of forced and bubble-induced convection in transport-limited organic electrosynthesis
Understanding the effects of forced and bubble-induced convection in transport-limited organic electrosynthesis
复制标题
了解传输限制有机电合成中强制对流和气泡诱导对流的影响
DOI：
10.1039/d3re00579h
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发表时间：
2024
影响因子：
3.9
通讯作者：
Modestino, Miguel A.
中科院分区：
文献类型：
--
作者：
Bloomquist, Casey K.;Dogan, Melisa;Harris, James S.;Herzog, Benjamin D.;Tenn III, William J.;Aydil, Eray S.;Modestino, Miguel A.
有机电合成通过将可再生能源整合到化学制造中，为化学工业脱碳提供了一条可持续的道路。然而，实现工业应用所需的选择性和能量效率是具有挑战性的，由于大多数电有机反应的固有传质限制。对流可以减轻质量传输的限制，但其对有机电化学过程的影响仍然知之甚少。在这里，我们表明，舍伍德数对流传质扩散传质的比例是一个至关重要的指标来表征传质，确定反应器的性能，并使有效的放大。我们研究了在已二腈的电合成过程中，在工业上最大的有机电化学过程之一的对流流动下的质量传递和电化学反应速率之间的相互作用。我们使用实验和数据驱动的预测模型来证明，强制液体对流和气泡诱导对流产生几乎相等的质量传输条件时，相应的舍伍德数是相等的。这一结论表明，舍伍德数表征的质量输运条件的基本对流机制无关。此外，我们表明，法拉第效率（即，电化学选择性）与给定电流密度和反应物浓度的舍伍德数成比例。这种可扩展性使性能预测的对流模式，以提高质量运输无关。我们的研究结果为从实验室到工业规模的对流方法的设计和选择提供了指导，并有助于开发更可持续的化学制造工艺。
Organic electrosynthesis offers a sustainable path to decarbonize the chemical industry by integrating renewable energy into chemical manufacturing. However, achieving the selectivity and energy efficiency required for industrial applications is challenging due to the inherent mass transport limitations of most electro-organic reactions. Convection can mitigate mass transport limitations, but its impact on organic electrochemical processes remains poorly understood. Here we show that the Sherwood number—the ratio of convective mass transport to diffusive mass transport—is a crucial metric to characterize mass transport, determine reactor performance, and enable effective scale-up. We investigate the interplay between mass transport and electrochemical reaction rates under convective flows in the context of the electrosynthesis of adiponitrile, one of the largest organic electrochemical processes in the industry. We use experiments and data-driven predictive models to demonstrate that forced liquid convection and bubble-induced convection produce nearly equivalent mass transport conditions when the corresponding Sherwood numbers are equal. This conclusion shows that the Sherwood number characterizes the mass transport condition independent of the underlying convection mechanism. Moreover, we show that the faradaic efficiency (i.e., the electrochemical selectivity) scales with the Sherwood number for a given current density and reactant concentration. This scalability enables performance to be predicted irrespective of the convection mode employed to enhance mass transport. Our results provide guidelines for the design and selection of convection methods, from lab to industrial scale, and contribute to the development of more sustainable chemical manufacturing processes.