Utilization of Nanobubbles for the Heterogeneously Catalyzed Hydrogenation of 2-Ethyl-9,10-anthraquinone

根据国际标准化组织20480-1：2017年的定义，纳米气泡是指直径小于1,000 nm的气泡。多年来，人们对纳米气泡的性质进行了科学的研究，特别是在水和水溶液中，在少数情况下，在其他液体介质中。与此同时，纳米气泡发生器已经商业化，纳米气泡悬浮液在农业、健康和营养领域的各种技术应用中得到了应用。小直径的纳米气泡导致气泡的内部压力高，气液界面比表面积大，上升速度很低。由于这些特性，纳米气泡在化学过程中的使用也应该是有趣的。纳米气泡悬浮液可以成功地用于化学反应的证据只在日本的N.Mase工作组的几个例子中得到了证明。这些例子-C-C双键的氢化，氮基的氢化，以及醛的氧化成醇-表明通过使用纳米气泡悬浮液可以显著提高化学反应的速度。烷基蒽醌的氢化是蒽醌工艺中的重要步骤，该工艺对从氢和氧中生产过氧化氢具有重要的经济意义。在拟议的工作框架内，将使用氢纳米气泡悬浮液进行2-乙基-9，10-蒽醌的加氢反应，并将其与通过管子进行气体加量进行比较，作为气体加量的经典方法的模型。由于纳米气泡的特性，与通过管子引入气体相比，预计反应速度要快得多。工业上通常在醇和甲基取代苯的混合物中进行蒽醌工艺。为了在反应介质中提供最大的气体浓度，将在不同温度下测定醇和甲基取代苯的混合物以及纯组分中的纳米气泡的寿命。为了实现反应介质中气体的最高浓度，将使用人工神经网络来研究与材料和工艺相关的特性和参数之间的关系以及它们对气泡尺寸分布和浓度的影响。如果可以通过使用纳米气泡悬浮液添加气体来显著提高反应速度，则可以在较低的工艺压力下进行工业化的氢气添加，从而在成本和安全性方面具有优势。

Nanobubbles are defined according to ISO 20480-1:2017 as bubbles with a diameter of less than 1000 nm. The properties of nanobubbles have been investigated scientifically since many years, especially in water and aqueous solutions and in a few cases in other liquid media. Meanwhile, nanobubble generators have become commercially available and nanobubble suspensions find use in various technical applications in the fields of agriculture, health and nutrition.The small diameters of nanobubbles result in a high internal pressure of the bubble, a large specific gas-liquid interfacial area, as well as a very low rise velocity. Due to these properties, nanobubbles should also be interesting for use in chemical processes. The evidence that nanobubble suspensions could be used successfully for chemical reactions has only been shown in a few examples by the working group of N. Mase in Japan. These examples—the hydrogenation of C-C double bonds, the hydrogenation of nitrogen groups, and the oxidation of aldehydes to alcohols—show a significant increase in the rate of the chemical reaction through the use of nanobubble suspensions.The hydrogenation of an alkyl-anthraquinone is an important step in the anthraquinone process, an economically important process for the production of hydrogen peroxide from hydrogen and oxygen. In the framework of the proposed work, the hydrogenation of 2-ethyl-9,10-anthraquinone will be carried out using hydrogen nanobubble suspensions and compared to the dosing of gas through a tube as a model of a classical method for the dosing of the gas. Due to the characteristic properties of nanobubbles, a significantly faster rate of reaction is expected compared to the introduction of gas through a tube. The anthraquinone process is often carried out industrially in mixtures of alcohols and methyl substituted benzenes. To provide a maximal gas concentration in the reaction medium, the lifetime of nanobubbles will be determined in mixtures of alcohols and methyl substituted benzenes as well as in the pure components at different temperatures. To achieve the highest concentration of gas in the reaction medium, an artificial neural network will be use to investigate the relationships between the characteristics and parameters related to the materials and process and their influence on the bubble size distribution and concentration. If a significant increase in the rate of reaction can be achieved by dosing the gas using nanobubble suspensions, the dosing of hydrogen gas could be performed industrially at lower process pressures, resulting in advantages with respect to cost and safety.