{"title":"Unraveling the role of ultrasound in hydrothermal interzeolite conversion using a tubular ultrasound-integrated reactor.","authors":"Elena Brozzi, Michiel Dusselier, Simon Kuhn","doi":"10.1039/d5re00149h","DOIUrl":null,"url":null,"abstract":"<p><p>In the past years, ultrasound has been considered a sustainable process intensification technique for zeolite synthesis. However, understanding the link between ultrasound phenomena and their related effects has remained a challenge due to the limited availability of hydrothermal ultrasonic reactors and parameter standardization among the studies. In this work, a novel ultrasound-integrated tubular coiled reactor is presented, which enables fast and efficient ultrasonic hydrothermal zeolite synthesis. Specifically, the effect of ultrasound irradiation and its underlying mechanisms on high silica FAU-to-MFI interzeolite conversion is studied. Unseeded syntheses in the presence of an organic structure-directing agent (OSDA) are performed at 160 °C for residence times up to 2 h. The presence of hydroxyl radicals generated by ultrasound is assessed <i>via</i> terephthalic acid dosimetry at different temperatures and pressures as a measurement of the cavitation activity. The application of 20 W mL<sup>-1</sup> of suspension reveals an enhanced MFI growth rate and faster crystallization completion, resulting in an overall increase in the mean crystal size. Ultrasound is also successful in counteracting solid deposition on the walls of the coiled reactor. Applying hydrothermal conditions to this setup suppresses radical formation, indicating very weak transient cavitation activity. Therefore, these observations are attributed to the enhanced mass transfer <i>via</i> ultrasonic wave propagation, which renders the dissolved material more readily available for crystal growth.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" ","pages":""},"PeriodicalIF":3.4000,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12223963/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Reaction Chemistry & Engineering","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d5re00149h","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
In the past years, ultrasound has been considered a sustainable process intensification technique for zeolite synthesis. However, understanding the link between ultrasound phenomena and their related effects has remained a challenge due to the limited availability of hydrothermal ultrasonic reactors and parameter standardization among the studies. In this work, a novel ultrasound-integrated tubular coiled reactor is presented, which enables fast and efficient ultrasonic hydrothermal zeolite synthesis. Specifically, the effect of ultrasound irradiation and its underlying mechanisms on high silica FAU-to-MFI interzeolite conversion is studied. Unseeded syntheses in the presence of an organic structure-directing agent (OSDA) are performed at 160 °C for residence times up to 2 h. The presence of hydroxyl radicals generated by ultrasound is assessed via terephthalic acid dosimetry at different temperatures and pressures as a measurement of the cavitation activity. The application of 20 W mL-1 of suspension reveals an enhanced MFI growth rate and faster crystallization completion, resulting in an overall increase in the mean crystal size. Ultrasound is also successful in counteracting solid deposition on the walls of the coiled reactor. Applying hydrothermal conditions to this setup suppresses radical formation, indicating very weak transient cavitation activity. Therefore, these observations are attributed to the enhanced mass transfer via ultrasonic wave propagation, which renders the dissolved material more readily available for crystal growth.
在过去的几年里,超声波被认为是一种可持续的沸石合成过程强化技术。然而,由于水热超声反应器的可用性和研究参数标准化的限制,了解超声现象及其相关效应之间的联系仍然是一个挑战。本文提出了一种新型超声集成管状盘管反应器,可实现超声水热沸石的快速高效合成。具体而言,研究了超声辐照对高硅fa - mfi分子筛转化的影响及其潜在机制。在有机结构导向剂(OSDA)存在下的非种子合成在160°C下进行,停留时间长达2小时。超声产生的羟基自由基的存在通过对苯二甲酸剂量法在不同温度和压力下进行评估,作为空化活性的测量。应用20 W mL-1的悬浮液,MFI生长速度加快,结晶完成速度加快,导致平均晶体尺寸总体增加。超声波也成功地抵消了盘式反应器壁上的固体沉积。应用热液条件抑制自由基的形成,表明非常弱的瞬态空化活性。因此,这些观察结果归因于通过超声波传播增强的传质,这使得溶解的物质更容易用于晶体生长。
期刊介绍:
Reaction Chemistry & Engineering is a new journal reporting cutting edge research into all aspects of making molecules for the benefit of fundamental research, applied processes and wider society.
From fundamental, molecular-level chemistry to large scale chemical production, Reaction Chemistry & Engineering brings together communities of chemists and chemical engineers working to ensure the crucial role of reaction chemistry in today’s world.