Mixing intensification: a key to advanced materials manufacturing

A recent study published in Engineering delves into the crucial role of mixing intensification in advanced materials manufacturing. The research, jointly led by co-first authors Chao Yang from the Chinese Academy of Sciences and Guang-Wen Chu from Beijing University of Chemical Technology, under the guidance of Jian-Feng Chen from Beijing University of Chemical Technology, explores how innovative mixing methods can overcome traditional mixing limitations in chemical reactors, thus enhancing industrial production efficiency.

Mixing is fundamental in chemical reactors as it directly impacts reaction efficiency and product selectivity. The mixing process is typically divided into macromixing and micromixing, occurring at the reactor scale and near the molecular scale respectively. However, establishing explicit quantitative relationships between mixing and reaction efficiency remains a challenge, despite their generally positive correlation.

In the study of multiphase mixing, accurate experimental measurement is essential. Techniques such as telecentric photography and high-speed cameras have provided valuable insights into multiphase flow phenomena. The chemical probe method, on the other hand, offers a convenient way to characterize mixing performance. With the development of AI, integrating it with traditional measurement techniques has further improved data analysis in this field, although challenges like data dependency still exist.

Macromixing and micromixing have been extensively studied. For macromixing, tracer experiments and computational fluid dynamics (CFD) simulations are common research methods. CFD simulations, in particular, have become crucial for simulating macromixing in reactors, especially for those with short residence times. Micromixing, which significantly influences fast competitive reactions, is often indirectly measured by micromixing time. Various chemical reaction systems have been developed to assess micromixing efficiency, and several models, both empirical and mechanistic, have been proposed to describe the process.

The application of mixing intensification theory has shown promising results in advanced materials manufacturing. In the lithium battery industry, a multiphase CFD–micromixing–population balance equation coupled model has been developed for ternary precursor co-precipitation reaction crystallizers. This has enabled the digital scaling of reactors, leading to high-quality industrial precursors and driving the growth of China’s lithium battery industry. In optical materials manufacturing, high-gravity technology, such as rotating packed-bed (RPB) reactors, has been used to achieve homogeneous micromixing, facilitating the production of nanocomposites with tunable optical properties. Additionally, in the agricultural sector, RPB reactors have been applied to produce hollow silica nanoparticles for smart pesticide delivery, addressing the challenge of large-scale production of nanopesticides.

Looking ahead, the researchers suggest several directions for future research. These include exploring advanced mixing technologies like ultrasonic and electric-field mixing, implementing multiscale simulation to better understand mixing processes in different systems, promoting interdisciplinary collaboration, and accelerating the translation of laboratory research into industrial applications. This study provides a comprehensive understanding of mixing intensification and offers valuable guidance for the development of advanced materials manufacturing processes.

The paper “Mixing Intensification for Advanced Materials Manufacturing,” authored by Chao Yang, Guang-Wen Chu, Xin Feng, Yan-Bin Li, Jie Chen, Dan Wang, Xiaoxia Duan, Jian-Feng Chen. Full text of the open access paper: https://doi.org/10.1016/j.eng.2024.12.019. For more information about the Engineering, follow us on X (https://twitter.com/EngineeringJrnl) & like us on Facebook (https://www.facebook.com/EngineeringJrnl).