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6 / July 2020 powderbulk.com T he industrial beginnings of process intensifi- cation date back to the 1970s when the process development group at Imperial Chemical Indus- tries in the UK innovated and implemented various technologies using high g-forces. These ideas slowly proliferated within the academic world and the indus- trial research groups in various European countries over the following two decades. Early concepts focused mainly on the miniaturization of equipment and com- bining various unit operations. As new ideas and approaches were introduced under the umbrella of process intensification, the term's definitions morphed to suit the problem at hand. Oftentimes, innovative ideas that exhibited substantial performance improve- ment (2X-100X), along with reduction in equipment size, lower operating costs, improved safety, and/or improvement in product quality, were rolled into this category. The diversity of definitions indicates the breadth of ideas and approaches taken to arrive at the same common goals (Stankiewicz et al., 2019), namely: • Maximizing the effectiveness of intra- and inter- molecular events • Giving each molecule the same processing experience • Optimizing driving forces at all scales • Maximizing synergistic effects In the past 20 years, process intensification has evolved beyond designing a highly efficient unit operation into an innovative design and process devel- opment framework. This allows for a more systematic approach to equipment and process innovation driven by the potential energy savings, smaller carbon dioxide footprint, lower capital and operating expenses, sustain- ability, better product quality, and faster time to market. In the world of solids processing, as the scale changes from molecules to particles, we encounter new challenges. There are limitations to miniaturization — the physics are very different compared to liquids and gases, the computational tools are scant, fouling is a challenge, and material characterization is more complex. Nevertheless, many successful applications in mixing, reactors, heat transfer, particle formation, flu- idization, and separation can be found in the literature. Solids processing clearly lags behind the liquid and gas world in the domain of process intensification. I see this as an opportunity rather than a shortcoming. Some possible avenues to explore could be: • New sources of energy (microwave, ultrasound, magnetic, solar) • Unit operations with synergistic combination of functionalities to simplify process flowsheet • Batch to continuous processes using better equip- ment, modeling, control, and instrumentation • Improved energy integration and waste recycle • Better energy efficiency through targeted applica- tion of energy in the process • Safer process design by reducing inventory Prevailing economic and competitive forces will drive us to innovate at an ever-faster pace. We can't rely only on occasional inspirations and unstructured cre- ative thinking to make progress. I've come to believe that the fundamental concepts and frameworks for process intensification, which have been developed mostly for gas and liquid systems, can be adapted to solids processing. This will prove to be a catalyst for rapid innovation in the years to come. INDUSTRY PERSPECTIVE PBE Shrikant Dhodapkar, PhD, Fellow, Performance Plastics Process R&D, Dow Inc. Process intensification — catalyst for innovation Recommended references on this topic include: 1. Stankiewicz, A., Van Gerven, T., and Stefanidis, G. "The Fundamentals of Process Intensification," Wiley-VCH Verlag GmbH & Co. (2019). 2. Wang, H., Mustaffar, A., Phan A.N., Zivkovic, V., Reay, D., Law, R., Boodhoo, K. "A review of process intensification applied to solids handling," Chemical Engineering & Processing: Process Intensification 118 (2017) 78–107. 3. "Process Intensification: Special Sections in Chemical Engineering Progress" (www.aiche.org/cep) March 2018, 2019, and 2020.