Plenary Lecture
Multiphase Reactors and Multiphase Flow Systems are the Key For Processes Development and Advancement: What are the Needs?
Professor Muthanna Al-Dahhan
Chairman of Chemical and Biochemical Engineering Department
Missouri University of Science and Technology (Missouri S&T)
USA
Email: aldahhanm@mst.edu
Abstract: Multiphase reactors (bubble/slurry bubble columns, packed beds, fluidized and circulating beds, etc.) and multiphase flow systems (blenders/mixers, separators, conveyers, heat exchanges, flow in pipes, etc.) have found extensive applications in every industrial processes related to energy, environmental applications and variety of products including the renewable and sustainable technologies and processes. These systems in general and multiphase reactors in particular are the key for any process development and advancement. However, they are complex and opaque and they can take various configurations and types based on to the way the phases are contacted and interacted. Their design, scale-up, proper operation and performance prediction are challenging tasks due to the lack of their understanding as a result of the complex interaction among phases. In addition, the complexity increases with the presence of internals that affect the hydrodynamics, mixing, transports (mass and heat), reactions and hence, the performance of these reactors. Therefore, in order to ensure proper processes development and advancement, there are needs to be fulfilled which include advancing the engineering knowledge and understanding of these systems, developing mechanistic scale up methodologies, validating CFD by quality benchmarking data, implementing CFD simulations as enabling tools for scale–up and troubleshooting. Computational fluid dynamics have been increasingly used to simulate, design and scale up these reactors and flow systems. Due to their complexity, most (if not all) of the used models and closures in the CFD to simulate these systems have not been based on proper physics or first principles. Accordingly, CFD validation is a must before it is implemented with fidelity. These can be achieved by implementing sophisticated measurement techniques that are integrated in a novel way to measure various hydrodynamic and transport parameters and their integration with kinetics. Since these systems are opaque, high energy gamma ray photons based techniques are needed besides other sophisticated measurement techniques to visualize these systems, to provide an effective diagnostic means, to provide benchmarking data and to advance the needed fundamental understanding of these complex reactors and flow systems. These advances should provide the mechanistic frame work to properly scale up the results from lab to commercial scales and to properly model and optimize these systems for performance prediction.
In our laboratory such needed sophisticated measurement techniques, facilities and methodologies have been developed, verified and implement on various complex reactors and flow systems that are extensively used in a wide range of processes including energy, products and environmental applications. Some of these measurement techniques are: I) techniques that are based on radioisotopes – radioactive particle tracking (RPT), dual source gamma ray tomography (DSCT), gamma ray densitometry (GRD) for 3D flow field, velocity and turbulent parameters, phases distribution and flow pattern identification measurements, and II) techniques that are not based on radioisotopes: 4-point optical probe for bubble dynamics, heat transfer probe, combination of bubble dynamics and heat transfer probe, optical probes for solids dynamics that measure simultaneously solids velocity and holdups and their fluctuations, integration of hot wire anemometry and heat transfer probe, gas tracer dynamics, optical probe for local mass transfer, gas tracer technique for global mass transfer, optical probe for liquid velocity distribution in packed beds, pressure transducers, and others. These techniques are augmented with sophisticated mathematical algorithms and programs that have been developed in our laboratory for data gathering, processing and image reconstruction. The utilization of these techniques is complemented by our advanced modeling, scale-up methodologies and computations capabilities. Also statistical methods, artificial neural network and chaotic analyses have been developed and used to further analyze the obtained results for flow pattern identification and for mechanistic approaches that we have developed for scale-up methodologies of these complex multiphase flow systems. In addition, validation of CFD simulations, models and closures for various types of multiphase reactors and flow systems have been conducted both in our laboratory and in collaboration with various research labs and groups.
In this presentation, an overview of our recent advancement which we have made on multiphase reactors and multiphase flow systems to address the question of what are the needs will be outlined and discussed.
Brief Biography of the Speaker: Dr. Muthanna Al-Dahhan is Professor and Chairman of the Chemical & Biochemical Engineering Department, Professor of Nuclear Engineering at Missouri University of Science and Technology (Missouri S&T), Rolla, Missouri since January 2009. He is AIChE Fellow. Prior to that he was a Professor at Washington University in St. Louis (1994-2008), Project Manager at Xytel Corporation, USA (1993/1994), Head of process, process engineer and project engineer in pilot plants – Iraq (1979-1985). He holds three degrees in chemical engineering (BSc in 1979, University of Baghdad-Iraq; Master degree in 1988, Oregon State University and Doctoral degree in 1993, Washington University). He directed from 1999-2008 industry-academia consortium on gas conversion to alternative clean fuels/chemicals using slurry bubble columns. He obtained over $10 million in external funding as PI and Co-PI. He has graduated over 50 PhD students and supervised a large number of post-doc fellows, research associates and undergraduate students on a wide range of topics. All of his students and co-workers are holding leading positions in industry and academia in the United States and around the world. His research activities include more than 150 publications in peer reviewed journals and over 350 of national and international conference presentations. In addition, he gave a large number of invited talks in industry, academia and national labs, plenary and keynote lectures. Dr. Al-Dahhan has received many awards and recognitions and also his graduate and undergraduate students received many awards and recognitions for the work done under his supervision. He formed and chaired a number of international conferences. He has been expert and consultant to IAEA, UNESCO, many companies and research organizations in USA and from around the world. Dr. Al-Dahhan has established extensive collaboration in USA and around the world with academia, industry and research centers. He has developed research laboratories which are unique in USA and in the world and can be considered a unique global resource.