ChBE Seminar - Gas Conversion to Clean Liquid Fuels and Chemicals via Fischer-Tropsch Slurry Bubble Columns: Some Recent Advances

The Chemical and Biological Engineering Department will be hosting a seminar featuring Professor and Chair of the Chemical and Biochemical Engineering Department at Missouri University of Science and Technology, Dr. Muthanna Al-Dahhan. The topic of the lecture will be Gas Conversion to Clean Liquid Fuels and Chemicals via Fischer-Tropsch Slurry Bubble Columns: Some Recent Advances.

ABSTRACT:

Gas to Liquid Fischer-Tropsch (FT) synthesis is an acknowledged catalytic route for production of clean fuels and chemicals from synthesis gas (a mixture of hydrogen and carbon monoxide) obtained from natural/shale gas (and also from coal, biomass, and biogas). FT conversions are associated with high exothermic heat for which an efficient mean of heat removal is needed. Therefore, slurry bubble column reactors operated in churn turbulent flow regimes are the reactor of choice since these reactors offer efficient heat removal, fast mass transfer, high conversion and high volumetric productivity when operated in the heterogeneous or churn turbulent regime. Due to complex interrelations among the many parameters that determine the behavior of these reactors, their scale-up, design, and operation are challenging tasks. In addition the complexity increases with the presence of intense cooling internals that affect the hydrodynamics, mixing, transports (mass and heat) and performance of slurry bubble columns. Hence, successful commercialization of these reactors and proper utilization of the natural/shale gas using such route need thorough understanding of prevailing hydrodynamics of phases (catalyst, liquid, gas) and transports. To achieve this, advanced measurement techniques are needed and have been developed and used in our laboratory which provide the needed fundamental understanding of these complex reactors. These techniques are: Radioactive particle tracking (RPT) for the measurement of 3D flow structure, velocity, turbulent parameters, residence time, etc. of multiple phases; computed tomography (CT) and dual source computed tomography (DSCT) for the measurement of the cross sectional phases distribution along the reactor height; gamma ray densitometry for flow pattern identification; 4-point optical probe for bubble dynamics measurements (bubble size, velocity, and frequency, local gas holdup and interfacial area); overall gas/liquid dynamic tracer; optical probe for mass transfer measurement and overall mass transfer coefficient measurement; heat transfer probe that mimicked the heat exchanging internals, etc. These techniques complement our advanced modeling and computations capabilities. Many recent advances have been made in our laboratory by implementing such sophisticated measurement and monitoring techniques. Among these advances are the integrated effects of dense cooling internals and solids loading on bubble dynamics, heat transfer, mass transfer, phase’s distribution, liquid/slurry velocity field and turbulent parameters. Some advances and findings will be outlined in this presentation.