Degree

Doctor of Philosophy (PhD)

Department

Chemical Engineering

Document Type

Dissertation

Abstract

The objective of this study is to model gas-liquid contact and separation problems (using Euler-Euler based Computational Fluid Dynamic (CFD) models) at different scales. We have explored process intensive solutions, design optimizations by introducing internals in these gas-liquid operations.

A 500L pilot plant scale and a 7000L industrial scale novel down-flow bubble column problems were modeled. Methodologies used to overcome challenges on large-bubble micro-bubble dynamics are discussed and the resulting fluid dynamic solutions were studied. These solutions were further modified and tailored toward intensification, by exploring horizontal plate internals. We then modeled mass transfer and reaction kinetics on this system and performed a number of parametric studies to study product yield variations.

In the next chapter, novel internal designs and their impact on hydrodynamics were studied on a semi-batch, lab scale bubble column. Conical cup shaped internals predicted a reverse re-circulation pattern which was able to delay the transition of the column toward heterogeneity and increase gas hold up at higher superficial gas velocity values. Image analysis on this column was performed using high speed camera & convolutional neural networks were trained to detect bubbles. Using this, we were able to obtain pixel based information on bubble location, obtain size distribution and similar bubble parameters to qualitatively validate conical internal flow patterns.

In the last chapter, we extended boycott effect to gas liquid separation problems by introducing inclined plate baffles for separator intensification. We compared performance of a number of inclined plate baffle designs, traditional vertical baffles, varying inlet positions, bent inclined plate baffles by studying separation efficiency. The ability of inclined plate baffles to dampen oscillating sinusoidal inlet dispersion flux were also studied using energy spectral plots.

Date

4-9-2020

Committee Chair

Nandakumar, Krishnaswamy

Available for download on Thursday, March 16, 2023

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