Doctoral Dissertations

Keywords and Phrases

Trickle Bed Reactor; Residence time distribution; Axial dispersion; Liquid holdup; Liquid phase; Acetylene hydrogenation; selective solvent; ethylene production; Kinetics; Packed bed reactors

Abstract

"Gas-phase catalytic hydrogenation of acetylene to produce ethylene, commonly practiced in industries, has green oil formation, which leads to catalyst deactivation and sometimes reactor runaway risks due to high exothermicity. To overcome these issues as well as to increase the selectivity and conversion, liquid-phase hydrogenation of acetylene was investigated in packed bed reactors (PBR) using a commercial catalyst. The reactor performance of two-phase flow PBRs was assessed experimentally complemented by a validated mathematical model at different scales.

The selective hydrogenation of acetylene in the liquid phase over a commercial 0.5 wt% Pd/Al2O3 catalyst was investigated in a slurry and basket stirred-tank reactor to extract the intrinsic and apparent kinetics respectively, and in packed bed reactors in trickle flow and upflow at selected operating conditions to study the reactor performance. The selective solvent, N-methyl pyrrolidone (NMP) with absorbed acetylene, was used as the liquid phase. Rate equation models were derived and fit to the experimental data to estimate the kinetic parameters. Using Residence Time Distribution (RTD) experiments at scaled-down operating conditions for different catalyst bed packings and types of reactors (with and without thermowell), the axial dispersion coefficient and dynamic liquid holdup were measured and correlated. The reactor performance was evaluated in the packed bed with the downflow and upflow of the reactants. Both the mode resulted in high conversion and ethylene selectivity while upflow performed better. The reactor scale model, integrating the kinetics and the hydrodynamic parameters along with the wetting and mass transfer correlations, was able to simulate the experimental data with good agreement"--Abstract, page iv.

Advisor(s)

Al-Dahhan, Muthanna H.

Committee Member(s)

Wang, Jee-Ching
Liang, Xinhua
Rownaghi, Ali A.
Foston, Marcus

Department(s)

Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2020

Journal article titles appearing in thesis/dissertation

  • Quantifying liquid dispersion and liquid holdup in a laboratory scale trickle bed reactor with and without thermowell using residence time distribution studies
  • Kinetic studies of liquid phase hydrogenation of acetylene for ethylene production using a selective solvent over a commercial palladium/alumina catalyst
  • Liquid phase ethylene production by hydrogenation of acetylene using a selective solvent in a fixed bed reactor: Experiments and modeling

Pagination

xv, 153 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2020 Humayun Shariff, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11691

Electronic OCLC #

1164773875

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