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Calcium-ion exchange of coal for retention of sulfur during combustion


Chang, Karl Kho-Chung (1985) Calcium-ion exchange of coal for retention of sulfur during combustion. Dissertation (Ph.D.), California Institute of Technology.


The kinetics of calcium-ion exchange of coal and the combustion of calcium-exchanged coals in a laminar flow furnace were investigated. Particle diffusion was found to be the rate-determining step for the process of ion exchange. A diffusion model gave good agreement with observed rates of ion exchange. Diffusion of ions in PSOC 680, a bituminous coal, was observed to be much slower than in PSOC 623, a lignite. Retention of sulfur during combustion of calcium-exchanged coals was observed to increase with increasing particle residence and oxygen concentration in the combustion gas. Chemical reaction was found to be the rate-determining step in the capture of SO2 by CaO in coal ash. The results of this study were interpreted in a proposed mechanism for the release and capture of SO2.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Chemical Engineering
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Gavalas, George R. (advisor)
  • Corcoran, William Harrison (advisor)
Thesis Committee:
  • Gavalas, George R. (chair)
  • Flagan, Richard C.
Defense Date:7 January 1985
Record Number:CaltechETD:etd-08092006-145027
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3074
Deposited By: Imported from ETD-db
Deposited On:23 Aug 2006
Last Modified:26 Dec 2012 02:56

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PDF (Chang_kkc_1985.pdf) - Final Version
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