•  
  •  
 

Turkish Journal of Chemistry

DOI

10.3906/kim-2008-4

Abstract

A gas mixture representing oxy-fuel combustion conditions was employed in a thermogravimetric analyser to determine the effect of water vapor and SO$_{2}$ concentration on limestone sulfation kinetics over the temperature range of 800 to 920 °C. Here, experiments used small samples of particles (4 mg), with small particle sizes (d$_{p}$ < 38 μm) and large gas flow rates (120 mL/min@ NTP) in order to minimize mass transfer interferences. The gas mixture contained 5000 ppm$_{v}$ SO$_{2}$, 2% O$_{2}$, and the H$_{2}$O content was changed from 0% to 25% with the balance CO$_{2}$. When water vapor was added to the gas mixture at lower temperatures (800-870 °C), the limestone SO$_{2}$ capture efficiency increased. However, as the temperature became higher, the enhancement in total conversion values decreased. As expected, Havelock limestone at higher temperatures (890 °C, 920 °C, and 950 °C) experienced indirect sulfation and reacted at a faster rate than for lower temperatures (800-870 °C) for direct sulfation over the first five minutes of reaction time. However, the total conversion of Havelock limestone for direct sulfation was generally greater than for indirect sulfation.

First Page

452

Last Page

462

Included in

Chemistry Commons

Share

COinS