Open AccessThe effect of H2O on the sulfation of Havelock limestone under oxy-fuel conditions in a thermogravimetric analyser
Author(s) -
Murat Varol,
Edward J. Anthony,
Arturo Macchi
Publication year - 2021
Publication title -
turkish journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.239
H-Index - 46
eISSN - 1303-6130
pISSN - 1300-0527
DOI - 10.3906/kim-2008-4
Subject(s) - chemistry , thermogravimetric analysis , sulfation , combustion , analyser , kinetics , mass transfer , analytical chemistry (journal) , organic chemistry , chromatography , biochemistry , physics , quantum mechanics
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.