Modeling limestone reactivity and sizing the dissolution tank in wet flue gas desulfurization scrubbers

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Claudio Carletti, Frej Bjondahl, Cataldo De Blasio, Jarl Ahlbeck, Lauri Järvinen, Tapio Westerlund
Publisher: WILEY-BLACKWELL
Publication year: 2013
Journal: Environmental Progress and Sustainable Energy
Journal acronym: ENVIRON PROG SUSTAIN
Volume number: 32
Issue number: 3
Start page: 663
End page: 672
Number of pages: 10
ISSN: 1944-7442
eISSN: 1944-7450


Abstract

Sulfur dioxide (SO2) is one of the pollutant gases that result from energy conversion by coal and oil combustion. Limestone slurries are widely utilized in wet flue gas desulfurization (WFGD) processes. The evaluation of the reagent's reactivity is fundamental for process design and plant operation. The comparison of different limestone and dolomite rocks through dissolution experiments was realized by applying a model for second-order kinetics. And a total of 12 different samples were tested, at three different size fractions. A simulation model was developed to identify each sample's impact on sizing the dissolution tank of a WFGD scrubber. A second-order model was applied within the scrubber's dissolution tank range of operation at pH values between 4 and 5. The regression coefficients for the second-order model were higher than 0.98 in all cases. The dissolution tank volume estimation was done based on the reagent's overall chemical reaction constant in dissolution experiments. The limestone rocks, where the prevailing mineral was calcite (CaCO3), demonstrated higher chemical reactivity yielding smaller dissolution tank volumes than the dolomite rocks, where the prevailing mineral was dolomite (CaMg(CO3)(2)). The CaO and MgO content of a sample can be used to predict the dissolution rate; nevertheless more factors influence the rate and the tank sizing. The knowledge of the sample's composition and its reactivity is necessary for the design of a desulfurization scrubber; the reagent used is determinant for the economy and optimal operation of such scrubbers.


Keywords

dissolution, flue gas desulfurization, limestone, simulation

Last updated on 2019-20-10 at 02:46