The Use of Limestones Built of Carbonate Phases with Increased Mg Content in Processes of Flue Gas Desulfurization

Abstract

The purpose of this article was to present the theory of the possibility of using limestone sorbents containing carbonate minerals with increased Mg content in processes of flue gas desulfurization in power stations. Data obtained as a result of the conducted research show that the analyzed Triassic (Muschelkalk) limestones of the south-west part of Poland are built of the following carbonate minerals: low magnesium calcite, high magnesium calcite, dolomite and huntite. These carbonate minerals are characterized by various magnesium contents. The increased content of magnesium in the sorbent has a positive effect on the technological process of flue gas desulfurization using the dry method, especially in the case of desulfurization with the application of Fluidized Bed Reactors. The positive influence of magnesium’s presence in sorbent in the desulfurization process is connected with the decarbonization of carbonate phases with magnesium at temperatures similar to the dolomite decarbonization temperatures, which are, thus, lower than typical for low magnesium calcite. The process would be easier because the structure of a solid solution containing magnesium ions, with a smaller ion radius to calcium ions, is unstable and the decomposition of these phases runs easier and faster. Therefore, the desulfurization process starts earlier and is more effective.

Modeling based on machine learning to investigate flue gas desulfurization performance by calcium silicate absorbent in a sand bed reactor

“…Most NO x was converted into harmless N 2 in the expanded granular sludge bed reactor. Stanienda-Pilecki 21 explored the use of limestone sorbents with increased magnesium content in FGD processes in power stations. Triassic limestones in Poland, consisting of low magnesium calcite, high magnesium calcite, dolomite, and huntite, have various magnesium contents.…”

Geochemical and Mineralogical Characteristics of Triassic Dolomites from Upper Silesia, Poland

“…The area of Upper Silesia, including the areas of Bytom and Piekary Śl ąskie, is an area where Triassic carbonate rocks occur, including the Lower, Middle, and Upper Muschelkalk formations [1,2]. These rocks, in contrast to the limestone deposits of the area of the Opole Silesia [3][4][5][6][7][8][9][10][11][12][13][14][15][16], have not been thoroughly investigated in terms of the presence of carbonate phases with different magnesium contents. In the limestones of Opole Silesia, five carbonate phases were identified, characterized by different Mg contents: low-Mg calcite, high-Mg calcite, protodolomite, ordered dolomite, and huntite.…”

“…In the limestones of Opole Silesia, five carbonate phases were identified, characterized by different Mg contents: low-Mg calcite, high-Mg calcite, protodolomite, ordered dolomite, and huntite. The carbonate rocks rich in magnesium are used in many branches of industry [6,11,13,[17][18][19][20].…”

“…Magnesium carbonatecontaining phosphate binder prevents connective tissue mineralization [20]. Knowledge of the Mg content in carbonate phases is very important for the application of rock as a sorbent in the desulphurization of flue gases in power plants and in lime production [6,13,18]. During the desulphurization process, the carbonate phases with higher Mg contents decompose at lower temperatures than the phases with low Mg contents or pure calcite without Mg substitution.…”

“…This is due to the lower stabilization of some carbonate phases with Mg substitution, like high-Mg calcite [21][22][23][24][25][26]. Because of this, the desulphurization process starts earlier and is more effective [6,13].…”