An experimental and chemical kinetic modeling study of the role of potassium in the moist oxidation of CO

The Chemical Coupling between Moist CO Oxidation and Gas-Phase Potassium Sulfation

“…As reported by Chanpirak et al [24], KCl inhibits strongly the CO oxidation in a flow reactor at atmospheric pressure and 773-1373 K. This is confirmed by the results illustrated in Fig. 2.…”

“…For the KCl/H 2 O/O 2 and CO/KCl/H 2 O/O 2 systems, the HCl profiles are similar; CO has no effect on HCl formation. As proposed by Chanpirak et al [24], the formation of HCl with no SO 2 addition can be explained by the heterogeneous KCl + SiO 2 reaction at the quartz reactor surface, forming potassium silicates.…”

“…The reaction mechanism and thermodynamic data were based on previous work on alkali chemistry by Glarborg and Marshal [41], Hindiyarti et al [42], Li et al [43], Weng et al [35], Berdugo Vilchez et al [28], and Chanpirak et al [24], together with subsets for chlorine [44], sulfur [45], and moist CO oxidation [24]. Table 1 shows thermodynamic properties for species revised in the present work, while Table 2 lists reactions important for the chemical coupling between the moist CO oxidation and the alkali chemistry.…”

“…Alkali species may act to recombine OH, H, O, and HO 2 radicals through gas-phase reactions at high temperature and result in inhibition or promotion of CO oxidation [20,23]. Previous studies [24] have suggested that this interaction involves the reactions KCl + H ⇄ K + HCl (R10b), K + OH + M ⇄ KOH + M (R6), K + O 2 + M ⇄ KO 2 + M (R7), KO 2 + OH ⇄ KOH + O 2 (R8), and KO + CO ⇄ K + CO 2 (R9) (the reaction numbers refer to Table 2…”

Sulfation of Gaseous KCl by H2SO4

“…25,30−36 deactivate SCR catalysts used for NO x reduction 37−39 and inhibit CO conversion. 40 To minimize these problems, reduction of alkali chlorides has been attempted by capturing the chloride salt with alumina silicate additives such as kaolin or coal fly ash 41,42 or by sulfating KCl to K 2 SO 4 by cofiring with a sulfur-rich fuel 43 or by using S-based additives. Pettersson et al 31 reported that K 2 SO 4 is less corrosive toward 304L steel than KCl and K 2 CO 3 .…”