An investigation into the influence of dissolution rate on flue gas desulfurization by limestone slurry

In the process of flue gas desulfurization, the dissolution of limestone is an important reaction control step. In this study, we try to improve the dispersion and solubility of desulfurizer based on introducing hydrophilic material to prompt desulfurization efficiency. Firstly, hydrophilic β-cyclodextrin was introduced onto the surface of CaCO 3 nanoparticles to improve the dispersion of nanoparticles. The same concentration of limestone slurry, CaCO 3 nanofluids and modified CaCO 3 nanofluids were prepared. The stability experiments indicated that the dispersion of modified CaCO 3 nanofluid was much better than limestone slurry and CaCO 3 nanofluids because of hydrophilic groups. Acid titration experiments indicated that the conversion rate of the modified CaCO 3 nanofluid could reach 99.2%. Combined with the theory of shrinking core model, the dissolution rate of modified CaCO 3 nanofluid was 0.0103 s −1 , which was 73.14% higher than that of limestone slurry. The desulfurization experiments indicated that the desulfurization effect of high concentration CaCO 3 nanofluid was no longer obvious because of the agglomeration of nanoparticles, while the desulfurization effect of modified CaCO 3 nanofluid was much better than that of limestone slurry and CaCO 3 nanofluid. The maximum saturated sulfur capacity and desulfurization rate of 7 wt% modified CaCO 3 nanofluids were 81.38 mg/mL and 98.23%.