The influence of calcium hydroxide crystal morphology on the desulfurization of cement kiln flue gas.

Ca(OH)2, a widely available and low-cost calcium-based desulfurizer, needs further improvement in calcium utilization in flue gas desulfurization. In this experiment, Ca(OH)2 crystals with different morphologies were prepared by doping impurity ions including SO42− and SiO32− by precipitation method, which played directing role in the process of crystal growth. The prepared Ca(OH)2 crystals were applied to cement kiln flue gas desulfurization environment to investigate the effect of crystal morphology on flue gas desulfurization. The observed results illustrated that Ca(OH)2 prepared by SO42− as impurity ion in hexagonal plate shape presents the best desulfurization performance with desulfurization efficiency up to 93%. The structural characterization of Ca(OH)2 crystals by XRD and SEM, and the investigation of the reasons for desulfurization by BET, EDS, and XPS showed that the hexagonal plate-shaped Ca(OH)2 crystals increased the specific surface area and had the highest elemental sulfur content of 5.04% on the (100) crystal plane, and the high surface energy on the (100) plane led to the high reactivity. This confirms the guiding significance of hexagonal plate-like morphology for improving the desulfurization performance of Ca(OH)2. [ABSTRACT FROM AUTHOR]