Effects of NaCl on the capture of SO2 by CaCO3 during coal combustion

The effects of NaCl on the capture of SO2 by CaCO3 during coal combustion were studied using a thermogravimetric analyzer. All experiments were carried out in a flowing air atmosphere at a heating rate of 10, 20 or 30 °C/min. The experimental results showed that more SO2 reduction was achieved as long as NaCl was added together with CaCO3 to coal. It indicated that NaCl improved the behavior of CaCO3 capturing SO2. NaCl alone reduced SO2 emission within the range from 300 to 700 °C in the experiments, while the capture of SO2 by NaCl alone would be reemitted when temperature was raised over 700 °C. Adding sorbents such as CaCO3 together with NaCl was necessary for a reliable SO2 reduction.