Kinetics of the sodium carbonate–sulfur dioxide reaction

The Kinetics of the SO2‐Na2CO3 reaction were studied at 353 to 413 K and atmospheric pressure with thermal gravimetric analysis data. Since the reaction is very fast, special precautions were taken to operate at conditions such that transport effects did not influence results. The data indicated that Na2SO3 was formed by two paths: direct reaction, and adsorption of SO2 followed by conversion of adsorbed SO2 to adsorbed CO2 and finally desorption to final product. Rate constants were evaluated for each step in the proposed mechanism. Product distribution predicted from the rate constants agreed well with the distribution calculated from the experimental data at temperatures from 353 to 413 K. At 413 K the results suggested a change in mechanism.