The effects of steam and carbon dioxide on calcite decomposition using dynamic X-ray diffraction

The effects of steam (H2O) and carbon dioxide (CO2) on the rates of calcite decomposition have been studied using dynamic X-ray diffraction (DXRD). Because the DXRD technique allows for considerably better control of heat and mass transfer complications, intrinsic decomposition rates are obtained for temperatures between 440–560°C and up to H2O and CO2 pressures of 0.2135 and 0.00087 atm, respectively. It is shown that the observed enhancement effect of steam is related to its adsorptive properties which are faster and more significant than CO2 adsorption. This, in turn, leads to the hypothesis of a quantitative Langmuir-Hinshelwood model which is totally compatible with the kinetic data. Separate adsorption experiments show that the effect of steam pressure is limited due to adsorption saturation capacity and the model is used to predict the steam pressure required to produce 95% of the maximum effect of steam as a function of temperature.

[1]  C. C. Furnas.  The Rate of Calcination of Limestone , 1931 .

[2]  D. W. Johnson,et al.  Effect of thermal transport mechanisms on the thermal decomposition of CaCO3 , 1977 .

[3]  T. Rao.  Kinetics of calcium carbonate decomposition , 1996 .

[4]  W. Thomson,et al.  The influence of steam on mullite formation from sol-gel precursors , 1993 .

[5]  栄久 橋本.  炭酸カルシウムの熱分解(II)-炭酸ガス圧力の影響- , 1961 .

[6]  Milton E. Wadsworth,et al.  Calcium Carbonate Decomposition in Carbon Dioxide Atmosphere , 1958 .

[7]  T. .. Ingraham,et al.  Kinetic studies on the thermal decomposition of calcium carbonate , 1963 .

[8]  J. H. Campbell,et al.  Laboratory and modelling investigation of a Colorado oil-shale block heated to 900 °C☆ , 1981 .

[9]  G. Narsimhan.  Thermal decomposition of calcium carbonate , 1961 .

[10]  John H. Sharp,et al.  The thermal decomposition of dolomite , 1990 .

[11]  Charles N. Satterfield,et al.  Heterogeneous catalysis in industrial practice , 1991 .

[12]  A.W.D. Hills,et al.  The mechanism of the thermal decomposition of calcium carbonate , 1968 .

[13]  D. W. Johnson,et al.  The effects of sample size and heating rate on the kinetics of the thermal decomposition of CaCO3 , 1973 .

[14]  Alan K. Burnham,et al.  Effects of gas environment on mineral reactions in Colorado oil shale , 1980 .

[15]  Irving Langmuir,et al.  The constitution and fundamental properties of solids and liquids. Part II.—Liquids , 1917 .

[16]  Robert S. Boynton.  Chemistry and Technology of Lime and Limestone , 1966 .

[17]  D. Beruto,et al.  Use of the Langmuir method for kinetic studies of decomposition reactions: calcite (CaCO3) , 1974 .

[18]  E. Winter,et al.  Thermal Dissociation Pressure of Calcium Carbonate , 1956 .

[19]  John S. Dennis,et al.  the effect of CO2 on the kinetics and extent of calcination of limestone and dolomite particles in fluidised beds , 1987 .

[20]  J. Mu,et al.  An equilibrium—interface model for solid decomposition , 1980 .

[21]  C. Satterfield,et al.  Kinetics of the thermal decomposition of calcium carbonate , 1959 .

[22]  A.Romero Salvador,et al.  Effects of sample weight, particle size, purge gas and crystalline structure on the observed kinetic parameters of calcium carbonate decomposition , 1989 .