Product Layer Diffusion during the Reaction of Calcium Oxide with Carbon Dioxide

摘要

The carbonation rate of 15-20 μm, nonporous, calcium oxide crystals has been studied over a temperature range of 550-1100 deg C and a CO_2 pressure range of 1-11.7 atm. At temeprature greater than 600 deg C, the carbonation rate decreases more rapidly with tiem than would be expected from diffusion through a unfiorm poduct laeyr and the activation energy is intitially low but increases with conversion. The product laeyr consists of crystalline grains, and these product laeyr grains grow by coalescence from less than one μm diameter to the approximate dimension of the particle.