Modelling The Sodium-Bicarbonate Production Process Using Carbon Dioxide

Sodium bicarbonate is produced in a bubble column by injection carbon dioxide gas into the carbonate and bicarbonate liquid solutions. This paper investigated a triple-phase mass transfer coupled with chemical reactions and crystallization. In this work, a mole balance has been written on flows and components, utilized the Danckwerts theory for mass transfer between gas and liquid phase and a population balance to obtain the nucleation and growth formula. The model results compared with the experimental data for validation. Finally, the effects of several parameters were investigated on the sodium bicarbonate crystal nucleation and growth rate and also crystals size distribution. Therefore, this model can predict the carbon dioxide conversion and the quantity and quality of produced solid crystals in various operating conditions. These predictions show that the production of sodium bicarbonate crystals and the size of these crystals increase by increasing the inlet gas pressure or inlet carbon dioxide mole fraction or decreasing the liquid temperature. But, the carbon dioxide conversion increases by increasing the inlet gas pressure.