The presence of water vapor is important to the functioning of LiOH beds. Chemisorption of CO2 is thought to take place via a two step reaction in which lithium hydroxide monohydrate is first formed by the exothermic reaction,
followed by the endothermic formation of lithium carbonate.
Significantly, water is required on both sides of these reaction equations. For the net reaction,
two moles of water are liberated for each mole of CO2 chemisorbed.
Boryta, D.A., and Maas, A.J., Factors Influencing Rate of Carbon Dioxide Reaction with Lithium Hydroxide, Ind. Eng. Chem., Process Des. Devel., 10, 489-494, 1971.
Copyright © 1996, James E. Atwater