Kinetics of the hydrolysis of MgCl/sub 2/ and the chlorination of magnesia

Technical Report · Tue Feb 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/7324966· OSTI ID:7324966

Haag, G. L.

Two alternatives to the reverse Deacon reaction, Cl/sub 2/ + H/sub 2/O reversible arrows 2HCl + /sup 1///sub 2/O/sub 2/, were examined from thermodynamic and kinetic perspectives. MgCl/sub 2/-MgO Cycle: 1-a, MgCl/sub 2/(s) + H/sub 2/O(g) reversible arrows MgO(s) + 2HCl(g); 1-b, MgO(s) + Cl/sub 2/(g) reversible arrows MgCl/sub 2/(s) + /sup 1///sub 2/O/sub 2/. MgCl-MgOHCl Cycle: 2-a, 2MgCl/sub 2/(s) + H/sub 2/O(g) reversible arrows 2MgOHCl(s) + 2HCl(g); 2-b, 2MgOHCl(s) + Cl/sub 2/(g) reversible arrows 2MgCl/sub 2/(s) + /sup 1///sub 2/O/sub 2/(g) + H/sub 2/O(g). A material balance about either cycle would give product gases common to the reverse Deacon reaction. The hydrolysis reactions, 1-a and 2-a, were found kinetically feasible although the rates appeared to be diffusion controlled and a function of MgCl/sub 2/ preparation. Particle degradation was noticeable for 1-a and attributed to a crystal structure change. Very little particle change was noted for 2-a, likely a result of no change in crystal structure as the valence of the cations did not change. Chlorination reactions 1-b and 2-b were found to be kinetically more difficult although possible. An attempt to examine the kinetic stability of MgOHCl at higher temperatures in an inert atmosphere was also made.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 7324966
• Report Number(s): IS-T-742
• Country of Publication: United States
• Language: English

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