Page 53 - Gas Purification 5E
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Alkanolamines for Hydrogen Sulfde and Carbon Dioxide Removal   43

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       Figure 2-1. High-pressure natural gas-treating plant using diethanolamine solution
       (S.N.P.A.-DEA  process). Courtesy of The Parsons Corp.



         Ionization of water:
         H20 = H+ + OH-
         Ionization of dissolved H2S:

         H2S = H+ + HS-

         Hydrolysis and ionization of dissolved COz:
         COZ + H20 = HC03- + H+

         Protonation of alkanolamine:
         RNH2 + H+ = RNH3+

         Carbamate formation:
         RNH2 + COZ = RNHCOO- + H+


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