Method for treating a liquid stream contaminated with an iodine-containing compound using a cation-exchanged crystalline manganese phosphate
AssigneeUop LLC
InventorsSanti Kulprathipanja, Gregory J. Lewis, Richard R. Willis
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Abstract
For the removal of trace quantities of iodine-containing contaminants from corrosive liquid feed streams, an alternative with distinct advantages over the prior art is provided. The treatment method involves the use of a crystalline manganese phosphate which has been cation-exchanged with an iodine-reactive metal. This inorganic adsorbent may be used in unbound form, or it can bound with a substantially insoluble porous inorganic refractory metal oxide binder. A reactivation technique for this material is also presented.
Claims9
A process for treating a liquid feed stream containing an iodine-containing compound comprising contacting the liquid feed stream with an adsorbent comprising a crystalline manganese phosphate which has an extended network and a composition on an anhydrous basis expressed by an empirical formula of:
- (Aa+)v(Mnb+)(Mc+)xPyOz
- where A is selected from the group consisting of alkali metals, alkaline earth metals. hydronium ion, ammonium ion, organoammonium ions, silver, copper (II), zinc (II), nickel (II) mercury (II), cadmium (II), and mixtures thereof, “a” represents a weighted average valence of A and varies from 1.0 to 2.0, “v” is the mole ratio of A to Mn and varies from about 0.1 to about 10.0, “b” is the average valence of Mn and has a value of greater than 2 to about 4, M is a metal selected from the group consisting of Al, Fe3+, Ga, Sn4+, Ti, Sb5+, Ag, Zn, Cu, Ni, Cd, and mixtures thereof, “x” is the mole ratio of M to Mn and varies from 0 to about 3.0, “c” is the weighted average valence of M and varies from about 1.0 to about 5.0, “y” is the mole ratio of P to Mn and varies from about 0.1 to about 8.0, and “z” is the mole ratio of O to Mn and has a value determined by the equation:
- z=½(a•v+b+x•c+5•y), and
- the crystalline manganese phosphate further has been cation exchanged with a metal selected from the group consisting of silver, mercury, copper, lead, thallium, palladium, and mixtures thereof;
- at conditions effective to adsorb the iodine-containing compound on the adsorbent to yield a treated liquid stream.
Dependencies are inferred from the claim text.