Improved Gas Purification Membranes

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					  Improved Gas Purification
        Membranes

        Benny D. Freeman, Ph.D.
   Department of Chemical Engineering




              Overall Need
Natural gas purification
                                   cu.ft.
    Annual production: 42 trillion cu.ft. (STP)
    20% has excess CO2
    CO2 gas processing equipment market: ~ $0.5
    billion/year
Hydrogen production
    Annual U.S. consumption: 8.1x109 kg
    Typically requires CO2 removal
Improved CO2 removal processes could lead to
enormous cost savings.
                                                  2




                                                      1
     Increasing Importance of
        Natural Gas as Fuel
                                     250




      Annual Worldwide Consumption
                                                                   Oil
                                     200


             [Quadrillion BTU]
                                     150
                                                           Natural Gas

                                                                         Coal
                                     100


                                                                Renewables
                                      50

                                                                    Nuclear
                                      0
                                      1975   1985   1995    2005    2015        2025
                                                       Year

  Improved CO2 removal processes could lead to
  enormous cost savings.
                                                                                       3




                         Market Applications
Removal of CO2 from natural gas
Removal of CO2 for H2 purification
Removal of CO2 from air or flue gas
H2S removal from natural gas
SO2 and NH3 removal from light gases
H2O removal from air



                                                                                       4




                                                                                           2
  Solution: Membrane Technology
   Pfeed         Pdown




                                                               Amine
                                                               Scrubber



                 Membrane

Permeability: inherent gas flux
Selectivity: permeability ratio of
             gas A to gas B




                                               Membrane Unit
                                                                   5




       Uniqueness of UT Approach
  Current membranes remove small molecules
  from mixtures, which would produce H2 at low
  pressure when it is needed at high pressure.
           UT membranes remove CO2, leaving H2 at high
                    (reverse-
           pressure (reverse-selective membranes).
  Current membranes lose separation properties
  in high-pressure natural gas environment.
           UT membranes exhibit little change in properties even
           at high pressure.

                                                                   6




                                                                          3
       Technology Overview
Our polymers
  Easy to prepare: monomers are cheap and off-the-
  shelf
  Excellent CO2 separation performance
  Potentially more stable
What is needed
  Partners to prepare membrane modules from our
  materials
  Proof-of-concept testing in industrial setting

                                                     7




                 Benefits
Products (i.e., H2 or CH4) are kept at high
pressure for further use
Lower temperature is beneficial
Small footprint
High energy efficiency
Reliability
Green chemistry (no solvents)

                                                     8




                                                         4
   Results: Gas Throughput

Polymer             CO2 Permeability [Barrer]

Polyimide                       11
Cellulose Acetate               6.9
XLPEO [UT]                  100 - 300


                Higher is better.
                                                9




    Results: Gas Selectivity

Polymer             CO2 /H2 Selectivity

Polyimide                      0.48
Cellulose Acetate              0.40
XLPEO [UT]                    10 - 40


                Higher is better.
                                                10




                                                     5
                Next Steps
Prototypes complete
  Better separation performance
  Potentially more stable
Commercialization plan
  Prepare commercial-scale membrane modules
  ($200-400k)
  License to gas processing companies
  Startup/corporate partner


                                              11




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