[323h] - Hydrogen from Methane in Millisecond Reactors: Partial
Oxidation and Water-Gas Shift
Author
Information:
- Emil J Klein
(speaker)
- University of
Minnesota
- 421 Washington Ave.
S.E.
- Minneapolis, MN
55455
- Phone: (612)
625-6083
- Fax:
- Email: emil@cems.umn.edu
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- Lanny Schmidt
- University of
Minnesota
- Department of Chemical
Engineering and Materials Science, 151 Amundson Hall, 421
Washington Ave. SE
- Minneapolis, MN
55455-0132
- Phone:
612-625-9391
- Fax: 612-626-7246
- Email: schmi001@tc.umn.edu
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Abstract:
Fuel cell fuel preparation, particularly
hydrogen production, has received increased interest in recent years
due to the increasing demand for more efficient power sources. The
high purity hydrogen, low concentration carbon monoxide fuel streams
required for PEM fuel cells have necessitated the design of a
reactor system that can convert available natural resources (such as
natural gas or gasoline) into high purity hydrogen streams. One
attractive design for hydrogen production couples partial oxidation
of hydrocarbons on rhodium, with high temperature water-gas shift of
the produced synthesis gas on various traditional and
non-traditional shift catalysts. This two-stage,
millisecond-contact-time system enables the combination of two
necessary hydrogen production stages into a single, potentially
adiabatic, reactor.
This presentation covers experiments
conducted in an effort to determine the extent that partial
oxidation and water-gas shift can be carried out in series on
metal-coated monoliths at millisecond contact times. Since the
temperatures associated with partial oxidation products are
typically in excess of 800C, initial water-gas shift reactions are
conducted at higher temperatures and on different catalyst (rhodium,
nickel, copper, etc.) than the industrial status quo. Maximum H2/CO
ratios (>10) and methane conversions (>90%) for given metal
catalysts under these millisecond-contact-time conditions were
determined by varying both the second-stage (WGS) temperature with
an external furnace and the amount of excess steam added to the POx
system. Kinetic rate expressions for water-gas shift reactions on
rhodium and other non-traditional shift catalyst were determined via
variable shift temperature experiments in single stage WGS
experiments. Further, heat integration was used via a coaxial
reactor with a vacuum jacket to determine the current levels of
methane conversion and the H2/CO ratios that could be achieved under
completely autothermal conditions.
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Contact Information: