NAMS 2002 Workshop - ICOM 2008

Facilitated Transport Membranes – 4
Friday July 18, 11:15 AM-11:45 AM, Wai’anae
CO2 Capture: Reduction in Greenhouse Gas Levels
D. Smith, Carbozyme, Inc., Monmouth Junction, New Jersey, USA
R. Cowan, Carbozyme, Inc., Monmouth Junction, New Jersey, USA
M. Trachtenberg (Speaker), Carbozyme, Inc., Monmouth Junction, New Jersey, USA -
mct@cz-na.com
Separation of flue gas carbon dioxide (CO2) from natural gas, petroleum or coal
fired furnaces is the single most difficult and expensive step (>65% of total) in the
capture-transport-geologic storage scenario proposed by national and
international organizations focused on control of greenhouse gases. The object,
as laid out by the DOE National Energy Technology Laboratory (NETL), is to
extract 90% of the CO2 to yield 95% purity with an energy penalty of less than
20% for the stream derived from combustion of pulverized coal and to have the
scalability to manage a gas flow of thousands of cubic meters (hundreds of
thousands of cubic feet) each day.
We have been developing an enzyme-based, contained liquid membrane (CLM),
dual hollow fiber permeator for this purpose. The key next step is progressive
scale up of this design and testing with actual flue gas under development facility
conditions in anticipation of later, yet larger, pilot scale field trials. The design and
operation of the permeator is critical to maximizing performance. However, a
multiple hollow fiber design of the type we developed has not been demonstrated
before nor has it been manufactured commercially. Key elements to successful
design are: " Thermal regulation as the evaporation of large quantities of water
will affect operating temperature. Control of this temperature by circulating the
CLM will affect system selectivity and CO2 recovery. Lack of control of this
temperature will result in condensation within the hollow fibers and/or membrane
pores. " Uniformity of thermal management effects driving forces for system flow.
" Permeate pressure control is necessary to minimize the energy burden
imposed by the capture system. However this will effect CO2 recovery and have
an effect on selectivity.
Each of these issues has now been addressed. Process engineering studies and
system simulations provide the basis for size selection.
Modeling of the effect of pulverized coal fired flue gas components on the CLM
has been carried out to determine the flue gas component acceptance values as
well as the preferred gas flow rates, pressure and temperature. Modeling has
been used to design post-capture treatment to provide a stream that satisfies
pipeline acceptance values. Primary interest is on the micro components of PC