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CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: April-June 2004

Description: For the purpose of process simulation and economic analysis of the proposed CO{sub 2} selective membrane process, we began to generate the equilibrium and rate data at the operating condition interested to our applications. In this quarter, we have concentrated on the experiments at 200 C and CO{sub 2} pressure of 0 to 1 bar. In this report we present the equilibrium isotherm and transport rate data and the mathematical treatment using the commonly accepted Langmuir and linear driving force equations. The results from this analysis were then compared with the literature published data. In general, our equilibrium capacity is higher than the literature reported data while the linear driving force model is adequate to describe the rate data obtained from 0 to 1 bar CO{sub 2} pressure. In the next month, we will begin the experimental study at higher temperatures (i.e., 300 and 400 C) to complete our thermodynamic and kinetic database for process simulation.
Date: August 1, 2004
Creator: Liu, Paul K.T.

CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: January-March 2003

Description: Hydrotalcite material properties, specifically its CO{sub 2} reversibility, are critical to the performance of the proposed hydrotalcite-based membrane. In this report, we summarize the fundamental study we have performed using TGA, TGA/MS, and DRIFTS to quantify the degree of CO{sub 2} reversibility for the temperature range from 200 to 300 C. Results from these three separate studies consistently exhibit the CO{sub 2} reversibility. In addition, water effect appears negligible. Finally a high-pressure experimental study was performed to determine the reversibility under the actual operating condition. The results from this high-pressure (CO{sub 2}) study also demonstrate the CO{sub 2} reversibility. In the next quarter, we will continue the high-pressure experiment in the presence of high-pressure steam to quantify its effect under the actual WGS environment. The quantitative information obtained from this study will then be incorporated in a mathematical model describing the CO{sub 2} permeance as a function of the membrane layer thickness.
Date: May 20, 2003
Creator: Liu, Paul K.T.

CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: January-March 2005

Description: In this quarter, we have focused on the completion of the loose ends of the experimental study. A series of CO{sub 2}-affinity membranes (carbonaceous base) prepared previously were characterized and evaluated for their suitability for the proposed application The CO{sub 2} permeance and selectivity are 0.5 to >3 m{sup 3}/m{sub 2}/hr/bar and 4 to 10 for CO{sub 2} over nitrogen respectively. Based upon its performance dependence on temperature and pore size, we conclude that this type of CO{sub 2} affinity membrane shows significant surface affinity to CO{sub 2} over nitrogen even at the temperature as high as 220 C, which is within the typical operating condition for LTS-WGS. Future study should focus on mixture separations for CO/CO{sub 2}/H{sub 2} to establish the selectivity of CO{sub 2} over CO and H{sub 2} which are present in the WGS reaction of the coal gasifier off-gas.
Date: June 1, 2005
Creator: Liu, Paul K.T.

CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: July-September 2004

Description: For the purpose of process simulation and economic analysis of the proposed CO{sub 2} selective membrane process, we began to generate the equilibrium and rate data at the operating condition interested to our applications. In the last quarter we presented the results obtained at 200 C. In this quarter, we have concentrated on the experiments at 250 C and CO{sub 2} pressure of 0 to 1 bar. In this report we present the equilibrium isotherm and the mathematical treatment using the commonly accepted Langmuir equation. The data fit the Langmuir isotherm well and will be used for future adsorber and membrane reactor modeling. In addition, unsupported hydrotalcite membranes have been successfully synthesized on the silicon wafer with micro-channels. The membrane developed in this quarter ranges 2 to 5 {micro}m in thickness. No visible cracks or defects were observed. Performance characterization of these membranes will begin in the next quarter. Since the interference from substrate in the characterization of the supported membrane is no longer existent, it is hoped that the hydrotalcite membrane thus formed can be optimized for its CO{sub 2} selectivity and performance with the aid of the morphological and performance characterization.
Date: November 1, 2004
Creator: Liu, Paul K. T.

CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: October - December 2001

Description: To become a viable CO{sub 2} transport membrane, a reversible interaction between CO{sub 2} and the membrane material at the operating condition is a must. In the past quarter, we have conducted a comprehensive reversibility study using TGA and MS at {approx}200 C for both adsorption and desorption. This quarterly report summarizes the results. Evidently, CO{sub 2} can be reversible adsorbed and desorbed on the hydrotalcite surface via a pressure swing operation (i.e., between 1 bar and vacuum). About 2wt% working capacity was obtained. Even in the presence of water, the reversibility still holds. In the next quarter, we will focus on the reversibility under other operating conditions and the kinetic aspect of the reversibility study.
Date: March 1, 2002
Creator: Liu, Paul K. T.

CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: October - December 2004

Description: Our CO{sub 2}-affinity material synthesis activities thus far have offered two base materials suitable for hydrogen production via low temperature water gas shift reaction (LTS-WGS) with concomitant removal of CO{sub 2} for sequestration. They include (i) a nanoporous CO{sub 2}-affinity membrane and (ii) a hydrotalcite based CO-affinity adsorbent. These two materials offer a commercially viable opportunity for implementing an innovative process concept termed the hybrid adsorbent-membrane reactor (HAMR) for LTS-WGS, proposed by us in a previous quarterly report. A complete mathematical model has been developed in this quarter to describe the HAMR system, which offers process flexibility to incorporate both catalysts and adsorbents in the reactor as well as permeate sides. In comparison with the preliminary mathematical model we reported previously, this improved model incorporates ''time'' as an independent variable to realistically simulate the unsteady state nature of the adsorptive portion of the process. In the next quarterly report, we will complete the simulation to demonstrate the potential benefit of the proposed process based upon the performance parameters experimentally obtained from the CO{sub 2}-affinity adsorbent and membrane developed from this project.
Date: January 31, 2005
Creator: Liu, Paul K. T.

CO2 Selective Ceramic Membrane for Water-Gas-Shift Reaction With Concomitant Recovery of CO2, Quarterly Report: September - December 2002

Description: In this quarter, we have made progress in the three approaches selected for preparing CO{sub 2}-affinity membrane. A defect free nanoporous membrane was prepared via slip casting. This membrane will then be used for post treatment to seal the micropores to become a non-porous membrane with CO{sub 2} affinity. This post treatment study will be our focus in the next several quarters. Polymeric gel as a precursor was successfully prepared, which will be used for subsequent thin film deposition. Preparation of a defect-free thin film from this precursor will be our future focus using the sol-gel approach. Finally, the third approach, in-situ impregnation approach, was modified. Although we were able to deposit the precursor within the porous of the membrane, we have not been able to enhance the pH in-situ. Designing an unconventional approach to alternate the pH in-situ will be our focus of the next quarter.
Date: March 14, 2003
Creator: Liu, Paul K. T.