(154c) Immobilization of Carbonic Anhydrase On Ordered Mesoporous Alumina for Use in Biocatalytic Carbon Dioxide Capture

Authors: 
Salem, S. - Presenter, University of Cincinnati
Thiel, S. W., University of Cincinnati



Carbon dioxide is considered to be a major greenhouse gas involved in global climate change, and the CO2 concentration in the atmosphere has increased from its pre-industrial value of 280 ppmv to 455 ppmv [1]. This increased CO2 concentration could, in turn, cause the average temperature at the Earth's surface to increase 1.8-4.0 K above the 1990 levels by the end of this century [2]. This warming is anticipated to cause sea level rise, increased intensity and frequency of extreme weather events, ice shelf disruption, and changes in rainfall patterns. Thus, much research is focused on developing methods to reduce CO2 production and release into the atmosphere. CO2 production can be reduced by using less carbon-intensive energy sources (wind, solar, and nuclear energy) and by increasing  the efficiency of the energy production and use [3]. However, these strategies are not sufficient to meet CO2 reduction targets.

Since combustion of carbon fuels will likely be a primary source of energy for the foreseeable future, it is critical to capture and sequester the resultant CO2  [3, 4]. Capturing CO2 from flue gas using absorption processes involves CO2 dissolution in the aqueous phase, hydration, dissociation to form bicarbonate, and finally formation of carbonate; the hydration step is often rate-controlling. Fortunately, a catalyst for the rapid reversible hydration of CO2 exists in biological systems: carbonic anhydrase (CA) [5-11]. This enzyme is so highly adapted to the hydration of CO2 that reaction rates are almost diffusion limited [12].

CA functions by activating hydroxyl ions formed through ligation to a zinc atom bound within the enzyme [13]. The enzyme further holds CO2 in the active site close to the activated hydroxyl group, while preventing water from gaining access to the hydroxyl group. The enzyme thus creates an extremely basic microenvironment that allows for the rapid formation of carbonate ions to occur without altering the pH of the bulk solution.

The broad objective of the research reported in this presentation to develop a biocatalytic membrane for the capture CO2 from combustion flue gas; the membrane consists of an inert matrix in which carbonic anhydrase (CA) is immobilized. Specifically, previously presented work demonstrating the temperature tolerance, pH tolerance, and storage stability of CA adsorbed on ordered mesoporous alumina (OMPA) is extended to amine-functionalized alumina.  The implications for the performance of a biocatalytic membrane incorporating CA are also explored.

References

[1] Rogner, H.-H., D. Zhou, R. Bradley. P. Crabbé, O. Edenhofer, B.Hare (Australia), L. Kuijpers, M. Yamaguchi, 2007: Introduction. In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

[2] Fisher, B.S., N. Nakicenovic, K. Alfsen, J. Corfee Morlot, F. de la Chesnaye, J.-Ch. Hourcade, K. Jiang, M. Kainuma, E. La Rovere, A. Matysek, A. Rana, K. Riahi, R. Richels, S. Rose, D. van Vuuren, R. Warren, 2007: Issues related to mitigation in the long term context, In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Inter-governmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

[3] Reichle, D., Houghton, J., Kane, B., and Ekmann, J. 1999. Carbon sequestration: Research and development. U.S. DOE report.

[4] Herzog, H. J. and Drake, E. M. 1996. Carbon dioxide recovery and disposal from large energy systems. Annual Review of Energy and the Environment. 21.145-166.

[5] Brown, R.S., in Aresta, M. and J.V. Schloss, editors, Enzymatic and Model Carboxylation and Reduction Reactions for Carbon Dioxide Utilization, NATO ASI Series, Series C: Mathematical and Physical Sciences, vol. 314, Kluwer Academic Publishers, Dordrecht (1990), 145-180.

[6] Dodgson, S.J., R.E. Tashian, G. Gros and N.D. Carter, editors, The Carbonic Anhydrases: Cellular Physiology and Molecular Genetics, Plenum Press, New York (1991).

[7]Pocker, Y., in Aresta, M. and J.V. Schloss, editors, Enzymatic and Model Carboxylation and Reduction Reactions for Carbon Dioxide Utilization, NATO ASI Series, Series C: Mathematical and Physical Sciences, vol. 314, Kluwer Academic Publishers, Dordrecht (1990), 129-143.

[8] Khalifah R.G., The Carbon dioxide hydration activity of carbonic anhydrase I. stop-flow kinetic studies on the native human isoenzymes B and C, The Journal of Biological Chemistry, 1971,246(8), 2561-2573.

[9] Bond G.M., Stringer J., Brandvold D.K., Simsek F.A., Medina .G., and Egeland G.2001. Development of Integrated System for Biomimetic CO2 SequestrationUsing the Enzyme Carbonic Anhydrase. Energy & Fuels, 15, 309-316. 7

[10] Cheng Li-H., Zhang L., Chen Huan-L., and Cong-Jie Gao Cong-J. 2008. Hollow fiber  contained hydrogel-CA membrane contactor for carbon dioxide removal from the enclosed spaces. Journal of Membrane Science 324 33–43.

[11] Trachtenberg, M.C., Lihong, B., CO2 Capture: Enzyme vs. Amine, Proc. The 4th Annual Conference on Carbon Capture and Sequestration DOE/NETL (2005).

[12] Khalifah, R. and Silverman D.N., Carbonic Anhydrase Kinetics and Molecular Function, The Carbonic Anhydrase, Plenum Press, New York, 1991, pp. 49‑64.

[13] Silverman D.N. and S.H. Vincent, “Proton Transfer in the Catalytic Mechanism of Carbonic  Anhydrase.” CRC Crit Rev Biochem. 1983, 14, 207‑55.

Topics: