(583e) Comparison of Cu-, Fe- and Ni- Based Oxygen Carriers for Chemical-Looping Combustion | AIChE

(583e) Comparison of Cu-, Fe- and Ni- Based Oxygen Carriers for Chemical-Looping Combustion


Zhou, Z. - Presenter, University of Connecticut
Nordness, O., University of Connecticut
Bollas, G., University of Connecticut

Chemical-looping combustion (CLC) is the indirect combustion of
fossil fuels for power generation taking place in two reactors (a Reducer and
an Oxidizer) with inherent CO2 separation, which is accomplished in
the Reducer reactor using an oxygen carrier (metal oxide) instead of air. Oxygen
carriers in a CLC power plant are expected to be carbon-resistant, exhibit high
reaction rates and conversions, and be regenerative over successive cycles. Different
metal oxides have been proposed and tested as promising candidates for the CLC
process, for instance, CuO, NiO, Fe2O3 and Mn2O3.
In this study, Cu-, Fe-, and Ni- oxygen carriers, prepared via the incipient
wetness impregnation on Al2O3-SiO2 supports
are compared in terms of their reactivity, selectivity and stability. A
fixed-bed reactor (Figure 1) is used to test the oxygen carrier reactivity and
CO2 separation efficiency. A sample of the experiments of this work
and the model prediction for Ni-based CLC is presented in Figure 2. Physical
and chemical properties of the fresh and used samples, such as active metal
oxide loading, available phases, surface structure, surface area and pore
volume are characterized by TGA, XRD, SEM and BET, respectively.

Kinetic networks and parameters are presented for all three oxygen
carriers. A summary of the fixed-bed experimental data analyzed and utilized to
validate the proposed kinetic network, including all the relevant published
data for CLC with CH4 and Fe2O3 and CuO as the
oxygen carrier, is presented in Table 1 (for the kinetics of Ni-based oxygen
carriers, see [1]).

fixed-bed units

In this presentation, operating conditions, design values and OC
characterization is presented for the three most common metal oxides and
natural gas. Implementation of the kinetic network in different fixed-bed units
of the various CLC laboratories will be shown.

Figure 1: Fixed-bed chemical-looping setup used in this work.

Figure 2: Chemical-looping reduction selectivity using Ni/NiO and CH4 in fixed-bed reactors; experimental data from UConn fixed-bed reactor at 800°C.

This material is based upon work supported by the National Science Foundation
under Grant No. 1054718.


[1]      Z. Zhou, G.M.
Bollas, Holistic Kinetic Study of the Reduction of CH4 with NiO in
Chemical-Looping Combustion, AIChE Annual Meeting, Pittsburgh, PA. (2012).

[2]      S.
Noorman, F. Gallucci, M. van Sint Annaland, J.A.M. Kuipers, Experimental
Investigation of Chemical-Looping Combustion in Packed Beds : A Parametric
Study, Industrial & Engineering Chemistry Research. (2011) 1968¨C1980.

[3]      P.
Ammendola, R. Chirone, L. Lisi, G. Ruoppolo, G. Russo, Copper catalysts for H2
production via CH4 decomposition, Journal of Molecular Catalysis A:
Chemical. 266 (2007) 31¨C39.

[4]      B.
Corbella, L. De Diego, F. Garcia, The performance in a fixed bed reactor of
copper-based oxides on titania as oxygen carriers for chemical looping
combustion of methane, Energy & Fuels. 19 (2005) 433¨C441.

[5]      F.
He, H. Wang, Y. Dai, Application of Fe2O3/Al2O3
Composite Particles as Oxygen Carrier of Chemical Looping Combustion, Journal
of Natural Gas Chemistry. 16 (2007) 155¨C161.

[6]      B.M.
Corbella, J.M. Palacios, Titania-supported iron oxide as oxygen carrier for
chemical-looping combustion of methane, Fuel. 86 (2007) 113¨C122.

[7]      W.C.
Cho, M.W. Seo, S.D. Kim, K.S. Kang, K.K. Bae, C.H. Kim, et al., Reactivity of
iron oxide as an oxygen carrier for chemical-looping hydrogen production,
International Journal of Hydrogen Energy. 37 (2012) 16852¨C16863.

[8]      T.
Mattisson, A. Lyngfelt, P. Cho, Possibility of using iron oxide as an oxygen
carrier for combustion of methane with removel of CO2 - application
of chemical looping combustion, in: Proc. 5th Int Conf Greenhouse Gas Control
Technologies (GHGT-5), Cairns, Australia, 2000.