Overcoming chemical equilibrium limitations using a thermodynamically reversible chemical reactor

Abstract

All real processes, be they chemical, mechanical or electrical, are thermodynamically irreversible and therefore suffer from thermodynamic losses. Here, we report the design and operation of a chemical reactor capable of approaching thermodynamically reversible operation. The reactor was employed for hydrogen production via the water–gas shift reaction, an important route to ‘green’ hydrogen. The reactor avoids mixing reactant gases by transferring oxygen from the (oxidizing) water stream to the (reducing) carbon monoxide stream via a solid-state oxygen reservoir consisting of a perovskite phase (La0.6Sr0.4FeO3-δ). This reservoir is able to remain close to equilibrium with the reacting gas streams because of its variable degree of non-stoichiometry and thus develops a ‘chemical memory’ that we employ to approach reversibility. We demonstrate this memory using operando, spatially resolved, real-time, high-resolution X-ray powder diffraction on a working reactor. The design leads to a reactor unconstrained by overall chemical equilibrium limitations, which can produce essentially pure hydrogen and carbon dioxide as separate product streams.

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Fig. 1: Thermodynamic reversibility in a WGS reactor.
Fig. 2: Conversion, reactor performance measure (K*) and outlet mole fractions (real and modelled) versus cycle number show that equilibrium limitations have been overcome.
Fig. 3: Representative shifts in 2θ peak positions and local oxygen content of the LSF versus reactor position showing changes in lattice parameter and oxygen content are a function of axial position.

Data availability

Data supporting this publication are openly available under an ‘Open Data Commons Open Database License’. The data, with additional metadata, are available at https://doi.org/10.17634/080913-1.

References

  1. 1.

    Dincer, I. & Cengel, Y. A. Energy, entropy and exergy concepts and their roles in thermal engineering. Entropy 3, 116–149 (2001).

  2. 2.

    Dunbar, W. R. & Lior, N. Sources of combustion irreversibility. Combust. Sci. Technol. 103, 41–61 (1994).

  3. 3.

    Dudukovic, M. P. Frontiers in reaction engineering. Science 325, 698–701 (2009).

  4. 4.

    Thursfield, A., Murugan, A., Franca, R. & Metcalfe, I. S. Chemical looping and oxygen permeable ceramic membranes for hydrogen production—a review. Energy Environ. Sci. 5, 7421–7459 (2012).

  5. 5.

    Adanez, J., Abad, A., Garcia-Labiano, F., Gayan, P. & de Diego, L. F. Progress in chemical-looping combustion and reforming technologies. Prog. Energy Combust. Sci. 38, 215–282 (2012).

  6. 6.

    Fan, L. S. in Chemical Looping Systems for Fossil Energy Conversions 241–249 (Wiley-AIChE, 2010).

  7. 7.

    Lyngfelt, A., Leckner, B. & Mattisson, T. A fluidised-bed combustion process with inherent CO2 separation; application of chemical-looping combustion. Chem. Eng. Sci. 56, 3101–3113 (2001).

  8. 8.

    Richter, H. J. & Knoche, K. F. Reversibility of combustion processes. ACS Symp. Ser. 235, 71–85 (1983).

  9. 9.

    Anhedena, M. & Svedberga, G. Exergy analysis of chemical-looping combustion systems. Energy Convers. Manag. 39, 1967–1980 (1998).

  10. 10.

    US Department of Energy Hydrogen and Fuel Cell Technical Advisory Committee Report of the Hydrogen Production Expert Panel (US Department of Energy, 2013); www.hydrogen.energy.gov/pdfs/hpep_report_2013.pdf

  11. 11.

    Lu, G. Q. et al. Inorganic membranes for hydrogen production and purification: a critical review and perspective. J. Colloid Interface Sci. 314, 589–603 (2007).

  12. 12.

    Giessler, S., Jordan, L., da Costa, J. C. D. & Lu, G. Q. Performance of hydrophobic and hydrophilic silica membrane reactors for the water gas shift reaction. Sep. Purif. Technol. 32, 255–264 (2003).

  13. 13.

    Basile, A., Criscuoli, A., Santella, F. & Drioli, E. Membrane reactor for water gas shift reaction. Gas Sep. Purif. 10, 243–254 (1996).

  14. 14.

    Noor, T., Gil, M. V. & Chen, D. Production of fuel-cell grade hydrogen by sorption enhanced water gas shift reaction using Pd/Ni-Co catalysts. Appl. Catal. B 150, 585–595 (2014).

  15. 15.

    Jang, H. M., Kang, W. R. & Lee, K. B. Sorption-enhanced water gas shift reaction using multi-section column for high-purity hydrogen production. Int. J. Hydrogen Energy 38, 6065–6071 (2013).

  16. 16.

    Jang, H. M., Lee, K. B., Caram, H. S. & Sircar, S. High-purity hydrogen production through sorption enhanced water gas shift reaction using K2CO3-promoted hydrotalcite. Chem. Eng. Sci. 73, 431–438 (2012).

  17. 17.

    Harrison, D. P. Sorption-enhanced hydrogen production: a review. Ind. Eng. Chem. Res. 47, 6486–6501 (2008).

  18. 18.

    Ortiz, A. L. & Harrison, D. P. Hydrogen production using sorption-enhanced reaction. Ind. Eng. Chem. Res. 40, 5102–5109 (2001).

  19. 19.

    Balasubramanian, B., Ortiz, A. L., Kaytakoglu, S. & Harrison, D. P. Hydrogen from methane in a single-step process. Chem. Eng. Sci. 54, 3543–3552 (1999).

  20. 20.

    Kathe, M. V., Empfield, A., Na, J., Blair, E. & Fan, L.-S. Hydrogen production from natural gas using an iron-based chemical looping technology: thermodynamic simulations and process system analysis. Appl. Energy 165, 183–201 (2016).

  21. 21.

    Mizusaki, J., Yoshihiro, M., Yamauchi, S. & Fueki, K. Nonstoichiometry and defect structure of the perovskite-type oxides La1-xSrxFeO3-δ. J. Solid State Chem. 58, 257–266 (1985).

  22. 22.

    Sogaard, M., Hendriksen, P. V. & Mogensen, M. Oxygen nonstoichiometry and transport properties of strontium substituted lanthanum ferrite. J. Solid State Chem. 180, 1489–1503 (2007).

  23. 23.

    Rydén, M. et al. Novel oxygen-carrier materials for chemical-looping combustion and chemical-looping reforming; LaxSr1-xFeyCo1-yO3-δ perovskites and mixed-metal oxides of NiO, Fe2O3 and Mn3O4. Int. J. Hydrog. Energy 2, 21–36 (2008).

  24. 24.

    Murugan, A., Thursfield, A. & Metcalfe, I. S. A chemical looping process for hydrogen production using iron-containing perovskites. Energy Environ. Sci. 4, 4639–4649 (2011).

  25. 25.

    Hodeau, J.-L. et al. Nine-crystal multi-analyser stage for high resolution powder diffraction between 6 and 40 keV. Proc. SPIE 3348, 353–361 (1998).

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Acknowledgements

C.R.T. and C.d.L. thank EPSRC for funding via a doctoral training award. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC grant agreement no. 320725 and from the EPSRC via grants EP/G012865/1, EP/J016454/1, EP/K029649/1, EP/P007767/1 and EP/P024807/1. The authors thank A. Fitch, C. Giacobbe, M. Coduri and O. Grimaldi at ESRF for help with XRD and T. Ingham, IGI Systems, for constructing the custom flow system and furnace. The authors also thank A. Coelho for developments in Topas to enable analysis of the multiple X-ray data sets produced, and B. Ladewig for help in producing the video.

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I.S.M. conceived the overall idea, secured funding and managed the work. I.S.M. and J.S.O.E. wrote the main text. I.S.M., B.R., W.H., C.d.L. and J.S.O.E. were responsible for the data analysis, modelling and interpretation. B.R., C.De., C.d.L., C.Du., F.R.G.-G., C.-M.M., E.I.P. and C.R.T. performed the experiments.

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Correspondence to Ian S. Metcalfe.

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Supplementary information

41557_2019_273_MOESM2_ESM.mov

A video that shows the principle of operation of the chemical memory reactor

Supplementary information

Supplementary Methods, Supplementary Analysis, Supplementary Results, Supplementary Modelling, Supplementary Figs. 1–10, Supplementary Tables 1–6

Supplementary Video 1

A video that shows the principle of operation of the chemical memory reactor

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Metcalfe, I.S., Ray, B., Dejoie, C. et al. Overcoming chemical equilibrium limitations using a thermodynamically reversible chemical reactor. Nat. Chem. 11, 638–643 (2019). https://doi.org/10.1038/s41557-019-0273-2

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