In his commentary article on the invention of the Fray-Farthing-Chen Cambridge Process, the late Professor ... focusing on some recent findings on trapping the ...
Following the Invention of the FFC Cambridge Process George Z. Chen1,2 1
Department of Chemical and Environmental Engineering, and Centre for Sustainable Energy Technologies, Faculty of Science and Engineering, University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315100, P. R. China 2 Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK In his commentary article on the invention of the Fray-Farthing-Chen Cambridge Process, the late Professor Harvey Flower of Imperial College described it as “A moving story of oxygen” which was published in September 2000 by the Nature magazine together with a Letter to Nature from the inventors.1,2 In the invention, a metal oxide is made the cathode and polarised to a sufficiently negative potential in a molten salt, typically CaCl2 and LiCl, so that the metal oxide is electro-deoxidised to produce the metal and oxide ion. The oxide ion then dissolves in and moves through the molten salt to discharge at the anode. Since the Nature publication, many efforts have been made in laboratories around the world and resulted in successful outcomes on making various metals and alloys, whilst commercial development also went on steadily but fairly quietly.3,4 In this presentation, I shall Alumina sleeve look backward and forward the FFC Chlorine gas (Cl2) (tube) Cambridge Process, particularly Carbon debris focusing on some recent findings on Porous pellet trapping the oxygen, instead of metal oxide Graphite anode moving it through the molten salt.5 (MOx) The relevant electrolytic cell is Molten salt (eutectic Alumina or illustrated in Figure 1, and the MgCl2-NaCl-KCl, graphite 700 oC) difference from previous studies is crucible that the oxide ion conducting molten Cathode: MOx + x MgCl2 + 2x e → M + x MgO + 2x Cl salt, such as CaCl2, is replaced by the Anode: 2x Cl → x Cl2 + 2x e mixture of MgCl2-NaCl-KCl which Cell: MOx + x MgCl2 = M + x MgO + x Cl2 has very poor solubility of the oxide ion. The technological potential of Figure 1. Schematic illustration of electrolysis this new proposal will be discussed in of solid metal oxide in oxide ion nonterms of fundamental understanding, conducting molten salts and the respective energy consumption, carbon dioxide cathode, anode and cell reactions. emission, and last but not the least an inert carbon anode. Acknowledgement The author acknowledges financial supports from the NSFC (and other sources in China as detailed in the presentation), EPRSC (EP/J000582/1) and Ningbo Municipal Government (3315 Plan and the IAMET Special Fund, 2014A35001-1).
Reference 1. Flower H M, Nature, 407(2000) 305-306. 2. Chen GZ, Fray DJ, Farthing TW, Nature, 407 (2000) 361-364. 3. Xiao W, Wang DH, Chem. Soc. Rev. 43 (2014) 3215-3228. 4. http://metalysis.com/ 5. Li W, Yuan YT, Jin XB, Chen HL, Chen GZ, Prog. Nat. Sci.-Mater. Int., (2015) in press.
