Partial oxidation of n-butane in a solid electrolyte membrane reactor: Periodic and steady-state operations

Reaction induced current generation by butane oxidation in high temperature electrochemical membrane reactor

“…8 As we see all the reactions are highly exothermic including remarkable release of Gibbs free energy, and therefore highly interesting to electrochemical processing. It is to be expected that it is not only the MA formation which induces the detected current in our investigations, but also the total oxidation of butane to CO/CO 2 is highly probable, as observed as competitive reactions to the formation of MA by numerous investigations by Ye et al under oxygen pumping conditions [15,24,26]. Furthermore, the current might be induced also by the overoxidation of MA to CO/CO 2 according to reactions (4) and (5) as well.…”

“…The maximum reaction induced current in the present investigation, 0.3 mA, corresponds to the oxygen flow of 7.77 × 10 −10 mol/s (2.98 × 10 −11 mol/(s cm 2 )). The operation in EMR with measurable quantitative results is only possible with applied voltage in the EOP modus as reported in [15,24,26]. The applied voltage between the electrodes increased the current more than one order of magnitude (up to 120 mA in the studies of Ye et al) at the temperatures from 720 to 790 K, where quantitative measurable MA amounts were synthesized.…”

Solid Electrolyte Membrane Reactors

“…The model, including the equations for charge transfer reactions of oxygen on the cathode and the anode ( 7.12 -7.14 ), was not able to predict the experimental results of the EMR operation conditions with electrochemically supplied oxygen. One reason for the discrepancies between the experimental data and the simulated was concuded to be the additional electrochemically induced side reactions, as suggested already by Chalakov et al ( 2007 ), Ye et al ( 2004 ) and Ye et al ( 2005 ). In contrary to the co -feed mode, where the oxygen on the anode exists only in form of gaseous O 2 , additional oxygen species, e.g.,…”

Bulk and Surface Properties of a VPO Catalyst Used in an Electrochemical Membrane Reactor: Conductivity-, XRD-, TPO- and XPS-study

“…In our EMR application, however, the catalyst is fixed on the electrolyte membrane in the anodic compartment, where the oxygen is supplied in a very low concentration. We have shown before [9,10,21,22], that under these conditions part of the transported oxygen ions is converted neither to MA nor to CO 2 or CO, but is recombined to gaseous dioxygen. Due to these parallel processes, the oxygen concentration in the anodic compartment can vary, which in turn might influence the conductivity.…”

“…Besides this porous membrane reactor concept, solid electrolyte membrane processes can also be an interesting option for the production of chemicals [8]. The feasibility of butane oxidation in a tubular electrochemical membrane reactor (EMR) using a VPO catalyst layer on an anodic electrode has been recently investigated (for a schematic illustration of the EMR, see figure 1) [9,10]. In the EMR, oxygen is reduced at the cathode and transferred through an oxygen ion conducting solid electrolyte membrane to the anode, where it can either react with hydrocarbons or form gaseous molecular oxygen.…”