Oxygen Conductivity

Unlike the PEM, the ionic conduction occurs for the oxygen ion instead of the hydrogen ion. SOFCs are made of ceramic materials like zirconium (Z = 40) stabilized by yttrium (Z = 39). High-temperature oxygen conductivity is achieved by creating oxygen vacancies in the lattice structure of the electrolyte material. The halfcell reactions in this case are... 

N.G. Torkelsen, and S. Raaen, Work function variations and oxygen conduction in a Pt/ZrC>2(Y203)/Pt solid electrolyte cell, Appl. Surf. Sci. 93, 199-203 (1996). 

The transport numbers of the ions can be determined by using a solid-state electrolyte. The cell voltage across an oxygen-conducting electrolyte subjected to an oxygen pressure gradient is given by the Nemst equation (Section 6.8.3) ... 

A lot of substances and components are present in wastewaters and can be measured, especially the emerging pollutants. However, in practice, the aggregate parameters (BOD, COD, TSS,...) and the physico-chemical ones (temperature, pH, dissolved oxygen, conductivity, turbidity,...) are more often monitored. The only specific compounds generally considered are the N and P forms, and in case of industrial wastewaters, some specific pollutants such as organics (phenolics, hydrocarbons,...) or metallic compounds. 

Oxygen-conductive electrodes for use at high temperatures. The most well-known electrodes of this type are the Zr02/02 interfaces, used as the oxygen-measuring electrode and/or reference electrode in studies in molten glass4 8. 

At the start of the Phase I TIE (Day 1), the untreated sample is initially tested for routine water quality parameters required by the test method (e.g., pH, dissolved oxygen, conductivity) and toxicity (Initial Test). Additional baseline tests using the untreated effluent are conducted at the start of the TIE sample manipulations and... 

Another class of important materials with oxygen ion conduction are perovskites (see Section 2.4.4). Perovskite phases have been, initially, considered as possible electrode materials for SOFCs. The first report of the existence of oxide conductivity in a perovskite material was made using a calcium-doped lanthanum aluminate [98], But the discovery of attractive oxygen conduction properties is rather recent [84],... 

Solid oxide fuel cells (SOFC), which use oxygen conducting ceramic membranes to electo-combust H2, at the anode, by 02 -anions provided by the cathodic reduction of ambient oxygen at high temperatures. 

Oxygen anion conductors solid electrolyte Oxygen, chemisorbed - chemisorption of oxygen Oxygen conducting solid electrolyte - solid electrolyte... 

The system (Figure 12) is based on sulfuric acid (H2SO4) synthesis and decomposition process (the Westinghouse process) developed earlier. The sulfur trioxide (SO3) decomposition process is facilitated by electrolysis with ionic oxygen conductive solid electrolyte to reduce the operation temperature 200°C-300°C lower than the Westinghouse process. 

Only 7.8% SO3 thermally decomposes in equilibrium condition at 500°C as shown in Figure 1, and also only about 20% in the case membrane reactor technique is used to increase decomposition fraction of SO3 at 500°C. Therefore, some other energy is required to obtain higher decomposition fraction of SO3. Electrolysis by ionic oxygen conductive solid electrolyte is applied to increase decomposition fraction of SO3 in HHLT. HHLT is composed of the reactions shown below. 

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