Dynamic Wetting of Ni-Al Alloy Under MCFC Conditions

Abstract

Ni-Al alloy is one of the most commonly used anode materials in the molten carbonate fuel cell (MCFC). Wettability of the Ni-Al influences the active reaction area inside the porous anode and is therefore an important parameter in determining the performance of the cell. Moreover, the amount of carbonate in the electrode changes over the lifetime of a cell, and so does the extent of wetting. Therefore, the dynamic wetting of dense as well as porous substrates of Ni-Al alloy by molten carbonate was investigated. The effect of Al content on the dynamic wetting was investigated under both pure CO 2 and reducing (80%H 2 +20%CO 2 humidified at 45 °C) atmospheres. The contact angle on dense Ni-Al alloy decreased with increase of Al content under both atmospheres. It was higher under pure CO 2 atmosphere than under reducing atmosphere. The effects of porosity and of degree-of-filling (the amount of carbonate in relation to the empty pore volume available) on the time-dependent behavior of the contact angle were investigated, and the rate of absorption of molten carbonate into the substrate was measured. The absorption rate was significantly slowed down only when the molten carbonate added exceeded the volume of empty pores inside the substrate.

Technologies for sustainable heat generation in food processing

“…MCFCs typically operate at temperatures between 600 and 700°C with a power generation of up to 2.8 MW and electrical efficiencies of around 47% were reported (Table 1) (Watanabe, 2017). Because of the higher operating temperature, the electrodes are not constructed from a noble catalyst such as platinum but consist of different nickel alloys that are placed on the electrolyte film that is a mixed carbonate system (e.g., Li 2 CO 3 and K 2 CO 3 ) filled into a ceramic matrix (Gao et al., 2020; Leo, 2012). Another advantage of MCFCs is that they can be operated with different fuel types such as biogas, methane, natural gas, and hydrogen (Inal & Deniz, 2020).…”

Wetting Kinetics of Molten Carbonate on Carbon

“…As shown in Figure a, the sessile drop method , is a widely used method to measure the contact angle. It was adopted to successfully investigate the dynamic wetting behavior of molten carbonate on porous Ni, dense Ni, Ni–Al alloy, and α-LiAlO 2 under MCFC conditions. However, during the measuring process, the salt melting process and wetting process of salts on the substrate take place simultaneously; therefore, it is difficult to determine the effect of temperature on the wetting kinetics.…”