Development of SOFC-GT Combined Cycle System with Tubular Type Cell Stack

Abstract

Mitsubishi Heavy Industries (MHI) has developed SOFC with tubular type cell stack since 1984. In this study, we report the current status toward commercialization of SOFC-GTCC power generation system at MHI. To Redox robustness of a cell stack, the sintering characteristics of interconnect was improved. To improve durability of cell stack, long-term change of the electrochemical characteristics had been measured, and analyzed the interface of cathode and electrolyte by SIMS. For compact module, the packing density of the cell stack was increased from 400 to 700 stack/m2, and confirmed I-V characteristics and the temperature distribution of improved module. The generation performance of improved module is roughly comparable to that of conventional type module, and the temperature distribution is also roughly agreement of simulation result.

Experimental Investigation of the Effect of Operating Pressure on the Performance of SOFC and SOEC

“…Two kinds of disc type planar cells were tested. Cell-A is an electrolyte supported cell (diameter: 60mm, active electrode area: 113cm 2 , electrolyte: La 0.8 Sr 0.2 Ga 0.8 Mg 0.15 Co 0.05 O 3-δ , 0.2mm thick, cathode: Sm 0.5 Sr 0.5 CoO 3-δ , 30-50µm thick, anode: Ni/Ce 0.8 Sm 0.2 O 2-δ , 30-50µm thick) (4), whereas cell-B, provided by Magnex Co., LTD, is an anode supported cell (diameter: 60mm、active electrode area: 100cm 2 、 electrolyte: YSZ ca. 10µm thick, cathode: LSCF, ca.…”

“…In this work, the diffusion in porous electrodes perpendicular to electrode/electrolyte interface and Butler-Volmer type relationship for the electrode kinetics (Eqs. [1]& [2] for anode and cathode, respectively) were additionally taken into account. Parameters in Butler-Volmer equation were adjusted to explain the experimental data as shown in the equations where subscripts tpb, ref, act, an and ca mean triple phase boundary, reference, activation, anode and cathode, respectively.…”

“…It is well known that the pressurization of SOFC operation makes it more efficient (1). The pressurized SOFC is also considered as a topping cycle in combined power generation system to make the whole system efficient (2). Although it is a common consensus that this high efficiency can be available mainly because of the increase in Nernst Potential with the pressure, precise mechanism of this beneficial phenomena is yet to be investigated.…”

Recent Progress of SOFC Combined Cycle System with Segmented-In-Series Tubular Type Cell Stack at MHI

“…Based on the results of these studies, we prototyped a new cell stack changing the cathode interlayer into (Sm, Ce)O 2 (SDC) from (La, Sr)MnO 3 -YSZ (LSM-YSZ) to reduce cation migration, which was assumed to be the main cause of deterioration. A long-term generation test was conducted at atmospheric pressure for over 7,000 hours as shown in Figure 4, and no voltage decay was measured well within the NEDO target of 0.25%/1,000 hours or lower (1)(2)(3).…”

Direct Conversion of Biomass to Electricity With Solid Oxide Fuel Cell Technology

“…For example, an anode-supported cell (Figure 2a), in which a thin electrolyte layer with a thickness of around 15 μm is formed on the anode substrate with a thickness of 1 mm, enables operation of an SOFC around 200 K lower in temperature as compared to an electrolyte-supported cell (Figure 2b) [1]. 70% by developing large-scale power generation system in which the SOFC integrates with gas turbines and steam turbines [14].…”