Matias Halinen

Feasibility of Autothermally Reformed Natural Gas on Anode Supported Solid Oxide Fuel Cells

Three different planar anode supported solid oxide fuel cells (SOFC) were tested with hydrogen, with autothermally prereformed natural gas from which sulfur was removed, and with autothermally prereformed natural gas that contained sulfur. The cells were obtained from Forschungszentrum Julich (FZJ), Energy research Centre of the Netherlands (ECN), and HTceramix SA (HTc). All cells were so called Real-SOFC first generation cells. Cell polarizations were first measured with hydrogen, followed by a 200 h test (25 A, 800°C) with a selected fuel, and finally cell polarizations were measured with hydrogen. When hydrogen was used as the fuel in the 200 h test, the performance for all cells was comparable and no degradation was observed. All cells underwent an initial deactivation process when reformate fuels were used but their cell voltage stabilized during the first 50 h. All cells also showed deactivation after the reformate tests when the area specific resistance values were compared to the values obtained from the hydrogen tests. The deactivation was comparable between the sulfur-free and sulfur-rich reformate tests. Sulfur-rich reformate, however, caused oscillation in cell voltages as the sulfur level in natural gas was not constant.

Dynamic Model of 5kW SOFC CHP Test Station

A dynamical model for a 5 kW class solid oxide fuel cell (SOFC) combined heat and power (CHP) test station has been composed using the APROS® environment. The model is based on a real test station being constructed and operated at VTT Technical Research Centre of Finland and it comprises the following main components of the real test system: the autothermal reforming unit, SOFC stack situated inside a furnace, catalytic afterburner, and three heat exchangers. The constructed model has been verified against experimental results obtained from the autothermal reforming unit, catalytic afterburner, and the two cathode side heat exchangers. The model has been used for the phenomenological studies of the system during current transient simulations using a simplified and fast zero-dimensional model including internal reforming reactions for the SOFC stack. The test station model was capable of operating at a speed of 18 times the real time using a standard personal computer.

Solid Oxide Fuel Cell System Development in VTT

The Finnish solid oxide fuel cell (SOFC) project (FINSOFC) was initiated in 2002 as a five-year project. It forms the core of the publicly funded SOFC research in Finland. The purpose of the project is to support the industry in its development of SOFC systems and components and other possible SOFC-based business to be created in the future. The project is coordinated by the VTT Technical Research Centre of Finland in cooperation with universities and industrial enterprises. The project is executed in close cooperation with several European partners both bilaterally and within Real-SOFC. The focus is to construct and run a natural gas-fueled 5 kW e SOFC power plant demonstration connected to heat and electricity grids. The power plant demonstration contains a stack and all BOP components from fuel processing to power conditioning and grid connections. The aim is also to thoroughly understand the behavior of the system. The subprojects needed to do this are (i) fuel processing, (ii) testing of fuel cells and stacks, (iii) construction of a 5 kW e power station demonstration, and (iv) system modeling.