Combustion Characterization and Model Fuel Development for Micro-tubular Flame-assisted Fuel Cells

Abstract

Combustion based power generation has been accomplished for many years through a number of heat engine systems. Recently, a move towards small scale power generation and micro combustion as well as development in fuel cell research has created new means of power generation that combine solid oxide fuel cells with open flames and combustion exhaust. Instead of relying upon the heat of combustion, these solid oxide fuel cell systems rely on reforming of the fuel via combustion to generate syngas for electrochemical power generation. Procedures were developed to assess the combustion by-products under a wide range of conditions. While theoretical and computational procedures have been developed for assessing fuel-rich combustion exhaust in these applications, experimental techniques have also emerged. The experimental procedures often rely upon a gas chromatograph or mass spectrometer analysis of the flame and exhaust to assess the combustion process as a fuel reformer and means of heat generation. The experimental techniques developed in these areas have been applied anew for the development of the micro-tubular flame-assisted fuel cell. The protocol discussed in this work builds on past techniques to specify a procedure for characterizing fuel-rich combustion exhaust and developing a model fuel-rich combustion exhaust for use in flame-assisted fuel cell testing. The development of the procedure and its applications and limitations are discussed.

Micro-tubular flame-assisted fuel cells

“…The details of the experimental approach taken in that work were also detailed elsewhere (Milcarek et al, 2016b). The combustion characterization experiment using propane as a fuel is described briefly here as the approach is similar to using methane fuel.…”

“…5 of Section 4 "Results and Discussion." More details for calculating the flow rates were reported previously (Milcarek et al, 2016b). As the total flow rate of fuel is fixed and the air flow rate varies in the combustion characterization experiment described in section 3.1 the total flow rate of exhaust to the fuel cell varies at each equivalence ratio.…”

“…A recent innovation on the DFFC design is to continue to utilize the flame for reforming of hydrocarbons to syngas and as a thermal energy source for the SOFC, while also utilizing a dual chamber configuration with sealing only on one end of a micro-tubular SOFC (mT-SOFC) (Milcarek et al, 2016a;Milcarek et al, 2016b;Milcarek et al, 2016c;Milcarek et al, 2016d). This DFFC operating in a dual chamber configuration has been termed a Flame-assisted Fuel Cell (FFC).…”

Micro-tubular flame-assisted fuel cells running methane

“…Thermocouples were placed along the length of the combustion chamber to measure the temperature of the flame and exhaust. A thorough description of the combustion chamber testing was already reported elsewhere [37]. Fig.…”

“…Obtaining the coefficients (i.e. a, b, c, d, and e) from the experimental data reported previously [36,37] the following table can be constructed. The fuel cell voltage based on the syngas composition can then be calculated based on Eqs.…”