A 27-3 fractional factorial optimization of polybenzimidazole based membrane electrode assemblies for H2/O2 fuel cells

Abstract

We describe the usefulness of a statistical fractional factorial design to obtain consistent and reproducible behavior of a membrane-electrode-assembly (MEA) based on a phosphoric acid (PA) doped polybenzimidazole (PBI) membrane, which allows a H 2 /O 2 fuel cell to operate above 150°C. Different parameters involved during the MEA fabrication including the catalyst loading, amount of binder, processing conditions like temperature and compaction load and also the amount of carbon in the gas diffusion layers (GDL) have been systematically varied according to a 2 7-3 fractional factorial design and the data thus obtained have been analyzed using Yates's algorithm. The mean effects estimated in this way suggest the crucial role played by carbon loading in the gas diffusion layer, hot compaction temperature and the binder to catalyst ratio in the catalyst layer for enabling continuous performance. These statistically designed electrodes provide a maximum current density and power density of 1,800 mA cm -2 and 280 mW cm -2 , respectively, at 160°C using hydrogen and oxygen under ambient pressure.

Optimization of Solid Circulation Rate in Compartmented Fluidized Bed Gasifier for Power Generation

“…Using standard statistical software, the SCR linear regression is (1) and R(II) = replications of experiment; TC = treatment condition; SOS = sum of square. Using method of steepest ascent [18]- [19] and given that the objective of the study is to identify the maximum SCR for a given bed height (D), i.e. low (0.2m) and high (0.4m) bed level, the experimental variable with the highest coefficient is v-valve (C) flow rate.…”

Modeling and optimization of gas transport characteristics of carbon molecular sieve membranes through statistical analysis

“…Modeling can effectively be used for examining the relationship between one or more response variables and a set of quantitative experimental variables in the field of membrane technology . Khayet et al used statistical approach for investigating the effect of various parameters including the polymer and additive (polyethylene glycol, PEG) concentrations in the casting solutions, solvent evaporation time and coagulation bath temperature on the structural characteristics of membranes as well as on the direct contact membrane distillation (DCMD) performance.…”

Gas diffusion electrodes for high temperature PEM-type fuel cells: role of a polymer binder and method of the catalyst layer deposition

“…It is clear that the structure and composition of the gas diffusion electrode (GDE) has to be compatible with a membrane used as a polymer electrolyte. Whereas significant attention has been paid in the past to the optimization of the GDE for the classical PEM fuel cell utilizing a PFSA membrane, reviewed by Wee et al [9], scarcely any systematic studies have been published on the optimization of the GDE for a PEM fuel cell based on phosphoric acid-doped PBI [10][11][12][13][14][15][16].…”

“…PTFE was used as a binder of the CL of the cathode. Kannan et al [16] published a parametric study of PBI membrane-based MEAs, investigating the role of carbon, electrocatalyst, and PTFE binder content in the GDL as well as in the CL of the GDE.…”