An innovative method of modeling direct methanol fuel cells

Abstract

In  this  paper  a  computer  model  of  a  direct methanol fuel cell (DMFC) developed with the use of HYSYS software was presented. Chemical reactions of methanol oxidation and oxygen reduction were executed in  HYSYS  software  which  eliminated  the need  of  creating  a  complex  electrochemical model of these reactions. Obtained resutls were used for determining maximum cell  voltage  and  limiting  current  density of  the  investigated  fuel  cell.  An  equivalent  electrical  circuit  served  for  calculating  cell  voltage  after  taking  ohmic  losses and methanol crossover losses into account. A  simulation  of  polarization  curve  for  a cell  supplied  with  0.5  mol/dm 3 methanol and  pure  oxygen  operating  at  70◦C  was performed and validated with experimental data. The effects of cathode gas humiditication and methanol concentration change in the range of 0.5 mol/dm 3 –3 mol/dm 3 on cell performance were investigated. Difficulties  with  detremining  methanol  oxidation rate and methanol crossover loss correctly enfrorced the use of experimental data thus greatly limiting the range of model’s applicability. Challenges encountered during direct methanol fuel cell modeling were described.