Environmental Aspects of Direct Methanol Fuel Cell: Experimental Detection of Methanol Electro-Oxidation Products

摘要

This study deals with the experimental investigation of compositional changes of various liquid/gas streams during mid-term (3 b) continuous operation of an active direct methanol fuel cell (DMFC). A test system is equipped with various sensors and with sampling ports to collect liquid samples to measure off-line methanol, formaldehyde, and formic acid concentrations by means of high pressure liquid chromatography (HPLC) and UV spectroscopy. Initially, polarization study is performed to select suitable operating ranges to be considered in an experimental plan according to which runs are performed to collect process data from the system. Then, the experimental data is fitted using regression analysis for the statistical evaluation of the impacts of operating variables on the compositions of methanol tank solution and cathode gas by means of response surface plots. The cathode gas composition is further discussed in the context of methanol crossover and catalytic chemical reactions on the cathode side. Experiments show that methanol, formaldehyde, and formic acid concentrations may exceed their safe limits of exposure depending on the operating conditions.