OP-II-3

PP-III-4OPTIMAL CONDITION OF GLYCEROL STEAM REFORMING FORDIFFERENT TYPES OF PEMFCAuthayanun S. and Arpornwichanop A.Department of Chemical Engineering, Faculty of Engineering, ChulalongkornUniversity, Bangkok 10330, Thailand, Amornchai.A@Chula.ac.thProton exchange membrane fuel cell (PEMFC) is an electrochemical conversiondevice that can efficiently generate electrical power with a wide range of applications.In general, PEMFC can be divided into two types depending on its operatingtemperature range: low temperature PEMFC (LT-PEMFC) (60-80 °C) and hightemperature PEMFC (HT-PEMFC) (100-200 °C). Due to its low temperatureoperation, the LT-PEMFC requires higher purity of H 2 than the HT-PEMFC. Thecontent of CO in H 2 feed for LT-PEMFC is limited to be less than 10-50 ppm [1]whereas HT-PEMFC can tolerate CO up to 2-5% at 180 °C without the degradationof cell performance [2]. As a result, a reforming process for H 2 production is differentfor the two types of PEMFC. A purification unit in the reforming process is necessaryfor LT-PEMFC. In contrast, reforming gas can be directly fed to HT-PEMFC withoutCO removal processes.The aim of this study was to find an optimal condition of a steam reformingprocess for both the LT-PEMFC and HT-PEMFC. Glycerol as a byproduct derivedfrom biodiesel production was considered to be a renewable fuel for the production ofhydrogen. From the thermodynamic analysis, it was found that for LT-PEMFC, thehighest amount of H 2 from a glycerol steam reformer integrated with a water gas shiftreactor is obtained at the temperature of 1000 K and the steam to glycerol molar ratioof 3. An increase in operating temperatures and steam to glycerol ratio slightlyenhances H 2 content but reduces CO content. In case of HT-PEMFC, the reformer isneeded to be operated at lower temperatures and high steam to glycerol ratio toproduce H 2 with the concentration of CO less than 2-5%. The result also reveals thatthe steam reformer can operate at higher temperatures to give more hydrogen yield ifhigher content of CO in reforming gas is allowed. Fig. 1 shows the boundary ofopearating conditions as a basic tool for designing a HT-PEMFC reforming processto generate H2 with specified CO limitation.448