SATNAC 2009 Conference Papers

Outside Plant & Transmission Issues

Title:                Development of a Proton Exchange Membrane (PEM) for Telecom Fuel Cell Applications


Authors:            A.S Abdulkareem (University of Witwatersrand), A.S Afolabi (University of Witwatersrand), C.A Idibie (University of Witwatersrand), S.E Iyuke (University of Witwatersrand), Christo Pienaar (Vaal University of Technology)


Abstract:           The high cost of fuel cells compared to other energy sources creates uncertainty about the projected full-scale commercialization of this device. This paper describes the synthesis of a proton exchange membrane from locally available polystyrene butadiene rubber for fuel cell applications. Chlorosulphonic acid was used as the sulphonating agent and the effect of the degree of sulphonation on the membrane characteristics were determined. Membranes were characterized according to their ion exchange capacity (IEC), degree of sulphonation (DS), proton conductivity, thermal stability and performance in a fuel cell stack. The synthesized membranes were found to have proton conductivities in the order of 10-3-10-2 S/cm in their fully hydrated state, which increased with an increase in the degree of sulphonation. Results obtained revealed that the synthesized membranes are thermally stable and its performance in a fuel cell.


Title:                Performance Evaluation of a 1.2 KW Fuel Cell


Authors:            Thapelo Pholo (Vaal University of Technology), Christo Pienaar (Vaal University of Technology)


Abstract:           Fuel cell (FC) systems have emerged as a promising alternative to conventional power technologies over the past decade owing to their high efficiency, low aggression to the environment, excellent dynamic response and superior reliability and durability. In this paper, the results of the evaluation of a 1.2 KW FC including the electrochemical model are reported. The FC stack dynamic simulation using SIMULINKTM and the experimental results are also presented. In the end the dynamic behaviour and modelling results are used to predict the output voltage, power, efficiency and the polarisation curves of the FC.


Title:                A Methanol Concentration Controller for Fuel Cells


Authors:            Marius Viljoen (Vaal University of Technology), Christo Pienaar (Vaal University of Technology)


Abstract:           Fuel cells are used for backup power in remote telecommunications sites. This paper focuses on a prototype methanol controller built with an ultrasonic sensor for detecting the density of the methanol/water mixture and a sensor for the temperature of the mixture. The controller was calibrated to determine the amount per volume of water and methanol which enables the controller to control the percentage of methanol in the water. The prototype addresses one of the problems in methanol fuel cells called “Methanol Crossover”.  Methanol crossover occurs when methanol is not completely used in the process of generating electrons, and a certain percentage of the methanol is wasted. Crossover may damage the proton exchange membrane of the fuel cell and also reduce the efficiency and lifespan of a DMFC.

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