Electricity Generation using Locust Bean Waste and Coal in a Molten Carbonate Direct Carbon Fuel Cell

Abstract

The quest for a sustainable source of energy has made researchers turn towards direct carbon fuel cell (DCFC). It is a device that directly converts the chemical energy of a biomass or fossil fuel into electrical energy. The combination of the coal and a renewable biomass Locust bean waste (LBW)(Parkia Biglobosa) can enhance the electrochemical performance of the DCFC. Pyrolysis pre-treatment process was initially carried out at heating rate of 10oC/min. This was done for each of the sample and their combination. The pyrolyzed biomass for both of them was then used to determine the electrochemical performance of DCFC using molten carbonate salt as electrolyte and using five different resistor loads (1Ω, 2Ω, 3Ω, 4Ω & 5Ω). Performance of coal in the DCFC was observed to be better than Parkia Biglobosa. However upon combination of both solid fuels, an enhanced performance was observed. At a temperature of 800oC and resistance of 1Ω, the combined fuel showed an open circuit voltage of 1.16 V, current density of 43.2 mA/cm2 , power density of 2.91 mW/cm2 with 73% efficiency. The SEM result of the carbon fuels was obtained using Nova NanoSEM 200 FEI, Netherlands. The SEM results of the combined fuel were observed to be better. The phase composition of each fuel was determined using Siemens D500 XRD System. The highest peak for the LBW, Coal and the combined fuel was at an angle of 25.988o , 26.24o , 26.637o respectively and the corresponding inter-planar spacing of 3.42Å for LBW fuel and 3.34Å for coal and the other fuel.