Experimental investigation of a biofuel cell

Abstract

This thesis presents an investigation of bioenergy generation through a soil-based microbial fuel cell (MFC). The MFC utilized soil samples of 100 g and various environmental and operational conditions to assess the generation of voltage. The parameters of interest included temperature, pH, glucose concentration, sodium chloride, and volume of water. The temperature experiment showed that moderate temperatures of 35 °C and 45 °C yielded stable voltage outputs. The maximum voltage obtained was approximately 55 mV at a temperature of 45 °C and 50 mV at a temperature of 35 °C. On the other hand, higher temperatures of 50 °C decreased the voltage from approximately 30 mV to as low as 16 mV. The experiment on glucose concentration showed the optimal concentration of glucose, as a voltage of approximately 66 mV was obtained at a glucose concentration of 1.0 g. The experiment on sodium chloride showed improved performance at moderate salinity. The addition of 1.5 g of sodium chloride at a temperature of 25 °C yielded a peak voltage of approximately 70 mV. On the other hand, the addition of 1.0 g of sodium chloride at a temperature of 40 °C yielded a peak voltage of approximately 100 mV. The experiment on pH and temperature showed exceptional performance at a pH of 7 and a temperature of 40 °C. The voltage was as high as approximately 950 mV. Soil moisture was also seen to greatly influence performance, as the addition of 300 mL of water yielded an initial voltage of approximately 427 mV. The voltage gradually decreased over time to approximately 230 mV due to mass transfer limitations. The results show that bioenergy generation through soil-based MFC improves at optimized environmental conditions. The scientific literature consistently shows that soil based microbial fuel cells generate more bioenergy when key environmental conditions are optimized.