Pretreatment methods play an important role in the improvement of biogas production from the anaerobic digestion of energy grass. In this study, conventional thermal and microwave methods were performed on raw material, namely, Pennisetum hybrid, to analyze the effect of pretreatment on anaerobic digestion by the calculation of performance parameters using Logistic function, modified Gompertz equation, and transference function. Results indicated that thermal pretreatment improved the biogas production of Pennisetum hybrid, whereas microwave method had an adverse effect on the performance. All the models fit the experimental data with R ² > 0.980, and the Reaction Curve presented the best agreement in the fitting process. Conventional thermal pretreatment showed an increasing effect on maximum production rate and total methane produced, with an improvement of around 7% and 8%, respectively. With regard to microwave pretreatment, maximum production rate and total methane produced decreased by 18% and 12%, respectively.

Microbial fuel cell (MFC), which can directly generate electricity from biodegradable materials, has been receiving increasing attention. Effects of temperature change on power density, electrode potential, columbic efficiency, chemical oxygen demand removal and internal resistance in two chambers MFCs were examined in this paper. The maximum power density of 7.89 W/m³ was achieved at 37 °C, with 199% higher at 10 °C (2.64 W/m³), 24% higher at 30 °C (6.34 W/m³) and 21% higher at 43 °C, no steady power generation was observed at 55 °C. Low temperature to 10 °C might have a huge effect on anode potential, especially at higher current, but increasing the temperature to 43 °C had a main effect on the cathode performance when the MFCs have been established at 37 °C. The internal resistance of MFC was about 29 Ω at 37 °C, and increased 62% and 303% when MFC switched to 30 °C and 10 °C. Similarly, internal resistance increased 48% at 43 °C. The effect of temperature on MFC performance was expressed by internal resistance, the higher the internal resistance of MFC, the lesser the power density obtained. The Columbic efficiencies were 8.65% at 30 °C, 8.53% at 37 °C, and 13.24% at 43 °C. These results demonstrate that MFCs can effectively be operated over a wide range of temperatures.