Effects of Seasonal Temperature Variation on Slurry Temperature and Biogas Composition of a Commercial Fixed-Dome Anaerobic Digester Used in Bangladesh

Abstract

Biogas is produced in Bangladesh mostly through fixed-dome anaerobic digesters, which usually operate without any temperature controller. An experiment was conducted to monitor the seasonal temperature variation inside a fixed-dome type digester and its effect on biogas composition. A commercial-scale digester with a working volume of 350 m3 was used for this study. Three k-type thermocouple sensors were used to monitor the ambient, biogas, and slurry temperatures in real-time. The results showed that the average ambient temperature in the autumn, late autumn, and winter was 29.05, 22.90, and 17.64 °C, respectively. The average slurry temperature in the autumn (30.38 °C) was higher than in the late autumn (29.36 °C) and in the winter (25.76 °C). The highest and lowest slurry temperatures were found to be 31.11 and 24.47 °C, respectively, which indicated that the digester worked within a wide temperature range, establishing both psychrophilic and mesophilic operational conditions. Higher methane concentrations were observed in the autumn than in the late autumn and winter. The CO2 and H2S concentrations were higher in the winter than those of in the autumn and late autumn. The electricity generation in the winter was 47.85% and 45.15% lower than in the autumn and late autumn, respectively.

Biodigestion System Made of Polyethylene and Polystyrene Insulator for Dog Farm (on the Example of the Republic of Chile)

“…If this system was installed in a PE greenhouse that obtained good results during the daylight hours, it would also be necessary to ensure that the structure was hermetically sealed in order to prevent the influence of cold weather during the night (maintaining more thermal inertia and less air exchange) [97]. In addition, a heat control unit could be used during colder seasons to increase biogas production [104].…”

Derivation of Optimal Operation Factors of Anaerobic Digesters through Artificial Neural Network Technology

“…Gas production and digestion efficiency are affected by seasonal factors. Factors, such as external temperature and rainfall, will affect the digester, thereby affecting gas production and digestion efficiency [44,46]. According to the results in Figures 3 and 4, the Good Case ratio is relatively large in the winter and spring; the percentages of digestion efficiency are 10% and 49%, and the percentages of gas production are 47% and 80%, respectively.…”

“…Dong Jin Lee et al [44]. investigated the seasonal effects of the organic loading rate and acid phase on methane production during anaerobic digestion at a food wastewater treatment plant in southern Korea.…”

Carbon Footprint and Energy Recovery Potential of Primary Wastewater Treatment in Decentralized Areas: A Critical Review on Septic and Imhoff Tanks

“…The explanation for the positive effect of temperature on biogas and methane production is immediate: temperature speeds up all biological processes including hydrolysis, fermentation, and, more importantly, methanogenic activity, resulting in higher biogas production, especially when moving from psychrophilic to mesophilic conditions [90,91]. In general, during cold seasons digestion is significantly slowed down and this results in an increased sludge accumulation [84], while summer temperatures allow for faster hydrolysis of biodegradable organic carbon and methanization with much lower sludge accumulation [92,93]. A positive effect of temperature on digestion till a threshold of 25-26.7 • C was reported, above which a further increase could slightly slow down the digestion and gas production [86].…”