Mesophilic and Thermophilic Anaerobic Digestion of Organic Fraction Separated during Mechanical Heat Treatment of Municipal Waste

Abstract

The objective of this study was to investigate the effect of process temperature on semi-continuous anaerobic digestion of the organic fraction separated during autoclaving of municipal waste. Tests were carried out in reactors with full mixing. Biogas production was higher in thermophilic conditions than in mesophilic conditions (0.92 L/g volatile solids at 55 °C vs. 0.42 L/g volatile solids at 37 °C, respectively). The resulting methane yields were 0.25-0.32 L CH4/g VS and 0.56–0.70 L CH4/g VS in mesophilic and thermophilic conditions, respectively. In both variants, the methane share was over 70% v/v. This work also discusses the potential impact of Maillard compounds on the efficiency of the fermentation process, which were probably produced during the process of autoclaving of municipal waste. These results indicate that, after autoclaving, the organic fraction of municipal waste can be an effective substrate for anaerobic digestion in thermophilic conditions.

An Investigation of Temperature Downshift Influences on Anaerobic Digestion in the Treatment of Municipal Wastewater Sludge

“…In some cases, the volumes of CH 4 generated per digester per day were observed to be lower under mesophilic operating conditions than under thermophilic conditions [18,19]. These findings show that AD biogas generation thrives under high temperatures.…”

Complementary Substrates-Brewery Wastewater and Piggery Effluent—Assessment and Microbial Community Profiling in a Hybrid Anaerobic Reactor

“…They resulted from a higher digestion process temperature and longer HRT than the conditions in this work (55 • C, 18 d HRT versus 37 • C, 6.7 d HRT) [12]. Thermophilic conditions of temperature, such as 55 • C, promote higher biogas productions than the mesophilic ones (37 • C) as shown by Kasinski [53]. On the other hand, the increase in HRT allows for a better conversion of organic matter and, consequently, greater volumes of biogas will be expected as concluded by Shi et al [54].…”

Analysis of cross-sectional area of digester on biogas production rate

“…The result of the recording in-reactor temperature showed values ranging from 26-30 o C (figure 3). This working temperature is categorized as mesophilic condition where the temperature is around the ambient temperature (Kasinski, 2020). The difference in temperature around 4 o C is due to different temperature conditions during the day and night.…”