Psychrophilic biomethanation for enhanced bioenergy production in cold regions

Research trends and strategies for the improvement of anaerobic digestion of food waste in psychrophilic temperatures conditions

“…[ 131 ] found that low temperatures have a negative effect on the efficiency of VFAs production in the acidogenic phase, at 35 °C the total VFAs content was 4403 mg/L and the acetic acid content was 77% of total VFAs, while at 20 °C the total VFAs content decreased to 1270 mg/L and the acetic acid content accounted for only 65% of total VFAs; the content of butyric acid and valeric acid remained stable at 35 and 20 °C. The pH is also reduced under low temperature conditions, because CO2 solubility increases [ 132 , 133 ]. Boullagui et al.…”

“…These adapted microorganisms possess physiological conditions suitable for cold environments, due to the characteristics of their cell membranes in terms of proteins, lipids and enzymes, which makes the microorganisms remain active in psychrophilic environments and show excellent genetic responses to thermal changes [ 130 , 145 , 168 ]. In this sense, psychrophilic microorganisms render AD possible in cold regions and could overcome thermodynamic constraints at low temperatures [ 133 , 169 ].…”

“…The most commonly used alternative to improve AD under psychrophilic conditions is to increase the digester temperature [ 133 ], however maintaining a high digester temperature is a costly affair [ 119 ]. Table 7 shows other improvement strategies and trends for future research that do not require heating, one of the most important is reactor design, because it can help increase the efficiency of methane production at low temperature [ 133 ].…”

The Current Status and Lost Biogas Production Potential of Kazakhstan from Anaerobic Digestion of Livestock and Poultry Manure

“…Temperature plays a crucial role in anaerobic digestion, as it shapes microbial ecosystems and, therefore, regulates the stability of the anaerobic digestion process [23]. In cold regions, biomethanation processes with efficient substrate composition, insulation, psychrophilic anaerobes, reactor systems, and additives are some advanced approaches that can improve biomethanation [24] (Figure 1). In addition to maintaining a comfortable temperature, the role of the cold-adapted microbial community in the efficient production of methane is clear.…”