The pressure effects on two-phase anaerobic digestion

Effects of Organic Loading Rate on the Performance of a Pressurized Anaerobic Filter in Two-Phase Anaerobic Digestion

“…SMYs of 9 bar and 1.5 bar were almost the same, approximately 0.32 L N ·g −1 COD. The pressure seemed to have little impact on SMY, which is in agreement with the observation from a previous study [5]. High CO 2 partial pressure brought the pH value of the reactor at 9 bar down to 6.5.…”

“…At a higher pressure, more CO 2 is dissolved in the liquid and then CH 4 becomes dominant in the gas phase. Methane enrichment in anaerobic digestion under pressure was also documented elsewhere [5][6][7]19]. However, in terms of the absolute value, the methane content was not as high as reported in other studies.…”

“…According to Abe and Horikoshi's [4] research, methanogens are metabolically active at pressures of up to 100 bar. This provides a theoretical base for the innovative concept of pressurized anaerobic digestion (pAD), developed at the University of Hohenheim in cooperation with the DVGW-research center [5]. In pressurized anaerobic digestion, the pressure of the biogas is gradually built up during fermentation.…”

Influence of Organic Loading Rate on the Performance of a Two-Phase Pressurized Biofilm (TPPB ) System Treating Food Waste

“…For a small-scale AD plant (biogas flows lower than 2,000 m 3 /d), the upgrading equipment for biogas is either not available or not costeffective. In 2011, an autogenerative high-pressure digestion (AHPD) reactor was described to upgraded biogas without additional upgrading equipment, where high CH 4 content of 90% at a pressure of 0.3-9.0 MPa was obtained [3]. Chen et al [4] further developed a two-phase pressurized anaerobic digestion (TPPAD) system to convert maize/grass silage into high-quality biogas (CH 4 >75%).…”

“…In 2011, an autogenerative high-pressure digestion (AHPD) reactor was described to upgraded biogas without additional upgrading equipment, where high CH 4 content of 90% at a pressure of 0.3-9.0 MPa was obtained [3]. Chen et al [4] further developed a two-phase pressurized anaerobic digestion (TPPAD) system to convert maize/grass silage into high-quality biogas (CH 4 >75%). Our previous study found that at an organic loading rate (OLR) of 3.1 g-COD/L/d, highcalorific biogas (higher calorific value of produced biogas was 36.2 MJ/m 3 ) was obtained via AD of food waste by using a two-phase pressurized biofilm (TPPB) system [5].…”