Hydrothermal pretreatment of source separated organics for enhanced solubilization and biomethane recovery

• Published in: Bioresource technology Vol. 274; pp. 502 - 511
• Main Authors: Razavi, A.S., Hosseini Koupaie, E., Azizi, A., Hafez, H., Elbeshbishy, E.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2019
• Subjects: Anaerobic digestion; Biomethane; Hydrothermal pretreatment; Solubilization; Source separated organics; Biomethane; Hydrothermal pretreatment; Solubilization; Anaerobic digestion; Source separated organics
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2018.12.024

•Pretreatment of SSO was done at 150–240 °C under 5 different severity index values.•The maximum methane yield of 280 mL/g TCODadded was achieved at 190 °C.•Pretreatment improved solubilization and methane recovery by 50 & 26%, respectively.•A significant correlation was found between soluble COD and methane yield.•Pretreatment temperature beyond 200 °C decreased the methane yield. The objective of this research was to evaluate the effect of the hydrothermal pretreatment on the solubilization of source separated organics (SSO) as well as the biomethane recovery through the mesophilic batch anaerobic digestion process. For this purpose, the SSO was subjected to fifteen different pretreatment conditions within five different severity index (SI) values (3, 3.5, 4, 4.5, and 5). The pretreatment temperature, holding time, and pressure ranged from 150 to 240 °C, 5 to 30 min, and 476 to 3367 kPa, respectively. The highest solubilization improvement of ∼50% was achieved under the pretreatment condition of “220 °C-10 min-2323 kPa” corresponding to the SI value of 4.5. However, the maximum biomethane production yield of 280 mL/g TCODadded and biomethane production rate of 30 mL/g TCODadded were obtained under the less intense pretreatment conditions of “190 °C-20 min-1247 kPa” and “170 °C-30 min-786 kPa”, respectively.