Improved energy recovery from food waste through hydrothermal carbonization and anaerobic digestion. (1st April 2022)

• Record Type: Journal Article
• Authors: Mannarino, Gemma; Sarrion, Andres; Diaz, Elena; Gori, Riccardo; De la Rubia, M. Angeles; Mohedano, Angel F.
• Is Part Of: Waste management. Volume 142(2022)
• Page Start: 9
• Page End: 18
• Publication Date: 2022-04-01
• Subjects: Anaerobic digestion -- Biofuel -- Energy recovery -- Food waste -- Hydrothermal carbonization; AD anaerobic digestion -- CCI comprehensive combustion index -- COD chemical oxygen demand -- Einput energy input -- Eoutput energy output -- FC fixed carbon -- FW food waste -- GC/MS gas chromatography-mass spectrometry -- HC hydrochar -- HHV higher heating value -- HTC hydrothermal carbonization -- PA partial alkalinity -- PW process water -- SCOD soluble COD -- SMP specific methane production -- TA total alkalinity -- TAN total ammonia nitrogen -- TN total nitrogen -- TP total phosphorus -- TS total solids -- TVFA total volatile fatty acids -- VM volatile matter -- VS volatile solids -- YHC hydrochar yield -- YPW process water yield; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2022.02.003
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: Food waste was valorized by hydrothermal carbonization and anaerobic digestion. The combustion properties of hydrochar complied with ISO/TS 17225–8. Methane yield of process water reached values up to 154 mL CH4 STP g −1 CODadded . Anaerobic digestion promoted the removal of specific recalcitrant compounds. Good energy recovery yield can be obtained from combustion of hydrochar and methane. Abstract: Here we studied energy valorization of food waste by hydrothermal carbonization coupled with anaerobic digestion. Hydrothermal treatment was carried out at 200 °C and 230 °C for 1 h, obtaining hydrochar with properties suitable for solid biofuel according to ISO/TS 17225–8. The increase in temperature improved the fuel properties of hydrochar (higher heating value 20.3 and 23.7 MJ kg −1, fuel ratio 0.33 and 0.37, energy density 1.07 and 1.25). The anaerobic digestion of process water achieved methane yields around 150 mL CH4 STP g −1 CODadded and made it possible to remove some specific recalcitrant compounds, such as 2-methylpyridine and 2-ethyl-3-methylpyrazine. Energy recovery from hydrochar and process water seems to be an interesting alternative way to sustain the process energetically and economically, despite the significant energy inputs required for hydrothermal carbonization.