Effects of Hydraulic Retention Time and Loading Rate on High-Solids Thermophilic Methane Fermentation of the Organic Fraction of Municipal Solid Waste.

An innovative system for stabilizing the organic fraction of municipal solid waste (OFMSW) has been documented on a pilot scale at the Civil Engineering Department of the University of California at Davis. The system involves the combined methods of high-solids anaerobic digestion and aerobic composting for the recovery of energy and the production of compost from the OFMSW. The performance of the high-solids anaerobic reactor was monitored for three mass retention times. The anaerobic digester was operated under extreme as well as normal conditions. The performance of the aerobic compost unit was monitored based on the physical and chemical characteristics of the final humus by-product. In general, the combined process was very stable at a 30 d retention time and is capable of removing essentially all of the biodegradable fraction of the organic fraction of MSW. A biogas production level of up to 6 liters per liter of active volume of reactor was achieved. The process stability and gas production decreased slightly when the retention time was reduced to 15 d. The output from the second stage is a fine humus-like material with a thermal content of about 14.80 MJ/kg.

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Influence of the Sludge Ratio on the High-solids Thermophilic Methane Fermentation of the Organic Fraction of Municipal Solid Waste and Bio-sludge

Journal of the Japan Society of Waste Management Experts ◽

10.3985/jswme.14.27 ◽

2003 ◽

Vol 14 (1) ◽

pp. 27-35

Author(s):

Yoshio Okuno ◽

Yu-You Li ◽

Hiroshi Sasaki ◽

Koji Seki ◽

Ikuo Kamigochi

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

High Solids ◽

Organic Fraction ◽

Methane Fermentation

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Energy recovery from biowaste: influence of hydraulic retention time on biogas production in dry-anaerobic digestion

E3S Web of Conferences ◽

10.1051/e3sconf/202123801007 ◽

2021 ◽

Vol 238 ◽

pp. 01007

Author(s):

Elena Rossi ◽

Isabella Pecorini ◽

Renato Iannelli

Keyword(s):

Anaerobic Digestion ◽

Municipal Solid Waste ◽

Solid Waste ◽

Retention Time ◽

Energy Recovery ◽

Hydraulic Retention Time ◽

Flow Reactor ◽

Biogas Production ◽

Organic Fraction ◽

Dry Anaerobic Digestion

The hydraulic retention time (HRT) is a key parameter in dry-anaerobic digestion to set during the reactor configuration in order to achieve the optimal biogas production. For this reason, the study compared the results of two experimental tests operating with an HRT of 23 and 14 days. During the tests, the feedstock was organic fraction of municipal solid waste with a solid content of 33% and the digester was a pilot-scale plug-flow reactor operating in thermophilic condition. The highest specific biogas production of 311.91 Nlbiogas kg-1 d-1 was achieved when the HRT was set to 23 days. On the contrary, the highest methane production rate of 1.43 NlCH4 l-1 d-1 was achieved for an HRT of 14 days. In addition, the volatile solids removal (49.15% on average) and the energy content o(4.8 MJ kg-1 on average) were higher for HRT 23 days than for HRT14 days. The results indicated that in dry-anaerobic digestion of organic fraction of municipal solid waste, 23 days is a suitable HRT for energy recovery.

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