State of the art and future perspectives of thermophilic anaerobic digestion

The state of the art of thermophilic digestion is discussed. Thermophilic digestion is a well established technology in Europe for treatment of mixtures of waste in common large scale biogas plants or for treatment of the organic fraction of municipal solid waste. Due to a large number of failures over time with thermophilic digestion of sewage sludge this process has lost its appeal in the USA. New demands on sanitation of biosolids before land use will, however, bring the attention back to the use of elevated temperatures during sludge stabilization. In the paper we show how the use of a start-up strategy based on the actual activity of key microbes can be used to ensure proper and fast transfer of mesophilic digesters into thermophilic operation. Extreme thermophilic temperatures of 65°C or more may be necessary in the future to meet the demands for full sanitation of the waste material before final disposal. We show data of anaerobic digestion at extreme thermophilic temperatures.

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Status on science and application of thermophilic anaerobic digestion

Water Science & Technology ◽

10.2166/wst.1994.0619 ◽

1994 ◽

Vol 30 (12) ◽

pp. 241-249 ◽

Cited By ~ 64

Author(s):

B. K. Ahring

Keyword(s):

Anaerobic Digestion ◽

Methanogenic Bacteria ◽

Full Scale ◽

Active Biomass ◽

Thermophilic Anaerobic Digestion ◽

Start Up ◽

Full Capacity ◽

Biogas Plants ◽

Thermophilic Digestion ◽

Operational Data

Thermophilic anaerobic processes are often regarded as less stable than mesophilic processes. In the paper this postulate is examined and disproved based on real operational data from of full-scale mesophilic and thermophilic biogas plants. The start-up procedure for the thermophilic plants was, however, found to be crucial for determining the period needed before full capacity of the thermophilic plant could be achieved. The importance of balanced loading, determined by the concentration of active biomass, is discussed. Finally, data will be shown on the optimal and maximal temperature for thermophilic digestion along with the implications for the methanogenic bacteria active at these temperatures.

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Assessment of the state of the art of technologies for the processing of digestate residue from anaerobic digesters

Water Science & Technology ◽

10.2166/wst.2013.075 ◽

2013 ◽

Vol 67 (9) ◽

pp. 1984-1993 ◽

Cited By ~ 77

Author(s):

W. Fuchs ◽

B. Drosg

Keyword(s):

Anaerobic Digestion ◽

Large Scale ◽

State Of The Art ◽

Biogas Production ◽

The State ◽

Anaerobic Digesters ◽

Adequate Treatment ◽

Biogas Plants ◽

Treatment Technologies ◽

Digestate Processing

Anaerobic digestion is widely used as an important source of renewable energy. With the increasing number and capacity of biogas plants also, adequate treatment technologies for whole digestate – the residue from anaerobic digestion – are gaining attention. In this study the state of the art of digestate processing is analysed, and currently used treatment schemes and the various technological processes involved are evaluated. The study combines data and experiences from existing large-scale digestate processing facilities in Austria, Germany, Switzerland and Italy, as well as know-how from technology providers and relevant research projects. However, the field of digestate processing is still quite new and little detailed information about the performance of different technologies at industrial scale is available. Digestate processing is gaining importance since digestate utilisation can become an important bottleneck when increasing biogas production. In addition, the production of renewable fertiliser from digestate is increasingly of interest to replace fossil fertilisers. This study is the first profound attempt to establish an assessment of the state-of-the-art technologies in use.

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