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BioSal Anlagenbau GmbH
Gewerbegebiet: An den Angerwiesen 6
D-04651 Bad Lausick
Tel:  ++49 (0) 34345-25151
Fax:  ++49 (0) 34345-25153
e-mail: info@biosal.eu.

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information about ammonia-scrubber

Information about ammonia-scrubber

D. Sattler, J. Sattler, R. Schneider

Combined exhaust air treatment for biowaste treatment processes

With different biowaste treatment processes (e.g. mechanical-biological waste treatment, handling of sewage sludge, anaerobic fermentation) beside smell-intensive substances partial larger quantities of NH3 are emitted into atmosphere.

In Germany at present no legal emission limits for NH3 in exhaust air are established (1. Dt. Allgemeine Verwaltungsvorschrift z. Bundesimmissionsgesetz: Technische Anleitung zur Reinhaltung der Luft [TA-Luft]).

In special cases for mass streams up from 0,3 kg/h e.g. pig stables an official limitation of NH3 emission to 30 mg/m³ is possible.

The company BioSal Anlagenbau GmbH / Germany - specialised in production of closed container biofilters, dynamic composting plants and plants for industrial water recycling - has developed a compact BioSal®-AMMON two-stage scrubber with high performance filling materials for purification of NH3-containing exhaust air and for the increase of the efficiency of downstream biofilter units.


The aim of the wash process is it to let ammonia in the exhaust air in presence of sulphuric acid react to ammonium sulphate:

2 NH3 + H2SO4 à (NH4)2SO4

After the wash process the prepurified and conditioned exhaust air can be cleaned e.g. with the help of a BioSal®-FIL biofilter system by further pollutants and smells.

During conversion process the concentration of (NH4)2SO4-solution increases and concentrated (NH4)2SO4-solution can be removed from the process.

A further use of the (NH4)2SO4-solution e.g. as liquid fertilizer (e.g. for oil fruits and other plants with high Nitrogen and Sulphur demand) is possible.

Beside the product (NH4)2SO4 no further secondary products or wastes result.

All components of the BioSal®-AMMON scrubber installed in a compact functional unit are made of stainless steel and high-quality plastics.

With help of an on-line pH electrode configuration in a special flow assembly and a metering and dosage station succeeds a delay-free determination of the respective pH-value and an optimum H2SO4 concentration.

That ensures that only as much H2SO4 is supplied to the respective scrubber cycle, as in accordance to the Input-NH3-Konzentration is absolutely necessary.

Thus e.g. concentration peaks in the raw gas can be reliably intercepted, while with very small NH3-Konzentration no significant consumption of H2SO4 occurs.

The BioSal®-AMMON scrubbers reach ammonia absorption performances up to 98 %.

The controlling of the operating-friendly and noiseless system takes place automatically with a PLC process control. The PLC is equipped if necessary with a long-distance data transmission for the monitoring and controlling of the system parameters.


Picture 1 Schematic diagram of a two-stage BioSal®-AMMON scrubber

The compact BioSal®-AMMON scrubber can be integrated due to its modular construction problem-free into existing exhaust air treatment systems.

For assembly of the equipment only a fresh water / power supply and in any cases a strip-foundation are necessary.

Interested customers can use on loan a combined BioSal®-AMMON scrubber / BioSal®-FIL biofilter system (throughput up to 3.000 m³/h) for preliminary tests.