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Volatile Organic Compound

Scrubbers

One of the most important systems for the abatement of V.O.C. (volatile organic compounds) used by Duscon are the wet pollution abatement systems or scrubbers, both for washing with water or with reagents. 

In these equipment, abatement takes places through impact between the nebulised washing liquid and the pollutants in the suctioned gases/fumes.

Duscon can supply two main configurations of the scrubbers: 

-    Horizontal scrubbers;

-    Vertical scrubber towers.

The above wet abatement systems can be composed of several washing stages and can be with different configurations like venturi scrubber, floating pack washing tower, static pack washing tower, horizontal scrubber etc. and with different washing solutions in accordance with the type of pollutants to be removed and to their inlet concentrations.

 
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Scrubbers

  • Horizontal scrubbers, mono or multi stage, with static packing or floating bed and chemical absorption for gaseous pollutants and odour control;

  • Vertical scrubber towers, mono or multi stage, with static packing or floating bed and chemical absorption for gaseous pollutants and odour control.

Thermal oxidation for V.O.C. abatement

On all thermal oxidizers, the thermal oxidation of pollutant molecules enables the CO, odors and V.O.C. abatement through the following reaction:

 

CO or V.O.C. + O2 + activation energy -> CO2 + H2O + heat

 

The reaction occurs in the combustion chamber, under suitable temperature, turbulence and residence time conditions.

Any type of volatile organic substance in gaseous form can be treated and, with pollutant concentrations above 1.5 g/Nm3, it is usually possible to go into self-support mode, by reducing fuel consumption to almost zero.

Duscon offers normal thermal oxidizers (non regenerative one) that are systems designed to obtain the reduction of pollutants in high temperature (about 650°C) by the thermal oxidation process and it operates simply and solely as a pure combustor with very high energy costs due to there is not any heat recovery system.  

Recently, from the necessary to recover as much as possible the heat and to reduce at the minimum any energy waste, has been studied and designed the regenerative thermal oxidizers, where the polluted air is preheated by layers of ceramic packing, which are heated or cooled according to the direction of the air stream passing through them, acting as heat accumulator and reducing the required energy.

DUSCON designs and supplies the regenerative thermal oxidisers that enable the oxidation of V.O.C., CO and odours by increasing the temperature of the polluted air over 750 - 800°C. During the full capacity system operation of this equipment, the heat produced by the exothermic oxidation reaction is sufficient to maintain the temperature of the combustion chamber at the desired value without the addition of auxiliary fuel (methane gas, etc.), reducing in this way the system management and operating costs to a minimum.

Duscon can supply tailor-made solutions of thermal oxidation systems, both with regenerative thermal oxidizers and not regenerative thermal oxidizers configurations. 

 
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Thermal combustion and thermal oxidation units

  • Thermal regenerative oxidizers (RTO) with or without concentration

  • Thermal oxidizers with or without concentration

 
Activated Carbon Filters 

For the abatement of V.O.C. (volatile organic compounds) and odours with higher efficiency, DUSCON can supply customised solutions that use Activated Carbon Filters.

Activated carbon Filtration is a gas treatment technology, based on a simply process where the gas with pollutant passes through a bed of a highly porous material, called activated carbon.

 

The term activated carbon refers to carbon that has been subjected to an activation treatment, giving it exceptional porosity and consequently making it adsorbent.

The adsorption consists of capturing and retaining the molecules of gas and other pollutants in the carbon’s cavities, thanks to electrostatic bonding.

In this way it is possible to drastically reduce the concentration of the polluting molecules present in the flow.
 

The adsorption efficiency depends on many factors, the main of which are:

  • relative humidity;

  • temperature;

  • speed at which the flow passes through;

  • active carbon surface area;

  • molecular weight, boiling point and concentration of the pollutants to be captured;

  • nature of the pollutant.

 

The nature of the pollutant is the characteristic that most influences the adsorption efficiency of the activated carbon.

The quantity and quality of adsorbent material effectively used depends on the concentration and type of the solvents (VOCs) to be treated.


Active carbon filters are particularly suitable for the abatement of VOC in general, but a particularly common use is for the deodorisation of industrial activities where unpleasant odours significantly affect production.

The use of common activated carbon is recommended for temperatures up to a maximum of 50-60 C. To prevent a rapid saturation of the activated carbon, it is necessary to work with a relative humidity lower than 60%.

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Activated Carbon Filters