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Home >> Selection Guide >> Acid Gases

Equipment Selection Guide        

Acid Gases

Acid gases are any gaseous compounds that form an acidic solution when dissolved in water.

The following is a list of generalised groupings of acid gases, click on each to go to their section below:

Hydrogen Halides

Equipment Options

Hydrogen halides (HCl, HF, HBr) often result from the burning of materials containing halide groups (plastics, salts, minerals, PCB etc.).  HCl is highly soluble in water and forms hydrochloric acid.  Hydrogen bromide is less soluble but forms hydrobromic acid.  Hydrogen fluoride is only weakly soluble and forms only a weak acid.  Because of these varying solubilities, the size and type of gas scrubbing varies with each.

We have multiple plants scrubbing hydrogen halides from simple tank vents to complex multi-stage systems. Contact us so that we can determine what is right for your system.
Hydrogen Chloride (HCl)

Chemical Scrubbers

Chemical Scrubbers
Hydrogen Bromide

Chemical Scrubbers

Chemical Scrubbers
Hydrogen Fluoride

Dry Scrubber

Dry Scrubber (including fabric filter)

Sulfur Oxides (SOx)

Equipment Options

Sulfur dioxide and sulfur trioxide often results from the burning in oxygen of materials containing sulfur compounds (coal, oil, metalurgical ores.).  Typically sulfur trioxide and sulfur dioxide co-exist in an exhaust stream with a ratio of around 20 to 25:1 SO2:SO3.  Both SO2 and SO3 are highly soluble in water, making water based scrubbing desireable at low temperatures.

We have multiple plants scrubbing SOx in various applications - from coal fired power station exhausts to steel mills. Contact us so that we can determine what is right for your system.
Chemical Scrubbers

SO2 Scrubber

Chemical Scrubbers
Dry Scrubber

Dry Scrubber (including fabric filter)

Nitrogen Oxides (NOx)

Equipment Options

NOx is typically a general term for a mixture of nitric oxide (NO) and nitrogen dioxide (NO2).  Both are formed in burning processes where oxygen is present, especially at high temperatures.  NOx is one of the prime constituents of photochemical smog.

Nitric oxide is low in solubility, hence it must be oxidised to nitrogen dioxide to be effectively scrubbed in a water based chemical scrubber.  Hence a multiple stage approach is required to remove NOx with a chemical scrubber.

At higher temperatures (above 340C), catalytic destruction of NOx is the preferred option.  Ammonia or urea is injected into the gas stream prior to the catalyst, and via a series of complex reactions, nitrogen (N2) and water are produced.

We have multiple plants in NOx removal.  As the pollutant mix can be very complex, please discuss options with our engineers.
DeNOx Chemical Scrubber

Multi-Stage Chemical Scrubbers
DeNOx Catalyst

Destruction via Catalyst

Other Acid gases

Equipment Options

Acid gases are typically water soluble, hence the predominant removal technique is packed bed chemical scrubbers with a caustic solution.

We have multiple plants in virtually every possible acid gas.  Contact us today for assistance with your issue.
Chemical Scrubbers

Chemical Scrubbers

If you can't identify your pollutant from this list, please give us a call or email us.

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