Ecopure® FGA – Exhaust gas scrubbers

The exhaust gas flows into the lower part of the Ecopure^® FGA system and makes its way upward through a bulk material that consists of special high-performance structured or random packed media. The washing liquid is distributed over this bulk material and runs down through it in the opposite direction to the rising exhaust gas. As a result, the exhaust air and the washing liquid come into contact with one another. Because of the large substance exchange surface of the structured or random packed media and the turbulence of the flow, the pollutants are transferred from the contaminated exhaust air to the washing liquid. A mist eliminator at the outlet of the column traps any remaining droplets in the clean gas.

The washing liquid collects in the recirculation tank and is extracted at the other end of the column. From there it is pumped back to the distributor. The washing liquid consists mainly of water, but also contains chemicals to neutralize acidic pollutants such as hydrogen chloride (HCl), hydrofluoric acid (HF), hydrobromic acid (HBr), sulfur dioxide (SO₂) etc. in the exhaust air. Addition of the chemicals is fully automated and depends on the pH value of the solution. If the exhaust air contains halogen elements (for example chlorine or bromine), a reducing agent is also added.

Dissolved salts build up in the washing solution because of the chemical additives. In order to keep the salt levels constant, some of the contaminated washing liquid can be removed if necessary and replaced with fresh water.

If the exhaust gas is at a high temperature, a quencher can be installed upstream of the Ecopure^® FGA exhaust gas scrubber for cooling purposes. This pumps washing liquid out of the recirculation tank and distributes it through a system of fine nozzles into the gas flow to reduce the temperature by means of evaporation.

The Ecopure^® FGA exhaust gas scrubber is found in a wide variety of industries from chemicals and pharmaceuticals to petrochemicals. It can also be used for Air Pollution Control after waste treatment or in fire testing facilities. Exhaust gases are also produced during the manufacture of carbon fiber and these also have to be cleaned. The food industry is another user of Dürr's exhaust gas scrubbers.

• Chemical Industry
• Pharmaceutical Industry
• Petrochemical Industry
• Fire Testing Facilities
• Carbon Fiber

Exhaust gas scrubbers are used as stand-alone systems for separating out pollutants. If there are pollutants present that the Ecopure^® FGA exhaust gas scrubber cannot remove, it must be combined with other wet processes and/or thermal processes for Air Pollution Control.
Individual systems can process volumetric flow rates of up to 200,000 Nm³/h. If the throughput is higher, the systems must be installed in parallel.

The following pollutants can be separated out with an Ecopure^® FGA exhaust gas scrubber:

• Ethanol and methanol
• Halocarbons (HBr, HCl, HF etc.)
• Halogen elements (Br₂, Cl₂ etc.)
• Sulfur compounds (SO₂, H₂S etc.)
• Ammonia (NH₃)
• Hydrocyanic acid (HCN)

Depending on the application, the systems can be manufactured in plastic, glass fiber-reinforced plastic (GFRP), or stainless steel. Coated or lined variants are also available. The accompanying washing liquid pipes and fittings are often made from plastic, together with the parts of the pumps that come into contact with the media.