Nowadays air emissions from animal housing systems are being examined more closely for ways to mitigate potentially harmful gases. Wet air scrubbers are one way to remove pollutants from air being exhausted from mechanically ventilated buildings. Wet scrubbers use liquid to collect dust or particulate matter (PM) and absorb gases from the air by using a wet surface, spray system, or wet material bed. Particulate matter (PM) is a major air pollutant from animal production with significant impacts on human health and the environment: effective PM control technologies are strongly needed. Some scrubbers use water for removing pollutants, while others use some type of acid or a base to shift the pH in order to absorb specific gases in the air.

Despite the widespread use of chemical, biological, and combined air scrubbing systems, there is still insufficient knowledge of process engineering aspects such as removal efficiency, energy design, and process control.

Wet scrubbers clean air by physically trapping PM on wet surfaces and absorbing gases into the liquid. In some cases, the gases react with chemicals in the liquid. Small liquid droplets are more effective because they have more surface area than fewer, larger droplets. Very small liquid droplets are difficult to remove from the airstream after they absorb or react with the gases.

Wet air scrubbers for animal housing generally are either acid scrubbers, bioscrubbers, or water-only scrubbers:

• Acid scrubbers trap alkaline material, such as ammonia, in a sulfuric acid solution that is circulated over a packed bed at a pH of 2 to 4. The ammonia removal efficiency tends to be over 90%, while the odor removal rate is around 30%;
• Bioscrubbers converts ammonia into nitrate and nitrite. They tend to use 8 to 10 times more water than acid scrubbers. The ammonia removal efficiency averages approximately 70%, and the odor removal efficiency averages 50%;
• Water-only scrubbers use water and not biomass or acid. This is less effective in ammonia scrubbing but still a viable choice.

At the moment a new generation of so-called “multi-pollutant scrubbers” is being developed and tested that not only removes ammonia but also aims for significant removal of odor and particulate matter from the air. Such multi-pollutant scrubbers usually consist of two or more scrubbing stages. However, it should be noted, odor and dust removal are less effective than ammonia removal, at least for now. Multi-pollutant scrubbers provide an option for large-scale livestock operations to remain in operation in areas nearby residential areas and sensitive ecosystems, but costs are considered high.

Being a new type of wet air scrubber, Scroiler™ cleans air from gases, dust, vapors and other admixtures using water or other cleaning liquid.

Scroiler™ produces the cleaning mist differently from other scrubber systems, which

results in running costs that are much lower than for a common wet air scrubber. Scroiler™ is the new type of wet air scrubber that saves water.

If you would like to purchase Scroiler™, please contact us at info@optromix.com.