The odors generated from industrial activates can pose both environmental and health problems, especially when emissions occur close to residential areas. The social demand for cleaner, odor-free air, has spurred the development of increasingly restrictive regulations concerning harmful gas emissions into the atmosphere. Thus, companies are obligated to seek solutions for gas purification and reduction of odors they emit.
The emission of unpleasant odors can come from a variety of industrial activities, although some industries are more likely to generate odors due to the “raw materials” with which they work. These industries include animal products, food, farming, chemical or waste management.
In many cases, unpleasant odors are not generated from the companies’ own activity, but rather from the waste generated in their production processes. In this sense, it is common to encounter problems with wastewater or contaminated sludge that is stored to be sent to treatment plants.
While necessary precautions are often observed in processes to help reduce and eliminate odors, in many cases, these measures can prove insufficient. Therefore, additional technology for odor reduction must be implemented.
Many different technologies exist to remove odors with air treatment to. The most suitable choice depends on diverse factors such as the nature of the pollutants, the amount or flow to be treated, and the concentration of emissions.
Regenerative thermal oxidation is a very efficient technology for removing VOCs and solvents. Depending on the concentration of VOCs to eliminate, energy consumption may be somewhat high. However, in return, the heat generated can be utilized. Regenerative thermal oxidation can utilized for varied flows between 2,000 and 150,000 Nm3 / h, with concentrations of VOCs ranging from 0.3 to 10 g/Nm3.
Activated carbon is a dry system that has limited effectiveness against small molecules such as ammonia, but it works very well for sporadic contamination. The carbon bed must be replaced frequently.
Scrubbers and washing towers are a good choice for high flow rates. However due to their complexities, these technologies require more maintenance by trained personnel.
Another system of purification to note is biological purification, or biofilters. These systems take advantage of the capacity of certain microorganisms to biochemically oxidize organic and inorganic substances that contain gases in need of treatment. In many cases, biofiltration is the most economic option while proving very effective. However, in many cases, this system can produce emissions that do not comply with permitted limits, due to the fact that not all pollutants are eliminated.