Solenis + NCH:<br/>Forward As One
NCH is now part of Solenis
Close 686C6711-FB74-47F4-AFEE-14D0F9C09B39

Controlling Odor in Industrial Processes

By: Light Industrial Solutions for Water Treatment | April 14, 2020 | Reading time: 4 minutes

As the world’s population has increased, urban centers have expanded and created sprawl. Cities and their suburbs have engulfed rural and industrial areas like never before. As a result, longtime residents of these areas, such as industrial plants and facilities, have been forced to adapt. Issues that were never a concern previously, are now taking precedence. Among these concerns are the odors that are emitted as a byproduct of processes. These odors must be controlled, reduced, or eliminated altogether. Plant stakeholders must understand a number of different aspects of their operations in order to prevent or address the odors that are being emitted. Renderers are among the most affected by this and thus will be the focus of this article. Some of the factors that renderers must consider are:

  1. Type/Age of the Material
  2. Byproducts being created
  3. Scrubbing process

It’s important to understand both the mechanical process that is producing the odors and the molecular makeup of the odor compounds that need to be controlled. Start by identifying the materials being used and the way in which these materials are being converted to the final product. Generally, odors that are released are a byproduct of this process.

Type/Age of the Material

Renderers process animal byproducts such as animal fat, bone, feathers, hides, blood, and internal organs. Generally, a 1,000-pound steer has about 600 pounds of edible meat. The remaining 400 pounds are processed by renderers. (Franco, 1996) The perishable nature of the material being processed results in odors being emitted from plants. The longer a material is stored without being processed, the more odor compounds are created and emitted. These odors are a very intricate mixture of organic compounds. 

Byproducts Being Created

There are thirty or more odor-causing byproducts being created in a rendering plant. Among the major compounds are organic sulfides, disulfides, aldehydes, amines, organic acids, alcohols, ketones, and hydrocarbons. (Burgwald TA., 1971)  Some of these compounds, such as Hydrogen Sulfide (H₂S), have very low odor thresholds. These compounds can be detected at levels as low as 1 ppb. As a result, highly efficient odor control processes are necessary.

Odor Removal Processes

The two most commonly used processes to remove odor compounds from the air are: boiler incineration and multistage wet scrubber systems.  

  • Incineration
    Incineration in boilers is a commonly used practice across the country. This is because rendering plants require steam for cooking and drying material and therefore have boilers. Odorous air is introduced to the boiler as either the primary or secondary combustion air, although precautions must be made to remove moisture and particulate matter. This is usually done with a scrubber and entrainment separator.
  • Multistage Wet Scrubbers
    Wet scrubbers, sometimes called packed-bed scrubbers are an alternative when incineration is not an option. A typical wet scrubber system consists of two or three stages; a venturi scrubber, which removes particulate matter, followed in sequence by a packed-bed scrubber(s). This scrubber contains plastic packing that varies in shape and size and is designed to maximize contact between the air and scrubber solution. The odorous air flows upward in the scrubber as recirculating water (scrubber solution) with an oxidizing solution, such as Chlorine Dioxide or odoreXile™, flows downward.
Conclusion

As demands for space and food continue to rise, manufacturers will continue to be pressed more and more. Renderers will be processing ever-increasing amounts of material while being told to reduce their odor emissions. Chem-Aqua has an expansive product line ready to address any odor control need or situation. We are also able to create and install generator systems customized to fit any application. Our field representatives have experience with Chlorine Dioxide, Paracetic Acid, odoreXile, and more. Contact Chem-Aqua today to have an experienced representative survey your facility and lend their expertise.

Written by: Tim Daniels

References

Burgwald TA. (1971). Identification of Chemical Constituents in Rendering Industry Odor Emissions, project no C8172. Chicago: IIT Research Institute.

Franco, D. A. (1996). The Original Recyclers. In D. A. Franco, The Original Recyclers (p. 33). The National Renderers Association.

 

Light Industrial Solutions for Water Treatment

Industrial Solutions Since 1919

A team of water treatment experts and a long history of helping customers optimize system performance, improve efficiency, and achieve their sustainability goals. Through customized solutions for boiler, cooling, process, wastewater, and mission-critical data center environments, we help customers reduce water and energy consumption, lower maintenance costs, and protect critical assets. Backed by innovative technologies, dedicated service, and a network of local specialists, we work in partnership with customers to deliver safe, reliable, and sustainable operations.