Odor measurement, control at industrial plants

Natural neutralizers mitigate malodors at industrial processing plants. By using instrumentation to measure and control natural plant-based odor removers and suppliers to research and prescribe tailormade formulas, processors are optimizing odor control techniques.

By Dr. Laura Haupert March 8, 2023
Courtesy: Ecosorb

 

Learning Objectives

  • The issue of odors is complex because they are difficult to quantify, so the success or failure of a mitigation project is typically judged subjectively.
  • Many conventional methods for odor neutralization are either hazardous, ineffective on organic or inorganic odors, unsuccessful at neutralizing odors or a combination of all these.
  • Through atomization, concentrated odor eliminators are mixed with water and pumped through pipes to affected areas. Droplets are sprayed into the air, neutralizing odor molecules on contact.

Odor control insights

  • There is hardly a process industry the effects of malodors do not touch, including chemical, pharmaceutical, pulp and paper, oil and gas, asphalt, metalcasting, food processing, water and wastewater, cannabis cultivation and composting.
  • Effective odor neutralization requires analysis because there is no one-size-fits-all solution, and accurately determining the offending constituents is challenging.
  • Where conventional methods fall short, modern plant-based odor eliminators get the job done safely and effectively. These formulations are research-based, optimized to chemically react with and neutralize odor-causing components at the molecular level.

The topic of odor abatement has always taken its place in the shadow of primary process control loops within industrial facilities, and it especially does not surface for discussion among family and friends at the dinner table. However, in the age of viral social media posts and heightened public expectations of companies, it cannot be overlooked.

Odor measurement and control are complex and difficult to quantify, so the success or failure of a mitigation project is typically judged subjectively. In decades past, limited information on malodors and the chemistry that causes them was little known, leading to meager masking solutions, such as concealing bad odors with another unsatisfactory coverup in its place. But in recent years, a few companies have invested significant resources into researching the components that produce unpleasant olfactory sensations to determine molecular means of neutralizing the offending constituents.

Effective odor neutralization requires analysis because there is no one-size-fits-all solution, and accurately determining the offending constituents is challenging. However, processors can enlist the help of suppliers with knowledge and access to advanced laboratory technologies—such as gas chromatographs—to identify molecular chemistry and mitigate odors. The experts at these suppliers can prescribe and provide products designed to neutralize unpleasant scents.

Figure 1: While conventional odor control methodologies perform well in certain applications, all have shortcomings. Modern plant-based odor removers occupy the sweet spot of safe and effective odor neutralization. Courtesy: Ecosorb

Figure 1: While conventional odor control methodologies perform well in certain applications, all have shortcomings. Modern plant-based odor removers occupy the sweet spot of safe and effective odor neutralization. Courtesy: Ecosorb

Conventional process odor control methods: Unwieldy, cost-prohibitive

There is hardly a process industry the effects of malodors do not touch, including chemical, pharmaceutical, pulp and paper, oil and gas, asphalt, metalcasting, food processing, water and wastewater, cannabis cultivation and composting, to name a few. These odors can be offensive at best, or harmful at worst, to plant personnel within and the public outside a facility.

While there are many odor control methodologies available, conventional solutions each have shortcomings in various forms. These methods include masking agents, chemical scrubbers, adsorption and carbon filters, ozone, biological filters and others (Figure 1).

Each of these conventional methods is hazardous, ineffective on organic or inorganic odors, unsuccessful at neutralizing odors or a combination. Additionally, many of these strategies require expensive equipment, materials, setup and maintenance from multiple vendors, rendering systems unwieldy and costly to operate. In contrast, modern plant-based odor removers require relatively little equipment to deploy, and they safely span all odor removal applications by using research-based formulations, each specific to the odor being targeted for removal.

Measurement for odor control: Research-intensive, plant-based solution

Where conventional methods fall short, modern plant-based odor eliminators get the job done safely and effectively. These formulations are research-based, optimized to chemically react with and neutralize odor-causing components at the molecular level.

To develop effective neutralization products, scientists collect gaseous samples from facilities and analyze them using gas chromatography mass spectrometry (GC-MS) to determine the precise molecular makeup of odors, even those present in minute amounts (Figure 2).

Figure 2: Ecosorb uses GC-MS instrumentation to identify the odor-causing substances in facility air, then develops custom plant-based formulas to neutralize these odors. Courtesy: Ecosorb

Figure 2: Ecosorb uses GC-MS instrumentation to identify the odor-causing substances in facility air, then develops custom plant-based formulas to neutralize these odors. Courtesy: Ecosorb

Each compound detected appears as a one peak on the graph, with the corresponding retention time value used for identification. Once the odor-causing compounds are identified, scientists concoct a formulation using plant oils to molecularly neutralize the odors when the compound is combined with the odors in the atmosphere.

This results in versatile and cost-efficient solutions, each specially crafted for maximum effectiveness in a specific application by leveraging customized concentrations of plant oils, biobased surfactants and water to neutralize odors. Dispersal of these agents is conducted via atomization or vaporization, depending on the application.

Figure 3: Each peak in a GC chromatogram represents the presence of a compound, identified and quantified by the x- and y-axes, respectively. Courtesy: Ecosorb

Figure 3: Each peak in a GC chromatogram represents the presence of a compound, identified and quantified by the x- and y-axes, respectively. Courtesy: Ecosorb

Actuation for odor control: Atomization and vaporization

Through atomization, concentrated odor eliminators are mixed with water and pumped through pipes to affected areas. Droplets are sprayed into the air, neutralizing odor molecules on contact (Figure 4). Atomization nozzle systems provide a significant level of control, with the ability to vary product volume, surface area and spray method.

Atomization can occur via hydraulic high-pressure or pneumatic low-pressure systems. High-pressure systems treat odors by dispersing a fine mist into the air to treat escaping gas emissions and surface odors, while low-pressure fan systems are effective in confined spaces and environments for containing multiple odors released in a small area.

Figure 4: An Ecosorb high-pressure atomization system neutralizes odors in a primary clarifier outside a food manufacturing facility. Courtesy: Ecosorb

Figure 4: An Ecosorb high-pressure atomization system neutralizes odors in a primary clarifier outside a food manufacturing facility. Courtesy: Ecosorb

These portable systems spray a mixture of odor eliminator and water through a fan’s jet stream, creating a fine mist throughout the area. Because atomization delivery systems are generally compact, they are flexible and customizable, and they are easily transitioned from one process area to another. Additionally, the use of concentrated odor eliminators eases shipping and storage because water, which makes up most of the bulk and weight, is added at the site.

Unlike atomization, no additional water is added in vaporization systems, which pump undiluted odor eliminators through perforated pipe distribution systems, creating a dry vapor to neutralize airborne odors. Vaporization uses less water compared to atomization, providing cost savings and a more eco-friendly delivery method (Figure 5), but it is limited to use in less humid locations.

Vapor phase systems deliver dry odor eliminator at rates as low as 130 cubic feet per minute (CFM) to as high as 2,400 CFM, making them adaptable to many locations and applications. These flexible and efficient delivery systems:

  • Provide smaller droplets and higher absorption for better odor control.

  • Require no additional water to operate.

  • Eliminate the need for mixing and diluting.

  • Reduce maintenance requirements because no nozzles are required.

Figure 5: An Ecosorb vapor phase delivery system carries an odor neutralization formulation around a wastewater treatment facility, neutralizing odors before they escape the plant perimeter (left). By leveraging vaporization ports instead of nozzles, maintenance requirements are minimized (right). Courtesy: Ecosorb

Figure 5: An Ecosorb vapor phase delivery system carries an odor neutralization formulation around a wastewater treatment facility, neutralizing odors before they escape the plant perimeter (left). By leveraging vaporization ports instead of nozzles, maintenance requirements are minimized (right). Courtesy: Ecosorb

Odor control results: pet food manufacturing

A large pet food manufacturer facing odor problems implemented an vapor phase distribution system to neutralize odors. The company’s operations produced significant amounts of wastewater to manufacture wet and dry pet foods of many kinds—using seafood, chicken, beef and other ingredients. With neighbors just a few hundred yards away, the manufacturer needed an effective solution to neutralize odors from its wastewater collection area.

The area included four large tanks—two equalization basin vessels, a bioreactor and a denitrification tank. To cover the area, engineers installed a 1,200 CFM vapor phase unit to deliver a proprietary blend of plant oils, biobased surfactants and water designed specifically to react with the chemical makeup of wastewater odors. These odors included the gases from compounds such as chicken, beef and seafood. The unit wrapped around the perimeter of each of the four tanks, neutralizing odors before they could escape the area (Figure 6).

After installation, the manufacturer experimented with different odor eliminator flow rates and concentrations, and since dialing in the ideal settings, neighbor complaints dropped sharply. As part of the service and warranty plan, the system undergoes quarterly maintenance and upkeep visits from the manufacturer to ensure efficient operation around the clock.

Figure 6: A pet food manufacturer installed an Ecosorb vapor phase system to neutralize odors from its equalization basins, bioreactor and denitrification tank. Courtesy: Ecosorb

Figure 6: A pet food manufacturer installed an Ecosorb vapor phase system to neutralize odors from its equalization basins, bioreactor and denitrification tank. Courtesy: Ecosorb

Odor control results: asphalt

An asphalt manufacturing plant—which breaks down used product, and makes 1,500 to 2,000 tons of new hot mix asphalt for paving and construction contractors daily—found itself in the middle of new housing developments, as a nearby town grew into the previously uninhabited vicinity around the facility. Being proactive, the plant knew it needed to mitigate its odorous releases, or else they would end up as a popular target for complaints online and at town hall meetings.

Initially, the plant tried using masking chemical products, but it found these agents did not adequately hide the asphalt processing smells, and the coverups made the problem worse in some cases. A lab then analyzed a sample to determine the most effective product for the unique odor combination.

Using GC-MS and a human nose panel, the team determined an additive blend made to reduce hydrogen sulfide, mercaptans, styrene and general hydrocarbons in asphalt neutralized the offending odors of the unique asphalt blend. The plant now adds about one gallon of this formulation to each of its 6,000-gallon hot mix tankers, and remains in the good graces of its neighbors.

Eco-products empower business growth

By applying plant-based odor removers in and around facilities, processors can effectively mitigate foul odors in multiple industries using safe, environmentally-friendly and cost-efficient methods. These custom formulations neutralize odors by breaking down and nullifying odor-causing molecules.

Simpler to operate and maintain than conventional odor control methodologies, the use of renewable and biobased ingredients via atomization and vaporization systems provides processors with the means to produce at high volumes, without sacrificing reputations. This empowers businesses to maintain strong rapport with neighbors, and focus on profits and production, instead of addressing odor complaints.

Laura Haupert is chief scientific officer, Ecosorb. Edited by David Miller, content manager, Control Engineering, CFE Media and Technology, dmiller@cfemedia.com.

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Keywords: Odor control, atomization

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Author Bio: Laura Haupert, Ph.D., is chief scientific officer for Ecosorb, where she leads research and development, regulatory, safety, and quality control. She earned her B.S. in chemistry from Manchester College and Ph.D. in physical chemistry at Purdue University, working with bond energies of solvated clusters. Dr. Haupert also completed her post-doctoral research at Purdue where she focused on the development of mass spectrometric methods for the structural elucidation of lignin catalytic degradation. Dr. Haupert has developed and directed Ecosorb’s many product lines—and she has overseen the state-of-the-art laboratory and production facility in Rising Sun, Indiana—for over ten years.