How to safely, sustainably absolve industrial malodors with standardized formulations

By using natural off-the-shelf plant-based formulations, process manufacturers can mitigate offensive odors to keep neighbors happy and production on track.

By Dr. Laura Haupert May 29, 2024
Courtesy: Ecosorb

 

Learning Objectives

  • Understand how reducing odors is a difficult challenge.
  • Learn four benefits of safe and effective modern odor neutralization for process manufacturing facilities.
  • Understand other benefits companies can reap from reducing odors.

Odor control insights

  • Industrial odor control advancements leverage scientific understanding of odor molecules, offering safe, versatile and effective solutions, enhancing worker productivity and community relations.
  • Modern odor neutralization techniques replace outdated methods, providing long-lasting effectiveness, environmental safety and tailored solutions for diverse industrial sectors, improving operational efficiency and community satisfaction.

Process manufacturers often face challenges with unwanted odors emanating from their processes, which is justifiably voiced by concerned or frustrated employees and neighbors. These odors often can be unpleasant for workers and nearby communities, and they must be mitigated to maintain long-term operational efficiency.

Odor abatement can be a difficult undertaking because of the complex makeup and variation of airborne process plant byproducts. However, process manufacturers can enlist the help of top suppliers with the knowledge and advanced laboratory technologies needed to chemically neutralize odor-causing components.

These experts address this issue by identifying the problematic compounds, and by then formulating and distributing standardized products to neutralize malodors in numerous industries.

Understanding odor molecules

Beyond the unpleasant nature of bad odors, explaining the need for industrial odor control begins with understanding the scientific relationship between components in the air and the ways humans perceive them.

Our sense of smell is a powerful tool, alerting us to potential dangers, like spoiled food and gas leaks, while also enabling us to enjoy other aromas—such as the smell of freshly baked cookies, pine trees in the mountains, or the subtle nuances of a fragrant flower.

Odors are caused by volatile organic compounds (VOCs), organic chemicals that evaporate at room temperature and become airborne. These VOCs can have a wide range of chemical structures, and their specific molecular makeup determines the perceived odor. For example, the aroma of coffee comprises hundreds of different VOCs, while the unpleasant smell of rotten eggs is caused almost solely by hydrogen sulfide.

While not as acute as some animals, human noses are sensitive to these airborne molecules and are capable of detecting odors even at low concentrations. During inhalation, air containing odor molecules enters the nasal cavity through the nostrils, where it travels to meet the epithelium, which is lined with millions of olfactory receptor neurons. The molecules bind to proteins on these neurons, each of which are designed to detect a specific range of odorant shapes and functionalities. This reaction triggers an electrical signal that travels to the brain, where it is processed and interpreted, triggering the perception of smell.

This refined and complex biochemical process is also the reason why industrial operations can pose a significant nuisance to surrounding communities. When neighbors are impacted, complaints can mount, which hinder productivity and profitability. Odor neutralization ideally delves into strategies to eliminate offensive odors at their source to keep the air surrounding a facility clean and free of malodorous molecules.

Shortcomings of traditional odor control methods

The control of industrial odors historically relied on methods like masking agents, thermal oxidation, and wet scrubbing. While some of these methods can reduce process-related malodors, they often are insufficient and may come with significant drawbacks (Figure 1).

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

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

To start with, masking agents — synthetic fragrances designed to overpower unpleasant smells with a more acceptable scent — do not address the root cause of odors. Oftentimes, these agents obscure one bad smell with another competing redolence, and this sometimes causes the formation of new and potentially obnoxious scents. Furthermore, the masking chemicals themselves can pose health risks.

Thermal oxidation is effective, but expensive. It requires burning odorous compounds at high temperatures, which consumes significant amounts of energy and generates harmful byproducts, such as nitrogen oxides, which add to air pollution.

Chemical scrubbing is also effective in some industries, but it is maintenance-intensive and costly. This procedure uses liquid chemical solutions to capture odorous molecules as they come into contact with the liquid. While effective for some water-soluble odorous compounds, chemical scrubbing systems require frequent maintenance to ensure optimal performance, as clogged nozzles, scaling and biological growth within the scrubber can significantly reduce odor removal efficiency.

This method also requires treatment and disposal of the wastewater stream as it removes contaminated molecules from the air, adding another layer of complexity and cost to the odor control process.

Four benefits of safe, effective modern odor neutralization

Odor neutralization offers a more sustainable and effective approach to odor control. Through advanced techniques like gas chromatography-mass spectrometry (GC-MS), odor neutralizer manufacturers identify the specific VOCs responsible for offensive odors generated by industrial processes (Figure 2). Based on the identified odor molecules, scientists create specialized formulations that contain complementary chemical compounds.

Figure 2: Ecosorb uses GC-MS instrumentation to identify odor-causing substances in air samples, and it then develops custom plant-based formulas to neutralize odors.

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

These formulations react with the odorants on contact, transforming the odorous VOCs into harmless byproducts that no longer trigger olfactory receptors in humans’ noses. By employing these methods, neutralizers can effectively remove unpleasant smells, leaving behind a clean and odor-free environment.

Compared to traditional methods, odor neutralization provides significant advantages:

  1. Long-lasting effectiveness: Odor neutralizers chemically combine with odorous molecules in the air, removing the source of the stench.

  2. Safe for people and the environment: Modern formulations are comprised of biologically- and ecologically-safe plant oils, biobased surfactants and water.

  3. Versatile and cost-efficient: Plant-based natural neutralizers are simple to apply and dispersion systems require little maintenance.

  4. Enhanced productivity: Unpleasant odors negatively impact worker morale and productivity, and conversely, safe and effective odor control creates a more pleasant and productive work environment.

Standardization provides end-user benefits

Leading suppliers of natural odor abatement products utilize their expertise, decades of research, and advanced laboratory technologies to carefully craft special malodor-fighting formulations, effective over a range of applications within each industrial sector.

In some cases, specialized blends are required. However, standard blends can be created to react with a significant majority of airborne contaminants found in typical processes in many industries. These blends neutralize odorous off gas that stirs up issues with workers and neighbors. These solutions provide many benefits for process manufacturers such as:

  • Leveraging leading suppliers’ extensive industry experience and tests conducted throughout many facilities over widespread regions.

  • Decreasing lead time after order with off-the-shelf product availability.

  • Reducing startup and commissioning time with turnkey solutions.

  • Instilling confidence in the product because of its use in numerous applications.

  • Providing flexibility to change raw materials used in plant processes, without the need to create new custom neutralizer formulations.

  • Ensuring supplier support is always at hand.

Custom formulations for demanding applications

Although general formulations are efficacious for most users, some niche facilities may require custom blends, and expert suppliers can help with these needs as well. In these situations, air samples are taken from the plant during multiple stages of production and stored in Markes-thermal desorption tubes. These tubes provide much longer sample life compared to conventional Tedlar bags — several weeks versus 24 hours — while remaining effective at lower sample volumes. These samples are then studied in a lab using GC-MS to determine the precise molecular makeup of odors, even those present in minute amounts.

The GC-MS analyzer produces a chromatogram, which plots detector response (y-axis) against retention time (x-axis). Each peak in the chromatogram represents the quantity of each substance detected, including those which cause malodors (Figure 3).

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

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

Equipped with this information, scientists formulate specific blends of plant oils to neutralize the substances of concern. Every product prescription is tailored to the specific needs of each plant or facility for optimal odor control.

Industrial odor neutralization success throughout industry

Leading industrial odor neutralization suppliers research, formulate and distribute a breadth of standardized plant-based odor control solutions for use in different industrial environments, including:

  • Pulp and paper mills, where the pulping process generates unpleasant odors.

  • Asphalt manufacturing, where hot mixes over 150 °C create significant VOC spikes, which are vented into the atmosphere.

  • Wastewater treatment plants, which often face pungent odors from organic matter decomposition.

  • Chemical manufacturing plants with many processes generating a variety of strong odors.

  • Food processing facilities, where odors from cooking, fermentation and other processes frequently escape the confines of the plant walls.

In one case, an asphalt pavement plant producing 1,500-2,000 tons of hot mix asphalt each day for contractors and construction firms relied on a basic odor-mitigating additive for years (Figure 4). However, seasonal asphalt mix variability spurred the need for a specially targeted formulation.

The varying crude oil sources and grades present in the mix began producing overpowering odors in the areas surrounding the plant and the manufacturer’s standard additive was no longer effective.

Figure 4: A hot mix asphalt plant blended a single Ecosorb formulation into its multiple asphalt mixes, reducing airborne sulfurous release by over 90%.

Figure 4: A hot mix asphalt plant blended a single Ecosorb formulation into its multiple asphalt mixes, reducing airborne sulfurous release by over 90%. Courtesy: Ecosorb

The plant shipped samples of three different asphalt mixes to Ecosorb’s lab to assess the levels of hydrogen sulfide, mercaptans and general hydrocarbons in each. The data from one asphalt mix, before and after treatment at 150 °C, is shown in Table 1.

Table 1: Application of an Ecosorb custom formulation significantly reduced odors at an asphalt plant.

Table 1: Application of an Ecosorb custom formulation significantly reduced odors at an asphalt plant. Courtesy: Ecosorb

Although the levels were different in each mix, the team of scientists determined its standard formulation for hot mix asphalt blending would substantially neutralize odors in all three mixes, eliminating the need for the asphalt manufacturer to match a different custom formulation with each mix (Figure 5).

Figure 5: The Ecosorb 1300 series comes in two varieties—water-based (left) for airborne dispersion, and oil-based (right) for blending directly into the mix—to combat a multitude of odor-causing compounds in a wide range of asphalt mixes, leveraging over six years of rigorous research and testing.

Figure 5: The Ecosorb 1300 series comes in two varieties—water-based (left) for airborne dispersion, and oil-based (right) for blending directly into the mix—to combat a multitude of odor-causing compounds in a wide range of asphalt mixes, leveraging over six years of rigorous research and testing. Courtesy: Ecosorb

The plant added this single blend to all its mixes, which reduced airborne sulfurous release by over 90%, while greatly reducing the cost and time required to apply a different formulation as mixes changed.

Overcome odors with natural neutralizers

Plant-based odor control products work by employing a different approach than traditional methods, utilizing a blend of naturally occurring plant extracts to molecularly interact with and neutralize odorous compounds, effectively removing them from the air.

This method provides a safe, effective, cost-efficient and sustainable approach to odor control with its versatility rendering it an invaluable tool in many industries to promote pleasant and healthy environments for employees and surrounding communities.

The science of odor neutralization provides a powerful foundation for addressing unwanted smells in industrial processes. By partnering with the right experts and employing targeted neutralization strategies, process manufacturers can create clean and odor-free production environments, promoting positive community relations and improved business operations.

Laura Haupert, Ph.D., is chief scientific officer for Ecosorb. Edited by Chris Vavra, web content manager, Control Engineering.

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Keywords: odor control, odor neutralization

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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.