Your questions answered: Managing Industrial Odors – Learn How to Pass the Smell Test

Plant Engineering hosted a webinar on an important topic: odor control. No matter the industry, manufacturing odors drain resources, decrease efficiency, and can shut down an operation entirely.

There’s no one-size-fits-all solution, and in fact, many odor solutions cause more harm than good – either by masking odor with another noisome smell, or by using a solution that harms the environment and draws regulatory scrutiny.

Following the webcast, attendees asked their questions of the panel. Those questions not answered during the webinar are answered below by Dr. Laura Haupert, director of research and development, and Brian McLaughlin, director of industrial sales, both with OMI Industries.

Question: What are options for operation of odor control systems in subzero temperatures with no or minimal heating systems?

McLaughlin: With Ecosorb, vapor systems there is no heating required in the ducting. The only heat requirement is for the Ecosorb container and the vapor system, which can be completed with placement inside a current building or a heated shed.

Question: How can you determine the specific odorous compounds for an industrial biological wastewater treatment plant?

Dr. Haupert: Using gas analysis the specific odorous compounds can be determined. Gas desorption tubes are pulled from this site and analyzed. This tells us exactly what chemicals are being emitted and need to be treated. Based on what is coming off the site, a specific Ecosorb formulation would be recommended for use. The R&D team has done this in the past for this type of application.

Question: Does Ecosorb offer solutions to control ammonia/cannabis?

Dr. Haupert: Yes, Ecosorb CNB 100 was scientifically blended to remove the odors associated with growing cannabis. This formulation is currently being used all over the U.S. and Canada. In addition, Ecosorb has its own 75 CFM vapor phase technology specifically designed to work with grow houses and produce a vapor of our Ecosorb CNB 100. The combination of this chemistry and technology produces a unique solution to remove cannabis odors.

Question: We have a regulatory permit restriction with VOC limits (to limit emissions below major source threshold). Is your product considered a VOC and would it need to be accounted for in overall facility emissions?

Dr. Haupert: Ecosorb formulations use plant oils (essential oils) as active ingredients. Most plant oils are non-hazardous volatile organic compounds (VOC). Some plant oils do fall under exception as they are low-vapor pressure volatile organic compounds (LVP-VOC). Plant oils that are defined as VOCs contribute to overall facility emissions. Ecosorb works with customers to provide them with the information needed to take the plant oil VOC into account.

Question: Does OMI Industries provide odor mitigation equipment?

McLaughlin: Yes, OMI Industries designs, engineers, and builds all technology required for systems using Ecosorb chemistry.

Question: Is there online continuous measurement technology to test odor in foul, liquid condensate, including sulphur compounds from pulp mills?

Dr. Haupert: There are many sensors available that detect sulfur-containing compound, in particular hydrogen sulfide. Ecosorb equipment have a sensor added to it to deliver our formulations when a set concentration of hydrogen sulfide is detected. This allows for treatment only when odorous gases are detected at a certain level.

Question: Is lab work available for efficacy testing?

Dr. Haupert: OMI’s R&D Center has a state-of-the-art laboratory containing technologies that allow for the efficacy testing. Using our gas chromatography mass spectrometer (GCMS), the R&D team analyzes samples (desorption tubes, head space or liquid) before and after treatment (when possible). By looking at samples before and after treatment, the efficacy can be determined as well as if they correct formulation is being utilized. In addition, the R&D team provides odor testing on site using a Nasal Ranger. Again, efficacy is determined by testing odors at a site before and after treatment.

Question: Have done any work with beef rendering plants?

McLaughlin: Ecosorb chemistry is successfully used in polishing caustic scrubbers or in stand-alone scenarios with the Ecosorb G chemistry.

Question: Have you used the spectrometer to measure the resulting gas after neutralization?

Dr. Haupert: Yes, the R&D team has used the GCMS to determine what substances remain after neutralization. This is a useful term to determine how effective our formulations are at neutralization.

Question: For an asphalt plant application, does the exhaust temperature have an impact on the effectiveness of the Ecosorb?

McLaughlin: Temperatures above 380 degrees F can have a negative effect on the success of Ecosorb additive chemistries with asphalt.

Question: We have a 450-cfm vapor phase unit at a solid waste incinerator. We have used Ecosorb 606 for years. Can we change over to 106 without modifying the equipment, i.e., the pump and atomizer nozzle?

McLaughlin: Absolutely. Ecosorb 106 is water-based chemistry and will function in all technology designed for Ecosorb 606.

Question: What is the best way to control odors from outdoor cannabis cultivation sites?

McLaughlin: Ecosorb CNB-100 chemistry was designed specifically for cannabis cultivation odors. It should be used with wind directional control at outdoor cultivation sites.

Question: What types of compounds interfere or obstruct the effectiveness of Ecosorb?

Dr. Haupert: In general, with Ecosorb, the greatest obstruction is understanding the chemistry and the application. For instance, Ecosorb has formulations that work great on polar molecules. If in this application, there are mainly non-polar molecules, then this formulation will not work. However, by understanding what gases are coming from the site, the correct formulation can be determined and used. It is essential to understand what chemistry needs to be used and what technology. The Ecosorb team must know the sources of the odor. Ecosorb cannot treat odors when there is no contact. You must know all the sources of the odor or Ecosorb will not be effective.

Question: Is there a simple way to quantify (measure) the odors in the industry or is just a matter of the person who is smelling the odors?

Dr. Haupert: In my opinion, the nasal ranger is the best technology on the market for quantifying odors. The nasal ranger uses the human nose to determine the odor units. Thus, allowing an industrial site to have someone determine how bad the odors are on site.

Question: How do you recommend improving indoor air quality and odors that are inherent in an HVAC setting?

Dr. Haupert: Yes, Fresh Wave IAQ chemistry was created specifically for improving indoor air quality. We have systems engineered to operate in HVAC systems.

Question: Are there white papers of verification/validation?

Dr. Haupert: Yes, Ecosorb has a range of white papers available for review. In addition, Ecosorb has had third-party testing done to demonstrate efficacy and neutralization. Please contact us for more information.

Question: Does E-nose technology effectively measure odor?

Dr. Haupert: In my opinion, no, the e-nose does not effectively measure odor. The e-nose is no substitute for the human nose. The human nose can distinguish hundreds of thousands of odors and great variations in intensity. Human noses are usually preferred, especially in critical applications such as industrial malodors. An e-nose is best used in controlled settings and needs consistent maintenance. The E-nose does not like the rigors of the field. It prefers a lab environment. It does not like strong signals nor long exposures to even low signals. It cannot respond to low signals consistently. An e-nose is prone to saturation and drift, requiring constant re-calibration. In addition, there are no formal standards for e-noses. Until there are, there will be little improvement in their performance or the correction of fundamental flaws.

Question: How can the smell of solvents like Toluene or Isopropyl be reduced?

Dr. Haupert: Yes, there are different Ecosorb formulations for each of those. Depending on the application, either oil-based (additives) or water-based formulations would be used. The oil-based formulations can be added directly into applications, especially where water is not tolerated. Ecosorb has technologies available to apply our water-based formulations. 

Question: We work with powdered bleach, which reacts with any moisture or humidity to create a strong bleach odor that causes eye watering. Is there a way to mitigate this?

Dr. Haupert: Ecosorb formulations have been used on “bleach” odors in the past. However, this situation would need to be examined further. Ecosorb water-based formulations contain water and could exaggerate this issue. It may be necessary to pull the air from the room and then treat it: allowing for odor control, without adding to safety issues.

Question: What are the constituents of Ecosorb and what is its reaction with sulphones?

Dr. Haupert: Ecosorb formulations react with sulfur containing compounds via different reactions. For instance, if RNH₂ represents a base found in natural plant oils, a reaction between that based and hydrogen sulfide would be as follows: RNH₂ + H₂S = RNH3+ SH-. In addition, reactions occur across double bonds of substances in plant oils (R=CHCHO) as follows: H+ + HS- + R=CHCHO = (SH)RCH=CHOH and H+ + HS- + R=CHCHO = (SH)RCH₂CHO. All of the above reactions result in neutralization of the hydrogen sulfide.

Question: Can you determine the ratio of Ecosorb to the PPM values of a pollutant? Is there still a breakdown of the Ecosorb after the injection?

Dr. Haupert: A direct correlation between pollutant and Ecosorb is not available. In most applications, there is more than one substance for Ecosorb to react with. Ecosorb formulations are not selective and will react with what is possible. Therefore, a direct correlation is not possible. Ecosorb will react and neutralize odors. The resulting organic salt is not pure Ecosorb.

Question: How can bad smell in robber parts be controlled?

Dr. Haupert: Yes, there are different Ecosorb formulations for the use in rubber. These formulations tend to be additives that can be directly added into a process. Depending on what type of rubber is being used and any other additives involved, will direct which Ecosorb formulation is needed.

Question: What is the mechanism by which of bad odor absorption occurs?

Dr. Haupert: For Ecosorb, odor control occurs by means of several mechanisms. First, Ecosorb droplets in the air come in contact with the malodor molecules in the air. The small droplets represent a large surface area and are covered in a film of plant oils. Once contact is accomplished, adsorption onto the surface of the atomized product occurs via Van der Waal’s forces. These forces cause an attraction between the atomized product and the malodor molecules. The electrostatic forces help hold the malodor molecules on the surface of the droplet until the next mechanism acts; that being absorption. Absorption of the malodor molecules relates to the solubility of the gas in a solution containing the product. OMI products enhance the solubility of many gasses. The atomized product droplets suspended in the ambient air dissolve the malodors into the droplets taking advantage of the enhanced solubility. Once dissolved the malodor gas will tend to leave the droplet to a point of equilibrium between gas and aqueous phases according to Henry’s Law. This relationship between phases is known as the “distribution constant” or “distribution ratio”. Usually at this point in the sequence of odor control mechanisms, malodors are under control of the product. However, another mechanism has been identified, that being chemical reaction(s). The active ingredients within the product form an acid buffer. This buffer has been found to react with many gasses, typically those that are mildly acid or mildly basic.

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