For its first two years of production, a food manufacturer based in South Wales, England, focused its production on potatoes. Neighborhood residents voiced no complaints about odors during this time period. However, as new production lines (including barbequed meats and curried chicken) were added, the complaints began, and it became clear that odor abatement equipment was needed to resolve the issue.
Onsite meetings were held to discuss the issue, concerned citizens and the local environmental health officer attended to discuss the best way to handle the situation. The company employs a large percentage of the local residents, and was concerned about maintaining good community relationships, while at the same time it was in need of a building expansion to introduce a new line of curried chicken products. Planning approval became contingent upon the installation of an odor abatement system to control the new and existing odors.
The two-year old factory had been designed to incorporate emission control equipment, and management was committed to installing the most effective technology available. After a thorough technical evaluation, ANGUIL ENVIRONMENTAL SYSTEMS, INC. was selected and contracted (due to its 20-plus years of experience in solving emission/carbon monoxide problems) to address the odor emission problem and satisfy the building expansion requirements.
Although several odor control technologies were discussed -- including masking sprays, wet scrubbing, bio-filtration, carbon absorption and catalytic and thermal oxidation -- the Regenerative Thermal Oxidizer (RTO) was the only technology that could guarantee the elimination of 99% of the odorous compounds.
Since future production may produce different odors, it was necessary that the installed technology have the ability to treat a wide range of odorous compounds to a high level of removal/destruction – guaranteed. Although, the guarantee of nearly complete elimination of the odors was the primary concern, capital and running costs were also of utmost importance. The RTO was selected due to its low operating costs and the fact that no waste is produced as a byproduct of its functioning.
The RTO consists of two insulated chambers filled with structured ceramic heat recovery media connected by a reaction chamber. The oxidizer uses two gas burners to maintain an activation temperature in the reaction chamber of 760º C. In operation, the odorous process emission enters the oxidizer through one of the energy recovery chambers where the ceramic media preheats the air stream prior to entering the reaction chamber. In the reaction chamber, 99% of the odorous compounds are oxidized, and the hot, clean, outgoing air heats the exit energy recovery bed. In order to maintain optimum heat recovery, the airstream’s direction is switched at regular intervals by automatic diverter valves controlled by the PLC control system. The thermal energy recovery of the beds is a nominal 95% resulting in very low operating costs. For this facility, the system was sized-up to treat a maximum of 57,600 m3/h of air. Since the typical factory exhausts in the region of 15,000 m3/h, this is a very large system and will accommodate the factory’s future growth.
Following the installation of the RTO, the results were dramatic, and as promised nearly all of the odors have been eliminated. Due to its well-designed odor control strategy, ANGUIL resolved RF Brookes odor emission problem, thereby resolving potential community relations/environmental issues, and meeting its requirements for obtaining planning approval for future expansions.