Problem
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.
Action
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 to address the odor emission problem
and satisfy the building expansion requirements.
Solution
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 the odor emission problem, thereby resolving
potential community relations/environmental issues, and meeting its
requirements for obtaining planning approval for future
expansions.