Facility Audit: Deer Park, TX - Clean Harbors

4.0 Process Description
Incineration
Deer Park utilizes state-of-the-art thermal treatment (incineration) technologies along with air
pollution control technology to treat thousands of tons of liquid, solid and gaseous hazardous
wastes annually. Wastes are incinerated in an oxidized atmosphere at temperatures high enough
to achieve required destruction.
The incineration system consists of two incineration Train units. Train I has a permitted thermal
capacity of 180 MM BTU/hr and includes a 3.6 meter diameter slagging rotary kiln, Loddby
liquids burner and a horizontal afterburner. Train II has a permitted thermal capacity of 213.5
MM BTU/hr and includes a 4.4 meter diameter slagging rotary kiln, the Rotary Reactor (RR), a
vertical afterburner and four (4) McGill liquid burners. Abatement hardware utilized for
emission control per Train incorporates a saturator, two parallel condensers, a collision scrubber
(Calvert) and a Chevron mist eliminator.
In addition to the above, each incineration train has two wet electrostatic precipitator (WESP)
systems for removal of sub-micron particulate (including heavy metals) and two selective
catalytic reduction (SCR) systems for the removal of NOx emissions.
Particulate matter is removed from the gas stream in each WESP by imparting a positive charge
on the particles in an electric field, and then collecting the positively charged particulate on a
grounded (negatively-charged) collection surface. A continuous spray of fresh water is injected
into the WESP to provide a conductive liquid film covering on the non-conductive plastic
collection tubes. The charged particles are collected in the conductive liquid film; this will
prevent build-up of particles on the collection tube surface. A periodic water flush cleans the
tubes. The water discharged from the WESP vessels in a blow-down tank and recycled or
discharged to the wastewater treatment plant.
Two 1,350 horsepower fans are also part of this system. They accommodate the system static
pressure introduced by the gas cleaning equipment (two new WESP vessels in series and one
SCR system per train) and ductwork. Fan inlet dampers are provided, in addition to the fan, to
accommodate the wide-ranging flow and pressure conditions.
The SCR equipment is installed downstream of the fan on each gas cleaning train and operated
under positive pressure. The SCR system requires heating the flue gas to the 525 – 600º F range
and then injecting ammonia (NH3) as ammonium hydroxide (NH4OH; aqueous ammonia). The
NH3 flue gas is then thoroughly mixed via a static mixer prior to it passing through a catalyst
bed, where NOx is converted into nitrogen and water vapor.
Two separate individual stacks are downstream of the SCR equipment for discharging the clean
flue gas to atmosphere.
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