UOP Callidus Thermal Oxidizers

Meet Emission Regulations For Gas and Liquid Waste

Use our extensive experience to evaluate your environmental challenges. We can provide custom designed solutions to meet or exceed stringent environmental regulations, including NOx standards.

Contact Us


Callidus Thermal Oxidizer Brochure


Our Thermal Oxidizers are used for both gas and liquid wastes; including inorganic particulate, various acids and hard-to-burn organic compounds. We offer Thermal Oxidizer systems to include: SRU tail gas, fume, halogenated waste, bound nitrogen, catalytic oxidizers, and downfired designs including units with ratings of more than 400 MM BTU/hr.

In addition, we provide total system solutions and supply all necessary equipment for a complete Thermal Oxidizer/incinerator package:

  • Heat recovery (i.e., waste heat boilers)
  • Heat exchangers for gas or air
  • System components (i.e. scrubbers, absorbers, bag houses, blowers, etc.)

Tail Gas Thermal Oxidizers

Our Tail Gas Thermal Oxidizer destroys a variety of sulfur compounds in Tail Gas from Sulfur Recovery Units.

The Tail Gas Thermal Oxidizer system can be natural draft or forced draft operated. Oxidizing temperatures can vary from 1200 -1800° F with residence times of 0.6 – 1.0 seconds.

Regulations require that H2S in the flue gas be generally limited to 10 ppmV and can require as low as 5 ppmV in certain cases. CO coming in with the tail gas may not be destroyed at 1200° F, however, a substantial portion will at 1400° F and above. Our technology will enable the balance between desired H2S destruction efficiencies, NOx formation and minimized CO production to meet regulations.


De-NOxidizer Systems

Thermal oxidation of nitrogen-bearing wastes require a specialized combustion approach. Single-stage combustion of these wastes can produce NOx emissions in excess of those allowed by most regulatory agencies. To maintain NOx emissions within acceptable limits, our De-NOxidizer systemuses a multi-stage process to destroy wastes.

  • The waste is burned in the first stage under substoichiometric, or reducing conditions. The high temperatures and lack of oxygen in the first stage cause the nitrogen-bearing compounds to form elemental nitrogen rather than NOx.
  • In the second stage, flue gas from the first stage is cooled to approximately 1400∞F by injection of water, steam or cooled recycled flue gas.
  • The combustion process is completed in stage three where the flue gas is oxidized at a temperature of 1700˚F to 2000˚F with excess oxygen present. NOx in the final flue gas typically ranges from 80 to 200 ppm depending on the waste composition. A destruction efficiency of 99.99 percent can be achieved for most compounds

Low NOx Thermal Oxidizer
Typical Equipment

  • High intensity burner
  • Brick lined furnace
  • Forced draft
  • Heat recovery equipment
  • Multi-stage process

Typical Waste Streams

  • Ammonia vents
  • Acrylonitrile vents
  • Nitrogen bound organic wastes

Representative Installation

  • Petrochemical plant in India
  • 10-60 MM BTU/hr
  • 2.0 seconds residence time
  • 2200˚F/1600˚F operating temperatures

Downfired Thermal Oxidizers for Organic Waste Systems

Aqueous or organic waste streams containing inorganic or organic salts require that the Thermal Oxidizer be down-fired to prevent the accumulation of molten salts in the oxidizer furnace.

Our Downfired Thermal Oxidizer systems routinely meet or exceed 99% destruction efficiencies for most waste components. Particulate matter emission rates may vary from as low as 10 mg/DSCM to as high as 110 mg/DSCM. The emission rate to some extent determines the type of particulate removal system necessary.

Downfired Thermal Oxidizer

Typical Equipment

  • Low emission burner
    • Low porosity brick refractory
    • Forced draft
    • Adiabatic quench
    • Particulate removal

Typical Waste Stream

  • Ethylene plant blowdown
  • Caustic waste streams

Typical Installation

  • Chemical plant
  • 20 to 80 MM BTU/hr burner
  • 2.0 seconds residence time
  • 1650˚F-1800˚F operating temperature

Halogenated Waste Thermal Oxidizer

Our Halogenated Waste Thermal Oxidizer Systems can meet destruction efficiencies up to 99.99%. Operating temperatures range from 1500ºF – 2200ºF with residence times of 1.0 -2.0 seconds depending on the destruction efficiency required.

Systems may utilize a direct quench or a boiler following the combustion process. An optional acid absorber may produce a diluted or concentrated acid stream. Alternatively, a caustic scrubber can be used to remove the halogen acid produced during the combustion process.

Because of the corrosive nature of halogen acids, our system minimizes the use of metals in the wet section. Similarly, our Halogenated Waste Thermal Oxidizer systems keep carbon steel surfaces in contact with the flue gas above the dew temperature by proper internal and external insulation.

uop-callidus-halegenated-waste-thermal-oxidizerTypical Equipment

  • Medium intensity burner
  • Forced draft
  • High alumina brick refractory
  • Heat recovery equipment
  • HCl recovery/scrubber

Typical Waste Stream

  • PVC plant vents
  • VCM waste liquids
  • Pharmaceutical vents
  • Bromine liquid wastes

Typical Installation

  • Chemical plant
  • 10 to 50 MM BTU/hr burner
  • 2.0 seconds residence time
  • 1800˚F operating temperature

Because they contain very little organics, a preheat exchanger downstream of the oxidizers is used to reduce fuel consumption by preheating the incoming fume stream.

A Catalytic Oxidizer may be used if the organic level is fairly low and the fume stream is free from dust or any substance poisonous to the catalyst.
An oxidizer for an inert based waste stream is no different from one for an air based fume stream except that air has to be injected for combustion purposes.

Fumes can be air, inert or organic based. An air based fume stream is generally destroyed at a temperature of 1400 to 1600° F. Destruction efficiency can range from 90- 99%.

Fume Thermal Oxidizer

uop-callidus-fume-thermal-oxidizersTypical Equipment

  • Low emissions burner
  • Ceramic fiber refractory
  • Forced draft operation
  • Heat recovery equipment
  • Burner management system
  • Stack

Typical Waste Streams

  • VOC streams
  • Process vents
  • Pharmaceutical vents
  • Dryer exhausts

Typical Installation

  • 5 to 100 MM BTU/hr burner
  • 1 second residence time
  • 1500˚F operating temperature