Thermal Oxidizer

What is a Thermal Oxidizer?

A Thermal Oxidizer (also referred to as a thermal oxidizer or incinerator) is a combustion device that controls volatile organic compounds (VOCs), hazardous air pollutants ( HAPs), and odors by converting (destroying) the emissions into CO2 and H2O through the use of heat before exhausting them to the atmosphere.

Thermal Oxidizers play a crucial role in promoting sustainable industrial practices by reducing emissions, conserving resources, and minimizing environmental impact.

Thermal Oxidizers significantly reduce harmful emissions from industrial processes resulting in cleaner air and mitigating the impact on public health and the environment.

Thermal Oxidizers can achieve thermal efficiencies up to 95% and destruction efficiencies that can exceed 99%.

How does a Thermal Oxidizer work?

Using extreme high temperatures (1500°F) to trigger a combustion reaction, the VOCs & air pollutants are fully oxidized, transforming the organic solvents into CO2 (carbon dioxide) and H2O (water).

Oxidizer performance depends on a combination of the three T’s of combustion: Time, Temperature, and Turbulence.

Retention time, or residence time, is the length of time that a VOC/organic is at the appropriate oxidation temperature. Both retention time and residence time refer to time inside the thermal oxidizer's combustion chamber.
Typical temperatures in the combustion chamber range between 1400°F and 1600°F and higher. For each organic, a specific temperature and a specific retention time is required to achieve the desired level of destruction.
Sufficient air mixing, also known as turbulence, must also be achieved.in the combustion chamber.

Who uses Thermal Oxidizers:

Air pollution control equipment is used in nearly all industrial processing and manufacturing industries to reduce emissions of volatile organic compounds (VOCs), hazardous air pollutants (HAPs), and other greenhouse gases (GHG). CPI provides innovative and cost-conscious solutions to the most complex VOC, NOx, and Odor pollution challenges for a wide range of applications and industrial processes.

Find thermal oxidizers for your industry.

Back to the table of contents

How to decide which thermal oxidizer is right for your process:

Initial capital cost: Each type of thermal oxidizer has a typical cost that varies based on the size of the equipment. Capital costs include equipment, shipping, installation, commissioning and startup.
Operating cost: Annual operating costs include electricity, natural gas, compressed air (if needed), maintenance costs, and personnel.
Break-even point: Capital and operating costs can vary widely between different thermal oxidizers. It is necessary to evaluate and understand the total cost of ownership and break-even timing when deciding which type of thermal oxidizer is the best long-term solution for your application.
Energy usage: Energy usage increases with the required airflow and size of equipment, but varies inversely with the upfront investment cost & thermal efficiency of the system.
Destruction efficiency: Regenerative Thermal Oxidizers (RTO) provide +98% destruction rate efficiency (DRE) while recuperative thermal oxidizers and direct-fired thermal oxidizers (DFTO) provide 99%+ DRE.
Footprint, Weight, Size: Some types of thermal oxidizers aren't feasible at certain sizes. The size, weight, and footprint of the equipment varies inversely with energy cost.

Back to the table of contents

Types of thermal oxidizers.

Direct Fired Thermal Oxidizer (DFTO)
Recuperative Thermal Oxidizer
Regenerative Thermal Oxidizer (RTO)

Direct Fired Thermal Oxidizer (DFTO)

A Direct Fired Thermal Oxidizer (DFTO), or non-recuperative thermal oxidizer, is very basic in design, with the main components consisting of a burner and a combustion (retention) chamber. Commonly referred to as afterburners, incinerators, or direct fired thermal oxidizers, our Thermal Oxidizer routinely exceeds all regulatory requirements.

Non-recuperative thermal oxidizers are used on applications where primary air to air heat exchangers are not necessary. Special applications that have very high solvent concentration levels, low air volumes, high energy demand or secondary heat recovery needs, among others can benefit from our QUADRANT NR-Thermal Oxidizers.

Direct fired thermal oxidizers are typically utilized for processes that have:

Low inlet volume (the cutoff is typically less than 1,000 standard cubic feet per minute [SCFM])
Very high concentration of VOCs (greater than 25% of the lower explosive limit [LEL])
Presence of particulate in the process gas
High process gas temperature (typically greater than 600° F)

The guidelines for applying a direct fired thermal oxidizer revolve around some key criteria: capital expenditure, operational costs, and safety. For example, low inlet volume operational savings usually do not justify the cost of the heat recovery that is necessary. Likewise, high VOC concentrations can cause issues with safety and control in oxidizers which utilize heat recovery.

As a Direct Fired Thermal Oxidizer manufacturer CPI can offer assistance with VOC control.

Learn more about QUADRANT NR (Non-Recuperative) Thermal Oxidizers here

Learn more about QUADRANT NRV (Non-Recuperative with Venturi Burner) Thermal Oxidizers here

Recuperative Thermal Oxidizer

A recuperative thermal oxidizer uses an air to air heat exchanger to preheat the incoming process air using the clean “hot” air from the oxidizer combustion chamber. This primary heat recovery raises the temperature of the process gas before entering the combustion chamber, resulting in lower fuel requirements for the oxidizer burner system. Thermal recuperative oxidizers utilize plate or shell and tube type heat exchangers.

Recuperative thermal oxidizers are typically utilized for processes that have:

Process gas volume ranging from 500 SCFM to 30,000 SCFM
VOC concentrations ranging from 10% to 25% of the LEL
Presence of particulate in the process gas or after combustion of the VOC
Process gas temperatures up to 600° F

This technology does have some aspects that warrant consideration, including what is typically a higher operating cost, as well as higher NOx emissions than those produced using a recuperative catalytic oxidizer or a regenerative thermal oxidizer. It is a good choice for any technology process that has a high continuous VOC stream, a small air flow rate, or batch type cycling. Also, a secondary system added to a recuperative oxidizer can raise efficiencies and reduce operational costs. Operation schedules should also be considered with recuperative thermal oxidizers, as the stainless-steel alloys utilized in the heat exchangers do have finite life spans if the system is going to be turned on and off each day.

As a manufacturer of Recuperative Thermal Oxidizers CPI can offer assistance with VOC control.

Learn more about QUADRANT SR (Recuperative) Thermal Oxidizers here

Learn more about QUADRANT SRS (Recuperative for Silicone Applications) Thermal Oxidizers here

Learn more about QUADRANT IR (Recuperative Integrated In-Line Design) Thermal Oxidizers here

Regenerative Thermal Oxidizer (RTO)

CPI TRITON 35,000 Regenerative Thermal Oxidizer

A Regenerative thermal oxidizer (RTO) utilizes ceramic heat exchange media instead of a stainless-steel air to air heat exchanger.

Regenerative thermal oxidizers are typically utilized for processes that have:

Process gas volume ranging from 2,000 SCFM to 80,000 SCFM for one system
VOC concentrations ranging from 0% to 15% of the LEL
Clean or low particulate in the process gas or after combustion of the VOC
Process gas temperatures up to 500° F

The advantages of a regenerative thermal oxidizer system revolve mainly around the capital and operation cost advantage for processes with larger airflow and low VOC concentrations (<8% LEL). The thermal effectiveness can be up to 97% with a regenerative thermal oxidizer.

CPI is an expert manufacturer of Regenerative Thermal Oxidizers and can assist with VOC control applications.

Learn more about Regenerative Thermal Oxidizers

Thermal Oxidizer E-Learning Series