What is a Regenerative Thermal Oxidizer?
A Regenerative Thermal Oxidizer (often referred to as RTO) destroys pollutants like Hazardous Air Pollutants (HAPs), Volatile Organic Compounds (VOCs), and odorous emissions that are often discharged during industrial processes.
Regenerative Thermal Oxidizers are the technology of choice today because they achieve the highest VOC destruction with the lowest operating cost, and highest reliability relative to other thermal oxidizer technologies. All regenerative thermal oxidizer technologies achieve VOC destruction by exposing pollutant-containing air to a high temperature, for a set period of time, in a turbulent flow path. Time, temperature and turbulence- Three T’s- are critical and co-dependent factors that determine oxidizer performance. Regenerative thermal oxidizer systems utilize a special heat recovery method – regeneration- that has proven to be the most cost-effective approach for typical industrial applications.
RTOs repurpose the thermal energy that is produced during operation, which means operating costs and total energy consumption are reduced significantly compared to other oxidizer technologies. It is possible for the RTO to operate with no fuel use whatsoever if process VOC concentration levels are >/3-4% LFL.
How Does a Regenerative Thermal Oxidizer Work?
A Regenerative Thermal Oxidizer (RTO) works by pushing a pollutant-filled airstream through the oxidizer, usually with a system fan. The flow of air is controlled by valves that direct this airstream into one of two recovery (beds) chambers. In a regenerative oxidizer, a minimum of two beds of ceramic media (saddles, and/or structured media block) is utilized to capture heat and release heat to the polluted airstream.
As the dirty air passes through the first media bed, the air absorbs heat from the hot ceramic media beds. The air exits the first media bed and enters the combustion chamber where oxidation occurs at high temperatures (>1500F), at a set temperature (>1500F) for a desired dwell time (>0.5 seconds) to convert over 98% of the VOCs to carbon dioxide and water vapor. This hot, clean air then continues through a second ceramic media bed. As the air passes through the bed it gives off heat to the ceramic media. The cooled, clean air is then exhausted to the atmosphere.
The valves switch every few minutes reversing the flow direction through the RTO, which gives the RTO its high fuel efficiency and low operating costs.
Questions to Consider When Purchasing a Regenerative Thermal Oxidizer (RTO):
- Is the RTO optimized for my exhaust airstream?
- RTO’s typically treat airstreams with a 0-10% Lower Explosive Limit (LEL)
- RTO systems can handle 25% Lower Explosive Limit (LEL) airstreams
- Hot gas bypass systems and other features may be needed
- Is the ceramic media in the RTO optimized for:
- maximum thermal efficiency
- lowest pressure drop
- Ability to handle organic/inorganic particulates
- Does the RTO main fan utilize a variable frequency drives (VFD)?
- Important for volume turn-down and idle operation
- Is the RTO skid mounted with little welding required in the field?
- Ease of installation will result in lower turnkey cost
- Does the RTO have telemetry (Ethernet) for remote troubleshooting access?
- Remote troubleshooting access can reduce service visit frequency
- Are visible emissions eliminated by this RTO?
- A puff capture feature may be required to eliminate visible emissions
- Is the RTO burner designed to maintain temperature during full flow, no VOC conditions?
- Would a fuel gas injection system be a wise choice for this application?
- Fuel injection can provide significant fuel savings
- Is there a used RTO system available with the features needed?
- Quality-built used regenerative thermal oxidizer (RTO) systems have a long life, can save 40-60% vs. new units, and offer performance and parts warranties
- Is there a risk of ceramic media plugging due to condensing VOCs?
- A Bake-out feature can address organic build-up
- Does the RTO have to address potentially corrosive emissions/halogens?
- Special materials of construction may be required
- Would an induced draft fan be a better choice than a forced draft fan?
- Is there sufficient heat in the RTO exhaust (>250F) to consider secondary heat recovery
- Is the process sensitive to pressure pulses possible with poppet valve?
- Do local codes require Low NOX operation?
- Low NOX burners can be retrofit for these applications.
The Kono Kogs philosophy is to provide innovative air pollution control technologies that provide the lowest cost, most reliable solution to our valued customers. We offer engineering, equipment manufacturing, installation, startup and post-sale service.
Benefits of Working with Kono Kogs:
- 24 Hour customer service and support (phone: 920-615-8804)
- Multiple OEM & technology offerings ensure unbiased recommendations
- Complete aftermarket sales department
- Management with over a century of oxidizer manufacturing and service experience