Flameless Regenerative Thermal Oxidizer | full electric
⚡ DEC.e-RTO™ ⚡
VOC emission control
Flameless Regenerative Thermal Oxidizers (DEC.e-RTO™) are a specific "full electric" (electrified) configuration of a Regenerative Thermal Oxidizer system (RTO™): in the RTO, multiple towers (or chambers) are used to achieve efficient and effective air pollution control. RTOs are widely used in industries such as manufacturing, printing, and chemical processing to comply with environmental regulations and reduce air pollution.
Looking for an advanced solution to tackle VOC emissions with minimal environmental impact? The DEC.e-RTO™, a flameless regenerative thermal oxidizer, delivers unmatched efficiency in VOC abatement for industries seeking sustainable air pollution control. Unlike traditional systems, this electric-powered technology eliminates open flames, slashing NOx emissions and energy costs while achieving over 99% VOC destruction efficiency. Whether you’re in chemicals, manufacturing, or printing, DEC’s innovative system ensures compliance with strict regulations, offering a low-maintenance, high-performance alternative to conventional thermal oxidizers. Ready to revolutionize your VOC control? Explore DEC’s cutting-edge e-RTO™ and request a quote today to see the difference.
The flameless DEC.e-RTO™ operates on a similar principle to its combustion-based counterpart RTO™, but without the use of an open flame and auxiliary support fossil fuel. Instead, electric heating elements provide the thermal auxiliary energy required to oxidize contaminants (VOCs).
As per the standard Regenerative Thermal Oxidizer system (RTO™), typically two or more towers (ideally 3 or more) are utilized in parallel: the exhaust gas flow is alternated between these towers, allowing for continuous operation; while one tower is used for the oxidation and removal of pollutants, the other tower(s) are undergoing a regeneration cycle to prepare for the next exhaust gas flow.
Flameless Regenerative Thermal Oxidizer | full electric • how it works?
- Inlet Phase: the contaminated air stream enters the RTO through an inlet duct, and a damper directs the flow into one of the ceramic honeycomb beds.
- Preheating Phase: the incoming air passes through the heated ceramic channels (honeycomb), where the thermal energy from the hot exhaust gases is transferred to the incoming air stream. This preheating step helps in reducing the energy consumption of the system.
- Combustion Phase: the preheated air stream enters the combustion chamber, where it is further heated to the required temperature (typically between 815°C and 980°C), through electric heater(s); in the presence of oxygen, the VOCs and other pollutants in the air stream undergo combustion, converting them into carbon dioxide (CO2) and water vapor (H2O).
- Exhaust Phase: the hot, purified air stream exits the combustion chamber and passes through the outlet duct; at the same time, a damper directs the flow into another ceramic honeycomb bed.
- Thermal Energy Recovery: the incoming air stream absorbs the thermal energy stored in the ceramic honeycomb bed, which helps in preheating the next batch of contaminated air; this heat exchange process is crucial for the high energy efficiency of RTOs.
This alternating process allows for energy recovery within the DEC.e-RTO™ system: the hot exhaust gases leaving the combustion chamber are passed through a ceramic heat exchanger, known as the "regenerator", in the tower undergoing the regeneration cycle. The regenerator absorbs the heat from the exhaust gases and stores it. During the next cycle, the stored heat is transferred to the incoming cold exhaust gases, reducing the energy consumption of the system.
The use of multiple towers in the DEC.e-RTO™ system provides several advantages, including improved operational efficiency, reduced energy consumption, and continuous operation. It allows for a safe, consistent and reliable treatment of industrial exhaust gases, while optimizing the use of energy resources.
Flameless Regenerative Thermal Oxidizer | full electric • oxidation reaction
The oxidation reaction is:
VOCs (CxHyOz) + O2 + thermal energy = CO2 + H2O + (HEAT)
The heat is usually recovered to pre-heat the SLA stream, in order to save on "thermal energy"; if producing extra heat through oxidation of solvents, an energy recovery system (DEC.WHR™) shall be foreseen (typical applications are ranging from heating up air for dryers, steam production, heat tranfer fluid heating, water heating - industrial or sanitary, etc.).
Flameless Regenerative Thermal Oxidizer | full electric • advantages
In a regenerative electric thermal oxidizer (e-RTO) with multiple towers, the VOCs are oxidized in the combustion chamber. The hot gas released from the combustion chamber contains thermal energy. This thermal energy is accumulated through the ceramic media bed in one tower. The hot gas then cools down as it exchanges thermal energy with the ceramic media. The cooled gas is then discharged through the stack.
e-RTOs are not equipped with a gas burner: electric heaters are a clean source of heat, producing no thermal NOx and negligible CO generation. This is a significant advantage over gas-fired systems, especially in areas with strict emissions regulations.
The process of accumulating and exchanging thermal energy in the ceramic media bed is called regenerative: this process allows the RTO to operate at a high efficiency, while also reducing the amount of energy required to heat the incoming gas.
Thanks to the specifically designed switching valves, the flow is alternatively reversed: thermal energy is recovered and the flow, in the following cycle, is pre-heated; this cycle is efficiently reducing the auxiliary heat requirement, with self-sustaining operation (with no auxiliary electricity usage) even at low concentrations, thus representing an operational cost reduction.
e-RTOs with multiple towers can operate at a higher efficiency than Direct Thermal Oxidizers (DTO™): the regenerative process allows the RTO to recover heat from the outgoing gas, which can then be used to pre-heat the incoming gas, resulting in lower energy consumptions.
e-RTOs often have a smaller footprint compared to standard RTOs, gas-fired systems.
Flameless Regenerative Thermal Oxidizer | full electric • Hot Gas Bypass module
In case of peaks of concentration, in order for the RTO to correctly perform its duties, to prevent overheating (or oxidation to occur in the ceramic media), the system can be equipped of an automatic hot-gas bypass. The DEC.HGB™ diverts a portion of the hot gases directly from the combustion chamber, bypassing the ceramic media beds.
As the concentration of volatile organic compounds (VOCs) in the incoming stream increases, the combustion chamber temperature rises due to the additional heat generated by the combustion process. When the temperature reaches a pre-set safety limit, the DEC.HGB™ module is automatically enabled, allowing a portion of the hot exhaust gases, to directly bypass the ceramic media beds and exit to the exhaust stack (FGS). By diverting the hot gases, the DEC.HGB™ module safeguards the ceramic media from exposure to excessively high temperatures. This is crucial because the media plays a vital role in preheating the incoming air stream and maintaining the overall efficiency of the RTO.
The DEC.HGB™ components directly exposed to the high-temperature exhaust gases (around 900°C) are typically constructed from special high-grade materials like Stainless Steel or Inconel.
In essence, the DEC.HGB™ module acts as a safety mechanism and a way to optimize RTO performance. It prevents damage to the ceramic media while ensuring the RTO can continue to function effectively even during abnormal or unexpected spikes in VOC concentration.
Flameless Regenerative Thermal Oxidizer | full electric • Waste Heat Recovery module
When the process conditions allows (e.g. when VOC in the emission stream reaches higher than normal), and the DEC.HGB™ module is installed, the diverted hot stream, can be used for beneficial purposes.
DEC.WHR™ module, acting as a secondary heat recovery, provides additional energy saving:
- heating thermal oil for industrial processes;
- heating water for various applications;
- recovering heat to generate steam;
- recovering heat to generate electricity.
By utilizing this waste heat, the facility may further reduce its reliance on traditional fuel sources like natural gas or propane. The specific application chosen will depend on factors like the facility's existing needs and the temperature of the recovered heat stream. This could translate to significant cost savings on the energy bill, leading to a more competitive operating cost structure.
DEC.WHR™ essentially allows the RTO to operate with a "closed-loop" approach for thermal energy. This reduces the overall energy demand of the system, making it more efficient. A more efficient system translates to lower operating costs and a smaller environmental footprint.
Overall, waste heat recovery in RTOs offers a compelling solution for manufacturing facilities. It lowers operating costs, enhances efficiency, improves sustainability, and even offers potential revenue generation opportunities. These combined benefits can significantly improve a facility's competitive advantage in today's market.
Flameless Regenerative Thermal Oxidizer | full electric • Waste To Energy module
By utilizing the solvent waste as fuel in the RTO, the system requires less external fuel to maintain the oxidation temperature. Instead of paying for solvent waste disposal, the facility can utilize it as a fuel source, potentially creating a cost-saving opportunity.
thermal oxidation | incinerators • GHG and by-products
Whenever you have to face a non-recoverable stream of VOCs, a XTO™ • thermal oxidizer could be the solution: sometimes the VOC stream composition may result too complex to be recovered or the quantity of solvents is not interesting to go for a SRU™ • solvent recovery units.
An oxidizer is handling the transformation of the pollutant(s) into different products, with a reduced environmental impact. However, it is important to consider the resulting GHG emissions, when selecting a VOC oxidizer; the amount of GHGs generated by a thermal oxidizer depends on the type of VOCs being treated, its quantity, the needed quantity of fuel to be added for sustaining the oxidation reaction and the selected oxidizer process configuration.
Any oxidizer will have to deal with all or most of the following issues:
- VOCs emission (= non complete oxidation);
- CO2 emission (= GHG, possible taxation);
- CO emission (= GHG, non complete oxidation);
- NOx emission (= nitrogen oxides, as a result of N2 presence);
- N2O emission (= nitrous oxide);
- Dioxin emission (as a result of possible chlorinated compounds );
- High temperature emission (as a result of non complete thermal energy recovery).
These emissions contribute to climate change and should be taken into account when assessing the overall environmental impact of the system. Thermal oxidizers typically require a significant amount of energy to operate: if this energy comes from non-renewable or carbon-intensive sources, it will dramatically contribute to environmental degradation and may offset the potential benefits of VOC emission reduction.
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FAQs • Frequently Asked Questions
Flameless Regenerative Thermal Oxidizer | full electric ⚡ e-RTO™ series
What is a flameless regenerative thermal oxidizer (e-RTO)?
The DEC.e-RTO™ is a full-electric, flameless configuration of a Regenerative Thermal Oxidizer (RTO™). Instead of an open flame and auxiliary fossil fuel, electric heating elements supply the thermal energy needed to oxidize VOCs. Multiple towers alternate between oxidation and heat regeneration to allow continuous operation.
How does the DEC.e-RTO™ work?
Contaminated air enters through an inlet duct and is directed into a ceramic honeycomb bed, where it is preheated by stored thermal energy. It then enters the combustion chamber, where electric heaters raise it to the required oxidation temperature, typically between 815°C and 980°C, converting VOCs into CO2 and water vapor. The purified air exits through another ceramic bed, which absorbs and stores heat for the next cycle, while dampers alternate the flow between towers.
What VOC destruction efficiency does the e-RTO achieve?
The DEC.e-RTO™ achieves over 99% VOC destruction efficiency while eliminating the open flame used in conventional thermal oxidizers.
Does the e-RTO produce NOx emissions?
No. e-RTOs are not equipped with a gas burner. Electric heaters are a clean heat source, producing no thermal NOx and negligible CO generation, which is a significant advantage over gas-fired systems in areas with strict emissions regulations.
How many towers does a DEC.e-RTO™ use?
As with a standard RTO, two or more towers are used in parallel, ideally three or more. The exhaust gas flow alternates between towers: while one tower oxidizes and removes pollutants, the others undergo a regeneration cycle to prepare for the next flow.
What is the DEC.HGB™ Hot Gas Bypass module for?
The DEC.HGB™ module automatically diverts a portion of the hot combustion gases directly to the exhaust stack, bypassing the ceramic media beds, whenever VOC concentration spikes push the combustion chamber toward a pre-set safety temperature limit. This protects the ceramic media from damage and keeps the RTO running safely during abnormal concentration peaks.
What is the DEC.WHR™ Waste Heat Recovery module?
DEC.WHR™ is a secondary heat recovery module that puts the hot stream diverted by DEC.HGB™ to beneficial use: heating thermal oil or water, generating steam, or generating electricity. It lets the RTO operate on a more closed-loop thermal energy basis, cutting reliance on natural gas or propane and lowering operating costs.
How is a flameless e-RTO different from a conventional gas-fired RTO?
Both use the same multi-tower regenerative principle, but the e-RTO replaces the open flame and fossil-fuel burner with electric heating elements. This eliminates thermal NOx, cuts CO generation, and typically results in a smaller footprint than standard gas-fired RTOs.
Which industries use the DEC.e-RTO™?
The DEC.e-RTO™ is applied across chemicals, manufacturing, and printing, among the other industrial markets DEC serves, wherever industrial exhaust streams need to comply with VOC and HAP emission regulations.
Is pricing available for the DEC.e-RTO™ system?
The DEC.e-RTO™ is a custom-engineered, quote-based system with no fixed list price: each unit is sized and priced according to the customer's exhaust flow, VOC/HAP loading, and site-specific process requirements. Contact DEC's Technical Sales & Applications engineering team to request a project-specific quote.
