In emission control technology, Regenerative Thermal Oxidizers (RTO) were developed for large volumes and low VOC concentration air pollution applications. They carry a low operating cost, and reliably harness the principle of thermal oxidation, which utilizes the process of regeneration for internal heat recovery. A superior pollution control device for air and vapor pollutants, it is highly energy-efficient, and ideal for long, continuous operations. They are highly effective and achieve some of the highest DRE numbers.
An Aqueous RTO is a specialized RTO created by GCES CEO, Mr. Chad Clark. It is an RTO that is specifically designed to handle vapor-rich streams, like those created by the rendering industry. A truly revolutionary technology, it provides the option to destroy wastewater as a standalone process. It can even be designed to handle both processes: air for VOC abatement, as well as the ability to destroy wastewater onsite. With some of the same challenges as vapor-tolerant systems, aqueous systems are a more controlled version. Where a vapor-tolerant system, such as those in rendering applications, can see a wide variety of vapor content, residues, and other contaminants, an aqueous oxidizer processes the water in a controlled and metered manner.
How Does the RTO Process Work?
Step 1: The RTO unit is brought up to combustion temperature using supplemental fuel such as natural gas, propane, diesel or biofuel. During this start up period, the RTO unit initially purges itself with fresh air and continues to process fresh air until it reaches combustion temperature equilibrium. The RTO unit is now ready to switch over to process air and begin the thermal oxidation of VOC with destruction efficiency up to 99%.
Step 2: The RTO switches from start-up mode running on clean air to operating on VOC process air from the source. To maximize heat recovery, the RTO will automatically cycle or alternate the inlet and outlet (see diagrams below) via a series of pneumatic valves.
Because the RTO is so efficient at reclaiming effluent heat, the units often times are capable of sustaining combustion temperatures without any supplemental fuel, utilizing the VOC as the only source of fuel.
The basic oxidizer is the same as a normal configuration with the added fluid-handling capability. This consists of pumps, mixing and storage tanks as needed, spray/injection nozzles and associated piping and controls. This system provides controlled injection and processing of the water into the inlet stream for processing through the oxidizer, using heat from the combustion chamber to help vaporize the fluid. Automatically synchronizing air flow, water pressure and flow, process temperature and pressure provides steady-state, reliable operation.
To handle potential moisture collection due to condensation in the inlet ductwork, fan and exhaust stack, condensate drains are installed to allow drainage of the liquid during maintenance. These drains for an RTO typically consist of multiple tap points with manual shut-off valves and piping routed to an appropriate drain.
The system includes the same bake-out feature as the vapor-tolerant system. The frequency of such bake-outs is dependent on the make-up of the wastewater stream, and how often the equipment receives annual maintenance and care. If it contains organics, oils and other solids or residues, these cycles may be more frequent.
Similarly, corrosion-resistant alloy materials are used to manufacture the cold condensable areas of aqueous RTO units, including incoming ductwork, valves, ceramic media supports, outlet ductwork, fan, and the exhaust stack.
- Offers a smaller footprint than the traditional full wastewater treatment facility
- Takes less energy to operate
- Reduces utility expenses
- Decreases labor required to run and maintain the unit because it is a smaller piece of equipment
- From a real estate perspective, takes up less space/land
- Waste heat recovery capabilities at around 95% and even, in some circumstances, up to 99%, greatly reducing fuel consumption
- Preferred method of oxidation, because of its variety of uses and applications
- Design simplicity
- No metal expansion issues
- High thermal efficiency
- Achieve high levels of VOC destruction, to keep processes well below required DRE emission levels
- Low NOx operation
- Perfect solution for continuous operation
- Several customizable options, based on specific output and applications, often allowing for a reduction in cost.
- Eliminates as much as 99% of VOCs, which meets all EPA requirements for MACT, RACT, BACT, and LAER
- Fluid handling capabilities
- Adjustable stack heights
- Reactor has ceramic lining, which reduces cracks and spallings, allowing for a longer product life
- Easy installation
- Ceramic media beds absorb heat, and recycle up to 95% for powering the equipment, reducing fuel costs.
- A digital controller, allowing proper maintained temperature control
- Weatherproof, high-density steel enclosure, allowing the processing of highly concentrated exhaust streams
- Modulating burner
- Typical sizing from 300 to 80,000 SCFM
- Custom built, turnkey systems
- Adjustable stacks, and multi-bed configurations
- Option of force, or induced, draft fan arrangements
- Designs available, for smaller or restricted spaces
- A variety of material options, to withstand corrosive and high temperature exhaust streams
- Primary and secondary heat recovery systems
- Control panels, that are built in-house
Aqueous RTO oxidizers are not off-the-shelf, out-of-the-box solutions; they are designed to size and specifications. These do not carry what could be considered drawbacks of other RTO solutions which can include: high electrical costs, the installation’s need for a larger real estate footprint, as well as a weight spec that can be up to three times that of a recuperative oxidizer. They are gas powered and can even be a feature added to an existing RTO. This technology can dramatically save a facility money, by reducing or eliminating onsite wastewater treatment or removal.
If you are interested in this patent pending technology, please contact one of our pollution control experts, today, at email@example.com or 832.476.9024