How to avoid excessive consumption of auxiliary fuels when using an industrial RTO system to treat low-concentration, high-volume waste gas?
Publish Time: 2025-12-16
In the field of industrial volatile organic compound (VOC) treatment, regenerative thermal oxidizers are highly effective due to their high purification efficiency and excellent heat recovery capabilities. However, RTO regenerative incineration system rely on auxiliary fuels such as natural gas and diesel for heating. Improper control can lead to soaring operating costs.
1. Optimize the regenerator design to maximize heat recovery efficiency.
The core of an RTO lies in the "capture" and "release" of heat from high-temperature flue gas by a ceramic regenerator. Under low-concentration conditions, every bit of heat is precious. By using honeycomb ceramics with high specific surface area, low resistance, and high heat capacity, and optimizing the filling height and channel structure, heat recovery efficiency can be increased to over 95%. This means that the temperature of the exhaust gas can be reduced to 100–150°C, while the waste gas entering the oxidation chamber is preheated to over 700°C, significantly reducing the external energy required for heating.
2. Precise Control of Switching Cycle and Airflow Distribution
RTO achieves continuous operation through alternating intake/exhaust in multiple chambers. Under low-calorific-value exhaust gas conditions, shortening the switching cycle reduces heat loss from the regenerator, maintaining stable bed temperature. Simultaneously, employing highly sealing, low-leakage lift valves or rotary distribution valves ensures precise airflow path switching, preventing short-circuiting of cold exhaust gas or back-mixing of high-temperature gas, thereby improving overall thermal efficiency.
3. Introduction of Concentration Adjustment or Exhaust Gas Concentration Pretreatment
For continuously low-concentration exhaust gas, front-end rotary concentrator technology can be used to concentrate large volumes of low-concentration exhaust gas into small volumes of high-concentration airflow before sending it to the RTO for treatment. The calorific value of the concentrated exhaust gas is significantly increased, often achieving "self-sustaining combustion." Although this increases equipment investment, the long-term fuel savings are significant, especially suitable for scenarios with intermittent emissions or large concentration fluctuations.
4. Intelligent Combustion Control and Comprehensive Waste Heat Utilization
The RTO regenerative incineration system is equipped with a PLC or DCS intelligent control system to monitor inlet concentration, temperature, flow rate, and furnace temperature in real time, dynamically adjusting the gas nozzle opening and combustion air volume to avoid overburning and waste. Furthermore, the 100–150℃ low-temperature flue gas discharged from the RTO can be used for workshop heating, hot water preparation, or to drive absorption chillers, achieving cascade utilization of waste heat, indirectly reducing overall energy costs and improving the system's overall energy efficiency.
5. Rational Selection and Optimized Operation Strategy
For extremely low-concentration waste gas, the suitability of the RTO needs careful evaluation. If the concentration is low for most of the year, a "RTO + burner intermittent start-stop" mode can be considered, or switching to bypass mode during non-production periods, initiating the oxidation process only when the waste gas reaches a certain calorific value threshold. Some new rotary RTOs, due to their continuous operation and small temperature fluctuations, exhibit more stable performance under low loads and can also be considered as a preferred option.
While RTO regenerative incineration systems face the challenge of high auxiliary fuel consumption when treating low-concentration, high-volume waste gas, they can significantly reduce energy consumption and achieve a win-win situation for both environmental protection and economic efficiency through multiple means, including efficient heat storage design, intelligent control, front-end concentration, waste heat recovery, and optimized operation strategies. In the future, with advancements in materials science, intelligent algorithms, and system integration technologies, the energy efficiency boundaries of RTOs in the field of low-concentration VOCs treatment will continue to expand, providing more sustainable solutions for industrial green transformation.
