A rotor concentrator does not, in itself, purify VOCs, but it is instead a step prior to combustion, which is necessary in the case of high air flow rates with a very low concentration of VOCs. The use of this technology helps to reduce the fuel used for combustion, which under these conditions would be very high otherwise.
Rotor-concentration with Zeolite is a technology that makes it possible to increase the concentration of a pollutant of a gas flow. The pollutant, generally a VOC, is retained through an adsorption process on a Zeolite wheel, obtaining the pollutant-free gas. A fraction of the treated gas, about 5%, is subsequently heated and fed into the rotor-concentrator in a counterflow. Thus, the pollutant that was previously retained on a Zeolite wheel is reabsorbed and the new gas flow is released, the Zeolite wheel being now again free of pollutants. The new gas flow has a pollutant concentration between 15 and 20 times greater than the initial concentration and it is fed into the combustion unit in order to oxidise the pollutant.
It is appropriate to use this technique when the flow of gas to be treated is high (up to 200,000 Nm3/h) and the VOC concentration is low or very low. In these circumstance, without the prior rotor-concentration stage, the fuel needed for the oxidation of the pollutant would be very high.
After the pollutant rotor-concentration stage, the pollutant may now be oxidised using the most optimal technology. Among the best possible options, the following may be highlighted:
The most usual comprehensive solution is Rotor-concentrator of Zeolite + Regenerative Thermal Oxidation (RTO). This system includes a Zeolite wheel through which an adsorption process is carried out that accumulates the solvents, generating a greater concentration of them before they are subsequently processed in the Regenerative Thermal Oxidation (RTO) unit.
The objective is to send a much more concentrated airflow (between 15 and 20 times lower than the initial volume) with a Volatile Organic Compound concentration that allows the oxidation system (RTO) to be autothermal.
Condorchem Envitech offers a combination of both of these technologies: Rotor-concentrator of Zeolite + Regenerative Thermal Oxidation for treating emissions of Volatile Organic Compounds.
The main advantages of this combination are:
- It makes it possible to treat large volumes: up to 200,000 Nm3/h per Zeolite.
- Low operating cost.
- Moderate consumption of gas and electricity.
- Both technologies require a low annual maintenance cost.
- A lower implementation cost than other technologies.