New flue solution for VOCs

Flue gas ducts: The system could be deployed in many industries as an effective gas treatment method, suggests Dr Suhan Kim.

A green technology for eliminating odorous volatile organic compounds (VOCs) and their by-products has been developed by a group from the Korea Institute of Industrial Technology (KITECH).

The research introduces a fuel-free technology for removing VOCs, thereby replacing incineration methods like thermal oxidizers and regenerative thermal oxidizers. This technology merges non-thermal plasma (NTP) with a wet scrubber (WS) system. Specifically, it employs atmospheric non-thermal plasma (ANTP) to enhance the scrubber’s VOC removal efficiency from 33% to 99.9% while minimizing the ozone generation typically produced by plasma, according to the group.

“NTP treatment stands out as a highly effective method for addressing odorous VOCs due to the production of high-energy electrons. These electrons destroy the structures of odorous gases and generate abundant radicals, which can be oxidized to CO2 and H2O, thereby increasing the reaction rate,” said the researchers.

WS systems are frequently used to remove odorous gases due to their relatively low cost and ease of handling. They have also been the subject of extensive research aimed at improving the economics of this kind of odour treatment.

This latest research introduces a process technology for removing VOCs that does not burn fuel, such as LNG, unlike conventional methods. As a result, it does not emit carbon dioxide through incineration. When deployed in industrial exhaust gas treatment facilities, both installation and operating costs are lower compared to those of the incineration method.

Compared to the separate use of NTP and WS, integrating a WS after NTP alters the kinetic characteristics and distribution of active particles, thereby improving the degradation efficiency of odorous VOCs. Additionally, the combined NTP and WS system can minimize or eliminate secondary air pollution by capturing ozone and other gaseous intermediate organics, which are by-products of the NTP process.

Because the NTP and WS system does not rely on chemicals or catalysts and eliminates the need for additional equipment to remove ozone, the total cost of the system, covering both installation and operation, can be reduced.

Dr Suhan Kim of KITECH said: “Our observations indicate that the removal efficiency within the NTP and WS system exceeds the VOC concentrations usually present in process gases from chemical facilities.”

He said he believed the combined NTP and WS system could be implemented in many industries as an effective gas treatment method, with the advantage that it does not produce ozone and is sparing of energy consumption.