Low-temperature plasma degradation of high-concentration n-hexane

Abstract

Low-temperature plasma (LTP) degradation, a green and efficient technology, is widely used in the treatment of organic waste gases. n-Hexane is the main component of tar during biomass gasification. The treatment of high concentration n-hexane is much needed for practical applications, but it is rarely reported. In this study, the degradation process and mechanism of high concentration n-hexane under LTP treatment were investigated. The results showed that the removal efficiency of n-hexane increased with increasing specific input energy (SIE) and residence time. However, it decreased with increasing concentration under constant SIE and residence time. Under humid air conditions, with a concentration of 130 000 ppm and a residence time of 13.3 s, the maximum removal efficiency of n-hexane reached 87.6%. At the same time, the introduction of water vapor enhances the dissociation process of n-hexane, leading to increased hydrogen, CO, and CO₂, improving the DBD environment, and preventing the attachment of solid residues. Through mechanism analysis, it is speculated that there are three possible conversion paths of n-hexane. This research not only fills a theoretical gap in this field but also provides a foundation for future low-temperature plasma degradation of n-hexane.