# Pentane Depletion by a Surface DBD and Catalysis Processing
## 1 Introduction
Then, the resulting chemical reactions between radicals promote their degradation and oxidation in the presence of oxygen species. Compared to the aforementioned thermal plasmas, they are characterized by lower dissociation rates, but not by lower efficiency [9]. As reported in the literature, one of the most employed cold plasma devices is the Dielectric Barrier Discharge, which has the advantage of requiring very low energy. DBDs are also used in combination with catalysis, an example of which is the dielectric packed bed discharge [18]. DBDs, as most of CAPs, have the drawback of processing only small gas volumes. In the DBD configuration, the gas is physically confined to pass between the two electrodes, the plasma state is mostly confined to a volume of a few mL, and gas air flows between a few mL/min and some L/min [9; 17]. Only very recently, a system composed of DBDs, a mineral adsorber, and a bio-scrubber [11] has been investigated for gas flows of up to 1000 m\({}^{3}\)/min, yielding a good VOC abatement efficiency. The scale-up factors and operating costs need to be investigated in order to evaluate their real economic sustainability in view of the most interesting applications. A possible way to overcome the difficulty of a redeeming technology on a large scale--that is, treating large gas volumes at low VOC concentrations--could be through the employment of a peculiar CAP: the surface DBD (SDBD) [20]. In SDBDs, the plasma is produced on a surface without being confined between two electrodes. In this new configuration, the gas can move on the surface and rapidly diffuse into larger volumes. Moreover, these devices have not been investigated in such a detail as the DBD and the packed DBD for their waste air remediation applications. Only recently have a few research papers been devoted to the application of SDBDs in VOC abatement [21; 22]. Starting from our previous knowledge on DBD [18; 23] and SDBD plasmas, this paper presents a study on the performance of a single SDBD module working at static conditions, aimed at evaluating the VOC abatement rates based on the relevant parameters, particularly including possible synergies with post-catalysis processing. More specifically, we employ an asymmetrical SDBD configuration [20] and investigate the chemical kinetics dissociation of a specific VOC in an air mixture while varying its concentrations and plasma energy. We choose pentane as a VOC and whose decomposition by-products are mainly acetylene and propane. The concentration of pentane and its by-products are measured according to time in order to analyze their decay law measured during the experiments. From these results,we can draw some conclusions about performance efficiencies for different parameters as well as estimate the best possible operating conditions, such as by evaluating the opportunity of using a number of SDBD modules fed in an asymmetrical configuration for specific real applications. Although NTPs have been largely studied in the last decades for their role in the depletion of VOCs in air, the literature on pentane abatement/conversion is still scarce. To the authors' knowledge, no experiments on the oxidation of pentane in air in low temperature atmospheric pressure plasmas have been reported in the literature. Thus, the present paper describes a novel application of NTP-catalysis and contributes to the enrichment of the available literature. The paper is organized as follows. In Section 2, we present the experimental setup and briefly discuss the calibration of the gas chromatograph. Section 3 is devoted to the experimental results, and Section 4 presents a discussion of our results as compared to others from the literature. Finally, in Section 5, we conclude with our final remarks.