Nonthermal plasma (NTP) methods present potential advantages in the treatment of dilute volatile organic compounds (VOCs) as well as NOx in exhaust effluents, with relatively low energy consumption. Efforts have been under way since at least the early 1990s to improve practical techniques via a better fundamental understanding of NTP phenomena. Mechanistic understanding of the early post discharge chemistry is fundamental to characterizing and then improving NTP remediation for various VOCs. However, direct study of post discharge chemistry has been limited, leading to a growing demand for general capabilities to identify numerous post discharge species, stable and reactive, neutral and ionic. Molecular beam methods afford this possibility. Indeed, vuv and resonant photoionization methods already are established in environmental compound trace detection. In order to study NPT remediation chemistry of alkylbenzenes, we first looked at post discharge products of toluene and other alkylbenzenes seeded in He, then co-added additional species, O2 in particular. Now employing ∼800 nm fs pulses for photoionization, we have extended our studies to additional alkylbenzenes as well as to pyridine. The newly obtained data reveal important information about the intermediate species in benzene, toluene and other alkylbenzene species following corona discharges. As established from discharge, flame, and pyrolysis product studies on benzene in rare gases, the product chemistry shows general similarities in each case, in particular the formation of higher mass polycyclic aromatic hydrocarbons (PAHs). The vuv and fs laser photoionization time-of-flight mass spectrometry combined with molecular beam technique have proven to be ideal and sensitive tools for a comprehensive diagnosis of product formation in plasma chemistry / acase@tulane.edu
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_25895 |
| Date | January 2011 |
| Contributors | He, Luning (Author), RUBTSOV, IGOR V (Thesis advisor) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Rights | Access requires a license to the Dissertations and Theses (ProQuest) database., Copyright is in accordance with U.S. Copyright law |
Page generated in 0.2572 seconds