A novel dielectric barrier discharge reactor with photocatalytic electrode based on sintered metal fibers for abatement of xylene

The Bibliometric Analysis and Review of the Application of Plasma in the Field of VOCs

The application of plasma in the field of volatile organic compounds (VOCs) can be traced back to the 1990s and has gradually developed into an important research field. In this regard, this article primarily sorts and analyzes the literature on the “application of plasma in the field of VOCs” in the Web of Science core collection database from 1992 to 2021 and, subsequently, obtains important data and trends, including the annual number of articles published, country, institution analysis, and journal, as well as discipline analysis, etc. The results show that China is not only in a leading position in the field of research, but also has six top-ten research institutions. This field has more research results in engineering, chemistry, physics, and environmental disciplines. In addition, this article summarizes dielectric barrier discharge (DBD) and titanium-containing catalysts, which represent the discharge characteristics and type of catalyst highlighted through the hot keywords. This review will provide certain guidance for future, related research.

A novel pilot-scale installation integrated of improved sieve-tray tower and wet electrostatic precipitator for paint mist removal

In order to overcome the problem of decrease of the spraying exhausts purification efficiency caused by the paint mist, the installation combining of the improved sieve-tray tower and the wet electrostatic precipitator (WEP) was used for the treatment of the pilot-scale 1,000 m³ paint waste gas. The characteristics of paint mist were investigated, showing that the size distribution of oil-based paint mist located in the range of 5.4-43.4 μm with an approximate symmetrical distribution under the pressure of 0.4 MPa. The size of paint mist less than 10 μm accounted for ~50% in quantity. It was revealed that the integrated setup was able to remove the concentration of oil-based paint mist with ~98% removal efficiency, in which the improved sieve-tray tower contributed ~94% particles removal. The soluble volatile organic pollutants (VOCs) of spraying exhaust gas were also captured by sieve-tray tower, promoting VOCs removal. At last, the feasibility of integrated setup used in paint mist removal was analyzed, including the secondary pollutants treatment. The results exhibited the setup has the potential for industrial applications.Implications: Fabricating a pilot-scale installation integrated of the improved sieve-tray tower and wet electrostatic precipitator to remove spraying exhaust gas in the furniture factory efficiently. This tech meets China's VOC emission policy.

A novel array of double dielectric barrier discharge combined with TiCo catalyst to remove high-flow-rate toluene: Performance evaluation and mechanism analysis

A novel array double dielectric barrier discharge (ADDBD) combined with a TiO₂/Al₂O₃-Co₃O₄/AC (TiCo) catalyst was applied to remove toluene. The effects of catalyst setting distance, catalyst combination mode, and process factors (including specific input energy, initial toluene concentration, and relative humidity) were investigated in terms of the toluene degradation efficiency (η_toluene) and the selectivity of CO₂ (S_CO2). When the specific input energy was 65 J·L^-1, the initial toluene concentration was 100 mg·m^-3, and the relative humidity was 30%, the highest η_toluene of 72% and S_CO2 of 44% could be achieved with TiO₂/Al₂O₃ 10 cm and Co₃O₄/AC 20 cm downstream of the ADDBD. Based on the determination of active substances (e.g., O₃, OH) and the catalyst activation mode, a synergistic effect of active substances and photon between the ADDBD and the TiCo catalyst was proposed for the removal of toluene. Finally, the biodegradability and toxicity of the outlet gas were evaluated, and the results showed that the outlet gas was more convenient for subsequent biopurification and less toxic to the surroundings after the treatment by the ADDBD combined with the TiCo catalyst.

Enhanced xylene removal by photocatalytic oxidation using fiber-illuminated honeycomb reactor at ppb level

The removal of volatile organic compounds (VOCs) at ppb level is one of the most critical challenges in clean rooms for the semiconductor industry. Photocatalytic oxidation is an innovative and promising technology for ppb-level VOCs degradation. We have designed a fiber-illuminated honeycomb reactor (FIHR) in which the removal efficiency of m-xylene is significantly enhanced to 96.5% as compared to 22.0% for UV irradiation only. The results indicate that photocatalysts not only play the role to substantially oxidize m-xylene, but also alter the chemical properties of xylene under UV illumination. Using the FIHR with Mn-TiO2 photocatalyst not only increased the m-xylene removal efficiency, but also increased the CO2 selectivity. Interestingly, Mn-TiO2 in FIHR also showed a very good reusability, 93% removal efficiency was still achieved in 72-h in reaction. Thus, the FIHR gave very high removal efficiency for xylene at ppb level under room temperature. The FIHR has great potential application in the clean room for the air purification system in the future.

Removal of H₂S in a novel dielectric barrier discharge reactor with photocatalytic electrode and activated carbon fiber

A novel dielectric barrier discharge (DBD) reactor was applied for removal of H2S. Activated carbon fiber (ACF) and a photocatalytic electrode prepared from sintered metal fibers (SMF) were introduced into the novel reactor. H2S removal rate was enhanced dramatically due to the synergism between DBD and ACF. Peak voltage, initial concentration, resident time and humidity were important factors that influenced the H2S removal rate. 75 mg/m(3) H2S removal rate reached 99.9% at a peak voltage of 25 kV and with a resident time of 2s in the novel reactor. Humidity had an inhibition to H2S decomposition at low peak voltages. And the inhibition became slight at high peak voltages (>20 kV). The novel reactor exhibited better by-products (SO2 and O3) control than other reactors did. And it also had excellent performance stabilization in a long-term operation (30 d).