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Revolutionizing Vehicle Emissions Control: A Game Changing Cold Plasma Technology
Reviewed by Dr Srikanth Ponnada
Revolutionizing Vehicle Emissions Control: A Game Changing Cold Plasma Technology
Humans have gotten entangled in a web of air pollution due to fast technological advancements and the rising of automobiles, industries, etc. Worldwide efforts are under way to develop innovative devices and systems to mitigate the issue. For the said purpose some traditional methods have been used, such as absorption, adsorption, condensing, etc. However, these are not efficient and also consume high-power. Non-equilibrium cold plasma (NECP) brought novelty to remove the toxicity of air by generating highly oxidizing reactive species. The concept of Dielectric Barrier Discharge (DBD) has been used to produce NECP in a cylindrical packed bed discharge system using dielectric and/or metal beads. In general, in packed bed reactors, different catalyst materials are used to remove toxic gases like VOCs and convert CO2, etc. Such materials play a very important role due to the discharge characteristics, which are significantly influenced by packing different materials into the discharge gap. Packing material with high dielectric constant increases the electron’s temperature and electric field strength near contact points of the catalyst resulting in an increase in the pollutant removal efficiency. The execution of the packed bed reactors depends on the type and the dielectric constant of the packing material are still sufficient studies are not available to choose a specified material.
Non-thermal Plasma (NTP)
Nonthermal Plasma (NTP) or cold Plasma is a plasma that is not in thermodynamic equilibrium because the temperature of electrons is much hotter than the temperature of ions and neutral atoms, and the remaining gas is at room temperature. Te>>Ti >Tg Where Te ~1-10eV, Tg ~ Room Temp. at low pressure. In other words, the method of generation of NTP is to apply an electric field to a neutral gas
Dielectric Barrier Discharge
Siemens looked into the production of ozone using Dielectric Barrier Discharge in 1857. It is also called silent discharge or ozone production discharge. Basically, DBD is electrical discharge between two electrodes, separated by dielectric material.
- Packing material between electrodes not only changes the discharge behavior of nonthermal plasma, while it can also improve the oxidation power of NTP.
- The configuration of the packed-bed DBD reactors, such as the powered electrode, ground electrode, and power supply, plays an important role in determining the energy efficiency of the reactor.
- The presence of packing material in the reactor enhances the electric field in the area near the contact points between the pellets and homogenously distributes the plasma in the reactor.
- Various properties of packing materials, such as dielectric constant, size, shape, and surface properties, affect the discharge characteristics.
Image of Plasma: generated with GEMINI for visualization purpose only
References & Suggested Reading
- Li, W., Alagumalai, A., Li, Z. and Song, H., 2024. Non-thermal plasma technology for air pollution control and bacterial deactivation. Cell Reports Physical Science, 5(7). https://doi.org/10.1016/j.xcrp.2024.102092
- Ollegott, K., Wirth, P., Oberste‐Beulmann, C., Awakowicz, P. and Muhler, M., 2020. Fundamental properties and applications of dielectric barrier discharges in plasma‐catalytic processes at atmospheric pressure. Chemie Ingenieur Technik, 92(10), pp.1542-1558. https://doi.org/10.1002/cite.202000075
- Haryanto, B. ed., 2012. Air pollution: A comprehensive perspective. BoD–Books on Demand.
Authored by Jyoti Verma
Jyoti Verma M.Sc
-Junior Scientific Content Author
Jyoti, as an accomplished researcher in the field of Physics, currently pursuing a PhD from Helmholtz zentrum dresden rossendorf, Germany. She holds a master's degree from the prestigious Indian Institute of Technology Jodhpur, having passed the IIT Joint Admission Test. She started her research journey with an internship at the Physical Research Laboratory in Ahmedabad, where she investigated ozone variation in the troposphere. Continuing to pursue her passion for atmospheric and physical sciences, they worked as research assistant at Academia Sinica, Taiwan. Her academic excellence is recognized with numerous awards, including the Gargi Award, Indira Priyadarshini Award, and the DST-Inspire Scholarship. Her strong interest in scientific writing led her to contribute as an author to SCIATLAS.
