Packed-bed Dielectric Barrier Discharge Research Articles

Importance of plasma discharge characteristics in plasma catalysis: Dry reforming of methane vs. ammonia synthesis

Plasma catalysis is a rapidly growing field, often employing a packed-bed dielectric barrier discharge plasma reactor. Such dielectric barrier discharges are complex, especially when a packing material (e.g., a catalyst) is introduced in the discharge volume. Catalysts are known to affect the plasma discharge, though the underlying mechanisms influencing the plasma physics are not fully understood. Moreover, the effect of the catalysts on the plasma discharge and its subsequent effect on the overall performance is often overlooked. In this work, we deliberately design and synthesize catalysts to affect the plasma discharge in different ways. These Ni or Co alumina-based catalysts are used in plasma-catalytic dry reforming of methane and ammonia synthesis. Our work shows that introducing a metal to the dielectric packing can affect the plasma discharge, and that the distribution of the metal is crucial in this regard. Further, the altered discharge can greatly influence the overall performance. In an atmospheric pressure dielectric barrier discharge reactor, this apparently more uniform plasma yields a significantly better performance for ammonia synthesis compared to the more conventional filamentary discharge, while it underperforms in dry reforming of methane. This study stresses the importance of analyzing the plasma discharge in plasma catalysis experiments. We hope this work encourages a more critical view on the plasma discharge characteristics when studying various catalysts in a plasma reactor.

Non-thermal plasma mitigation of low concentration of air pollutants: removal of isopropyl alcohol using transition metal-oxide integration.

The present work studied the decomposition of isopropyl alcohol (IPA), widely used in chemical industries and households, in a packed-bed dielectric barrier discharge (DBD) plasma reactor. Metal oxide (MOx) coated on γ-Al2O3 (M = Cu, Mn, Co) was utilized for packing. The plasma-packed mode was a likely alternative to the conventional removal techniques, as it aids the conversion of dilute concentrations of IPA to CO and CO2 at ambient conditions (room temperature and atmospheric pressure). The mean electron energy calculations suggest that electrons with higher energy are generated when the discharge zone is packed with catalysts. When comparing IPA conversion (input concentration of 25ppm) for no packing mode and MOx/γ-Al2O3 coupled plasma mode, the latter method enhances conversion to greater than 90% at an applied voltage of 18kV. Also, MOx/γ-Al2O3 showed the highest selectivity to CO2 (70%) compared to plasma-only mode (45%). The metal-oxide layer provides the necessary catalytic surface facilitating the oxidation of IPA to COx through active oxygen species or the interaction of surface hydroxyl groups. The use of MOx/γ-Al2O3 resulted in about 90% carbon balance and reduced ozone generation, demonstrating the significance of integrating metal oxide to achieve efficient conversion and maximal selectivity towards the desired products.

Electrical characterization and imaging of discharge morphology in a small-scale packed bed dielectric barrier discharge

Packed bed dielectric barrier discharges (DBDs) exhibit an improved energy efficiency and selectivity in nonthermal plasma based gas conversion. They enable the direct interaction between plasma and catalyst. In this contribution a compact coaxial DBD reactor enabling the end-on imaging of the discharge with and without packed beds is studied. The discharge morphology is correlated with electrical measurements such as voltage-charge (V-Q) plots. The studies are performed for different packed bed materials, binary gas compositions of argon and carbon dioxide, voltage amplitudes, average powers, and pressures. The analysis points outs the role of parasitic capacitances and parasitic discharges as often overlooked aspects. The introduction of the packed bed material into the coaxial barrier discharge arrangement increases the total capacitance, but the barrier of the outer glass tube mostly determines the maximum effective dielectric capacitance. The choice of the packed bed material determines the voltage threshold and the average discharge power. The investigations leads to a revision of the equivalent circuit for packed bed barrier discharge reactors, which also accounts the properties of different filling materials.

Investigation of Plasma Propagation in Packed-Bed Dielectric Barrier Discharge Based on a Customized Particle-in-Cell/Monte Carlo Collision Model

This study investigates the propagation dynamics of plasma streamers in a packed-bed dielectric barrier discharge using a 2D particle-in-cell/Monte Carlo collision model. To accurately simulate the high-intensity discharge and streamer propagation mechanism at atmospheric pressure, additional algorithms for particle merging and a new electron mechanism are incorporated into the traditional particle-in-cell/Monte Carlo collision model. To validate the accuracy of this improved model, qualitative comparisons are made with experimental measurements from the existing literature. The results show that the speed of streamer propagation and the distribution of plasma are strongly influenced by the dielectric constant of the packed pellet, which is commonly used as a catalyst. In cases with a moderate dielectric constant, the presence of a strong electric field between the pellet and dielectric layer on the electrode significantly enhances the discharge. This enables the streamer to propagate swiftly along the pellet surface and results in a wider spread of plasma. Conversely, a very high dielectric constant impedes streamer propagation and leads to localized discharge with high intensity. The improved model algorithms derived from this research offer valuable insights for simulating high-density plasma discharge and optimizing plasma processing applications.

Full cycle, self-consistent, two-dimensional analysis of a packed bed DBD reactor for plasma-assisted splitting: spatiotemporal inhomogeneous, glow to streamer to surface discharge transitions

We investigate the full-cycle operation of a coaxial Packed Bed Dielectric Barrier Discharge (PB-DBD) reactor operating in pure . The reactor is packed with high permittivity dielectric rods and is analyzed with a two-dimensional (2D) self-consistent plasma model. We show that the PB-DBD operation is governed by both glow and volume/surface streamer discharges, forming alternatively and non-uniformly inside the gas volume. The presence and surface charging of the dielectric rods and dielectric layer is crucial for the initiation, propagation, annihilation and afterglow of these microdischarges. Our calculations show maximum electron and densities in the order 1020 m−3, an average discharge power of 353.42 W m−1 in the first cycle, microdischarge peak currents in the order of 50–400 A m−1, total half-cycle plasma charge of around 6 µC m−1, which compare well with experimental findings. Dominant negative ions are found to be . CO molecules and O atoms are mainly formed during the MDs development and the streamer-surface ionization waves. Molecular oxygen () is preferentially formed during the glow, current-decaying and afterglow phase of each microdischarge. The spatially average reduced electric field inside the reactor lies in the 20–100 Td range. Each MD, presents distinct non-uniform and non-repeatable glow and volume/streamer discharges owed to the non-uniform surface charging processes which dictate the complex spatial distribution of produced neutral (and ion) species. These detailed results shed light on crucial, largely non-uniform plasma spatiotemporal characteristics that can help design efficient PB-DBD reactors for splitting and beyond, while emphasizing the important insights obtained by 2D simulations which can not be captured with 0D-global or 1D models.

Non-Oxidative Ethane Dehydrogenation in a Packed-Bed DBD Plasma Reactor

Plasma-assisted conversion of ethane (C2H6) can produce value-added chemical building blocks using green electricity. Here we employ a simple packed-bed coaxial dielectric barrier discharge (DBD) reactor to convert C2H6 at mild operating conditions unattainable by conventional thermocatalysis. Ethylene (C2H4), acetylene (C2H2), and methane (CH4) are the main products along with small fractions of C3 and C4 hydrocarbons. Interestingly, the C2H4 selectivity is primarily correlated to C2H6 conversion, dominated by electron dissociation and recombination reactions irrespective of the dielectric properties of the packed bed material (SiO2, Al2O3, ZrO2, TiO2, and BaTiO3), packing material size, supplied power, and C2H6 concentration. While a distortion of the electric field and discharge propagation results in varying dissipated power as materials change, the C2H4 energy yield remains constant. The particle size appears to affect conversion mainly due to pressure alterations. Pd/SiO2 catalyst can change the selectivity, favoring saturated species by expending hydrogen.

The catalytic efficiency of Ru/Mn/Ce-Al2O3 in the reduction of HCN in dry methane reforming with CO2 assisted by non-thermal plasma

This study investigates the catalytic activity of Ru/Mn/Ce-Al2O3 in eliminating HCN via dry reforming CH4 with CO2 in the packed-bed dielectric barrier discharge non-thermal plasma (DBD NTP). A packed bed DBD configuration method was carried out in the non-thermal plasma with Ru/Mn/Ce-Al2O3 catalyst, whereby BaTiO3 beads was the dielectric medium. The carrier gas for dry methane reforming was N2, the peak-to-peak voltage was 24 kV and the total flow rate was 100 sccm with a ratio of 5:5:90 (CH4:CO2:N2), respectively. Gaseous products and by-products were analysed by Fourier transform infra-red (FTIR) spectroscopy. Experimental results revealed that Ru/Mn/Ce-Al2O3 catalyst could eliminate HCN at approximately 82% and had a low selectivity in decomposing NH3. Besides, the conversion of CH4 achieved was approximately 68%.

Plasma-assisted ammonia synthesis over Ni/LaOF: Dual active centers consisting of oxygen vacancies and Ni

Ammonia (NH3) is one of the most important chemicals and can also be used as an energy storage carrier. The catalytic synthesis of ammonia coupled with plasma can be achieved under mild conditions. Currently, the efficiency of the plasma catalytic ammonia synthesis is low. Herein we demonstrate the ammonia synthesis on nNi/LaOF (n = 0, 0.25, 0.5) containing dual active sites via atmospheric pressure packed-bed dielectric barrier discharge (AP-PBDBD). The 0.5Ni/LaOF sample resulted in an ammonia synthesis rate at least 30 times higher than that under the only plasma. The vibrationally-excited N2 in plasmas is activated and adsorbed by oxygen vacancy on Ni/LaOF surface. The adsorbed N2 and the H atoms on Ni gradually undergo a hydrogenation reaction to produce NH3. Our results illustrate the role of dual active centers, i.e., the oxygen vacancies and Ni, and introduce a design concept of the catalyst with dual active centers for plasma-assisted ammonia synthesis.

Experimental study on particulate matter removal using packed-bed dielectric barrier discharge plasma reactor

In this study, a packed-bed dielectric barrier discharge (DBD) reactor was developed for particulate matter (PM) removal. The effects of operating conditions such as the packing materials, applied power, and discharging gap were systematically investigated. The results revealed that Zeolite 13X exhibited the highest PM removal efficiency based on its high electrostatic adsorption capacity. A narrow discharge gap (2.4 mm) and increased power density resulted in an enhancement of the PM removal efficiency in the system. Further, these operating conditions increased the electric field strength, which was proportional to the current density in the system. The energy yield decreased with an increase in the specific energy input into the packed-bed DBD reactor. Among the tested operating parameters, maintaining a narrow discharging gap was determined to be the most important for achieving high energy efficiency and PM removal in the system. Moreover, an air cleaning procedure was applied for the regeneration of the packing materials, resulting in a high recovery rate of over 80%.

Plasma-catalytic ammonia decomposition using a packed-bed dielectric barrier discharge reactor

Plasma-catalytic ammonia decomposition as a method for producing hydrogen was studied in a packed-bed dielectric barrier discharge (DBD) reactor at ambient pressure and a fixed plasma power. The influence of packing the plasma zone with various dielectric materials, typically used as catalyst supports, was examined. At conditions (21 W, 75 Nml/min NH3) where an NH3 conversion of 5% was achieved with plasma alone, an improved decomposition was found when introducing dielectric materials with dielectric constants between 4 and 30. Of the tested materials, MgAl2O4 yielded the highest conversion (15.1%). The particle size (0.3–1.4 mm) of the MgAl2O4 packing was found to have a modest influence on the conversion, which dropped from 15.1% to 12.6% with increasing particle size. Impregnation of MgAl2O4 with different metals was found to decrease the NH3 conversion, with the Ni impregnation still showing an improved conversion (7%) compared to plasma-only. The plasma-assisted ammonia decomposition occurs in the gas phase due to micro-discharges, as evident from a linear correlation between the conversion and the frequency of micro-discharges for both plasma alone and with the various solid packing materials. The primary function of the solid is thus to facilitate the gas phase reaction by assisting the creation of micro-discharges. Lastly, insulation of the reactor to raise the temperature to 230 °C in the plasma zone was found to have a negative effect on the conversion, as a change from volume discharges to surface discharges occurred. The study shows that NH3 can be decomposed to provide hydrogen by exposure to a non-thermal plasma, but further developments are needed for it to become an energy efficient technology.

SF 6 catalytic degradation in a γ‐Al 2 O 3 packed bed plasma system: A combined experimental and theoretical study

Effective abatement of the greenhouse gas sulphur hexafluoride (SF6) waste is of great importance for the environment protection. This work investigates the size effect and the surface properties of γ-Al2O3 pellets on SF6 degradation in a packed bed dielectric barrier discharge (PB-DBD) system. Experimental results show that decreasing the packing size improves the filamentary discharges and promotes the ignition and the maintenance of plasma, enhancing the degradation performance at low input powers. However, too small packing pellets decrease the gas residence time and reduce the degradation efficiency, especially for the input power beyond 80 W. Besides, lowering the packing size promotes the generation of SO2, while reduces the yields of S-O-F products, corresponding to a better degradation. After the discharge, the pellet surface becomes smoother with the appearance of S and F elements. Density functional theory calculations show that SF6 is likely to be adsorbed at the AlIII site over the γ-Al2O3(110) surface, and it is much more easily to decompose than in the gas phase. The fluorine gaseous products can decompose and stably adsorb on the pellet surface to change the surface element composition. This work provides a better understanding of SF6 degradation in a PB-DBD system.

Effect of non-thermal plasma in the activation and regeneration of 13X zeolite for enhanced VOC elimination by cycled storage and discharge process

A non-thermal plasma (NTP) discharge is used in this study for the activation and regeneration of MS-13X pellets packed in a MS-13X & glass beads packed bed dielectric barrier discharge (DBD) reactor. NTP activation (in-situ) of MS-13X efficiently removes the adsorbed carbonaceous compounds and moisture resulting in an improved VOC adsorption. In addition, NTP exposure is used for the regeneration of the used MS-13X for cycled storage and discharge (CSD) removal of VOC from air. The amount of adsorbed toluene, products formed and the surface and bulk properties of the regenerated used MS-13X shows complete regeneration of used MS-13X. Finally, the stability of MS-13X during 10 cycles of CSD shows no degradation in performance. Thus, NTP exposure is proven to be successful for both the activation and regeneration of MS-13X pellets used for cyclic CSD process.

Plasma-catalytic ammonia synthesis over BaTiO3 supported metal catalysts: Process optimization using response surface methodology

Non-thermal plasma (NTP) assisted ammonia (NH3) synthesis has been performed in a packed-bed dielectric barrier discharge (DBD) reactor. The presence of M/BaTiO3 (M = Fe, Co and Ni) catalysts in the DBD reactor significantly improved the NH3 concentration and energy efficiency with a sequence of Ni/BaTiO3 > Co/BaTiO3 > Fe/BaTiO3 > BaTiO3. Catalyst characterization, including N2 adsorption-desorption, X-ray diffraction analysis and temperature-programmed desorption of CO2, was performed to get insights into the relationships between the plasma-assisted NH3 synthesis process and M/BaTiO3 catalysts. The improved performance of plasma-assisted NH3 synthesis over Ni/BaTiO3 could be attributed to abundant basic sites and weaker metal-nitrogen (M-N) binding on its surfaces, which benefit the generation of NHx species and desorption of formed NH3. Response surface methodology (RSM) was used to assess the contribution of each independent process parameter and explore their mutual effects on the NH3 synthesis process systematically. The results of analysis of variance (AVONA) suggested that plasma discharge power and gas flow rate were the most significant factors in affecting the NH3 concentration and energy efficiency of the plasma-assisted NH3 synthesis process, respectively. Based on the proposed polynomial regression model, the maximum energy efficiency of 2.37 g kWh−1 was achieved at the predicted optimal operating conditions over Ni/BaTiO3.

CO2 dissociation in a packed bed DBD reactor: effect of streamer discharge

Non-thermal plasma catalysis, as a special heterogeneous catalytic reaction, needs to consider both gas discharge and catalytic reaction. Packed bed dielectric barrier discharge (PB-DBD) is widely used in non-thermal plasma catalysis, but the exact control principle of gas discharge, especially streamer discharge, is not clear. In this study, therefore, the orderly arranged dielectric rods were packed in the discharge gap of PB-DBD, and the streamer discharge behaviors were controlled by adjusting their diameter(s), quantity(ies), location(s) and dielectric constant(s). Al2O3 and ZrO2 dielectric rods with dielectric constants of about 9 and 25 were used as packing material. Pure CO2 was used as reaction gas and discharge gas. Discharge images showed that stable and controllable streamer discharges can be formed between the dielectric rod and ground electrode. The intensity, width and length of the streamer discharge can be significantly changed by optimizing the dielectric constant, diameter, packing number and position of the dielectric rod, thereby affecting the CO2 conversion efficiency. Increasing dielectric constant and the distance between the dielectric rod and ground electrode can increase the intensity of streamer discharge, thus promoting the CO2 conversion efficiency. Compared with an empty reactor, after packing 24 ZrO2 dielectric rods with a diameter of 1 mm, the CO2 conversion and energy efficiency increased from 9.58% to 20.1% and from 1.67% to 2.89%, respectively. In short, this research has important implications for plasma catalysis. This study not only reveals the synergistic characteristics between streamer discharge and CO2 dissociation, but also provides an important idea for structural optimization of PB-DBD catalyst.

The Effect of Voltage Pulse Shape on the Discharge Characteristics in the Packed Bed Reactor under Air and Nitrogen

In this paper, the packed bed dielectric barrier discharge (DBD) with needle-plate electrode configuration is presented to study the effects of electrical parameters, such as pulse duration and pulse rising and falling time, on discharge characteristics under air and nitrogen. The waveforms of the voltage and the discharge current, discharge evolution images, and the emission spectral of N2 (C3Пu → B3Пg) and N2+ (B2Σu+ → X2Σg+) are collected to investigate the discharge current, as well as the spatial distribution of the discharge modes and the reactive species in the packed bed reactor specifically. It is found that the pulse duration and pulse rising and falling time can regulate the discharge current. Firstly, increasing the pulse duration and the pulse rising and falling time can both increase the discharge duration. Secondly, the peak value of the discharge current has an obvious increasing trend with the pulse duration. Finally, the discharge start time can be delayed by increasing the pulse rising and falling time. A bright discharge channel is distributed at the top of the reactor, while the discharge is diffused at the bottom of the reactor. The generation of N2+ (B2Σu+) tends to depend on the existence of the streamer channel, and N2 (C3Пu) can be generated in the entire discharge area. In addition, the discharge operated in pure nitrogen can reach higher current values, a stronger discharge intensity, and longer existence time for the reactive species than in the air.

Plasma-assisted ammonia synthesis in a packed-bed dielectric barrier discharge reactor: roles of dielectric constant and thermal conductivity of packing materials

In this article, plasma-assisted NH3 synthesis directly from N2 and H2 over packing materials with different dielectric constants (BaTiO3, TiO2 and SiO2) and thermal conductivities (BeO, AlN and Al2O3) at room temperature and atmospheric pressure is reported. The higher dielectric constant and thermal conductivity of packing material are found to be the key parameters in enhancing the NH3 synthesis performance. The NH3 concentration of 1344 ppm is achieved in the presence of BaTiO3, which is 106% higher than that of SiO2, at the specific input energy (SIE) of 5.4 kJ·l−1. The presence of materials with higher dielectric constant, i.e. BaTiO3 and TiO2 in this work, would contribute to the increase of electron energy and energy injected to plasma, which is conductive to the generation of chemically active species by electron-impact reactions. Therefore, the employment of packing materials with higher dielectric constant has proved to be beneficial for NH3 synthesis. Compared to that of Al2O3, the presence of BeO and AlN yields 31.0% and 16.9% improvement in NH3 concentration, respectively, at the SIE of 5.4 kJ·l−1. The results of IR imaging show that the addition of BeO decreases the surface temperature of the packed region by 20.5% to 70.3°C and results in an extension of entropy increment compared to that of Al2O3, at the SIE of 5.4 kJ·l−1. The results indicate that the presence of materials with higher thermal conductivity is beneficial for NH3 synthesis, which has been confirmed by the lower surface temperature and higher entropy increment of the packed region. In addition, when SIE is higher than the optimal value, further increasing SIE would lead to the decrease of energy efficiency, which would be related to the exacerbation in reverse reaction of NH3 formation reactions.

Effects of removing carbon particles of different size with nonthermal plasma generated by packed-bed dielectric barrier discharge reactor

A self-designed packed-bed dielectric barrier discharge (PB-DBD) reactor was used to explore the effects of carbon particle size distribution, reaction chamber temperature and reactor inlet flow on the removal effect of carbon particles with different particle sizes. The results indicated that in the process of non-thermal plasma (NTP) oxidation of carbon particles, particles with larger particle size are decomposed into new nanoparticles. When the temperature of the reaction chamber increased from 25 to 200 ℃, the number concentration removal efficiency and rate of nanoparticles, ultrafine particles and total particles increased. With the increase of the inlet flow of the reactor, the O3 concentration first increased and then decreased and the number concentration removal rate of nanoparticles, ultrafine particles and total particles showed the same trend as the O3 concentration. At the inlet oxygen flow of 3 L/min, the O3 concentration and carbon particle removal rate were the maximum.

Plasma-assisted ammonia synthesis in a packed-bed dielectric barrier discharge reactor: effect of argon addition

The effect of argon (Ar) addition on plasma-assisted ammonia (NH3) synthesis in a packed-bed dielectric barrier discharge (DBD) reactor is investigated in this work. Both higher normalized NH3 concentration and N2 conversion are achieved by adding Ar to N2–H2 plasma. The 18.6% increment of normalized NH3 concentration and 15% increment of N2 conversion are realized with 30 vol.% Ar addition compared with the case of N2–H2 plasma only, indicating that Ar addition would contribute to NH3 formation. The mechanisms of NH3 synthesis with Ar addition are proposed based on electrical characteristics and electron energy distribution function of the N2–H2–Ar plasma. The intensity of microdischarges, mean electron energy and quantity of energetic electrons increase upon Ar addition. Hence, the electron-impact reactions would be enhanced upon Ar addition. Meanwhile, the effective capacitance of the plasma reactor is improved, which suggests Ar addition contributes to achieve fully-bridged plasma discharge and transfer energy into chemical process in plasma. Moreover, the presence of Ar introduces Penning excitation and ionization reactions in N2-H2 plasma, which would benefit N2 conversion and then accelerate NH3 formation as well.

Drastically Increase in Atomic Nitrogen Production Depending on the Dielectric Constant of Beads Filled in the Discharge Space.

Nitrogen activation, especially dissociation (production of atomic nitrogen), is a key step for efficient nitrogen fixation, such as nitrogen reduction to produce ammonia. Nitrogen reduction reactions using water as a direct hydrogen source have been studied by many researchers as a green ammonia process. We studied the reaction mechanism and found that the nitrogen reduction could be significantly improved via efficient production of atomic nitrogen through electric discharge. In the present study, we focused on packed-bed dielectric barrier discharge (PbDBD) using dielectric beads as the packing material. The experimental results showed that more atomic nitrogen was produced in the nitrogen activation by the discharge in which the discharge space was filled with the dielectric beads than in the nitrogen activation by the discharge without using the dielectric beads. Then, it was clarified that the amount of atomic nitrogen increased as the dielectric constant of the beads to be filled increased, and the amount of atomic nitrogen produced increased up to 13.48 times. Based on the results, we attempted ammonia synthesis using water as a direct hydrogen source with the efficiently generated atomic nitrogen. When the atomic nitrogen gas generated by the PbDBD was sprayed onto the surface of the water phase and subsequently reacted as a plasma/liquid interfacial reaction, the nitrogen fixation rate increased by 7.26-fold compared to that when using the discharge without dielectric beads, and the ammonia production selectivity increased to 83.7%.

Experimental study on the parameter optimization and application of a packed-bed dielectric barrier discharge reactor in diesel particulate filter regeneration

To compensate for the shortcomings of the thermal and catalytic regeneration of the diesel particulate filter (DPF), a self-designed packed-bed dielectric barrier discharge (DBD) reactor for DPF regeneration was developed. The DBD reactor with the main active substance of nonthermal plasma (NTP) as the target parameter was optimized by adjusting the feed gas, packing particles (material or size), and cooling water temperature. Moreover, a set of optimal working parameters (gas source, O2; packing particles, 1.2–1.4 mm ZrO2; and cooling water temperature, 20 °C) was selected to evaluate the effect of different O3 concentrations on DPF regeneration. The research results showed that selecting packing particles with high dielectric constant and large particles, as well as reducing the cooling water temperature, with oxygen as the feed gas, contributed to an increase in O3 concentration. During DPF regeneration, the following changes were observed: the power of the NTP reactor decreased to lower than 100 W, the O3 concentration increased from 15 g m−3 to 45 g m−3, the CO and CO2 volume fractions of the particulate matter decomposition products increased, and the peak regeneration temperature increased to 173.4 °C. The peak temperature arrival time was 60 min earlier, indicating that the regeneration rate of DPF increased with the increase in O3 concentration. However, the O3 utilization rate (the amount of carbon deposit removed per unit volume O3) initially increased and then decreased; when the O3 concentration was set to 25 g m−3, the highest O3 utilization rate was reached. The packed-bed DBD technology contributed to the increase in the concentration of NTP active substances and the regeneration efficiency of DPF. It provides a theoretical and experimental basis for high-efficiency regeneration of DPF at low temperatures (<200 °C).