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A touchable plasma device based on coplanar dielectric barrier discharge (CDBD) is designed for hand hygiene. The biological safety is evaluated from the aspects of electrical and thermal properties. The peak value of current through the human body (~3.5 mA) and the highest device surface temperature (~40°C) are lower than the threshold of perception current and thermal damage temperature, respectively. The typical bacteria that are present on our hands in daily life Escherichia coli and Staphylococcus aureus are selected to verify the sterilization performance of the device. The results of human contact safety evaluation and sterilization test have demonstrated that this proposed CDBD device is reliable and user‐friendly for applications in hand hygiene. [ABSTRACT FROM AUTHOR]

In this work, a coaxial dielectric barrier discharge reactor has been developed for the decomposition of CO2 at atmospheric pressure. The response surface methodology based on a three-factor, three-level Box-Behnken design has been developed to investigate the effects of key independent process parameters (discharge power, feed flow rate, and discharge length) and their interactions on the reaction performance in terms of CO2 conversion and the energy efficiency of the plasma process. Two quadratic polynomial regression models have been established to understand the relationships between the plasma process parameters and the performance of the CO2 conversion process. The results indicate that the discharge power is the most important factor affecting CO2 conversion, while the feed flow rate has the most significant impact on the energy efficiency of the process. The interactions between different plasma process parameters have a very weak effect on the conversion of CO2. However, the interactions of the discharge length with either discharge power or gas flow rate have a significant effect on the energy efficiency of the plasma process. The optimal process performance- CO2 conversion (14.3%) and energy efficiency (8.0%) for the plasma CO2 conversion process is achieved at a discharge power of 15.8 W, a feed flow rate of 41.9 ml · min−1 and a discharge length of 150 mm as the highest global desirability of 0.816 is obtained at these conditions. The reproducibility of the experimental results successfully demonstrates the feasibility and reliability of the design of experiments approach for the optimization of the plasma CO2 conversion process. [ABSTRACT FROM AUTHOR]

A post-plasma catalysis system has been developed for the removal of methanol over Mn–Ce oxide catalysts with different Mn/Ce molar ratios at low temperatures. The Mn 50 Ce 50 oxide catalyst (Mn/Ce = 1:1) shows the best performance in terms of methanol removal efficiency and energy efficiency of the plasma-catalytic process. The maximum methanol removal efficiency of 95.4% can be achieved at a discharge power of 15 W and a gas flow rate of 1 L/min, while the highest energy efficiency of the plasma-catalytic process is 47.5 g/kW h at 1.9 W. The combination of plasma and Mn–Ce catalysts significantly reduces the formation of major by-products (methane, formaldehyde and formic acid) based on the Fourier transform infrared spectra. Possible reaction mechanisms and pathways of the post-plasma catalytic removal of methanol are also proposed. A three-layer back propagation artificial neural network (ANN) model has been developed to get a better understanding of the roles of different process parameters on methanol removal efficiency and energy efficiency in the post-plasma catalytic process. The predicted data from the ANN model show a good agreement with the experimental results. Catalyst composition (i.e. Mn/Ce ratio) is found to be the most important factor affecting methanol removal efficiency with a relative importance of 31.53%, while the discharge power is the most influential parameter for energy efficiency with a relative weight of 30.40%. These results indicate that the well-trained ANN model provides an alternative approach for accurate and fast prediction of the plasma-catalytic chemical reactions. [ABSTRACT FROM AUTHOR]

Dry reforming of CH 4 (DRM) using a plasma-enabled catalytic process is an appealing approach for reducing greenhouse gas emissions while producing fuels and chemicals. However, this is a complex process that is influenced by both catalysts and discharge plasmas, and low energy efficiency remains a challenge for this technology. Here, we developed a water-cooled dielectric barrier discharge (DBD) reactor for plasma DRM reactions over supported catalysts (Ni/γ-Al 2 O 3 , Ag/γ-Al 2 O 3 and Pt/γ-Al 2 O 3) prepared via plasma-modified impregnation. Results show that metal loading on γ-Al 2 O 3 enhanced the basic nature of the catalysts and promoted the formation of discharge channels and reactive species. The maximum conversion of CO 2 (21.4 %) and CH 4 (27.6 %) was obtained when using Ag/γ-Al 2 O 3. The basic nature of the catalytic materials dominated CO 2 conversion, whereas the properties of the catalyst and discharge plasma determined CH 4 conversion. The highest selectivity of hydrogen (∼34.5 %) and carbon-containing gas products (∼81.0 %) were attained when using the noble metal catalysts (Ag/γ-Al 2 O 3 and Pt/γ-Al 2 O 3), while the highest total selectivity of liquid products (14.1 %) was achieved in the presence of Ni/γ-Al 2 O 3. Compared with γ-Al 2 O 3 , the supported catalysts demonstrated higher stability, especially for Ag/γ-Al 2 O 3 and Pt/γ-Al 2 O 3 , which also provided higher energy efficiency for gas conversion and product formation. • Plasma-catalytic CH 4 reforming with CO 2 was carried out in a DBD reactor. • Three γ-Al 2 O 3 supported catalysts were prepared by a modified impregnation method. • CO 2 conversion and CO selectivity are closely related to the catalyst basicity. • Ag/γ-Al 2 O 3 had the highest conversion of CO 2 (21.4%) and CH 4 (27.6%). • Ni/γ-Al 2 O 3 showed the highest total selectivity of liquid products. [ABSTRACT FROM AUTHOR]

• CO 2 reforming of CH 4 was performed in DBDs with different dielectric layers. • More intensified filamentary microdischarges were displayed in DBD-SD. • DBD-SD exhibited higher reactant conversion and liquid product selectivity. • Higher gas product selectivity and stable carbon balance were achieved in DBD-DD. • Higher energy efficiency for plasma reforming process was obtained in DBD-SD. CO 2 reforming of CH 4 in a non-thermal plasma process (e.g., dielectric barrier discharge, DBD) possesses dual benefits for our environment and energy needs. However, this process is strongly influenced by the dielectric structure of the DBD. Here, plasma CO 2 reforming of CH 4 has been performed in both single-dielectric and double-dielectric DBD (DBD-SD and DBD-DD) reactors under atmospheric pressure. Electrical and optical characterization, along with temperature measurements are performed to understand the influence of the DBD-SD and DBD-DD designs. Reactor performance for reforming is compared under different discharge powers. The results show that CO 2 /CH 4 discharges in both DBD-SD and DBD-DD display typical filamentary microdischarges. Compared with the DBD-DD, the DBD-SD reactor exhibits a larger number and higher intensity of current pulses, which leads to a higher electron density and formation of reactive species. The highest conversion of CO 2 (24.1 %) and CH 4 (49.2 %) are achieved in the DBD-SD at a high discharge power (75 W). Moreover, higher selectivities of gaseous products are obtained in the DBD-DD, while the DBD-SD reactor shows a higher selectivity for liquid products, mainly including methanol and acetic acid. The highest energy efficiencies for reactant conversion (0.34 mmol/kJ), gaseous and liquid production formation (0.26 mmol/kJ and 0.015 mmol/kJ) are achieved in the DBD-SD reactor at a low discharge power (22 W), resulting from the low energy loss to the environment. However, the carbon deposited on the inner electrode surface in the DBD-SD would have an adverse influence on the reactor's performance. Further research on the optimization of the DBD reactor to establish an efficient plasma-catalysis system is required for industrial applications. [ABSTRACT FROM AUTHOR]