Ozone Synthesis Research Articles

The Effect of Misalignment of Coaxial Electrodes in Barrier Ozonizers on the Efficiency of Ozone Synthesis

The Effect of Misalignment of Coaxial Electrodes in Barrier Ozonizers on the Efficiency of Ozone Synthesis

Tuning Intermediate-Enriched microenvironment of pt-loaded porous TiN nanorods for enhanced electrochemical ozone production and hydrogen evolution reaction

Electrochemical ozone production (EOP) is a technology with great promise for ozone synthesis, where electrochemical anode and cathode reactions play key roles in electrolytic ozone generators. In this work, mesoporous three-dimensional Pt/TiN nanorods (NRs) have been designed and prepared for EOP and HER, exhibited impressive performance with the faraday efficiency of the anodic EOP was 13 %. The overpotential of cathodic HER was 38 mV at 10 mA·cm−2 with 0.5 M H2SO4. The porous structure of Pt/TiN NRs provides microenvironments favorable for enrichment of reaction intermediates, accelerating the kinetic processes of EOP and HER. Theoretical calculations have revealed that metal-support interactions (MSI) between Pt and TiN play an influential role in the adsorption of reactive intermediates. Furthermore, promising efficiencies in the electrochemical degradation of organic pollutants have been investigated, highlighting the potential application of the Pt/TiN NRs-1 || Pt/TiN NRs-2 in advanced electrochemical oxidation.

Study of the efficiency of ozone synthesis in a point‐to‐plain discharge in N2–O2 mixtures

AbstractThe experimental results of the ozone synthesis and electrodynamic characteristics of the point‐to‐plane DC voltage corona discharge in N2–O2 mixtures at atmospheric pressure are presented. Four different modes of DC corona discharge were investigated: stationary mode of positive point‐to‐plane discharge, two non‐stationary (streamers) modes of positive point‐to‐plane discharge, and mode of negative point‐to‐plane discharge. It was shown that ozone synthesis highly depends on discharge modes and correlates with discharge conditions appropriated to dissociative attachment processes. In the case of positive point‐to‐plane discharge, ozone synthesis behavior is similar to that of the pulse component of the discharge current. It was shown that the mode with secondary streamers propagation is the most effective for ozone production among the four different modes of the point‐to‐plane DC corona discharge.

Corona discharge ozonizers with vacuum coatings and their use for processing agricultural products

At present the majority of ozonizers in the world are manufactured on the basis of a barrier discharge. But the special ceramic electrodes used for such ozonizers are highly sensitive to humidity and pollution of the air supplied to the device. Typically, these devices use cartridges to filter and dehumidify the air. In this research, corona discharge ozone generators were used due to sufficient energy efficiency and ease of implementation of this method of ozone synthesis from oxygen-containing gases. The results showed that that coatings with a thickness of up to 3-5 μm made it possible to create a layer on the electrode surface that protects against oxidation or has a conductive oxide that maintains the operability of the point electrode. Furthermore, In the system of electrodes of the point-plane type, a voltage of positive polarity was applied to the point electrode. The initial voltage applied to the discharge gap was 14–15 kV. As the surface properties of the samples changed, the voltage had to be reduced to avoid spark breakdown.

Recent trends in ozone sensing technology.

The harmful impact of ozone on humans and the environment makes the development of economical, accurate, and efficient ozone monitoring technologies necessary. Therefore, in the present review, we critically discuss developments in the methods for the synthesis of ozone sensing materials such as metal oxides (Ni, Co, Pd, In, Cu, Zn, Fe, Sn, W, Ti and Mo), carbon nanotubes, organic compounds, perovskites, and quartz. Additionally, the recent advancements and innovations in ozone technology will be discussed. In this review, we focus on assembling ozone-sensing devices and developing related wireless communication, data transferring, and analyzing technologies together with satellite, airborne, and ground-based novel ozone-sensing strategies for monitoring the atmosphere, urban areas, and working environments. Furthermore, the developments in ozone-monitoring miniaturized devices technology will be considered. The effects of different factors, such as spatial-temporal variation, humidity, and calibration, on ozone measurements will also be discussed. It is anticipated that this review will bridge the knowledge gaps among materials chemists, engineers, and industry.

Влияние материала мишени и размеров облучаемого объема на эффективность синтеза озона в плазме, создаваемой импульсным пучком электронов в воздухе

The effect of the target material and the size of the irradiated volume on the efficiency of ozone synthesis in air under the action of a pulsed electron beam is investigated. Graphite and lead targets were used. The highest concentration of ozone was observed in a chamber without a target, and the highest specific ozone yield without consideration of electron reflection (230 g(kWh)–1) was observed in a chamber with a lead target at a minimum air gap (3 cm). The results are explained by the processes of multiple reflection of electrons from elements with a high atomic number at small air gaps compared to the size of the target.

Evaluating the Environmental and Economic Performance of Municipal Solid Waste Disposal by All-Component Resource Recovery

Disposal of municipal solid waste (MSW) has become increasingly challenging. In this study, we used life cycle assessment (LCA) to evaluate environmental impacts and financial performance of a new approach for MSW disposals, namely All-components Resource Recovery (AcRR), which is based on automatic sorting. We compared AcRR with the standardized Waste-to-Energy incineration (WtE) to provide decision-making support for MSW management. The results show that WtE and AcRR are both good MSW resource treatment methods. Through MSW disposal, WtE generates electricity, while AcRR generates secondary resources such as metals, plastics, pulp and organic fertilizers. WtE releases trace amounts of HCl, PM10, heavy metals, dioxins and dust, while AcRR does not produce such pollutants; AcRR produces more odor gases such as SO2 and H2S. AcRR produces four environmental issues, i.e., Global Warming, Acidification, Photochemical Ozone Synthesis, and Eutrophication, each of which has a smaller impact than WtE; WtE has two more impacts than AcRR: Human Toxicity and Soot and Ashes. The total environmental impact potential of WtE is 3.38 times that of AcRR, and the greenhouse gas emission equivalent is 6.82 times that of AcRR. The cost of construction and operation of AcRR is lower than that of WtE, while the net profit of AcRR is much higher. In conclusion, AcRR is able to screen the mixed MSW into various secondary resources with less environmental emissions and environmental impacts and better financial performance; it may be a promising MSW disposal approach, especially for small cities, but a corresponding supporting industrial system is needed.

Research of ozonation process of the biologically pre-purified municipal wastewater

The paper considers the problem of post-treatment of municipal wastewater in Odessa using ozone. A significant place is given to the effect of the breakdown of toxic substances and important carcinogens. Based on theoretical studies, it was concluded that biological wastewater treatment does not guarantee a significant effect of the neutralization of many toxicants. The authors hypothesize the significant advantage of ozonation for the disposal and disinfection of wastewater compared to other methods, for example, chlorination. An important place is occupied by the search for optimal ozone treatment parameters. In laboratory conditions, data for mathematical modeling and optimization have been obtained. It has been established that the best treatment effect is achieved for the main wastewater pollutants, especially for synthetic surface-active substances (90 %) and BOD5 (65 %). Moreover, the processing time is 15 minutes at a dose of ozone of 20–25 mg/l. The concentration of total nitrogen decreases the least (20 %). It was found that a significant effect of disinfection by E. coli during ozonation is achieved by treating wastewater for 4 min at a dose of 3 mg/l of ozone. in a mixture of wastewater and natural water, this effect is achieved in 24 hours. The author's hypothesis of the gentle action of ozonation products for the widespread aquatic culture of Chlorella pyrenoidosa is confirmed. A significant effect of destruction under the influence of ozone of carcinogens was observed. It was found that up to 82 % of benzpyrene in wastewater is destroyed within 16 minutes at a dose of 15 mg/l. The authors conclude that ozonation is a universal method for the purification of biologically treated municipal wastewater, which has a significant effect on the destruction of many toxicants and pathogenic microflora, without the presence of ozonation products that inhibit the development of natural aquatic cultures. Further research should focus on finding low cost ozone synthesis methods.

Swift heavy ions irradiation of water ice at different temperatures: hydrogen peroxide and ozone synthesis and sputtering yield

ABSTRACT Water ices at 15 and 144 K were bombarded by swift heavy ions, 45.8 MeV 58Ni11 + and 606 MeV 64Zn26 +, to measure the induced chemical and physical effects. The column densities of water and the synthesized species, hydrogen peroxide (H2O2) and ozone (O3), were monitored via infrared spectroscopy. The formation and destruction cross-sections of precursor and products were determined and compared with literature. The H2O2 formation and destruction cross-sections reveal a linear dependence with electronic stopping power, σ ∝ Se. The sputtering yield (Y0) shows a power law with electronic energy lost, $Y_0\propto S_\mathrm{e}^2$, and an exponential increase with the sample temperature. The findings indicate that the radiolysis rate of water ice is higher at low temperatures while the desorption yield increases at higher temperatures. A large amount of water ice is located in the grain mantles of the circumstellar envelopes and the interstellar medium regions, which are exposed to galactic cosmic rays (GCRs). The synthesis of H2O2 and O3 molecules as a function of absorbed doses of GCR irradiation and their irradiation time is analysed in detail. Besides, the extrapolation of the sputtering yield rates, as a function of time and temperature, for astrophysical conditions can contribute to a better understanding of non-thermal sputtering of water ices.

Effects of O2 addition on the plasma uniformity and reactivity of Ar DBD excited by ns pulsed and AC power supplies

Dielectric barrier discharges (DBDs) have been widely used in ozone synthesis, materials surface treatment, and plasma medicine for their advantages of uniform discharge and high plasma-chemical reactivity. To improve the reactivity of DBDs, in this work, the O2 is added into Ar nanosecond (ns) pulsed and AC DBDs. The uniformity and discharge characteristics of Ar ns pulsed and AC DBDs with different O2 contents are investigated with optical and electrical diagnosis methods. The DBD uniformity is quantitatively analyzed by gray value standard deviation method. The electrical parameters are extracted from voltage and current waveforms separation to characterize the discharge processes and calculate electron density n e. The optical emission spectroscopy is measured to show the plasma reactivity and calculate the trend of electron temperature T e with the ratio of two emission lines. It is found that the ns pulsed DBD has a much better uniformity than AC DBD for the fast rising and falling time. With the addition of O2, the uniformity of ns pulsed DBD gets worse for the space electric field distortion by O2 −, which promotes the filamentary formation. While, in AC DBD, the added O2 can reduce the intensity of filaments, which enhances the discharge uniformity. The ns pulsed DBD has a much higher instantaneous power and energy efficiency than AC DBD. The ratio of Ar emission intensities indicates that the T e drops quickly with the addition of O2 both ns pulsed and AC DBDs and the ns pulsed DBD has an obvious higher T e and n e than AC DBD. The results are helpful for the realization of the reactive and uniform low temperature plasma sources.

Life cycle assessment on the environmental impacts of different pig manure management techniques

The management of livestock waste is an effective way to achieve emission reduction and carbon fixation in agriculture and rural areas. At present, aerobic composting and anaerobic fermentation are widely used in livestock waste treatment technology. In this study, pig manure management was taken as an example, a comprehensive environmental load index was constructed to quantitatively evaluate the environmental impacts of global warming, environmental acidification, eutrophication, and photochemical ozone synthesis during aerobic composting and anaerobic fermentation based on the life cycle assessment. The results showed that the potential values of aerobic composting and anaerobic fermentation were similar, and the order was global warming, environmental acidification, eutrophication, and photochemical ozone synthesis. Anaerobic fermentation contributed more to global warming, while aerobic composting contributed more to environmental acidification, eutrophication, and photochemical ozone synthesis. In addition, the environmental load index of aerobic composting was significantly higher than that of anaerobic fermentation. There were certainly regional differences in the environmental load index, and the environmental impact effect of anaerobic fermentation was low and more environmentally friendly. These findings provided a technical basis for livestock manure management in different regions of China, which was conducive to promoting animal husbandry emission reduction and carbon sequestration. Keywords: manure management, life cycle assessment, low carbon treatment, aerobic composting, anaerobic fermentation, environmental impact assessment, emission reduction and carbon sequestration DOI: 10.25165/j.ijabe.20221503.6212 Citation: Dong B C, Song C J, Li H B, Lin A J, Wang J C, Li W. Life cycle assessment on the environmental impacts of different pig manure management techniques. Int J Agric & Biol Eng, 2022; 15(3): 78–84.

THE INFLUENCE OF CATHODE MATERIAL ON THE CHARACTERISTICS OF PULSED NEGATIVE CORONA IN OXYGEN

Change in time for the shape of the discharge current pulses of the pulsed negative corona in oxygen with cop-per and stainless steel cathodes has been studied for two discharge modes. The change lies in the decrease of the pulse amplitude and duration at half maximum. It is shown that for stainless steel cathodes, the amount of electric charge transferred in one pulse of the discharge current is 15% greater than for copper cathodes. It is also shown that under the maximum load mode, the amount of charge transferred in one pulse of the discharge current is de-creased with time by 10% for both types of cathodes. It is shown that ozone synthesis in the electrode system with copper cathodes is 25% more efficient.

A Novel Dielectric Barrier Discharge (DBD) Reactor with Streamer and Glow Corona Discharge for Improved Ozone Generation at Atmospheric Pressure.

Discharge mode is an important parameter for ozone synthesis by dielectric barrier discharge (DBD). Currently, it is still challenging to stably generate glow discharge with oxygen at atmospheric pressure. In this paper, a DBD reactor with a layer of silver placed between the electrode and the dielectric layer (SL-DBD) was developed. Experimental results show that both streamer and glow corona discharge were stably generated under sinusoidal excitation with a 0.5 mm discharge gap in a parallel-plate DBD, due to the increased electric field strength in the discharge gap by the silver layer. It was also found that, in the SL-DBD reactor, glow corona discharge enhances the discharge strength by 50 times. The spectral peak of O at 777 nm in SL-DBD is increased to 28,800, compared with 18,389 in a reactor with a streamer only. The SL-DBD reactor produces ozone with a concentration of as high as 150 g/m3 and shows good stability in an 8 h durability test.

The influence of gas temperature on ozone generation and decomposition in ozone generator. How is ozone decomposed?

The ozone synthesis and decomposition processes in a heated ozone generator (10–70 °C) in a pulse discharge was investigated. Concentrated ozone (up to 200 g Nm−3) was also decomposed at temperatures of 10–90 °C without discharges for comparison. It was found that for residence times up to approx. 4 s, the gas temperature in the gap has no significant effect on the ozone concentration drop. However, the appearance of electrical discharges in the gap causes that even at low temperatures and at very low powers, ozone decomposition is intensive. It has been shown that ozone decomposition is caused by a momentary increase in gas temperature (energy) within the microdischarge channels, and not by high gas temperature in the entire discharge gap. Ozone decomposition occurs mainly in microdischarge channels. The increase in gas temperature adversely affects the ozone concentration achieved, as it hinders the removal of heat from the microdischarge channels.

DEVELOPMENT AND RESEARCH OF A HIGH-PERFORMANCE ELECTRONIC DEVICE FOR OZONE SYNTHESIS IN A VIBRATION DRYER

The article analyzes the features of drying grain raw materials using a vibrating dryer, in which the drying agent is a mixture of heated air in combination with ozone of a certain concentration. Based on the analysis to intensify this process, we propose to develop a high-performance electronic device for ozone synthesis. The scientific study considers oscillations that increase and update the heat transfer surface regardless of the method of supply of the drying agent. Due to this, the removal of moisture intensifies, the drying speed increases. Having conducted a search and analyzed the process of vibration drying, we can say that in the future will progress two main trends in their development. This is the use of vibration in combination with the action of ozone on the raw material entering the drying. Ozone interacts with the membrane structure of bacteria, fungi, the structural unit of viruses, which leads to a violation of its barrier function and their death. The bactericidal effect of ozonation is superior to the effect of ultraviolet quartz radiation. Bactericidal effect from quartz irradiation for 60 minutes identical to the bactericidal effect of ozone for 3 minutes Ozone has a high penetrating ability and also shows antibacterial activity against gram-positive flora, Escherichia coli, epidermal staphylococcus. This method is the most effective general method of controlling the dynamic state of the processed raw materials. The analysis allows us to suggest possible solutions for the use of low-frequency oscillations for separation processes and outline the prospects for their application. It is proved that the existing equipment is used with significant energy consumption and high cost. The constructions and technologies considered in the work do not completely exhaust the possibilities of using vibration and ozone, although they testify to the expediency of their application and combination not only in agricultural production, but also in other industries in order to intensify processes and obtain quality products.

Enhancement of Ozone Synthesis via ZnO Coating for Hybrid Discharge in Pure Oxygen

Enhancement of Ozone Synthesis via ZnO Coating for Hybrid Discharge in Pure Oxygen

Nonlinearity of initiating and extinguishing boundaries of DBDs with airflows

Various applications of volume dielectric barrier discharges (DBDs) with airflows have attracted significant attention such as in the fields of plasma medicine, surface modification, ozone synthesis, etc. In this work, the nonlinearity characteristics of DBDs in initiating and extinguishing boundaries with airflows are experimentally investigated. It is found that the difference between initiating pulse repetition frequencies (PRFs) and extinguishing PRFs is affected by the addition of airflows. A hysteresis region is produced between these two PRFs. A topological rule of Thom’s classification theorem is proposed to investigate the hysteresis phenomenon of discharges with airflows. It is concluded that the discharge state is dependent on the operation route. The discharge state would transit from initiating to extinguishing, or in the opposite direction, while passing along a specific operation route. Based on the topological method, two nonlinear laws of discharge structure transition under the typical operation routes are predicted and verified in the discharge experiments.

Increasing the Efficiency of Ozonizing Devices in Agriculture

There is a sufficient degree of using ozone in agricultural production. First of all, it is used for equipment and poultry farms’ rooms disinfection, water sanitation for animals’ watering and for air and food treatment as well. There are some other known uses of ozone in agriculture. Needed amount of ozone can be generated with different electrical and physical methods. Ozone synthesis in the barrier discharge is the most common. There are given recommendations for ozone generators constructive settings in the researches. They are magnitude and frequency of the connection voltage; surface area and constructive features of the electrodes and a gap between them. Furthermore, they are composition and characteristics of the air for ozone synthesis, temperature and humidity level. A construction of ozone generator was developed and patented according to the results of the research. A scheme of a power source for ozone generator is given. It increases the efficiency of ozone production and decreases its cost.

INVESTIGATION OF OZONE SYNTHESIS IN THE NEGATIVE PULSED CORONA DISCHARGE IN OXYGEN AT THE COMBINED SUPPLY VOLTAGE

The influence of combined supply voltage parameters (bias voltage and voltage pulse amplitude) on efficiency of ozone synthesis in the negative pulsed corona discharge in oxygen was obtained. Pulse overvoltage led to intensification of discharge processes. Bias voltage applied during the discharge channel relaxation essentially increased the efficiency of ozone synthesis. It was established that the “optimal” bias voltage which provides maximum ozone generation doesn’t depend on voltage pulse amplitude, but depends on input oxygen concentration and generated ozone concentration.

Mass-independent fractionation of titanium isotopes

Forty years ago, the synthesis of ozone has revealed mass-independent fractionation (MIF) of oxygen isotopes. Among the numerous published interpretations of this ozone effect, the present paper reports that a titanium MIF observed during chemical reactions in plasma can be accounted for by one of these theoretical treatments. A gaseous mixture of TiCl 4 /C 5 H 12 carried in a glass tube by a continuous flow of N 2 was submitted to a HF discharge. Carbonaceous grains, presumably resulting from homogeneous condensation, show radial variations in Ti concentration with isotopic variations ranging from −25 to +125% for all m Ti / 48 Ti isotope ratios ( m standing for masses 46, 47, 49 and 50). It is proposed that the reduction rates by carbon radicals, of the metastable molecules formed by the isotope exchange reactions between Ti and TiCl 4 are different if they involve distinguishable or indistinguishable isotopes. A numerical simulation reproduces the experimental isotope patterns defined by the m Ti / 48 Ti isotope ratios.