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The reactivity worth of many fission product samples was measured in fast spectrum conditions in the STEK facility during the early 1970s. These results were then used to improve and validate nuclear data evaluations for fission products, but in the last 2 decades STEK has not been used: the nuclear data evaluations for fission products in the current versions of libraries like ENDF/B or JEFF have not been tested against STEK results. Here we argue that the STEK data are still valuable, because there is no other data set that can replace them, and the interest in fast spectrum conditions is picking up strongly of late. It should be considered to evaluate whether a benchmark can be defined for the International Reactor Physics Experiments Handbook.

Abstract The conversion of biomass is a favorable alternative to the fossil energy route to solve the energy crisis and environmental pollution. As one of the most versatile platform compounds, 5‐hydroxymethylfural (HMF) can be transformed to various value‐added chemicals via electrolysis combining with renewable energy. Here, the recent advances in electrochemical oxidation of HMF, from reaction mechanism to reactor design are reviewed. First, the reaction mechanism and pathway are summarized systematically. Second, the parameters easy to be ignored are emphasized and discussed. Then, the electrocatalysts are reviewed comprehensively for different products and the reactors are introduced. Finally, future efforts on exploring reaction mechanism, electrocatalysts, and reactor are prospected. This review provides a deeper understanding of mechanism for electrochemical oxidation of HMF, the design of electrocatalyst and reactor, which is expected to promote the economical and efficient electrochemical conversion of biomass for industrial applications.

The National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS) in the Device Assembly Facility (DAF) and operated by Los Alamos National Laboratory (LANL) is the only general purpose critical experiments facility in the United States. Experiments from subcritical to critical and above prompt critical are carried out at NCERC on a regular basis. In recent years, NCERC has become more involved in experiments related to nuclear energy, including the Kilopower/KRUSTY demonstration and the recent Hypatia experiment. Multiple nuclear energy related projects are currently ongoing at NCERC. This paper discusses NCERC’s role in advanced reactor design and how that role may change in the future.

The supervision mode, monitoring basis and monitoring scheme of radiation environment monitoring concerning typical research reactors in China were investigated in this study. Summary and analysis were concluded of the present situation of supervised monitoring of radiation environment, such as monitoring objects, points, frequency and so on, based on the relevant data of monitoring points of four typical research reactors in China. Some experiences and existing problems were analyzed concerning the supervised monitoring of China's research reactors. Tips on topics related to strengthen the monitoring of radiation environment around the research reactors has noted.

China’s nuclear energy ambitions, backed by the strong financial potential of the national economy, and the consequent desire to extend its successes in international economic cooperation to the nuclear industry have attracted the researchers’ attention to a closer examination of the current state and nuclear industry prospects of China, taking into account its technological component. The unfulfilled development plan for nuclear power in the 13th Five-Year Plan, as a result of systemic mistakes and failures in the projects selected for implementation, leads to the conclusion that it is necessary to involve foreign leaders in this field, including “Rosatom” corporation, which has in its portfolio virtually verified modern technical solutions.

The decommissioning of a nuclear power plant is a costly and highly complex process, requiring not only a planning and rigorous chronogram execution as well as funds large enough to cost it. The Long-Term Operation of the plant is not only interesting since it allows the plant to keep producing energy with low-carbon footprint as well as postpone to future these expenses. Around the world several nuclear power plants are being evaluated for Long-Term Operation due to these reasons. In Brazil the oldest nuclear plant, Angra 1, is also being evaluated for Long-Term Operation, otherwise it should be retired/shutdown in next future. However, besides the technical reasons, also the plant’s decommissioning fund seems to be not enough to cost its decommissioning. In the present work, the decommissioning fund of Angra 1 is evaluated considering two different interest rates and compared with the decommissioning cost. The results demonstrates that the Long-Term Operation is necessary and a good decision since it allow an additional time to the provisions on the decommissioning cost increase, avoiding the lack of funds.

Thermochemical heat storage has attracted significant attention in recent years due to potential advantages associated with very high-energy density at the material scale and its suitability for long-duration energy storage because of almost zero loss during storage. Despite the potential, thermochemical heat storage technologies are still in the early stage of development and little has been reported on thermochemical reactors. In this paper, our recent work on the charging and discharging behavior of a fixed-bed thermochemical reactor is reported. Silica gels were used as the sorbent for the experimental work. An effective model was established to numerically study the effect of different charging conditions on the discharging behavior of the reactor, which was found to have a maximum deviation of 10.08% in terms of the root mean square error compared with the experimental results. The experimentally validated modelling also showed that the discharging temperature lift increased by 5.84 times by changing the flow direction of the air in the discharging process when the charging level was at 20%. At a charging termination temperature of 51.25 °C, the maximum discharging temperature was increased by 2.35 °C by reducing the charging flow velocity from 0.64 m/s to 0.21 m/s. An increase in the charging temperature and a decrease in the air humidity increased the maximum discharging outlet temperature lift by 3.37 and 1.89 times, respectively. [ABSTRACT FROM AUTHOR]

An improved higher-efficiency alkylation reactor design has been developed and the principle of operation of such reactor is given. The components of the reactor are described. The flow velocity isocontours in the control sections of the reactors of conventional and modernized designs, based on which the efficiency of use of new technical solutions is confirmed, are obtained. [ABSTRACT FROM AUTHOR]

Copyright of Journal of East China University of Science & Technology is the property of Journal of East China University of Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A continuous flow photocatalytic reactor was developed by combining the reaction kinetics and mass balance concept. The concept of cascade aerator was also considered in designing it as a stepped reactor. The reactor was used to investigate the photocatalytic degradation of methylene blue in aqueous solution by Ag+ doped TiO2 (2 g/L) under UV irradiation by 15 W UV lamps (254 nm). Methylene blue solution (20 ppm) was found to be decolorized by >99, 97, 85 and 57 % under flow rates of 1, 1.5, 2 and 3 L/h, respectively after 120 minutes. The corresponding mineralization was >80, 78, 75 and 54 %, respectively. At higher flow rates (Re number 208.2 and 415.5) >99 % decolourization was achieved by recycling the solution 5 and 7 times with fresh doses of photocatalyst. At steady state, maintained by repeating the addition of photocatalyst at fixed time intervals, the dye solution could be decolourized continuously by >99, 97 and 76 % at flow rates of 1, 2 and 3 L/h, respectively while the mineralization was >82, 79 and 62 %, respectively. The reactor was also effectively used to mineralize textile wastewater collected from a textile mill in Kolkata. The mineralization was greater than 75, 73 and 64 % at flow rates of 1, 2 and 3 L/h, respectively after 120 minutes. The efficiency of the reactor depended upon the residence time of the contaminant in the reactor. At steady state, the design data simulated well with the corresponding experimental data. [ABSTRACT FROM AUTHOR]

The disadvantages of the reaction units of hydrotreatment plants are considered and an approach to process improvement by means of the characteristics of hydrodesulfurization reactions of organosulfur impurities of various nature is substantiated. The mathematical modeling method demonstrates that when dividing the feedstock into three wide fractions, each containing several narrow fractions, differential hydrotreatment of these wide fractions is ensured by a reduction in the catalyst load in the reactor unit of the facility. [ABSTRACT FROM AUTHOR]

Biological reactors are employed in industrial applications to break down organic waste. Here we consider the stability of an open loop CSTR, with a general growth rate function, having both a bacterial and substrate feed and a death rate. Reactors with a bacterial feed are important as every reactor after the first in a cascade will have both bacterial and substrate feeds. We show that stability of a critical point is related to the sign of the slope of the growth rate function, when no bacterial feed is present, and to the sign of the slope of a function, being the product of the growth rate function and a function involving the substrate and bacterial feed concentrations, when a bacterial feed is present. [ABSTRACT FROM AUTHOR]

In power electronic equipment, magnetic devices are important parts, and their working condition and reliability are closely related to turn‐to‐turn insulation. With the increasing application of high‐frequency square wave voltage in the fields of frequency conversion technology and motor control, the high voltage stress on magnetic devices will accelerate insulation aging, so it is necessary to monitor the aging state of turn‐to‐turn insulation. At present, researchers mainly detect insulation aging by detecting partial discharge signal. However, this method cannot realize the early monitoring of aging, and the measurement cost is high and the accuracy is low. Therefore, for the dry‐type core reactor with epoxy resin as the insulation medium, this paper proposes a turn‐to‐turn insulation aging state detection method under high‐frequency square wave voltage excitation. According to the relationship between the turn‐to‐turn insulation aging state of the reactor and its parasitic capacitance, the turn‐to‐turn insulation aging degree of the reactor is predicted by measuring and analyzing the phase information of high‐frequency components of the current signal. Finally, the measuring principle and method are introduced and verified by experiments. [ABSTRACT FROM AUTHOR]

Straight grate furnaces are widely used for induration of hematite pellets where typically 1%– 2% carbon is added to the green mix to help in generating heat by combustion. The quality of the pellets in such reactor varies from top to bottom of the bed as different layers of pellets are exposed to varying thermal and gaseous environments. The thermal evolution (as a function of time) at a specific location in a moving pallet car was studied through plant scale experiments. Subsequently, these experimental temperature measurements were supplemented with a 1-D heat transfer model of the pellet bed. It was observed, from simulation results, that peak temperature faced by the pellets in top layer and bottom layer of the pellet bed differed by 105°C. The effect of bed height and grate velocity on the pellet bed thermal profile was studied using the model. With increase in production rate through increase in grate velocity and bed height, this difference further intensified. These findings can provide insight to plant operator to optimise production rate. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate the estimated people's fatalities percentage due to methanol reactor incident from a newly proposed plant in Perak, Malaysia. This work investigated the possibility of (1) various events occurring in term of toxicity, thermal radiation, and overpressure, and (2) the fatalities percentage when these events occurred due to the release of chemical mixtures from the reference plant, which has 42 m3 reactor volume and operates at 76.4 bar; and three reactor scenarios in which the reactor volume is reduced to 7.6 m3, while operating pressures are 76.4, 150, and 300 bars. HYSYS software was employed to simulate the process and obtain the mass density of the mixture, mass fraction, and volume fraction, while ALOHA and MARPLOT software was used to calculate the amount of toxicity, thermal radiation, overpressure and area affected. The methanol reactor contains a mixture of hydrogen, carbon dioxide, methanol, carbon monoxide, and water, where only water is not considered hazardous. Release of chemical mixture via three-hole size scenarios, 10 mm, 25 mm, and 160 mm was proposed, and the simulation was carried out. Results showed that reference plant and plant 300 bar exhibit the highest fatalities percentage for overall and reduced reactor volume (15.7% and 11.2%), both caused from the release of carbon dioxide at night through a 160 mm hole leakage. This study can be used to suggest the best location for the methanol plant to be built to avoid any deaths to people living surrounding area. [ABSTRACT FROM AUTHOR]

In the present study, a novel fixed-bed continuous reactor with a preheating chamber was designed to be utilized for the practical application of removal studies of dangerous pollutants, especially NO X removal by NO X Storage Reduction (NSR) catalysts on a laboratory scale. The reactor's design and operational parameters, including outer wall temperature (50-600 °C), volumetric flow rate (0.3-3 L/min), wall temperature time (0.16-10 min), and granule surface area inside the preheating chamber (0-270 cm 2 ), were statistically modeled and optimized using Response Surface Methodology (RSM). For more logical and effective parameter optimization, the ratio of gas and catalyst temperatures and pressure drop to the reactor outer wall temperature (GT/ROWT, CT/ROWT, and PD/ROWT) were also included in the optimization process. Experimental results showed that gas temperature, catalyst temperature, and pressure drop ranged from 31 to 177 °C, 51-585 °C, and 7-153 Pa, respectively. Optimal conditions were determined to be an outer wall temperature of 230 °C, a volumetric flow rate of 3 L/min, a wall temperature time of 0.16 min, and a granule surface area of 67.3 cm 2 . The results demonstrated that outer wall temperature, flow rate, time, and surface area of granules have significant and interaction effects on the responses and should be considered when researchers assess the removal efficiency of thermal catalysts., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

In the proton exchange membrane fuel cells, the required hydrogen must be produced in some way. The power generators in the path of these fuel cells generally include a steam reactor that, through other fuels, provides the needed energy to produce hydrogen. This study investigates a steam reactor powered by propane fuel consisting of a shell and tube heat exchanger. The shell contains a catalyst that receives the mixture of propane and steam, and the tubes embedded inside the reformer contain hot gases that provide a suitable substrate for the reaction. Velocity and temperature fields inside the reformer, species concentration control, and reaction rate are studied. The conversion of reactants and yield of products are investigated according to the reaction rate. The results show that the hydrogen production yield can vary from 77.5 % to 92.2 %. The reaction rate can be controlled by the velocity and temperatures of the hot gases. However, for the T=900 K, full propane consumption is achieved at the reformer outlet.

Abstract Globally, the reserves of heavy crude oil are seven times more abundant than that of light crude, and yet, they are underutilized because of their high viscosity and density, which is largely due to the presence of large amounts of asphaltenes. Biotransformation of heavy oil asphaltenes into smaller metabolites can be used for reducing their viscosity. Several microorganisms capable of asphaltene biodegradation have been reported but only few have been characterized for its biotransformation. In the present study, a 9-membered microbial consortium was isolated from an oil contaminated soil. About 72% and 75% asphaltene biotransformation was achieved by growing cells at shake flask level and in a 1.5 l bioreactor, respectively. A representative structure of asphaltene was constructed based on LC–MS, 1H-NMR, 13C-NMR, FT-IR, ICPMS and elemental analysis (CHNS) of n-heptane purified asphaltene from Maya crude oil. Biotransformation of asphaltene, as analyzed by performing 1H-NMR, FT-IR and elemental analysis, resulted in 80% decrease in S and N when compared to the control along with incorporation of oxygen in the structure of asphaltene. About 91% decrease in the viscosity of the Maya crude oil was observed after two weeks when oil: aqueous phase ratio was 1:9. The results suggest that the isolated microbial consortium can be used for biological upgradation of heavy crude oil. To our knowledge, this is the first report where a microbial consortium resulted in such high asphaltene biotransformation.

The suitable cooling of fuel elements in a nuclear reactor is an important requirement that must be met to avoid that the fuel temperature rises above the safety limits according to the reactor design. During the reactor operation, there are transients that could lead to a temperature that overcomes these limits, such as those related to the cooling system. The CFD codes are tools that could aid in the understand effort of the phenomenon during such transients, allowing to access details of the flow that are not possible, or are possible only with limitations, by using other kind of codes or experiments. In the present work the results obtained using ANSYS-CFXÒ code for the IEA-R1 reactor during a steady state and transient of slow loss of cooling accident event are presented. The results obtained shown a good agreement with experimental data reported and works that used this reactor as case of study. These results are part of a research in which the main objective is to simulate the flow of the coolant in the fuel element channels during transients. These results would support an initial analysis of the flow during the transition from forced to natural convection that occurs when the coolant flow falls below a settled value and the valve on the bottom of the fuel element opens by gravity, aiming to understand better phenomena involved and the limitations of the models available in the ANSYS-CFXÒ code.

Hydrogen is the promising carbon-free fuel to be used massively in future transport based on fuel cell electric vehicles (FCEV) and internal combustion engines (ICE). The reliable and safe way to store hydrogen in vehicles is an open question. As a promising potential solution, hydrogen storage in liquid ammonia is postulated. In this case, the hydrogen is released due to ammonia decomposition under heat energy supply. In the hydrogen ICE, the ammonia decomposition could be provided at the expense of exhaust gas energy. The current article deals with developing test tools and methods for the experimental study of catalysts and reactor prototypes appropriate to the hydrogen ICE. A thermal-hydraulic approach without chromatography and mass spectrometry has been proposed to determine ammonia decomposition kinetics at different fluid pressure, temperature, and flow rate. The tests have validated the approach with the decomposition of ammonia in catalysts with aluminium shavings in stainless steel tube with an inner diameter of 10 mm. The identified ammonia decomposition rate is 0.0119 mol of H2 per gram of catalysts in 1 h.

In 2022, the physical start-up stage of the IVG.1M research reactor was successfully completed, initiated by reducing the fuel enrichment of 235U. This phase included the loading of nuclear fuel into the reactor core and conducting experiments to determine the neutron-physical characteristics of the reactor. Prior to the physical start-up, preliminary calculations were performed using the computational code MCNP6 and a full-scale model of the IVG.1M reactor with low-enriched uranium fuel (LEU). During the start-up series, the reactivity worth curves of the reactor control and protection system’s operating and compensating elements were determined. Additionally, experiments were performed to measure the reactivity effects of technological channel draining and to obtain activation reaction rates in the central experimental channel using nickel and gold activation indicators. The results of determining the neutron-physical characteristics of the IVG.1M reactor have confirmed the operability of the reactor core with LEU fuel.

SaLurated core fault currenl limiler will cause higher harmonic pollulion when used in series compensaLion. In order Lo ensure Lhe safe and sLable operalion of the power system, Lhe saturaled core fault currenL limiter with improved air gap structure is designed based on the principle of segment saturated core. The simulation models of saturated core fault current limiter with different air gap structures are established by JMAC. The relationship between current and flux of the current limiter is imported into MATLAB/ Simulink and the corresponding simulation system model is established to further analyze and compare the control characteristics, harmonic content and fault current limiting abiliLy of Lhe Lwo currenl limiLer models. The resulLs show thaL Lhe saLurated core faulL currenl limiter with improved air gap structure has aboul 1. 5 Limes of reactance regulation range and lower harmonic dislortion rale when compared with the full air gap structure without losing the current limiting capacity. [ABSTRACT FROM AUTHOR]

Co-pyrolysis technology is an important direction for high quality conversion and high value utilization of biomass and plastics. Mastering the co-pyrolysis analysis technology and development trend of biomass and plastics is conducive to accelerating the treatment and utilization of biomass, waste plastics and other wastes. By introducing the latest research progress of co-pyrolysis technology of biomass and plastics, the kinetic model of co-pyrolysis process and the synergistic effect between components are summarized, and the characterization of co-pyrolysis of biomass and plastics under different methods and reactors is discussed. Co-pyrolysis of biomass and plastics can reduce the activation energy required for thermal conversion, and the synergistic effect of co-pyrolysis can promote the formation of liquid and gaseous products. Pyrolysis temperature, heating rate and pyrolysis time are the main factors affecting the co-pyrolysis process and products. This paper provides a reference for the selection of biomass and plastic co-pyrolysis reactor types and related technical analysis. [ABSTRACT FROM AUTHOR]

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrogenation of metals is an exothermic and reversible process. Thus, metal hydride reactors/devices become essentially heat-driven. Excellent heat control in the MH reactor is required to develop metal hydride devices such as H2 storage systems successfully. Few attempts at nature-inspired designs have proven to have good heat transfer capabilities. Based on this idea, the present study investigates novel bio-inspired leaf-vein type fins for the metal hydride reactor. Two reactor designs are proposed for heat transfer fluid flow, namely (i) central straight tube and (ii) narrow trapezoidal channels with 10 kg of LaNi 5 as a sample alloy. Compared to longitudinal finned single tube reactors (LFSTR), these designs provided better heat transmission and temperature uniformity. For LFSTR, Case-1, and Case-2, 90% storage capacity was reached in 210, 145, and 80 s. Different fin configurations, such as parallel, inclined fins, and fins of different thicknesses, are investigated further in the design with narrow trapezoidal channels. The inclined fin configuration shows better performance, and it is further optimized by varying the inclination angle from 3 to 9° and the fin number from 2 to 4. The optimized design with a 7° inclination angle and four fins required 57 s to attain 90% storage capacity and reduced absorption time by 73% compared to LFSTR. The influence of operating parameters such as hydrogen supply pressure, inlet temperature, and velocity of the heat transfer fluid on the performance is evaluated for the optimized design. [Display omitted] • Novel bio-inspired leaf-vein-shaped fins are proposed for the metal hydride reactor. • Absorption time is reduced by 62% with leaf-type fins compared to basic design. • The design is optimized by varying fin inclination angle and fin number. • The optimal design is achieved with four fins with a 7° fin inclination angle. [ABSTRACT FROM AUTHOR]

Summary: The disposal of food waste has become an environmental issue of great concern with the increasing consumption of materials. The conversion of food waste into biofuels using biotechnology is a very promising approach. Food waste can be converted into fuels such as bio‐methane, bio‐hydrogen, bio‐ethanol, and bio‐diesel by different biotechnologies. Food wastes as raw materials for biofuel preparation are mainly classified into protein, fat, starch, sugar, and cellulose. Carbohydrate‐rich wastes such as straw, bagasse, grape and apple pomace, and kitchen garbage can produce biofuels, which can be converted into biofuels through anaerobic digestion, aerobic digestion, and microbial fermentation processes. Co‐substrates are increasingly used to increase biofuel production and to overcome the shortcomings of a single substrate. The main raw materials for each biofuel are different. Anaerobic digestion technology can be utilized for the production of biomethane, and the digestion efficiency can be changed by the adjustment of the substrate combination, and reactor configuration. The process of methane production by anaerobic digestion mainly includes hydrolysis, acid production, acetic acid production, and methane production. The main raw materials used for methane preparation are livestock manure (pig manure, chicken manure, cow manure, etc.), straw and kitchen waste. Each raw material has a different methane yield and environmental friendliness. Fermentation technology of Saccharomyces cerevisiae can be used to produce bio‐ethanol, which consists mainly of raw material pretreatment, enzymatic digestion (saccharification), fermentation, and ethanol production. Cellulosic raw materials (including hemicellulose) are the most promising raw materials for ethanol production on earth, mainly straw, wood chips, peanut shells, and corn. Coupled biomass dark and photo‐fermentation technologies can be utilized to produce bio‐hydrogen, which includes degradation, dark fermentation, photo‐fermentation, and hydrogen production. Food waste containing lipids, proteins, and complex carbohydrates is a good substrate for the dark fermentation stage. The main raw materials for hydrogen production are kitchen wastewater, sugars (glucose), starch (cassava), and cellulose (water hyacinth and rice straw). Hydrothermal liquefaction, hydrothermal gasification, and hydrothermal carbonization technologies can be utilized to produce bio‐oil or bio‐char. The raw materials for bio‐oil/biochar are mainly Edible vegetable oil, nonedible vegetable oil, animal oil, waste edible oil, coffee residue, peanut shell, brewer's grains, grape pomace, sugarcane peel, straw, and wood chips, etc. The industrialization of biofuel technologies is limited by the lack of relevant research and needs to be extensively and thoroughly evaluated. In this paper, the respective advantages and disadvantages of each biofuel technology are clarified and the effects of culture conditions, pretreatment technologies, and reactors on biofuel production are discussed from a technological perspective. In the future, the technology of producing biofuels from various food wastes needs more research in waste conversion rate, product yield, treatment cycle, and cost effectiveness. [ABSTRACT FROM AUTHOR]

The operation of an unsteady-state well-stirred flow-through biochemical reactor is studied. Nonlinear boundary-value problems describing the operation of such reactors are considered. Nontrivial solutions under homogeneous boundary conditions are sought. The analysis is based on the equations of the diffusion model. The switch of the operating modes of the reactors in the case of several solutions of the equations of the process is analyzed. [ABSTRACT FROM AUTHOR]

Zr1 –хUхN nitrides have been synthesized via nitridation of solid solutions of uranium in zirconium. High-temperature saturation of the solid solutions with nitrogen has been shown to yield Zr1 –хUхN ceramics uranium-enriched in their central part. We have presented the concept of a new type of fuel, based on Zr1 –хUхN, for high-temperature gas-cooled reactors. Nuclear calculations of a reactor core demonstrate the feasibility of reaching the critical mass at uranium contents of 10 and 20 wt %. The core size of a conceptual reactor has been determined. We have performed thermophysical calculations of the reactor core and demonstrated the feasibility of obtaining high-grade heat. [ABSTRACT FROM AUTHOR]

The Anammox process has attracted widespread attention because of its high denitrification efficiency, no need for oxygen supply, no need for organic carbon sources, less sludge production, small process area and low capital investment. The denitrification characteristics and influencing factors (temperature, dissolved oxygen, pH value, metal ions, light, and ammonia nitrogen concentration) of Anammox bacteria were reviewed. At the same time, the latest research progress of starting Anammox process using MBR, SBR, SBBR and UASB reactors at home and abroad is summarized, as well 血 the actual engineering application of Anammox in China. In ohIet to provide reference for the practical engineering application of Anammox process. [ABSTRACT FROM AUTHOR]

A semi-analytical model is presented for the determination of the electric field in reactors used for cold atmospheric pressure plasma (CAPP) jet production, based on the concept of dielectric barrier discharge (DBD). These systems are associated with various applications in contemporary engineering, ranging from material processing to biomedicine, and at the same time they provide many challenges for fundamental research. Here, we consider a simplified system configuration of a single driven electrode, surrounding a thin dielectric tube, which does not contribute to the electric field, since the potential variation is immediate due to its negligible size. By employing the cylindrical coordinate system that perfectly fits the present plasma jet reactor, we separate the area of electric activity into three distinct domains according to the imposed external conditions, while our analysis is restricted to the electrostatic limit of Maxwell’s equations. To this end, cylindrical harmonic field expansions are used for the potential, which produce the corresponding electric fields in each subdomain. Due to the imposed mixed-type boundary value problem, additional linear terms are incorporated, leading to three possible analytical solutions of the physical problem under consideration. The efficiency of the method is demonstrated by comparing the final formulae with a numerical solution, followed by the relevant discussion.

This study delves into the promising realm of clean energy production through thermochemical conversion and chemical advancements. As the global demand for sustainable energy intensifies, exploring innovative technologies becomes imperative. The focus here is on harnessing the potential of thermochemical conversion, coupled with advancements in chemical processes. This dual approach holds significant promises for generating clean energy. The abstract underscores the critical role of these technologies in meeting escalating energy needs while shedding light on the advancements, challenges, and opportunities that pave the way for their successful implementation. Waste biomass represents an excellent bioresource that can be harnessed to produce numerous types of energy carriers, including bio-oil, bio-crude oil, biodiesel, syngas, biochar, and hydrogen. This article reviews the potential of various types of biomasses, including food waste, agricultural and forestry biomass, energy crops & oilseed crops, municipal solid waste, and animal manure, and also discusses the different types of reactors. In this review, comprehensively discusses all thermochemical methods for bio-oil production, including pyrolysis, gasification, and liquefaction. Each method is examined in detail, highlighting their respective processes, advantages, and challenges. Additionally, various types of reactors used in these methods are analyzed, emphasizing their roles and efficiencies in optimizing bio-oil yield and quality. Therefore, this review article will help in understanding the potentiality of waste biomasses for the production of clean energy via thermochemical techniques. [Display omitted] • A systematic review for production of clean energy from biomasses. • Biomass conversion via torrefaction, pyrolysis, gasification, and liquefaction. • Types of biomasses for efficient conversion and their effect on fuel properties. • Challenges and strategies for improving efficiency in catalytic pyrolysis. • Advancements, challenges, & opportunities of biomass-based clean energy generation. [ABSTRACT FROM AUTHOR]

A new measurement of the reactor antineutrino flux and energy spectrum by the Daya Bay reactor neutrino experiment is reported. The antineutrinos were generated by six 2.9 GWth nuclear reactors and detected by eight antineutrino detectors deployed in two near (560 m and 600 m flux-weighted baselines) and one far (1640 m flux-weighted baseline) underground experimental halls. With 621 days of data, more than 1.2 million inverse beta decay (IBD) candidates were detected. The IBD yield in the eight detectors was measured, and the ratio of measured to predicted flux was found to be 0.946±0.020 (0.992±0.021) for the Huber+Mueller (ILL+Vogel) model. A 2.9σ deviation was found in the measured IBD positron energy spectrum compared to the predictions. In particular, an excess of events in the region of 4-6 MeV was found in the measured spectrum, with a local significance of 4.4σ. A reactor antineutrino spectrum weighted by the IBD cross section is extracted for model-independent predictions.

As a heat storage method with high heat storage density, long storage time and long transportation distance, the chemical heat storage has been widely studied in recent years. This article firstly summarized the basic principles and research progress of several existing solid-gas two-phase chemical heat storage reaction systems, mainly involving the metal hydroxide reaction, metal oxide reaction, carbonate reaction, and hydration salt reaction. Then, according to the moving state of solid phase reactant in the reactor, the reactor was divided into three types: the fixed bed reactor, fluidized bed reactor and moving bed reactor. Moreover, their research progress was summarized respectively. Finally, based on the current deficiencies in the research of chemical heat storage, the future development trend of chemical heat storage was analyzed. At present, the storage still needs further research, and there are still technical difficulties in strengthening and matching the chemical reaction rate and heat transfer. The cyclic stability of chemical heat storage under long-term operation condition still needs to be further explored.

Time-frequency analysis technique is an effective analysis tool for non-stationary processes. In the field of reactor neutron noise, the time-frequency analysis method has not been thoroughly researched and widely used. This work has studied the time-frequency analysis of the reactor neutron noise experimental signals under bubble disturbance and control rod vibration. First, an experimental platform was established, and it could be employed to reactor neutron noise experiment and data acquisition. Secondly, two types of reactor neutron noise experiments were performed, and valid experimental data was obtained. Finally, time-frequency analysis was conducted on the experimental data, and effective analysis results were obtained in the low-frequency part. Through this work, it can be concluded that the time-frequency analysis technique can effectively investigate the core dynamics behavior and deepen the identification of the unstable core process.

The problems of reprocessing and long-term storage of spent nuclear fuel (SNF) at nuclear power plants with RBMK reactors have not been fully resolved so far. For this reason, nuclear power plants are forced to search for new options for the disposal of spent fuel, which can provide at least temporary SNF storage. One of the possible solutions to this problem is to switch to compacted SNF storage in reactor spent fuel pools (SFPs). As the number of spent fuel assemblies (SFAs) in SFPs increases, a greater amount of heat is released. In addition, no less important is the fact that a place for emergency FA discharging should be provided in SFPs. The paper presents the results of a numerical simulation of the temperature conditions in SFPs both for compacted SNF storage and for emergency FA discharging. Several types of disturbances in normal SFP cooling mode are considered, including partial loss of cooling water and exposure of SFAs. The simulation was performed using the ANSYS CFX software tool. Estimates were made of the time for heating water to the boiling point, as well as the time for heating the cladding of the fuel elements to a temperature of 650 °С. The most critical conditions are observed in the emergency FA discharging compartment. The results obtained make it possible to estimate the time that the personnel have to restore normal cooling mode of the spent fuel pool until the maximum temperature for water and spent fuel assemblies is reached.

[Display omitted] • Long-term operation has proved the superiority of this catalytic ozonation process. • The gas–liquid counter-current flow better than co-current for COD removal. • The importance of catalyst packing was proved by setting wastewater short-circuiting. • After 5 years of use, the micro-porous aerator operated well-maintained. In this study, from the feasibility verification of the lab-scale test to the working condition study of the pilot-scale test the large-scale engineering application of the display manufacturing industry wastewater advanced treatment by ozonation with iron (Fe)-based monolithic catalyst packing was finally realized. Different from chemical packings, the catalyst packing has large porosity and specific surface area, while the pore size is small, which meets the requirements of •OH reaction, and these characteristics are necessary for engineering applications. Under the three scales, the reaction procedure and the corresponding reactor structure were introduced in detail. The importance of gas–liquid flow patterns and gas distribution device on treatment effect were proved in pilot-scale test. The treatment effect under gas–liquid counter-current flow was better than that of co-current flow. Through the analysis of the working conditions, the working parameters for high wastewater quantity and high organic loading were obtained. The large-scale test achieved the same excellent treatment effect as the lab/pilot-scale test, after 5 years of operation, the average chemical oxygen demand (COD) removal was about 72.0 %, and the COD concentrations after treatment were all lower than 30 mg/L. The biochemical oxygen demand (BOD 5) decreased from 10.22 to 2.50 mg/L on average. Under the short-circuiting phenomenon, the wastewater through the catalyst area unevenly and the organic pollutants were not effectively oxidized and decomposed. This also proved the importance of Fe-based monolithic catalyst packing in advanced treatment. This work proved the importance of gas–liquid flow patterns and wastewater flow regimes in the reactor, which can provide reference for other catalytic ozonation technology in large-scale engineering applications. [ABSTRACT FROM AUTHOR]

Solar thermochemical cycling is a promising approach to utilizing solar energy to produce H 2 and CO, which can be further synthesized into liquid fuels via Fischer-Tropsch reactions, making storage and transportation easier. Despite the potential high theoretical efficiency, factors such as the high temperature and low oxygen partial pressure required for the reduction restrict the large-scale application of this technology. In the near-to-medium term, in order to accelerate the popularization and application of this technology, according to Le Chatelier's principle, the assisted reduction of methane can greatly reduce the demand for high-temperature materials and ultra-low oxygen partial pressure. However, the addition of methane will also bring additional challenges, such as carbon emissions and carbon deposition. Reducing the influence of factors such as material sintering and irreversible loss on system efficiency in the experiment will be essential for the development of this technology. This paper focuses on the methane-driven two-step thermochemical cycle hydrogen production process, summarizes its reaction mechanism, thermodynamic analysis, kinetic analysis, oxygen carrier material doping, and experimental research in detail, and comprehensively analyzes the effect of material properties and irreversible loss on the system. According to thermodynamic and kinetic analysis, rational selection and doping of metal oxygen carrier materials can effectively reduce the reaction temperature, improve gas production rates, and enhance structural stability. Analyzing and trying to reduce various irreversible losses of the system, such as reradiation energy loss, conduction energy loss, etc., and taking appropriate heat recovery measures will help to improve the system efficiency of the actual cycle. This paper would be valuable for the development of this technology and for achieving the goal of carbon neutrality. [Display omitted] • The process of methane-driven two-step thermochemical cycles is reviewed. • Searching for high-performance oxygen carriers through doping and modification. • Significantly reduce the temperature and oxygen partial pressure of the reaction. • Pros and cons between methane-driven and non-methane-driven cycles are compared. [ABSTRACT FROM AUTHOR]

Hydrogen cyanide (HCN) is a crucial building block for various industrial chemicals in organic synthesis. Due to its high toxicity to humans and the environment, meticulous care is required in the synthesis, use, and disposal of HCN and its derivatives. This study investigated the premature failure of the HCN reactor, a core component of the HCN production system. Despite a design life of 20 years, the reactor experienced abnormal leakage after only 4 years of operation. Comprehensive investigations revealed that corrosion pits caused by localized corrosion formed at the circumferential welding seam of the reactor shell. This problem was further aggravated by vortex scouring from the pressurized water medium. Additionally, residual stress at the welding seam contributed to decreased toughness. The analysis highlighted the intricate relationship between localized corrosion and vortex scouring as the primary mechanisms leading to perforation and leakage of the reactor shell. Based on these findings, effective countermeasures were proposed to prevent similar future failures, potentially enhancing the operational safety and reliability of the HCN production system. • Premature failure of the HCN reactor occurred after only 4 years, despite a 20-year design life. • Localized corrosion pits formed at the circumferential welding seam of the reactor shell, leading to abnormal leakage. • Vortex scouring of pressurized water worsened the problem, highlighting the link between corrosion and hydraulic forces. • Proposed countermeasures aim to prevent similar failures, enhancing operational safety and reliability in HCN production. [ABSTRACT FROM AUTHOR]