Destruction Efficiency Research Articles

Potential Evaluation of Power-to-Gas system by using Wind Turbine and PEM

The Power-to-Gas (PTG) is one of the progressing technologies that enables the conversion of electrical energy into hydrogen or methane gas. This study focuses on the comprehensive analysis of energy efficiency, exergy efficiency, and exergy destruction rate within the PTG overall system. The investigation covers the evaluation of the wind turbine for power generation, the proton exchange membrane (PEM) employed in hydrogen production, and the methanation unit dedicated to methane production. The analysis examines the overall system as well as each individual component. By quantifying the energy and exergy efficiencies, this study provides potential improvements for maximizing the PTG system's overall effectiveness. The outcomes of this study contribute to the advancement and deployment of PTG technologies, thereby facilitating the integration of renewable energy sources and promoting sustainable energy solutions.

Bacterial Degradation of PCB 70 and its Hydroxy Derivatives is an Environmentally Friendly Way to Destroy Pops

One of the problems of our time is the environmentally safe destruction of polychlorinated biphenyls (PCBs) and their hydroxylated derivatives. The aim of the study was to investigate the features and prospects of the decomposition of PCB 70 (2,5,3’,4’-tetrachlorobiphenyl) and hydroxylated chlorobiphenyls derived from it by Rhodococcus wratislaviensis strain CH628. As a result of the application of methods of periodic cultivation, gas chromatography and light spectrometry, it was found that the efficiency of destruction of PCB 70 1 g of cells of strain CH628 was 90 mg PCB/day, and the same indicator for a mixture consisting of hydroxy derivatives obtained from PCB 70 was 56 mg PCB/day. It was shown that the strain uses all components of the mixture of hydroxy-PCB 70 as a growth substrate, but with different degradation rates. When cultivated in a mineral medium with PCB 70 or a mixture of hydroxy-PCB 70, strain CH628 forms biofilms. The analysis of the obtained results shows that the use of the Rhodococcus wratislaviensis CH628 strain will make it possible to develop a technology for the environmentally safe destruction of PCB 70 and hydroxy-PCBs derived from it.

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ ЗАБОЙКИ НА ПРИМЕРЕ РАЗРУШЕНИЯ БЕТОННЫХ КОНСТРУКЦИЙ МЕТОДОМ ДЕФЛАГРАЦИИ

Extensive practical experience in conducting drilling and blasting operations confirms the relevance of the application of the face in the context of explosion quality. However, based on the experience of some quarries, there are doubts about the need to use slaughtering as one of the main factors in increasing the efficiency and, accordingly, abandoning it. The authors of different studies are divided in their opinions. Many researchers claim that the slaughtering contributes to an increase in the useful use of the energy of the explosion, however, under certain conditions, the slaughtering does not affect the efficiency of destruction. The article presents a laboratory study of the effectiveness of the slaughtering during crushing by deflagration method.

Mechanochemical destruction of per- and polyfluoroalkyl substances in aqueous film-forming foams and contaminated soil.

Per- and polyfluoroalkyl substances (PFASs) are a class of synthetic chemicals of concern that exhibit extreme persistence within the environment and possess physicochemical properties that are resistant to targeted degradation. Comprising substantial concentrations of PFASs, aqueous film-forming foams (AFFFs) present a major exposure pathway to the environment having been applied to land at firefighting-training sites globally for decades. This has led to significant contamination of environmental media. Herein, we demonstrate that mechanochemical destruction (MCD) is an effective method for the destruction of PFASs in an AFFF concentrate and an authentic sample of PFAS-contaminated soil derived from a decommissioned firefighting training facility. Both targeted analysis and non-targeted analysis were used in this study to evaluate the degradation of PFASs in complex substrates during MCD treatment. Destruction efficiencies of target PFAS subgroups ranged from 99.88% to 100%. The only additive employed for MCD treatment was quartz sand, which was used only for the liquid AFFF sample, with no additives required for the destruction of PFASs in the contaminated soil. This confirms the viability of MCD for both the remediation of PFAS-contaminated land and the destruction of stockpiled AFFFs.

Thermodynamically analysis and optimization of potato drying in a combined infrared/convective dryer

The present work dealt with a detailed energy and exergy analysis for potatoes drying in a hybrid infrared/hot air dryer. Studying optimization factors of drying air temperature and velocity and infrared power, response surface methodology (RSM) was also used to model and optimize performance of the dryer based on thermodynamic responses including drying time, energy loss, exergy destruction, and energy and exergy efficiencies. The results revealed that practicing higher temperatures and lower infrared powers generally resulted in better thermodynamic performance. Although higher drying air velocities enhanced the thermodynamic performance of the drying chamber but decreased energy and exergy efficiencies of the process. Modeling and RSM optimization of the investigated drying parameters resulted in air temperature and velocity and the infrared power of 70 °C, 1 m/s and 0.225 kW, respectively by maximum 0.878 desirability factor. Validation of the RSM revealed a good conformity between the experimental and predicted values with a maximum relative error of 3.15%.

Performance Evaluation of Split Air Conditioner with Consideration of Pressure Drop in Evaporator and Condenser

In this research, a split air conditioner's performance has been evaluated using exergy analysis on three different low global warming potential (GWP) refrigerants, namely R32, R447A, and R447B, to find a replacement for the GWP-high refrigerant R410A. With regard for pressure loss in the evaporator and condenser, a computational model is built to recreate the operational conditions of a split air conditioner. GENETRON Properties 1.4 software is used to calculate performance metrics such as coefficient of performance (COP), exergy destruction ratio, exergetic efficiency, and efficiency defect. Result shows that pressure drop in evaporator alone has an adverse effect on COP and total exergy destruction and it is higher at higher pressure drop. Effect of pressure drop on exergetic efficiency and exergy destruction ratio is found to be less significant with condenser pressure drop compared to evaporator pressure drop. Exergy efficiency is found to be maximum with R447A followed by R447B, R32, and R410A.

Thermodynamic analysis of the Chemical Looping Electricity Storage system incorporating an electric heater

Chemical Looping Electricity Storage system is a new energy storage approach with satisfactory thermal efficiency and high capacity density, especially when the material with high decomposition temperature is selected as the storage medium. In this study, two CLES systems, one using an electric heater directly, the other using a compressor and an electric heater, were investigated. A comprehensively analysis were performed from the perspectives of first and second laws of thermodynamics. The feasibility of the system configuration, as well as the round-trip efficiency and exergy destruction of each part under different operation temperatures were determined. Finally, the approaches to further improving the round-trip efficiency were discussed. Results show that for the CLES system using an electric heater and a compressor for heating, the increase in the charge temperature will increase the exergy destruction rate of the electric heater and reduce the round-trip efficiency. The operating temperature range and the round-trip efficiency can be improved by placing two reactor vessels in series for charge and parallel for discharge. For the CLES system direct heating with an electric heater, the efficiency in the low temperature section is extremely low, and the exergy loss caused by heat removal during discharge can be up to 8.9 %. Multi-stage compression intercooling or isothermal compression can be used during discharge to reduce this loss and increase the round-trip efficiency by 8.2 %–16.3 %.

Solvent-Free, Ambient Temperature and Pressure Destruction of Perfluorosulfonic Acids under Mechanochemical Conditions: Degradation Intermediates and Fluorine Fate.

Perfluorosulfonic acids (PFSAs) are a recalcitrant subclass of per- and polyfluoroalkyl substances (PFASs) linked to numerous negative health effects in humans. Scalable technologies that effectively destroy PFSAs will greatly reduce the future health and ecological impact of these "forever chemicals". Herein, we show that several PFSAs undergo facile mechanochemical destruction (MCD) in the presence of quartz sand (SiO2). This process operates in the absence of solvent, at ambient temperature and pressure, generating a benign solid byproduct. Quantitative analysis of milled samples revealed high destruction efficiencies of 99.95% to 100% for five different PFSAs subjected to MCD conditions in the presence of SiO2 only. Extensive nontargeted analysis showed that, during degradation, other PFASs form and are ultimately destroyed upon extended mechanochemical treatment. Direct polarization (DP) and cross-polarization (CP) solid-state nuclear magnetic resonance (SSNMR) spectroscopy showed abundant silicon-fluorine (Si-F) bond formation post-MCD, indicating that fluorine was secured in a stable reservoir. Collectively, these results identified the degradation profile for an environmentally sound and effective PFSA degradation process that is amenable to scale-up.

Experimental analysis of a transcritical heat pump system with CO2 refrigerant

Today, it is seen that increasing environmental pollution is getting ahead of the increasing energy need. Therefore, more environmentally friendly and more economical refrigerants are needed. In this context, carbon dioxide appears as a natural refrigerant in cooling systems and heat pump (HP) systems, and it has been widely used in recent years. In this study, a single-stage heat pump system with a CO2 refrigerant, with a transcritical cycle, has been experimentally studied. The system is designed as a water-to-water heat pump. The performance of the system has been determined experimentally. In the system, capillary pipes with a diameter of 2.00 mm and two different lengths are used. It is aimed to create different evaporation pressures with two capillary tubes. The first capillary tube is 2.40 m long and the second is 1.20 m long. Gas cooler pressures, gas cooler and evaporator cooling water mass flow rates were kept the same for both cases. A certain gas charge was made and measurements were made for both cases. Thermodynamic analysis and comparison of the system were made. In the short capillary tube system, it was observed that the COPHP value was 7.2% higher, the CO2 mass flow rate increased by 9.1% to achieve the same gas refrigerant pressure value, and the power consumption in the compressor decreased by 1.8%. In addition, the gas cooler outlet temperature, the evaporator outlet temperature and the change in ambient temperatures, as well as the exergetic destruction and exergetic efficiencies in the system and system components are presented in figures with EES.

Influence of Bacteria of the Genus Pseudomonas on Leguminous Plants and Their Joint Application for Bioremediation of Oil Contaminated Soils

The modern approach to the creation of biological products to stimulate plant growth is based on the study of specific inter-bacterial interactions. This study describes the impact that the introduction of strains of the genus Pseudomonas has on annual and perennial leguminous plants and the ecosystem of the leguminous plant-the indigenous microbial community. The objects of research under the conditions of vegetation experiments were plants of field peas (Pisum sativum L.), white lupine (Lupinus albus L.), chickpea (Cicer arietinum L.), alfalfa (Medicago sativa subsp. varia (Martyn) Arcang.), and white sweet clover (Melilotus albus Medik.). For the treatment of plant seeds, a liquid culture of strains of growth-stimulating bacteria Pseudomonas koreensis IB-4, and P. laurentiana ANT 17 was used. The positive effect of the studied strains on the germination, growth and development of plants was established. There was no inhibitory effect of inoculants on rhizobia; on the contrary, an increase in nodule formation was observed. The possibility of recultivation of oil-contaminated soil using chickpea and alfalfa as phytomeliorants and growth-stimulating strains P. koreensis IB-4, P. laurentiana ANT 17 as inoculants was evaluated. It is proved that seed treatment improved the morphological parameters of plants, as well as the efficiency of oil destruction.

Magneto laminar mixed convection and entropy generation analyses of an impinging slot jet of Al2O3-water and Novec-649

In this study, the cooling capability and heat transfer characteristics in the mixed convective regime of a hot surface by a confined impinging slot jet in the presence of a uniform magnetic field have been investigated numerically. Besides, the second law of thermodynamics is applied to analyze the entropy generation inside the simulation medium. The simulations are for a two-dimensional slot jet that is directed vertically downward and impinges on a hot isothermal surface at the bottom. The set of non-dimensional governing equations is solved using ANSYS Fluent, which employs a finite volume approach in combination with a non-dimensionalization scheme. Flow patterns, isotherms, and entropy generation rates were calculated for various fluids (Air, Water, Novec-649, Al2O3-Water (3 %) nanofluid), that cover a wide range of Prandtl number values (Pr = 0.71–12.64), in the presence of a uniform magnetic field with Hartmann number values ranging from 0 (no magnetic field) to 100 (strong magnetic field). We prove that the Prandtl number plays a key role in determining heat transfer efficiency and entropy generation. Fluids with a high Pr number are more efficient for surface cooling, although they generate more entropy than low Pr fluids. Nanofluid with a high-volume fraction can be a better choice rather than air and water. On the other hand, we show that applying the magnetic field result in a very efficient method to reduce entropy generation although they degrade heat transfer efficiency. It is interesting that at a higher magnetic field, a high Prandtl number plays a better role. The percentage of reduction of Nuave by applying magnetic field is 28.5 % for air (Pr = 0.71), 45.2 % for water (Pr = 6.2), 43.4 % for Al2O3-water nanofluid (Pr = 4.91) and 48.3 % for Novec-649 (Pr = 12.64).We postulate that applying magnetic fields combined with high Pr number fluids, could provide an excellent balance between heat transfer efficiency and exergy destruction, thus providing efficient control options for thermal management and heat transfer.

Efficient source-independent full waveform dual-parameter inversion of common-offset GPR data

Full waveform inversion (FWI) of common-offset ground penetrating radar (GPR) data can make up for the defects of the traditional prospecting technology such as destructive, cumbersome, and low efficiency, which also provides a robust and high-precision tool for quantitative assessment of subsurface prospecting. Nonetheless, conventional GPR-FWI is of limited practicality since the deficiency of accurate source wavelet and tremendous computational cost. We develop an efficient source-independent inversion algorithm based on the convolution method to eliminate the influence of source wavelet and enhance the algorithm efficiency to inverse field data. To suppress the noises induced by the convolution and cross-correlation operations, the time window is introduced in the reference trace which is selected automatically by singular value decomposition (SVD). The stochastic strategy reduces the computational cost by source subsampling. The synthetic model of a complex lens body demonstrates that source-independent FWI with time window has more tolerant to the initial model and noise, and the stochastic strategy improves the efficiency with ensured inversion accuracy. In the field GPR data of a sand trough containing two anomalous bodies, our algorithm has good adaptability and can accurately reconstruct the distribution of the permittivity and conductivity of the subsurface media without accurate estimation of the source wavelet. The results above indicate that the proposed algorithm in this study is valid for common-offset GPR data and improves the inversion efficiency by 1.24 to 3.10 times, which shows great potential to promote qualitative assessment in real-time subsurface exploration.

Exergy assessment and sustainability of a simple off-shore oscillating water column device

This paper present a research on the performance efficiency and sustainability of an Oscillating Water Column (OWC) simple off-shore device, accounting for the influence of governing thermodynamic variables (moisture, temperature, pressure) in the compression/expansion polytropic process. The work proposes a simple off-shore OWC experimental set up as the basis of the study. The analysis takes into consideration both gas subsystems inside and outside the OWC, to achieve a better understanding of the conservative nature of entropy system variable, the net exchange balance, the effects on efficiency and exergy destruction, and the interpretation of the OWC as a thermodynamic engine. Results show that, within the context of the set up, moderate wave climate conditions contribute to a better efficiency of the device in terms of output power, providing with a low impact on exergy destruction and high sustainability in terms of renewability index.

Study on multi-objective decision-making operation strategy of heat supply tower

In northern China, the long-term operation of ground source heat pumps brings the problem of soil cold accumulation, which can be effectively solved by adopting the heat supply tower to recharge the ground in summer. In this paper, seven indexes affecting the performance of the heat supply tower, such as temperature difference between inlet and outlet water, heating approach, thermal efficiency, and exergy destruction, are studied experimentally, and the energy efficiency ratio of the heat supply tower is analyzed. Then, based on the experimental data, the decision of the operating conditions is made. The results show that it is impossible to judge the performance of the heat supply tower based on a single index, and multiple criteria need to be considered at the same time. The energy efficiency ratios of the heat supply tower range from 12.7 to 22.5 and the optimal operating conditions of the heat supply tower under the experimental conditions are derived based on the TOPSIS decision. This paper provides a theoretical basis for the performance analysis and operation condition study of the heat supply tower.

Volatile fatty acid production from food waste: The effect of retention time and lipid content

The bioconversion of food waste to renewable products has an important role in alleviating the environmental burden of food wastage. This study evaluates the effect of solids retention time (1.5, 4, and 7 days) and lipid content (up to 30 % DS) on the solid’s destruction efficiency and VFA yield from food waste fermentation. Although SRT below 4 days and lipid content beyond 20 % reduced the solids destruction efficiency (SRT −12 %, lipids −13 %), the VFA yield improved (SRT 0.36 to 0.48 g CODVFA/TCODFED; lipids 0.17 to 0.39 g CODVFA/TCODFED). This appeared to be a mechanism of improved acidification which doubled to 0.77 gCODVFA/g SCOD at 1.5-day SRT. The introduction of easily degradable organics in waste oils and methanogen inhibition by LCFAs were likely causes of process instability when lipids >20 %. Further research is needed considering the COD fractionation of the feed to maximize recoverable products on a commercial scale.

МОДЕЛЮВАННЯ ПРОЦЕСІВ АЕРОДИНАМІЧНОГО НАГРІВУ І ПЛАВЛЕННЯ КОСМІЧНИХ ОБ’ЄКТІВ В АТМОСФЕРІ ЗЕМЛІ

The results of modeling the processes of thermal destruction of large-sized space debris objects due to aerodynamic heating and melting in the upper atmosphere are presented in order to determine the feasibility of using a combined method for their de-orbiting. The cylindrical and spherical models of space debris elements were considered to estimation of the parameters of thermal destruction. The guess, that melt layer which is formed on an object surface, is carried away by a running atmospheric flow, was assumed. The value of heat flux depends on the location on the body surface, thus, two cases were considered: stagnation point, where the heat flux is maximum, and the point on a flat surface. It is shown that the efficiency of destruction of cylindrical bodies (first stages of launch vehicles) depends on the
 angle of attack during object movement in the atmosphere. The most advantageous, to provide the maximum thermal load, are the angles of attack not less than 40°. At small angles of attack, the thermal load on the side surface is insignificant, which can lead to incomplete destruction of the object. Calculations also showed effective combustion of objects spherical shape (fuel tanks of upper stages in the atmosphere. The presented trajectories of deorbiting of space debris objects confirm the effectiveness of thermal destruction for reentry angles: 0°; 0,5°; 1,0°; 1,5°. At the same time, the melting rate increases when reentry angle is increasing. Complete thermal destruction (melting) of the discharge objects is possible for the structural material from aluminum alloys, in particular АМг6. This case takes place in aerospace design practice. Thus, the use of a combined method of deorbiting the large-sized space debris into the dense layers of the Earth's atmosphere is quite appropriate, because it provides the productive aerodynamic heating and thermal destruction in the atmosphere some objects like as used first stages of launch vehicles or fuel tanks, which are the most typical components of space debris

The effect of metallicity on the abundances of molecules in protoplanetary disks

Context. Diverse studies have shown that it is important to consider the impact of metallicity on the chemodynamical evolution of protoplanetary disks. It has been suggested that there may be different chemistry cycles in non-solar metallicity environments at work or that the efficiency of mass transport in protostars and pre-main-sequence stars is dependent on metallicity to a certain extent. Aims. We study the influence of different metallicities on the physical, thermal, and chemical properties of protoplanetary disks, particularly with regard to the formation and destruction of carbon-based molecules. Methods. With the thermo-chemical code ProDiMo (PROtoplanetary DIsk MOdel), we investigated the impact of lower metallicities on the radiation field, disk temperature, and the abundance of different molecules (H2O, CH4, CO, CO2, HCN, CN, HCO+, and N2H+). We used a fiducial disk model as a reference and produced two derivative models based on lower metallicity. We studied the resulting influence on different chemical species by analyzing their abundance distribution throughout the disk and their vertical column density. Furthermore, we examined the formation and destruction reactions of the chemical species. Results. Our results demonstrate a relation between the metallicity of the disk and the strength of the stellar radiation field inside the disk. As the metallicity decreases, the radiation field is capable of penetrating deeper regions of the disk. As a result, there is a stronger radiation field in the disk overall with lower metallicity, which also heats up the disk. This triggers a series of changes in the chemical formation and destruction efficiencies for different chemical species. In most cases, the available species abundances change and have greater values compared to scaled-down abundances by constant factors. Metallicity has a clear impact on the snowline of the molecules studied here as well. As metallicity decreases the snowlines are pushed further out and existing snow rings shrink in size. Conclusions. We find that the abundances of the studied molecules in lower metallicity disks cannot be understood or reproduced by scaling down the respective species abundances of the reference disk model. This is because the chemical reactions responsible for the destruction and formation of the studied molecules change as the metallicity of the disk is reduced. We found a strong overabundance (relative to scaled-down values) in the models with lower metallicity for gaseous species (CN, CO, HCO+, N2H+), which are particularly useful in observations. This could be advantageous for future observations in low-metallicity environments. Further studies considering different aspects of the disk are needed to gain a deeper understanding of the relation between metallicity and disk thermochemical evolution. Future studies ought to consider other processes, such as different dust grain size distribution, different stellar radiation fields, and stellar burst scenarios.

N-Rich, Polyphenolic Porous Organic Polymer and Its In Vitro Anticancer Activity on Colorectal Cancer

N-rich organic materials bearing polyphenolic moieties in their building networks and nanoscale porosities are very demanding in the context of designing efficient biomaterials or drug carriers for the cancer treatment. Here, we report the synthesis of a new triazine-based secondary-amine- and imine-linked polyphenolic porous organic polymer material TrzTFPPOP and explored its potential for in vitro anticancer activity on the human colorectal carcinoma (HCT 116) cell line. This functionalized (-OH, -NH-, -C=N-) organic material displayed an exceptionally high BET surface area of 2140 m2 g-1 along with hierarchical porosity (micropores and mesopores), and it induced apoptotic changes leading to high efficiency in colon cancer cell destruction via p53-regulated DNA damage pathway. The IC30, IC50, and IC70 values obtained from the MTT assay are 1.24, 3.25, and 5.25 μg/mL, respectively.

Increasing the content of coarse fractions in the mined coal mass by a combine using paired cuts

The main volume of coal is mined underground using shearers. In modern shearers, auger actuators are mainly used, which are distinguished by the simplicity of design, manufacturability and reliability. However, in the process of separating coal from mass by cutting, the yield of fine grades is 40-50 % of the total production volume. Therefore, the search and development of technical solutions that provide an increase in the yield of large fractions in the process of coal mining with auger shearers is an urgent task. Traditionally, this problem is solved by increasing the thickness of the slices, which is achieved by installing cutters with a larger radial reach and increasing the shearer feed rate. An unconventional way to increase the cross section of slices by forming energy-efficient paired and group slices with mutual superposition of stress fields in the mass from the action of neighboring cutters is considered. The results of modeling the process of cutting coal confirm that an increase in the efficiency of destruction of the rock mass by the cutters of the auger executive bodies of the shearer can be achieved by a complex technical solution, including the formation of paired cuts and combined stress zones in the rock mass. As a result, the output of large fragments when cutting with paired cutters increases by 1.3-1.8 times compared with cutting with a single cutter.

Assessment on energy and exergy of combined supercritical CO2 Brayton cycles with sizing printed-circuit-heat-exchangers

The supercritical carbon dioxide Brayton cycle is one of the alternative thermal schemes for advanced energy systems. In this study, ammonia absorption Refrigeration-reheat supercritical carbon dioxide Brayton combined cycle is constructed, and the thermodynamic performance of reheat supercritical carbon dioxide Brayton cycle with ammonia absorption refrigeration cycle are analyzed. The characteristics of Brayton cycle and ammonia absorption refrigeration cycle configuring with Printed Circuit Heat Exchanger are analyzed. The result shows that under controlled freezing-point storage condition, optimized combined cycle energy and exergy efficiency is 46% and 64.98%, electricity output and refrigeration capacity is 11.4 MW and 1.78 MW. Under air-conditioning refrigeration condition, optimized combined cycle energy and exergy efficiency is 50.28% and 65.04%, and electricity output and refrigeration capacity is 11.4 MW and 3 MW. Compared with combined cycle performance before optimization, average improvement of cycle energy efficiency, exergy efficiency and exergy destruction is 4.19%, 0.73% and 3.64%, which shows obvious improvement of cycle performance after optimization. Comparative analysis of printed circuit heat exchanger applied at recuperator and subcooler shows that heat transfer performance of single-faced etched printed circuit heat exchanger in straight channel is better than that of double-faced etched printed circuit heat exchanger for same heat transfer and pressure drop.