Records Added in October 2022
Records added in October 2022
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Showing records 51 to 75 of 95. [First] Page: 1 2 3 4 Last
Recovery of Raw Materials from Ceramic Waste Materials for the Refractory Industry
Severin Seifert, Sebastian Dittrich, Jürgen Bach
October 13, 2022 (v1)
Subject: Materials
Keywords: electrodynamic fragmentation, innovative process, recycling, refractory, regenerate
Products of the refractory industry are key for the production of heavy industry goods such as steel and iron, cement, aluminum and glass. Corresponding industries are dependent on thermal processes to manufacture their products, which in turn would not be possible if there were no refractory materials, such as refractory bricks or refractory mixes. For the production of refractory materials, primary raw materials or semi-finished products such as corundum, bauxite or zircon are used. Industrial recycling of refractory raw materials would reduce dependencies, conserve resources and reduce global CO2 emissions. Today, only a small quantity of the refractory materials used can be recycled because raw materials (regenerates) obtained from end-of-life materials are of insufficient quality. In this study, regenerates from different refractory waste products could be obtained using the innovative processing method of electrodynamic fragmentation. It was shown that these regenerates have a hi... [more]
A Fault Identification Method in Distillation Process Based on Dynamic Mechanism Analysis and Signed Directed Graph
Wende Tian, Shifa Zhang, Zhe Cui, Zijian Liu, Shaochen Wang, Ya Zhao, Hao Zou
October 13, 2022 (v1)
Keywords: distillation process, fault identification, mechanism analysis, SDG model
Due to the complexity of materials and energy cycles, the distillation system has numerous working conditions difficult to troubleshoot in time. To address the problem, a novel DMA-SDG fault identification method that combines dynamic mechanism analysis based on process simulation and signed directed graph is proposed for the distillation process. Firstly, dynamic simulation is employed to build a mechanism model to provide the potential relationships between variables. Secondly, sensitivity analysis and dynamic mechanism analysis in process simulation are introduced to the SDG model to improve the completeness of this model based on expert knowledge. Finally, a quantitative analysis based on complex network theory is used to select the most important nodes in SDG model for identifying the severe malfunctions. The application of DMA-SDG method in a benzene-toluene-xylene (BTX) hydrogenation prefractionation system shows sound fault identification performance.
Cumulative Production of Bioactive Rg3, Rg5, Rk1, and CK from Fermented Black Ginseng Using Novel Aspergillus niger KHNT-1 Strain Isolated from Korean Traditional Food
Jin Kyu Park, Dong Uk Yang, Lakshminarayanan Arunkumar, Yaxi Han, Seung Jin Lee, Muhammad Huzaifa Arif, Jin Feng Li, Yue Huo, Jong Pyo Kang, Van An Hoang, Jong Chan Ahn, Deok Chun Yang, Se Chan Kang
October 13, 2022 (v1)
Keywords: Aspergillus niger, B16BL6 (Murine melanoma) cell line, ginseng, Ginseng Lateral root (GLR), Ginseng Main root (GMR), ginsenosides, human keratinocyte cell line (HaCaT) cells, processing, soybean
Ginseng is an ancient herb widely consumed due to its healing property of active ginsenosides. Recent researchers were explored to increase its absorption and bioavailability of ginsenosides at the metabolic sites, due to its pharmacological activity. The purpose of this study was to investigate the isolation and characteristics of components obtained by a shorter steaming cycle (seven cycles) of white ginseng to fermented black ginseng, using a novel strain of Aspergillus niger KHNT-1 isolated from fermented soybean. The degree of bioactive of Rg3 increased effectively during the steaming process, and biotransformation converted the color towards black along active ginsenosides. Glycol moiety associated with C-3, C-6, or C-20 underwent rapid biotransformation and hydrolysis, such as Rb1, Rb2, Rc, Rd → Rg3, F2, and was converted to CK. Dehydration produces Rg3 → Rk1, Rg5. Rh2 → Rk2; thus, converted fermented black ginseng was solvent-extracted, and the isolated components were identifi... [more]
Enhanced Degradation of Sulfonamide Antibiotics by UV Irradiation Combined with Persulfate
Zhentao Liu, Wanpeng Hu, Haiping Zhang, Hui Wang, Ping Sun
October 13, 2022 (v1)
Subject: Other
Keywords: advanced oxidation process, persulfate, removal efficiency, sulfonamide antibiotics, UV irradiation
In this study, the degradation of sulfonamide antibiotics was investigated through persulfate-enhanced UV advanced oxidation process. Factors that may affect the degradation efficiency were analyzed. Results showed that the persulfate imposed a significant enhancement on the UV oxidation process during the sulfathiazole degradation. The combined process of UV/persulfate can effectively remove about 96% of sulfathiazole within 60 min. With the increase in the dosage of persulfate, the removal efficiency increased as well. Different water matrix almost had no effect on the removal efficiency. Two intermediates were found during the sulfathiazole degradation. It can be predicted that the combined process of UV/persulfate has a broad application prospect for removing sulfonamide antibiotics in water treatment.
Multi-Enzyme Systems in Flow Chemistry
Pedro Fernandes, Carla C. C. R. de Carvalho
October 13, 2022 (v1)
Subject: Biosystems
Keywords: immobilization, microreactor, reaction cascade, scale-up, whole cell
Recent years have witnessed a growing interest in the use of biocatalysts in flow reactors. This merging combines the high selectivity and mild operation conditions typical of biocatalysis with enhanced mass transfer and resource efficiency associated to flow chemistry. Additionally, it provides a sound environment to emulate Nature by mimicking metabolic pathways in living cells and to produce goods through the systematic organization of enzymes towards efficient cascade reactions. Moreover, by enabling the combination of enzymes from different hosts, this approach paves the way for novel pathways. The present review aims to present recent developments within the scope of flow chemistry involving multi-enzymatic cascade reactions. The types of reactors used are briefly addressed. Immobilization methodologies and strategies for the application of the immobilized biocatalysts are presented and discussed. Key aspects related to the use of whole cells in flow chemistry are presented. The... [more]
Biofunctional Peptide-Modified Extracellular Vesicles Enable Effective Intracellular Delivery via the Induction of Macropinocytosis
Ikuhiko Nakase
October 13, 2022 (v1)
Subject: Biosystems
Keywords: biofunctional peptides, exosomes, intracellular delivery systems, macropinocytosis
We previously reported that macropinocytosis (accompanied by actin reorganization, ruffling of the plasma membrane, and engulfment of large volumes of extracellular fluid) is an important process for the cellular uptake of extracellular vesicles, exosomes. Accordingly, we developed techniques to induce macropinocytosis by the modification of biofunctional peptides on exosomal membranes, thereby enhancing their cellular uptake. Arginine-rich cell-penetrating peptides have been shown to induce macropinocytosis via proteoglycans; accordingly, we developed peptide-modified exosomes that could actively induce macropinocytotic uptake by cells. In addition, the activation of EGFR induces macropinocytosis; based on this knowledge, we developed artificial leucine-zipper peptide (K4)-modified exosomes. These exosomes can recognize E3 sequence-fused EGFR (E3-EGFR), leading to the clustering and activation of E3-EGFR by coiled-coil formation (E3/K4), which induces cellular exosome uptake by macrop... [more]
Apple Fermented Products: An Overview of Technology, Properties and Health Effects
Raquel P. F. Guiné, Maria João Barroca, Teodora Emilia Coldea, Elena Bartkiene, Ofélia Anjos
October 13, 2022 (v1)
Keywords: acetic fermentation, alcoholic fermentation, apple pomace, cider, malolactic fermentation, probiotic beverage, spirit, vinegar
As an easily adapted culture, with overloaded production in some parts of the globe, apples and their by-products are being redirected to pharmaceutical, canning and beverages industries, both alcoholic and non-alcoholic. Fermentation is generally considered to increase the bioavailability of bioactive compounds found in apple, by impacting, through a high degree of changes, the product’s properties, including composition and health-promoting attributes, as well as their sensory profile. Probiotic apple beverages and apple vinegar are generally considered as safe and healthy products by the consumers. Recently, contributions to human health, both in vivo and in vitro studies, of non-alcoholic fermented apple-based products have been described. This review highlighted the advances in the process optimization of apple-based products considering vinegar, cider, pomace, probiotic beverages and spirits’ technologies. The different processing impacts on physical-chemical, nutritional and sen... [more]
On Electromobility Development and the Calculation of the Infrastructural Country Electromobility Coefficient
Erika Feckova Skrabulakova, Monika Ivanova, Andrea Rosova, Elena Gresova, Marian Sofranko, Vojtech Ferencz
October 13, 2022 (v1)
Subject: Energy Policy
Keywords: charging stations, electric vehicles, electromobility, infrastructural country electromobility coefficient, infrastructure development
The question of electromobility is greatly discussed theme of the present especially in connection with the reduction of greenhouse gas emissions. In order to fulfill decarbonization targets, incentives of many countries lead to the support of electromobility. In this paper we ask to which extend are Visegrád Group countries prepared for the widespread utilization of electric cars and define a new coefficient K called the infrastructural country electromobility coefficient. Its computing is covered by appropriate analysis and calculations done previously. Several indices that keep particular information about the state of preparation for electromobility are defined and debated here, as well. Their product forms the coefficient K. Obtained results include outcomes and discussion regarding the level of infrastructural electromobility preparedness for the chosen states, among which we extra focus on the position of Slovakia compared to the European Union average and European electromobili... [more]
Position Control Study on Pump-Controlled Servomotor for Steam Control Valve
Guishan Yan, Zhenlin Jin, Tiangui Zhang, Penghui Zhao
October 13, 2022 (v1)
Keywords: position control, pump-controlled servomotor, sliding mode variable structure, steam control valve, steam turbine
In steam turbine control and actuation, the steam control valve plays a key role in operability and reliability. The electrohydraulic regulating system for the steam control valve, usually called the servomotor, needs to be reliable and high performing under nonlinear excitation interference in actual conditions. Currently, electrohydraulic servo valve control technology is widely used in servomotors. Although this technology has good control performance, it still has some technical defects, such as poor antipollution ability, low energy efficiency, large volume size, and limited installation space. Aiming at the abovementioned technical shortcomings of electrohydraulic servo valve control technology, a servomotor-pump-hydraulic cylinder volume control scheme is proposed in this paper, forming a pump-controlled servomotor for the steam control valve. By analyzing the working principle of the pump-controlled servomotor position control in the steam control valve, the mathematical model... [more]
Improved Hybrid Heuristic Algorithm Inspired by Tissue-Like Membrane System to Solve Job Shop Scheduling Problem
Xiang Tian, Xiyu Liu
October 13, 2022 (v1)
Keywords: hybrid heuristic algorithm, job shop scheduling problem, tissue-like membrane system
In real industrial engineering, job shop scheduling problem (JSSP) is considered to be one of the most difficult and tricky non-deterministic polynomial-time (NP)-hard problems. This study proposes a new hybrid heuristic algorithm for solving JSSP inspired by the tissue-like membrane system. The framework of the proposed algorithm incorporates improved genetic algorithms (GA), modified rumor particle swarm optimization (PSO), and fine-grained local search methods (LSM). To effectively alleviate the premature convergence of GA, the improved GA uses adaptive crossover and mutation probabilities. Taking into account the improvement of the diversity of the population, the rumor PSO is discretized to interactively optimize the population. In addition, a local search operator incorporating critical path recognition is designed to enhance the local search ability of the population. Experiment with 24 benchmark instances show that the proposed algorithm outperforms other latest comparative alg... [more]
Sequential Abatement of FeII and CrVI Water Pollution by Use of Walnut Shell-Based Adsorbents
Marius Gheju, Ionel Balcu
October 13, 2022 (v1)
Subject: Materials
Keywords: acid mine drainage, heavy metals, hexavalent chromium, innovative adsorbent, sustainable water treatment, water treatment residuals
In this study walnut shells, an inexpensive and readily available waste, were used as carbonaceous precursor for preparation of an innovative adsorbent (walnut-shell powder (WSP)) which was successfully tested for the removal of FeII from synthetic acid mine drainage (AMD). Then, the exhausted iron-contaminated adsorbent (WSP-FeII) was recovered and treated with sodium borohydride for the reduction of adsorbed FeII to Fe0. The resulting material (WSP-Fe0) was subsequently tested for the removal of CrVI from aqueous solutions. Treatability batch experiments were employed for both FeII and CrVI-contaminated solutions, and the influence of some important experimental parameters was studied. In addition, the experimental data was interpreted by applying three kinetic models and the mechanism of heavy metal removal was discussed. The overall data presented in this study indicated that fresh WSP and WSP-Fe0 can be considered as promising materials for the removal of FeII and CrVI, respective... [more]
Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions
Marin Ugrina, Martin Gaberšek, Aleksandra Daković, Ivona Nuić
October 13, 2022 (v1)
Subject: Materials
Keywords: chemical modification, leaching, mercury sorption, natural zeolite clinoptilolite, sulfur impregnation
Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge... [more]
The Impact of Moisture and Number of Contact Points on the Process of Friction in Plant Granular Materials
Aneta Kopeć-Jarosz, Artur Wójcik
October 13, 2022 (v1)
Subject: Other
Keywords: buckwheat, friction, granular material, moisture, number of contact points, wheat
Friction occurs in the processes of transport and storage of granular plant materials used in the energy (RES—Renewable Energy Sources) and food sectors. This paper presents the results of a study on the impact of the moisture content of the material and the number of its contact points with a smooth surface (a steel sheet) on the process of friction in grains of wheat and buckwheat. The friction process was studied for four different levels of moisture (9.5%, 13.5%, 17.5% and 21.5%) and three different average numbers of contact points. To measure the force of friction, an universal testing machine with appropriate instrumentation was used. To determine the number of contact points, computer imaging analysis was conducted. An increase in static and kinetic friction was observed along with the increase in moisture level and the increase in the number of contact points. Correlation and regression analysis was performed for the data obtained.
Dry Mesophilic Anaerobic Digestion of Separately Collected Organic Fraction of Municipal Solid Waste: Two-Year Experience in an Industrial-Scale Plant
Adolfo Le Pera, Miriam Sellaro, Massimo Migliori, Micaela Bianco, Giuseppe Zanardi
October 12, 2022 (v1)
Keywords: biogas, biomethane, dry anaerobic digestion, industrial scale plant, organic waste, separately collected organic fraction of municipal solid waste
In this paper, performance analysis over two years’ operation of an industrial anaerobic digestion (AD) plant of a separately collected organic fraction of municipal solid waste is presented. The continuous plug-flow AD plant is still regularly operating and it has been fully operational since September 2018. Since then, it has been supplied with 40,000 t/y of pretreated separately collected organic fraction of municipal solid waste from municipalities of the Calabria region in Southern Italy. The AD process is carried out in a mesophilic regime at 40 ± 0.5 °C, using a constant hydraulic retention time (HRT) of 22 days and a substrate with average total solids and average total volatile solids of 30.0% and 22.2%, respectively. In the last two years, the plant produced an average of 191 m3 and 860 m3 of biogas per tonne (t) of organic input material and of total volatile solids, respectively, with an average methane specific production of 508 m3/t (total volatile solids). The average CH... [more]
Construction of an Artificial Cell Capable of Protein Expression at Low Temperatures Using a Cell Extract Derived from Pseudomonas fluorescens
Mana Fukumoto, Taishi Tonooka
October 12, 2022 (v1)
Subject: Biosystems
Keywords: artificial cell, cell-free protein expression, liposome, Pseudomonas fluorescens
A liposome-based artificial cell (LBAC) consists of a liposome encapsulating a cell-free protein expression system (CFPES) and protein-encoding DNA. It is surrounded by a lipid bilayer membrane and synthesizes proteins that resemble actual cells. Hence, they have been one of the most studied artificial cells. According to recent studies, they have been able to sense bio-functional molecules by synthesizing fluorescent proteins in response to target molecules. Therefore, they are expected to be used as biosensors. However, previously reported LBACs encapsulated the CFPES derived from Escherichia coli, resulting in the most productive protein expression at 20−40 °C. To broaden the range of their working temperatures to lower temperatures, in this study, we constructed LBACs using a CFPES derived from Pseudomonas fluorescens that grows at a temperature range of 4 °C to 30 °C. We then demonstrated that the constructed LBAC expressed proteins at 8 °C and that, the protein expression capabil... [more]
Energy, Exergy, and Thermo-Economic Analysis of Renewable Energy-Driven Polygeneration Systems for Sustainable Desalination
Mohammad Hasan Khoshgoftar Manesh, Viviani Caroline Onishi
October 12, 2022 (v1)
Keywords: economic analysis, energy and exergy analysis, exergoeconomic analysis, exergoenvironmental analysis, Renewable and Sustainable Energy, sustainable development
Reliable production of freshwater and energy is vital for tackling two of the most critical issues the world is facing today: climate change and sustainable development. In this light, a comprehensive review is performed on the foremost renewable energy-driven polygeneration systems for freshwater production using thermal and membrane desalination. Thus, this review is designed to outline the latest developments on integrated polygeneration and desalination systems based on multi-stage flash (MSF), multi-effect distillation (MED), humidification-dehumidification (HDH), and reverse osmosis (RO) technologies. Special attention is paid to innovative approaches for modelling, design, simulation, and optimization to improve energy, exergy, and thermo-economic performance of decentralized polygeneration plants accounting for electricity, space heating and cooling, domestic hot water, and freshwater production, among others. Different integrated renewable energy-driven polygeneration and desa... [more]
Model-Based Analysis of Feedback Control Strategies in Aerobic Biotrickling Filters for Biogas Desulfurization
Luis Rafael López, Mabel Mora, Caroline Van der Heyden, Juan Antonio Baeza, Eveline Volcke, David Gabriel
October 12, 2022 (v1)
Keywords: biogas, biotrickling filter, control strategies, feedback control, H2S removal, process modeling
Biotrickling filters are one of the most widely used biological technologies to perform biogas desulfurization. Their industrial application has been hampered due to the difficulty to achieve a robust and reliable operation of this bioreactor. Specifically, biotrickling filters process performance is affected mostly by fluctuations in the hydrogen sulfide (H2S) loading rate due to changes in the gas inlet concentration or in the volumetric gas flowrate. The process can be controlled by means of the regulation of the air flowrate (AFR) to control the oxygen (O2) gas outlet concentration ([O2]out) and the trickling liquid velocity (TLV) to control the H2S gas outlet concentration ([H2S]out). In this work, efforts were placed towards the understanding and development of control strategies in biological H2S removal in a biotrickling filter under aerobic conditions. Classical proportional and proportional-integral feedback controllers were applied in a model of an aerobic biotrickling filte... [more]
A Novel Method to Investigate the Activity Tests of Fresh FCC Catalysts: An Experimental and Prediction Process from Lab Scale to Commercial Scale
Yanqing Ma, Yitao Liao, Yi Su, Dong Ji, Hongwei Li, Yong Yang
October 12, 2022 (v1)
Subject: Materials
Keywords: commercial equilibrium catalyst, deactivation, FCC catalyst, industrial evaluation, yield distribution
The issues of feedstocks, product markets, and environmental emissions have continuously proposed a number of challenges for industrial evaluation of fresh fluid catalytic cracking (FCC) catalyst before its application in commercial units. In this work, a convenient method was proposed by comparing with the existing commercial equilibrium catalyst. A series of laboratory experiments for steam treatments and microactivity tests were established to collect reliable data, and the standalone catalyst or co-catalysts were assessed to show the evaluation process and the predicted unit performance. The results had deviation, but a consistent yield distribution than that of a commercial equilibrium catalyst. These evaluations and predictions would provide us with not only the view of hydrothermal stability and yield distribution at the unit level, but also the economic potential for fresh catalyst based on the existing industrial catalyst, which will provide refiners with industrial basis for... [more]
Comparative Investigation of Different CO2 Capture Technologies for Coal to Ethylene Glycol Process
Yanqing Ma, Yitao Liao, Yi Su, Baojie Wang, Yong Yang, Dong Ji, Hongwei Li, Huairong Zhou, Dongliang Wang
October 12, 2022 (v1)
Keywords: acid gas removal, Carbon Dioxide Capture, coal to ethylene glycol, performance analysis, process simulation
The coal to ethylene glycol (CTEG) process has drawn much attention due to the serious conflict between supply and demand of ethylene glycol in China. However, it is inevitably accompanied by the problem of high CO2 emissions. Carbon capture is one of the most promising potential effective ways to address this issue. However, the CTEG process, integrated with carbon capture technology, will lead to energy and economic penalties. Thus, a comprehensive evaluation of CTEG process with different CO2 capture technologies is urgently needed. This study analyzed the technoeconomic performance of four CO2 capture alternatives for the CTEG process: Rectisol, mono-ethanol amine (MEA), chilled ammonia process (CAP) and dimethyl carbonate (DMC) technologies. Results show the energy consumption of CO2 capture of the Rectisol process is the lowest, 1.88 GJ/tCO2, followed by the DMC process, 2.10 GJ/tCO2, the CAP process, 3.64 GJ/tCO2, and the MEA process, 5.20 GJ/tCO2. The CO2 capture cost of the Re... [more]
Advanced Bioethanol Production: From Novel Raw Materials to Integrated Biorefineries
Aleta Duque, Cristina Álvarez, Pablo Doménech, Paloma Manzanares, Antonio D. Moreno
October 12, 2022 (v1)
Keywords: bio-based products, biochemical route, Biofuels, biomass fractionation
The production of so-called advanced bioethanol offers several advantages compared to traditional bioethanol production processes in terms of sustainability criteria. This includes, for instance, the use of nonfood crops or residual biomass as raw material and a higher potential for reducing greenhouse gas emissions. The present review focuses on the recent progress related to the production of advanced bioethanol, (i) highlighting current results from using novel biomass sources such as the organic fraction of municipal solid waste and certain industrial residues (e.g., residues from the paper, food, and beverage industries); (ii) describing new developments in pretreatment technologies for the fractionation and conversion of lignocellulosic biomass, such as the bioextrusion process or the use of novel ionic liquids; (iii) listing the use of new enzyme catalysts and microbial strains during saccharification and fermentation processes. Furthermore, the most promising biorefinery approa... [more]
Methyl Orange Photo-Degradation by TiO2 in a Pilot Unit under Different Chemical, Physical, and Hydraulic Conditions
Andrea Petrella, Danilo Spasiano, Pinalysa Cosma, Vito Rizzi, Marco Race, Maria Cristina Mascolo, Ezio Ranieri
October 12, 2022 (v1)
Subject: Materials
Keywords: azo dye, hydraulic and hydrodynamic parameters, kinetic study, photo-catalysis, TiO2
The photo-catalytic degradation of a textile azo-dye as Methyl Orange was studied in an innovative unit constituted by a channel over which a layer of titanium dioxide (TiO2) catalyst in anatase form was deposited and activated by UVB irradiation. The degradation kinetics were followed after variation of the chemical, physical, and hydraulic/hydrodynamic parameters of the system. For this purpose, the influence of the TiO2 dosage (g/cm3), dye concentration (mg/L), pH of the solution, flow-rate (L/s), hydraulic load (cm), and irradiation power (W) were evaluated on the degradation rates. It was observed that the maximum dosage of TiO2 was 0.79 g/cm3 while for higher dosage a reduction of homogeneity of the cement conglomerate occurred. The Langmuir−Hinshelwood (LH) kinetic model was followed up to a dye concentration around 1 mg/L. It was observed that with the increase of the flow rate, an increase of the degradation kinetics was obtained, while the further increase of the flow-rate as... [more]
Combined Approach to Analysis and Regulation of Thermodynamic Processes in the Energy Technology Complex
Anatoliy Alabugin, Sergei Aliukov, Konstantin Osintsev
October 12, 2022 (v1)
Keywords: analog-to-digital methods of signal transmission, approximation methods, approximation of functions of abrupt development, combination of methods, data science tool, energy technology complexes (ETCs)
The purpose of this work is to increase the theoretical and methodological approaches to value and regulate the dynamics of management processes. Application of these dynamics is implemented via methods of improving the quality of management of complex energy technology systems in the organization of recycling processes. As a result of the research, a technological model of a rotary kiln with a division into separate sections corresponding to the combustion zones for the production of cement clinker in recycling technology was developed. Mathematical modeling, analytical calculations of thermodynamic and gas-dynamic processes in the drums of rotating furnaces, and experimental studies were carried out. As a scientific novelty, an approximation of piecewise linear functions is obtained for modeling the processes of improving the quality of control by the criterion of reducing the error of data transmission for monitoring and regulating the thermodynamic parameters of the furnace via ana... [more]
Role of Microalgae in the Recovery of Nutrients from Pig Manure
Ana Sánchez-Zurano, Martina Ciardi, Tomás Lafarga, José María Fernández-Sevilla, Ruperto Bermejo, Emilio Molina-Grima
October 12, 2022 (v1)
Keywords: Biomass, biotechnology, photosynthesis, respirometry, Scenedesmus, waste treatment
Animal production inevitably causes the emission of greenhouse gases and the generation of large amounts of slurry, both representing a serious environmental problem. Photosynthetic microorganisms such as microalgae and cyanobacteria have been proposed as alternative strategies to bioremediate agricultural waste while consuming carbon dioxide and producing valuable biomass. The current study assessed the potential of the microalga Scenedesmus sp. to remove nutrients from piggery wastewater (PWW) and the influence of the microalga on the microbial consortia. Maximum N-NH4+ consumption was 55.3 ± 3.7 mg·L−1·day−1 while P-PO43− removal rates were in the range 0.1−1.9 mg·L−1·day−1. N-NH4+ removal was partially caused by the action of nitrifying bacteria, which led to the production of N-NO3−. N-NO3− production values where lower when microalgae were more active. This work demonstrated that the photosynthetic activity of microalgae allows us to increase nutrient removal rates from PWW and t... [more]
Effects of Osmotic Dehydration on the Hot Air Drying of Apricot Halves: Drying Kinetics, Mass Transfer, and Shrinkage
Ivan Pavkov, Milivoj Radojčin, Zoran Stamenković, Krstan Kešelj, Urszula Tylewicz, Péter Sipos, Ondrej Ponjičan, Aleksandar Sedlar
October 12, 2022 (v1)
Subject: Materials
Keywords: apricot, drying, kinetics, mass transfer, Modelling, osmotic dehydration, shrinkage
This study aimed to determine the effects of osmotic dehydration on the kinetics of hot air drying of apricot halves under conditions that were similar to the industrial ones. The osmotic process was performed in a sucrose solution at 40 and 60 °C and concentrations of 50% and 65%. As expected increased temperatures and concentrations of the solution resulted in increased water loss, solid gain and shrinkage. The kinetics of osmotic dehydration were well described by the Peleg model. The effective diffusivity of water 5.50−7.387 × 10−9 m2/s and solute 8.315 × 10−10−1.113 × 10−9 m2/s was calculated for osmotic dehydration. Hot air drying was carried out at 40, 50, and 60 °C with air flow velocities of 1.0 m/s and 1.5 m/s. The drying time shortened with higher temperature and air velocity. The calculated effective diffusion of water was from 3.002 × 10−10 m2/s to 1.970 × 10−9 m2/s. The activation energy was sensitive to selected air temperatures, so greater air velocity resulted in great... [more]
Equilibrium and Kinetics of CO2 Adsorption by Coconut Shell Activated Carbon Impregnated with Sodium Hydroxide
Chaiyot Tangsathitkulchai, Suravit Naksusuk, Atichat Wongkoblap, Poomiwat Phadungbut, Prapassorn Borisut
October 12, 2022 (v1)
Subject: Materials
Keywords: activated carbon, adsorption isotherms, adsorption kinetics, alkali impregnation, carbon dioxide adsorption
The equilibrium and kinetics of CO2 adsorption at 273 K by coconut-shell activated carbon impregnated with sodium hydroxide (NaOH) was investigated. Based on nitrogen adsorption isotherms, porous properties of the tested activated carbons decreased with the increase of NaOH loading, with the decrease resulting primarily from the reduction of pore space available for nitrogen adsorption. Equilibrium isotherms of CO2 adsorption by activated carbons impregnated with NaOH at 273 K and the pressure up to 100 kPa displayed an initial part of Type I isotherm with most adsorption taking place in micropores in the range of 0.7−0.9 nm by pore-filling mechanisms. The amount of CO2 adsorbed increased with the increase of NaOH loading and passed through a maximum at the optimum NaOH loading of 180 mg/g. The CO2 isotherm data were best fitted with the three-parameter Sips equation, followed by Freundlich and Langmuir equations. The pore diffusion model, characterized by the effective pore diffusivit... [more]
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