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Records Added in April 2021
Records added in April 2021
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Showing records 51 to 75 of 175. [First] Page: 1 2 3 4 5 6 7 Last
A New Low-Cost and Reliable Method to Evaluate the Release of Hg0 from Synthetic Materials
Marta Lazzaroni, Barbara Nisi, Daniele Rappuoli, Jacopo Cabassi, Orlando Vaselli
April 29, 2021 (v1)
Subject: Materials
Keywords: Abbadia San Salvatore, gaseous mercury, Lumex® RA-915M, mining areas, synthetic materials
Mercury is a toxic and noxious element and is the only metal that naturally occurs as gas. One of the most challenging topics (included in the United Nations Minimata convention) is to understand the adsorption−release processes of manmade materials (e.g., concrete, bricks, tiles, painting). Adsorption of Hg by construction and demolition waste materials has recently been studied, but investigations on how much Hg0 can be released from these products are rather poor. The abandoned mining site of Abbadia San Salvatore (Siena, central Italy) where, for about one century, cinnabar was roasted to produce liquid mercury, is known for the high concentrations of (i) Hg0 in edifices and structures and (ii) total and leachate Hg in synthetic materials. In the present paper, a new, simple and low-cost method to measure the amount of GEM (Gaseous Elemental Mercury) released from anthropic materials (concrete, wall rocks, and tiles) located in the Hg0-rich environments of the former mining site, i... [more]
Modelling Unconfined Groundwater Recharge Using Adaptive Neuro-Fuzzy Inference System
Khaled Mohamed Nabil I. Elsayed, Rabee Rustum, Adebayo J. Adeloye
April 29, 2021 (v1)
Keywords: adaptive neuro-fuzzy inference system, fuzzy logic, groundwater recharge, lysimeter, soil water balance, water budget
Estimating groundwater recharge using mathematical models such as water budget or soil water balance method has been proved to be very difficult due to the complex, uncertain multidimensional nature of the process, despite the simplicity of the concept. Artificial Intelligence (AI) techniques have been proposed to deal with this complexity and uncertainty in a similar way to human thinking and reasoning. This study proposed the use of the Adaptive Neuro-Fuzzy Inference System (ANFIS) to model unconfined groundwater recharge using a set of data records from Kaharoa monitoring site in the North Island of New Zealand. Fifty-three data points, comprising a set of input parameters such as rainfall, temperature, sunshine hours, and radiation, for a period of approximately four and a half years, have been used to estimate ground water recharge. The results suggest that the ANFIS model is overall a reliable estimator for groundwater recharge, the correlation coefficient of the model reached 93... [more]
Numerical Investigation on the Transient Flow of a Boiler Circulating Pump Based on the Shear Stress Transport Turbulence Model
Fei Zhao, Fanyu Kong, Xiaohui Duan, Huiyuan Wu, Jun Wang
April 29, 2021 (v1)
Keywords: boiler circulating pump, energy loss of disc, leakage of seal ring, outlet pipe angle, radial force, SST
Based on the shear stress transport (SST) turbulence model, the influence of different outlet pipe angles on the head and efficiency of a boiler circulating pump was analyzed. When the outlet pipe angle changed from 115° to 130°, the head and efficiency of the pump reduced significantly. The boiler circulating pump with 115° outlet pipe angle was selected as the further research object, and the reliability of the numerical simulation was verified by experiments. The transient flow of the prototype pump under the design flow rate condition (1.0Qd) and four other flow rate conditions (0.6Qd, 0.8Qd, 1.2Qd, and 1.4Qd) was studied. The results show that, under the conditions of design flow and large flow rate (1.0Qd, 1.2Qd, and 1.4Qd), the centrality and regularity of radial force distribution are obviously better than those of small flow rate (0.6Qd, 0.8Qd). The leakage of the rear seal ring is less than that of the front seal ring under five flow rate conditions. As the flow rate increase... [more]
The Impacts of Tracking System Inaccuracy on CPV Module Power
Henrik Zsiborács, Nóra Hegedűsné Baranyai, András Vincze, Philipp Weihs, Stefan F. Schreier, Christian Gützer, Michael Revesz, Gábor Pintér
April 29, 2021 (v1)
Keywords: azimuth angle, concentrator photovoltaic module, solar energy, sun-tracking, sun-tracking sensor, tilt angle
The accuracy and reliability of solar tracking greatly impacts the performance of concentrator photovoltaic modules (CPV). Thus, it is of utmost significance to know how deviations in tracking influence CPV module power. In this work, the positioning characteristics of CPV modules compared to the focus points were investigated. The performance of CPV modules mounted on a dual-axis tracking system was analysed as a function of their orientation and inclination. The actual experiment was carried out with CPV cells of 3 mm in diameter. By using a dual tracking system under real weather conditions, the module’s position was gradually modified until the inclination differed by 5° relative to the optimal position of the focus point of the CPV module. The difference in inclination was established by the perfect perpendicularity to the Sun’s rays. The results obtained specifically for CPV technology help determine the level of accuracy that solar tracking photovoltaic systems are required to h... [more]
Thermodynamic Optimization of a Geothermal Power Plant with a Genetic Algorithm in Two Stages
Mehdi A. Ehyaei, Abolfazl Ahmadi, Marc A. Rosen, Afshin Davarpanah
April 29, 2021 (v1)
Keywords: Genetic Algorithm, geothermal cycle, Optimization, organic Rankine cycle
Due to the harmful effects and depletion of non-renewable energy resources, the major concerns are focused on using renewable energy resources. Among them, the geothermal energy has a high potential in volcano regions such as the Middle East. The optimization of an organic Rankine cycle with a geothermal heat source is investigated based on a genetic algorithm having two stages. In the first stage, the optimal variables are the depth of the well and the extraction flow rate of the geothermal fluid mass. The optimal value of the depth of the well, extraction mass flow rate, and the geothermal fluid temperature is found to be 2100 m, 15 kg/s, and 150 °C. In the second stage, the efficiency and output power of the power plant are optimized. To achieve maximum output power as well as cycle efficiency, the optimization variable is the maximum organic fluid pressure in the high-temperature heat exchanger. The optimum values of energy efficiency and cycle power production are equal to 0.433 M... [more]
Photochemical Oxidation Process of Copper from Electroplating Wastewater: Process Performance and Kinetic Study
Aji Prasetyaningrum, Teguh Riyanto, Mohamad Djaeni, Widayat Widayat
April 29, 2021 (v1)
Keywords: advanced oxidation process, Cu, kinetics, ozone, photochemical oxidation, ultraviolet irradiation
An investigation of the process of ozone combined with ultraviolet radiation has been carried out in order to establish the kinetics for photochemical oxidation of copper (Cu) from electroplating wastewater. The effects of operating parameters, including initial Cu concentration, ozone dosage, UV irradiation intensity, and pH value on the photochemical oxidation of Cu have been studied comprehensively. The Cu concentration during the reaction was identified using atomic absorption spectroscopy (AAS) method. The solid product was analyzed using X-ray diffraction (XRD) and scanning electron microscope−energy-dispersive X-ray (SEM−EDX) methods. It was found that the UV-Ozone process has high performance on Cu removal compared to UV and Ozone processes due to the high production rate of HO• radicals. It was also found that the solid product from the UV-Ozone process was CuO monoclinic crystal phase. The initial Cu concentration, ozone dosage, and pH value were significantly affected the Cu... [more]
A Critical Review on Advancement and Challenges of Biochar Application in Paddy Fields: Environmental and Life Cycle Cost Analysis
Ali Mohammadi, Benyamin Khoshnevisan, G. Venkatesh, Samieh Eskandari
April 29, 2021 (v1)
Keywords: biochar, carbon abatement, E-LCA, economic analysis, human health, pyrolysis gas, rice cropping systems
Paddy fields emit considerable amounts of methane (CH4), which is a potent greenhouse gas (GHG) and, thereby, causes significant environmental impacts, even as they generate wealth and jobs directly in the agricultural sector, and indirectly in the food-processing sector. Application of biochar in rice production systems will not just help to truncate their carbon footprints, but also add to the bottom-line. In this work, the authors have reviewed the literature on climate change, human health, and economic impacts of using organic residues to make biochar for the addition to croplands especially to rice paddy fields. Biochar-bioenergy systems range in scale from small household cook-stoves to large industrial pyrolysis plants. Biochar can be purveyed in different forms—raw, mineral-enriched, or blended with compost. The review of published environmental life cycle assessment (E-LCA) studies showed biochar has the potential to mitigate the carbon footprint of farming systems through a... [more]
Integrated Ozonation-Enzymatic Hydrolysis Pretreatment of Sugarcane Bagasse: Enhancement of Sugars Released to Expended Ozone Ratio
Daryl Rafael Osuna-Laveaga, Octavio García-Depraect, Ramiro Vallejo-Rodríguez, Alberto López-López, Elizabeth León-Becerril
April 29, 2021 (v1)
Keywords: lignocellulosic biomass, moisture content, ozone dose, particle size, pretreatment, sugar yield
The combined effects of three key ozonation process parameters on the integrated ozonation-enzymatic hydrolysis pretreatment of sugarcane bagasse (SCB) were investigated, with emphasis on the relationship between sugar release and ozone consumption. A lab-scale fixed bed reactor was employed for ozonation at varying ozone doses (50, 75 and 100 mg O3/g SCB), particle sizes (420, 710 and 1000 µm) and moisture contents (30, 45 and 60% w/w) in multifactorial experiments, keeping a residence time of 30 min. The ozonated SCB showed a reduction in the content of acid-insoluble lignin from 26.6 down to 19.1% w/w, while those of cellulose and hemicellulose were retained above 45.5 and 13.6% w/w, with recoveries of 100−89.9 and 83.5−72.7%, respectively. Ozone-assisted enzymatic hydrolysis allowed attaining glucose and xylose yields as high as 45.0 and 37.8%, respectively. The sugars released/ozone expended ratio ranged between 2.3 and 5.7 g sugars/g O3, being the higher value achieved with an ap... [more]
Phosphorus-Doped Carbon Supported Vanadium Phosphate Oxides for Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran
Sha Wen, Kai Liu, Yi Tian, Yanping Xiang, Xianxiang Liu, Dulin Yin
April 29, 2021 (v1)
Keywords: 2,5-diformylfuran, 5-hydroxymethylfurfural, Catalysis, selective oxidation, vanadium phosphate oxides
2,5-diformylfuran (DFF) is an important downstream product obtained by selective oxidation of the biomass-based platform compound 5-hydroxymethylfurfural (HMF). In this study, a phosphorus-doped carbon (P-C) supported vanadium phosphate oxide (VPO) catalyst was successfully prepared and showed remarkably high catalytic activity in the selective oxidation of HMF to produce DFF with air as an oxidant. The effects of the reaction temperature, reaction time, solvent, catalyst amount, and VPO loading amount were investigated. The results showed that an HMF conversion rate of 100% and a DFF yield of 97.0% were obtained under suitable conditions, and DMSO was found to be the most suitable solvent under an air atmosphere.
Numerical Simulation of Combustion in 35 t/h Industrial Pulverized Coal Furnace with Burners Arranged on Front Wall
Jiade Han, Lingbo Zhu, Yiping Lu, Yu Mu, Azeem Mustafa, Yajun Ge
April 29, 2021 (v1)
Keywords: combustion characteristics, Computational Fluid Dynamics, industrial pulverized coal furnace, swirling burner
Coal-fired industrial boilers should operate across a wide range of loads and with a higher reduction of pollutant emission in China. In order to achieve these tasks, a physical model including two swirling burners on the front wall and boiler furnace was established for a 35 t/h pulverized coal-fired boiler. Based on Computational Fluid Dynamics (CFD) theory and the commercial software ANSYS Fluent, mathematical modeling was used to simulate the flow and combustion processes under 75% and 60% load operating conditions. The combustion characteristics in the furnace were obtained. The flue gas temperature simulation results were in good agreement with experimental data. The simulation results showed that there was a critical distance L along the direction of the furnace depth (x) and Hc along the direction of the furnace height (y) on the burner axis. When x < L, the concentration of NO decreased sharply as the height increased. When y < Hc, the NO concentration decreased sharply... [more]
Design and Development of Novel Continuous Flow Stirred Multiphase Reactor: Liquid−Liquid−Liquid Phase Transfer Catalysed Synthesis of Guaiacol Glycidyl Ether
Nikhil H. Margi, Ganapati D. Yadav
April 29, 2021 (v1)
Keywords: continuous flow stirred tank reactor (CSTR), epichlorohydrin, green chemistry, guaiacol, guaiacol glycidyl ether, liquid–liquid–liquid reactions, multiphase reactor, phase transfer catalysis (PTC)
Phase transfer catalysed (PTC) reactions are used in several pharmaceutical and fine chemical industrial processes. We have developed a novel stirred tank reactor (Yadav reactor) to conduct batch and continuous liquid−liquid−liquid (L-L-L) PTC reactions. The reactor had a provision of using three independent stirrers for each phase, thereby having complete control over the rate of mass transfer across the two interfaces. In the continuous mode of operation, the top and bottom phases were continuously fed into the reactor while the middle phase was used as a batch. All three stirrers were used independently, thereby having independent control of mass transfer resistances. The reactor in a batch mode showed higher conversion and selectivity compared to a conventional batch reactor. L-L-L PTC reaction in the continuous mode was successfully performed without loss of the middle catalyst phase and with steady conversion and selectivity. The reaction of guaiacol with epichlorohydrin was cond... [more]
Special Issue on “Hydrogen Production Technologies”
Suttichai Assabumrungrat, Suwimol Wongsakulphasatch, Pattaraporn Lohsoontorn Kim, Alírio E. Rodrigues
April 29, 2021 (v1)
According to energy crisis and environmental concerns, hydrogen has been driven to become one of the most promising alternative energy carriers for power generation and high valued chemical products [...]
The Investigation of Optimizing Leaching Efficiency of Al in Secondary Aluminum Dross via Pretreatment Operations
Haigang Feng, Guofan Zhang, Qun Yang, Luobing Xun, Siyuan Zhen, Dezhi Liu
April 29, 2021 (v1)
Subject: Other
Keywords: ball grinding, process mineralogy, secondary aluminum dross, water leaching
Secondary aluminum dross (SAD) is an inevitable by-product from the secondary aluminum industry and has caused serious environmental issues. In this study, the effect of pretreatment operations on the subsequent acid leaching operation was studied by process mineralogy, a series of leaching experiments, XRD, and SEM. Leaching results showed that the leaching efficiency of Al in direct acid leaching was only 22.99%. Process mineralogy showed the complex intertexture and continuous network structure in the SAD. Pretreatment operations were extremely efficient in destroying the structure by physical and chemical interaction. Interestingly, by adding the grinding and water leaching operations, the leaching efficiency of total aluminum in the SAD reached approximately 28.70%. XRD results showed that nearly all metallic Al, AlN, and partial Al2O3 were leached by grinding−water leaching−acid leaching. The scanning electron micrographs showed that the residue particles mainly included some ins... [more]
Aspen Plus Simulations of Acetone-Butanol-Ethanol Separation and Recovery Processes
Giancarlo Dalle Ave, Thomas A Adams II
April 27, 2021 (v1)
Keywords: 2-ethyl-hexanol, Acetone-Butanol-Ethanol, Aspen Plus, Decane, Decanol, Extracton, Fermentation, Hexanol, Oleyl Alcohol, Simulation
This is a collection of Aspen Plus v8.8 Simulation Files that were used to conduct the research published in Dalle Ave G, Adams TA II, "Techno-economic comparison of Acetone-Butanol-Ethanol fermentation using various extractants", Energy Conversion and Management, Volume 156, 15 January 2018, Pages 288-300. The LAPSE postprint of this work is available at LAPSE:2018.0132.

Each simulation file contains a flowsheet model of the process to recover acetone, butanol, and ethanol from the ABE fermentation broth for the following case studies:

1. Direct distillation of the ABE Broth
2. Product extraction and purification from ABE Broth using 2-Ethyl-1-Hexanol
3. Product extraction and purification from ABE Broth using Decane
4. Product extraction and purification from ABE Broth using Decanol
5. Product extraction and purification from ABE Broth using Hexanol
6. Product extraction and purification from ABE Broth using Mesitylene
7. Product extraction and purification from ABE... [more]
Oxygen Transfer Capacity as a Measure of Water Aeration by Floating Reed Plants: Initial Laboratory Studies
Antonio Albuquerque, Peter Randerson, Andrzej Białowiec
April 27, 2021 (v1)
Keywords: constructed wetlands, oxygen release, oxygen transfer capacity, Phragmites australis (Cav.) Trin. ex Steud, reed, reed floating cover, rhizosphere
Reed-Phragmites australis (Cav.) Trin. ex Steud, an aquatic plant, commonly used in constructed wetlands for wastewater treatment, supplies oxygen into the subsurface environment. Reed may be used as a ‘green machine’ in the form of a floating vegetation cover with many applications: wastewater lagoons, manure lagoons or sewage sludge lagoons. An important measure of the performance of the plant system is the oxygen transfer capacity (OTC). Accurate prediction of the OTC in relation to reed biomass would be crucial in modelling its influence on organic matter degradation and ammonia−nitrogen oxygenation in such lagoons. Laboratory experiments aiming to determine OTC and its dependence on reed biomass were carried out. Eight plants with a total dry mass ranging from approximately 3 to 7 g were tested. Mean OTC was determined per plant: 0.18 ± 0.21 (g O2·m−3·h−1·plant−1), with respect to leaves-and-stem dry mass (dlsm): 44.91 ± 35.21 (g O2·m−3·h−1·g dlsm−1), and to total dry mass (dtm):... [more]
Intracellular Sodium Changes in Cancer Cells Using a Microcavity Array-Based Bioreactor System and Sodium Triple-Quantum MR Signal
Dennis Kleimaier, Victor Schepkin, Cordula Nies, Eric Gottwald, Lothar R. Schad
April 27, 2021 (v1)
Subject: Biosystems
Keywords: 3D cell culture, bioreactor system, electric quadrupole interaction, microcavity array, Na/K-ATPase, organotypic culture, sodium NMR, sodium triple-quantum signal, TQTPPI
The sodium triple-quantum (TQ) magnetic resonance (MR) signal created by interactions of sodium ions with macromolecules has been demonstrated to be a valuable biomarker for cell viability. The aim of this study was to monitor a cellular response using the sodium TQ signal during inhibition of Na/K-ATPase in living cancer cells (HepG2). The cells were dynamically investigated after exposure to 1 mM ouabain or K+-free medium for 60 min using an MR-compatible bioreactor system. An improved TQ time proportional phase incrementation (TQTPPI) pulse sequence with almost four times TQ signal-to-noise ratio (SNR) gain allowed for conducting experiments with 12−14 × 106 cells using a 9.4 T MR scanner. During cell intervention experiments, the sodium TQ signal increased to 138.9 ± 4.1% and 183.4 ± 8.9% for 1 mM ouabain (n = 3) and K+-free medium (n = 3), respectively. During reperfusion with normal medium, the sodium TQ signal further increased to 169.2 ± 5.3% for the ouabain experiment, while i... [more]
Porous Venturi-Orifice Microbubble Generator for Oxygen Dissolution in Water
Kelly Chung Shi Liew, Athina Rasdi, Wiratni Budhijanto, Mohd Hizami Mohd Yusoff, Muhmmad Roil Bilad, Norazanita Shamsuddin, Nik Abdul Hadi Md Nordin, Zulfan Adi Putra
April 27, 2021 (v1)
Subject: Other
Keywords: aeration efficiency, aeration efficiency, microbubble generator, oxygen dissolution, venturi-orifice type
Microbubbles with slow rising speed, higher specific area and greater oxygen dissolution are desired to enhance gas/liquid mass transfer rate. Such attributes are very important to tackle challenges on the low efficiency of gas/liquid mass transfer that occurs in aerobic wastewater treatment systems or in the aquaculture industries. Many reports focus on the formation mechanisms of the microbubbles, but with less emphasis on the system optimization and assessment of the aeration efficiency. This work assesses the performance and evaluates the aeration efficiency of a porous venturi-orifice microbubble generator (MBG). The increment of stream velocity along the venturi pathway and orifice ring leads to a pressure drop (Patm > Pabs) and subsequently to increased cavitation. The experiments were run under three conditions: various liquid velocity (QL) of 2.35−2.60 m/s at fixed gas velocity (Qg) of 3 L/min; various Qg of 1−5 L/min at fixed QL of 2.46 m/s; and free flowing air at variable Q... [more]
Wild Strawberry Fragaria vesca L.: Kinetics of Fruit Drying and Quality Characteristics of the Dried Fruits
Andrzej Krzykowski, Dariusz Dziki, Stanisław Rudy, Urszula Gawlik-Dziki, Emilia Janiszewska-Turak, Beata Biernacka
April 27, 2021 (v1)
Keywords: antioxidant properties, color changes, drying, L-ascorbic acid changes, wild strawberry
The aim of this study was to determine the effect of the temperature of convection and freeze−drying of wild strawberry Fragaria vesca L. fruits on the drying kinetics and on selected quality features of the dried fruits. The process of convection drying was carried out at the temperatures of 25 °C, 40 °C, and 60 °C, whereas freeze−drying was carried out at the temperatures of 20 °C, 40 °C, and 60 °C of the heating shelves and at the pressure of 63 Pa in the lyophilizer chamber. The drying kinetics were best described by the Midilli model for both drying methods. An increase of the drying temperature to 60 °C, for both convection drying and freeze−drying, resulted in a decrease of the total content of phenolic compounds and of the antioxidant activity of the dried fruits. An increase in the temperature of convection drying reduced the lightness of the dried fruits. However, during freeze−drying, these features changed little despite the increase in the drying temperature. The dried fru... [more]
Energy and Exergy Assessment of S-CO2 Brayton Cycle Coupled with a Solar Tower System
Muhammad Ehtisham Siddiqui, Khalid H. Almitani
April 27, 2021 (v1)
Keywords: energy and exergy analysis, heliostat field, improved heat recuperation, optical efficiency, S-CO2 Brayton cycle, solar tower power system
In this research, we performed energy and exergy assessments of a solar driven power plant. Supercritical carbon dioxide (S-CO2) Brayton cycle is used for the conversion of heat to work. The plant runs on solar energy from 8 a.m. to 4 p.m. and to account for the fluctuations in the solar energy, the plant is equipped with an auxiliary heater operating on hot combustion gases from the combustion chamber. The capital city of Saudi Arabia (Riyadh) is chosen in this study and the solar insolation levels for this location are calculated using the ASHRAE clear-sky model. The solar collector (central receiver) receives solar energy reflected by the heliostats; therefore, a radially staggered heliostat field is generated for this purpose. A suite of code is developed to calculate various parameters of the heliostat field, such as optical efficiencies, intercept factors, attenuation factors and heliostat characteristic angles. S-CO2 Brayton cycle is simulated in commercial software, Aspen HYSYS... [more]
Controlling Ice Nucleation during Lyophilization: Process Optimization of Vacuum-Induced Surface Freezing
Andrea Allmendinger, Yuen Li Butt, Raphael Mietzner, Felix Schmidt, Joerg Luemkemann, Carmen Lema Martinez
April 27, 2021 (v1)
Keywords: amorphous, controlled ice nucleation, freeze-drying, lyophilization, protein formulations, sucrose
Biopharmaceuticals are often lyophilized to improve their storage stability. Controlling ice nucleation during the freezing step of the lyophilization process is desired to increase homogeneity of product properties across a drug product batch and shorten the primary drying time. The present communication summarizes the process optimization of the freezing process when using vacuum-induced surface freezing to control ice nucleation, in particular for amorphous samples. We characterized freeze-dried samples for solid state properties, and compared these to uncontrolled nucleated samples using bovine serum albumin (BSA) as a model protein. Freezing parameters were optimized to obtain complete nucleation, adequate cake resistance during the subsequent lyophilization cycle, and elegant cakes. We highlight the challenges associated with vacuum-induced surface freezing and propose optimized freezing parameters to control ice nucleation, enabling manufacturing of amorphous samples.
Green Dairy Plant: Process Simulation and Economic Analysis of Biogas Use in Milk Drying
Ján Janošovský, Eva Marková, Adriána Kačmárová, Miroslav Variny
April 27, 2021 (v1)
Keywords: biogas, industrial cluster, milk drying, process simulation, sensitivity analysis
A project of a new milk drying unit processing 4800 kg/h of fresh milk into milk powder with expected steam consumption of 1000 kg/h (equivalent to ca. 2.6 GJ/h) was assessed. In this paper, investment profitability of this project was analyzed combining mathematical modeling, market analysis, and parametric sensitivity study. Aspen Plus was used as the simulation environment to determine values of key process variables—major streams, mass flows, and energy consumption. Co-digestion of cattle manure in an adjacent biogas plant was considered to provide biogas to partially or completely substitute natural gas as an energy source. As biogas composition from potential co-digestion was unknown, variable methane content from 45 to 60 mol.% was considered. In the next step, thorough economic analysis was conducted. Diverse effects of biogas addition depending on market prices, biogas treatment costs, and biogas methane content were simulated and evaluated. In a market situation closest to re... [more]
Opportunities and Barriers of Hydrogen−Electric Hybrid Powertrain Vans: A Systematic Literature Review
Oscar Castillo, Roberto Álvarez, Rosario Domingo
April 27, 2021 (v1)
Keywords: delivery van, fuel cell, Hydrogen, last-mile delivery, light commercial vehicles, medium-duty vehicles, range extender, sustainable city logistics, urban freight transport, urban logistics
The environmental impact of the road transport sector, together with urban freight transport growth, has a notable repercussions in global warming, health and economy. The need to reduce emissions caused by fossil fuel dependence and to foster the use of renewable energy sources has driven the development of zero-emissions powertrains. These clean transportation technologies are not only necessary to move people but to transport the increasing demand for goods and services that is currently taking place in the larger cities. Full electric battery-powered vans seem to be the best-placed solution to the problem. However, despite the progress in driving range and recharge options, those and other market barriers remain unsolved and the current market share of battery electric vehicles (BEVs) is not significant. Based on the development of hydrogen fuel cell stacks, this work explains an emerging powertrain architecture concept for N1 class type vans, that combines a battery-electric confi... [more]
Carbon Dioxide Capture in Homogeneous and Heterogeneous Surfaces of Porous Silica Glass
Chontira Boonfung, Chaiyot Tangsathitkulchai, Atichat Wongkoblap
April 27, 2021 (v1)
Subject: Materials
Keywords: Adsorption, Carbon Dioxide Capture, defective surface, Grand Canonical Monte Carlo, porous silica glass, surface functional groups
Experimental and simulation studies for carbon dioxide (CO2) adsorption on porous silica glass were performed to reveal how surface heterogeneity can affect the adsorption mechanism of CO2. In performing the simulation, the structure of porous silica glass was modeled as a slit pore consisting of parallel walls of connected SiO4 units. The adsorption isotherms of CO2 at 283 K were generated for a series of pore widths using a Monte Carlo ensemble. The defective surfaces created by random removal of surface atoms and the surfaces containing hydroxyl functional groups were chosen to represent the surface heterogeneity for the simulation tasks. The isotherms derived for the defective surfaces showed a rapid adsorption at low pressures because of the stronger interaction between the rough nonuniform surfaces and CO2 molecules. For the role of surface functional groups, the adsorption isotherms dramatically increased with an increasing number of functional groups. The amount of CO2 adsorbed... [more]
Influence of Acoustic Oscillations on Continuous-Flow Water Disinfection
Anna V. Abramova, Vadim M. Bayazitov, Igor S. Fedulov, Roman V. Nikonov, Vladimir G. Sister, Giancarlo Cravotto
April 27, 2021 (v1)
Keywords: broadband hydrodynamic emitter, deionized water, disinfection, hybrid technology, overpressure, ultrasonic waveguide
Water disinfection and potential sterilization in continuous flow was achieved in a hybrid reactor with a broadband hydrodynamic emitter combined with ultrasonic vibrations at different frequencies and with excess pressure. Such a combination showed synergistic effects by increasing the acoustic power in the reactor vortex flow. The present combined physical treatment, compared with sonication alone, could increase microorganism inactivation by 15−20%.
Enhanced Degradation of Phenolic Compounds in Coal Gasification Wastewater by Methods of Microelectrolysis Fe-C and Anaerobic-Anoxic—Oxic Moving Bed Biofilm Reactor (A2O-MBBR)
Do Tra Huong, Van Tu Nguyen, Xuan Linh Ha, Hien Lan Nguyen Thi, Thi Thoa Duong, Duy Chinh Nguyen, Hong-Tham Nguyen Thi
April 27, 2021 (v1)
Keywords: A2O-MBBR, coal gasification wastewater, Fe-C materials, internal electrolysis
The coal gasification wastewater figures prominently among types of industrial effluents due to its complex and phenolic composition, posing great difficulty for conventional water treatment processes. Since the coking wastewater is toxic and mutagenic to humans and animals, treatment of coal gasification wastewater is genuinely necessary. In this study, we established a lab-scale A2O (Anaerobic-Anoxic—Oxic) with moving bed biological reactor (MBBR) system and evaluated some water indicators of wastewater pretreated with internal electrolysis, of wastewater output of the established A2O-MBBR system, and of the wastewater treated by the combination thereof. The wastewater was taken from a coking plant at Thai Nguyen Iron and Steel Joint Stock Company in Vietnam. COD, BOD5, NH4+-N, phenol, and pH of the input coal gasification wastewater were 2359, 1105, 319, 172 mg/L, and 8 ± 0.1, respectively. The conditions of internal electrolysis were as follows: 720 min of reaction time, pH = 4, 25... [more]
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