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Records with Subject: Energy Systems
Showing records 911 to 935 of 9566. [First] Page: 1 34 35 36 37 38 39 40 41 42 Last
Renewable Energy in Final Energy Consumption and Income in the EU-28 Countries
Mihaela Simionescu, Wadim Strielkowski, Manuela Tvaronavičienė
April 25, 2023 (v1)
Keywords: energy consumption, European Union, GDP per capita, renewable energy sources
The deployment of renewable energy sources (RES) is considered to be an important objective for the energy sector in the European Union (EU). The EU Directive adapted in 2009 fixed mandatory national targets for the use of renewable energy in transport as well as for the share of RES in the gross final energy consumption. Contrary to previous studies, this paper does not examine the link between the RES and economic growth but rather focuses on real gross domestic product (GDP) and the implementation of national renewable energy targets. We employ panel data models for the case of the EU-28 countries covering the period between 2007 and 2017 that yield a low and positive relationship between the impact of GDP per capita and the share of RES in the final consumption. Our results show that there is a significant causality only from real GDP per capita to the share of renewable energy in final consumption, marking the potential of developed countries to consume more RES. We list some grou... [more]
A Smart Hybrid Energy System Grid for Energy Efficiency in Remote Areas for the Army
Umberto Berardi, Elisa Tomassoni, Khaled Khaled
April 25, 2023 (v1)
Keywords: Energy Efficiency, hybrid energy system, microgrid, military applications, remote areas, Renewable and Sustainable Energy
The current energy inefficiencies in relocatable temporary camps of the Armed Force troops create logistic challenges associated with fuel supply. The energy needs of these camps are primarily satisfied by diesel engine generators, which imply that a significant amount of fuel needs to be continuously provided to these camps, often built in remote areas. This paper presents an alternative solution, named Smart Hybrid Energy System (SHES), aiming towards significantly reducing the amount of fuel needed and minimizing transportation logistics while meeting camp energy demands. The SHES combines the existing diesel generators with solar power generation, energy storage, and waste heat recovery technologies, all connected to a microgrid, ensuring uninterrupted electricity and hot water supplies. All components are controlled by an energy management system that prioritizes output and switches between different power generators, ensuring operation at optimum efficiencies. The SHES components... [more]
High-Capacity Dual-Electrolyte Aluminum−Air Battery with Circulating Methanol Anolyte
Pemika Teabnamang, Wathanyu Kao-ian, Mai Thanh Nguyen, Tetsu Yonezawa, Rongrong Cheacharoen, Soorathep Kheawhom
April 25, 2023 (v1)
Keywords: aluminum, aluminum–air battery, anion exchange membrane, dual electrolyte, flow battery, Methanol, potassium hydroxide
Aluminum−air batteries (AABs) have recently received extensive attention because of their high energy density and low cost. Nevertheless, a critical issue limiting their practical application is corrosion of aluminum (Al) anode in an alkaline aqueous electrolyte, which results from hydrogen evolution reaction (HER). To effectively solve the corrosion issue, dissolution of Al anode should be carried out in a nonaqueous electrolyte. However, the main cathodic reaction, known as oxygen reduction reaction (ORR), is sluggish in such a nonaqueous electrolyte. A dual-electrolyte configuration with an anion exchange membrane separator allows AABs to implement a nonaqueous anolyte along with an aqueous catholyte. Thus, this work addresses the issue of anode corrosion in an alkaline Al−air flow battery via a dual-electrolyte system. The battery configuration consisted of an Al anode | anolyte | anion exchange membrane | catholyte | air cathode. The anolytes were methanol solutions containing 3 M... [more]
Macroscopic Spray Behavior of a Single-Hole Common Rail Diesel Injector Using Gasoline-Blended 5% Biodiesel
Sakda Thongchai, Ocktaeck Lim
April 25, 2023 (v1)
Keywords: biodiesel, gasoline spray, PLIF-PIV
This research studies the macroscopic spray structure from a single-hole common rail diesel injector using gasoline-blended 5% biodiesel for use in compression ignition engines. To reduce the NOX/PM trade-off emissions, researchers are investigating gasoline used in compression ignition engines, called gasoline compression ignition. As a result that gasoline is injected directly into the combustion chamber, its spray field has a significant effect on combustion and emissions. Due to its low lubricity, gasoline is blended with biodiesel 5%, as a lubricity enhancer, to prevent the failure of the high-pressure injection system. The macroscopic spray structures of this gasoline blend were investigated Schlieren photography and planar laser-induced fluorescence-particle image velocimetry. Injection pressure was handled by a conventional common rail system, while ambient pressure was controlled by supplying nitrogen into the constant-volume combustion chamber. The effects of injection pressu... [more]
The Causal Connection of Natural Resources and Globalization with Energy Consumption in Top Asian Countries: Evidence from a Nonparametric Causality-in-Quantile Approach
Hafezali Iqbal Hussain, Muhammad Haseeb, Manuela Tvaronavičienė, Leonardus W. W. Mihardjo, Kittisak Jermsittiparsert
April 25, 2023 (v1)
Keywords: Energy, globalization, natural resources, nonparametric causality in quantiles
Given the significance of energy conservation as a prime objective of environmental sustainability, countries all around the world are keen to identify significant factors that lead to the augmentation of energy utilization. Considering the rising emphasis of economies in utilizing natural resources to attain higher levels of globalization, the current research was aimed at investigating how the returns of natural resources and globalization affect energy consumption in top Asian economies. In doing so, the study emphasized the nonlinear relationship among the variables and applied the novel nonparametric method of causality in quantile to identify the quantile-based causal connection of natural resources and globalization on the returns and volatility of energy utilization in selected Asian countries. Moreover, the presence of nonlinearity in the variables was tested by the Brock- Dechert-Scheinkman test (BDS test), which confirmed that all variables showed nonlinear behavior. Further... [more]
Electrical Loads and Power Systems for the DEMO Nuclear Fusion Project
Simone Minucci, Stefano Panella, Sergio Ciattaglia, Maria Carmen Falvo, Alessandro Lampasi
April 25, 2023 (v1)
Keywords: balance of plant, DEMO, electric loads, nuclear fusion, plasma, power flow, power supply, power systems
EU-DEMO is a European project, having the ambitious goal to be the first demonstrative power plant based on nuclear fusion. The electrical power that is expected to be produced is in the order of 700−800 MW, to be delivered via a connection to the European High Voltage electrical grid. The initiation and control of fusion processes, besides the problems related to the nuclear physics, need very complex electrical systems. Moreover, also the conversion of the output power is not trivial, especially because of the inherent discontinuity in the EU-DEMO operations. The present article concerns preliminary studies for the feasibility and realization of the nuclear fusion power plant EU-DEMO, with a special focus on the power electrical systems. In particular, the first stage of the study deals with the survey and analysis of the electrical loads, starting from the steady-state loads. Their impact is so relevant that could jeopardy the efficiency and the convenience of the plant itself. Afte... [more]
Analysis of the Thermal Characteristics of Welding Spatters in SMAW Using Simplified Model in Fire Technology
Yeon Je Shin, Woo Jun You
April 25, 2023 (v1)
Keywords: distribution, fire risk, particle heat transfer, shield arc metal welding, welding spatter
In this study, the thermal characteristics of welding spatters were analyzed to predict the risk of fire spread in the shield metal arc welding. The mean diameters and the distribution shapes of the particles were investigated with the variation of the distribution coefficients using the modified gamma distribution function. To quantify the heat source of the welding spatters, the previous empirical equation for the heat transfer coefficient of Ranz and Marshall was analyzed regarding the particle velocity and surface temperature. The order of magnitude for the convection and the radiation were as performed to the particles and the base metal, respectively. The results, which are only valid for Tp,m = 750 K and Tb,s = 2300 K, show that the radiation term is only 10% for a particle but the convective term is only 6% for the base metal. Finally, the simplified model for the temperature of the welding spatters was obtained and the validation results were within ±13%. The variations of ele... [more]
Flare Gas Waste Heat Recovery: Assessment of Organic Rankine Cycle for Electricity Production and Possible Coupling with Absorption Chiller
Hamza Semmari, Abdelkader Filali, Sofiane Aberkane, Renaud Feidt, Michel Feidt
April 25, 2023 (v1)
Keywords: absorption chiller, electricity production, flare gas, ORC, thermodynamic performance
Every year, flare gas is responsible for more than 350 million tons of CO2 emissions. Aside from thermal and environmental pollution impacts, flare gas contributes to global warming and enormous economic losses. Thus, waste heat recovery due to flaring gas can be explored through Organic Rankine Cycle ORC systems for electricity production. In this context, the assessment of a toluene ORC system is proposed for a potential application in an Algerian petrochemical unit. The study focuses mainly on highlighting the potential and thermodynamic performances of the ORC application to produce electricity and potential cooling thanks to coupling an absorption chiller by recovering heat due to flaring gas. Such a solution can easily be implemented as an energy efficiency key solution. The ORC electrical production can meet the increasing demand of natural gas initially intended to be provided to a gas power plant and assures the major part of the Algerian electrical production.
How Is Mortality Affected by Fossil Fuel Consumption, CO2 Emissions and Economic Factors in CIS Region?
Ehsan Rasoulinezhad, Farhad Taghizadeh-Hesary, Farzad Taghizadeh-Hesary
April 25, 2023 (v1)
Keywords: CO2 emissions, econometrics, economic growth, mortality rate
It is widely discussed that GDP growth has a vague impact on environmental pollution due to carbon dioxide emissions from fossil fuels consumed in production, transportation, and power generation. The main purpose of this study is to investigate the relationships between economic growth, fossil fuel consumption, mortality (from cardiovascular disease (CVD), diabetes mellitus (DM), cancer, and chronic respiratory disease (CRD), and environmental pollution since environmental pollution can be a reason for societal mortality rate increases. This study uses the generalized method of moments (GMM) estimation technique for the Commonwealth of Independent States (CIS) members for the period from 1993−2018. The major results revealed that the highest variability of mortality could be explained by CO2 variability. Regarding fossil fuel consumption, the estimation proved that this variable positively affects mortality from CVD, DM, cancer, and CRD. Additionally, any improvements in the human dev... [more]
Gasification of Coal Dust in a Cyclone Furnace in an O2/H2O Atmosphere
Robert Zarzycki, Justyna Jędras, Rafał Kobyłecki
April 25, 2023 (v1)
Keywords: coal dust, cyclone furnace, gasification, numerical simulations, oxy-fuel combustion, steam
This paper presents the results of the modeling of coal dust gasification using oxygen and steam in a cyclone furnace. The combustion process leads to the release of gas composed mainly of CO and H2. The composition of this gas can be controlled through changes in the content of O2 and H2O in the gasifying agent. It is possible for the process conditions adopted in the study to obtain the CO content at the level of 50% with the content of the gasifying agent O2/H2O of 50/50. In the case of the composition of the gasifying agent O2/H2O of 80/20, the H2 content was 50%. The maximal calorific value of the gas was obtained for O2/H2O 50/50 (11.2 MJ/kg).
TRIC: A Thermal Resistance and Impedance Calculator for Electronic Packages
Lorenzo Codecasa, Francesca De Viti, Vincenzo d’Alessandro, Donata Gualandris, Arianna Morelli, Claudio Maria Villa
April 25, 2023 (v1)
Keywords: detailed thermal model, electronic packages, Joint Electron Device Engineering Council (JEDEC) metrics, thermal impedance, thermal simulation
This paper presents the Thermal Resistance and Impedance Calculator (TRIC) tool devised for the automatic extraction of thermal metrics of package families of electronic components in both static and transient conditions. TRIC relies on a solution algorithm based on a novel projection-based approach, which—unlike previous techniques—allows (i) dealing with parametric detailed thermal models (pDTMs) of package families that exhibit generic non-Manhattan variations of geometries and meshes, and (ii) transforming such pDTMs into compact thermal models that can be solved in short times. Thermal models of several package families are available, and dies with multiple active areas can be handled. It is shown that transient thermal responses of chosen packages can be obtained in a CPU (central processing unit) time much shorter than that required by a widely used software relying on the finite-volume method without sacrificing accuracy.
Study of How Photoelectrodes Modified by TiO2/Ag Nanofibers in Various Structures Enhance the Efficiency of Dye-Sensitized Solar Cells under Low Illumination
Yu-Hsun Nien, Huang-Hua Chen, Hui-Hsuan Hsu, Manjunath Rangasamy, Geng-Ming Hu, Zhen-Rong Yong, Po-Yu Kuo, Jung-Chuan Chou, Chih-Hsien Lai, Cheng-Chu Ko, Jun-Xiang Chang
April 25, 2023 (v1)
Keywords: dye-sensitized solar cells, electrospinning, low illumination, nanofibers, photovoltaic conversion efficiency
Dye-sensitized solar cells (DSSCs) are low-cost solar cells belonging to the thin-film photovoltaic cell type. In this study, we studied the photovoltaic performances of DSSCs based on titanium dioxide (TiO2) nanofibers (NFs) containing silver (Ag) nanoparticles (NPs) under low illumination. We used the sol-gel method with the electrospinning technique to prepare the TiO2 NFs containing Ag NPs. Herein, we used two ways to add TiO2/Ag NFs to modify the photoelectrode successfully and enhance the performance of DSSCs. One way was that the TiO2/Ag NFs were mixed with pristine TiO2; the other way was that the TiO2/Ag NFs were seeded beside the TiO2 colloid layer as an additional layer on the photoelectrode of the DSSC. According to this experiment, the photovoltaic conversion efficiency of the DSSC which had TiO2/Ag NF seeded as an additional layer on the photoelectrode (5.13%) was increased by 28% compared to the DSSC without the photoelectrode modification (3.99%). This was due to the su... [more]
Adapt or Perish: A New Approach for Industry Needs-Driven Master’s Level Low-Carbon Energy Engineering Education in the UK
Paul Rowley, Caroline Walker
April 25, 2023 (v1)
Keywords: blended learning, competency-based training, distance learning, Master of Science (MSc), masters level training, needs-driven training, training needs analysis
This paper describes the results of recent research carried out with the UK energy sector to assess low-carbon related skills gaps and training requirements at the masters-level. Via iterative engagement across the industry, the characteristics of the market for new ‘needs-driven’ industry-focussed masters-level training offerings were defined. The results, taken together with the outcomes of a gap analysis of existing masters-level training, support the creation of a new framework for masters-level energy education that will more effectively meet the growing unmet need for such skills in the UK and beyond. The outcomes of the research indicate that flexibility in both delivery mode and curriculum content across both technical and non-technical disciplines is essential, along with improved supplier agility to rapidly develop new courses in evolving engineering specialisations. Without responding effectively to such demands from industry, we conclude that the advanced skills needed acro... [more]
Potentials of Thermal Energy Storage Integrated into Steam Power Plants
Michael Krüger, Selman Muslubas, Thomas Loeper, Freerk Klasing, Philipp Knödler, Christian Mielke
April 25, 2023 (v1)
Keywords: coal power plants, TES, thermal energy storage
For conventional power plants, the integration of thermal energy storage opens up a promising opportunity to meet future technical requirements in terms of flexibility while at the same time improving cost-effectiveness. In the FLEXI- TES joint project, the flexibilization of coal-fired steam power plants by integrating thermal energy storage (TES) into the power plant process is being investigated. In the concept phase at the beginning of the research project, various storage integration concepts were developed and evaluated. Finally, three lead concepts with different storage technologies and integration points in the power plant were identified. By means of stationary system simulations, the changes of net power output during charging and discharging as well as different storage efficiencies were calculated. Depending on the concept and the operating strategy, a reduction of the minimum load by up to 4% of the net capacity during charging and a load increase by up to 5% of the net c... [more]
Experimental Study on the Strengthen Heat Transfer Performance of PCM by Active Stirring
Yanjun Zhang, Shuli Liu, Liu Yang, Xiue Yang, Yongliang Shen, Xiaojing Han
April 25, 2023 (v1)
Keywords: convection, heat transfer, latent heat, phase change, stirring
Latent heat storage has higher energy density, but most phase change materials (PCMs) have low thermal conductivity. Current research focuses on conduction dominated heat transfer mechanism to increase the heat transfer performance. However, convection also has important effects on promoting PCM melting and solidification processes. Therefore, an active stirring method with conduction dominated heat transfer mechanism was studied. A shell storage with stirrer inside was constructed and tested. Paraffin was selected as the PCM; the heat transfer fluid (HTF) was water. The results show that average charging rate increased by 32.23 J/s than that without stirring, and the average discharging rate increased by 47.39 J/s. Completion time for charging/discharging with stirring was shortened by 9.61% and 48.61% than that without stirring. In the charging process, the average power of motor was 16.08 W, and the average discharging rate was greater than 500 J/s, accounting for less than 3.2%. In... [more]
Pinecone-Derived Activated Carbons as an Effective Medium for Hydrogen Storage
Sara Stelitano, Giuseppe Conte, Alfonso Policicchio, Alfredo Aloise, Giovanni Desiderio, Raffaele G. Agostino
April 25, 2023 (v1)
Keywords: biomass waste, hydrogen storage, nanoporous activated carbon, Pinecones, renewable
Pinecones, a common biomass waste, has an interesting composition in terms of cellulose and lignine content that makes them excellent precursors in various activated carbon production processes. The synthesized, nanostructured, activated carbon materials show textural properties, a high specific surface area, and a large volume of micropores, which are all features that make them suitable for various applications ranging from the purification of water to energy storage. Amongst them, a very interesting application is hydrogen storage. For this purpose, activated carbon from pinecones were prepared using chemical activation with different KOH/precursor ratios, and their hydrogen adsorption capacity was evaluated at liquid nitrogen temperatures (77 K) at pressures of up to 80 bar using a Sievert’s type volumetric apparatus. Regarding the comprehensive characterization of the samples’ textural properties, the measurement of the surface area was carried out using the Brunauer−Emmett−Teller... [more]
The Effect of Elliptical Diesel Nozzles on Spray Liquid-Phase Penetration under Evaporative Conditions
Bifeng Yin, Bin Xu, Hekun Jia, Shenghao Yu
April 25, 2023 (v1)
Keywords: biodiesel, diesel nozzle, elliptical orifice, liquid-phase penetration
Elliptical diesel nozzles affect the fuel−air mixing process, and thus combustion and exhaust emissions. Experiments were conducted to study biodiesel spray liquid-phase behaviors for elliptical and circular nozzles through the Mie-scattering method under evaporative conditions. Based on the measurements, the results show that the elliptical nozzle spray liquid-phase penetration is smaller than the circular one under steady-state conditions. The deformation and the axis-switching behaviors of the elliptical jet are helpful in accelerating the breakup of the liquid core. Moreover, the injection pressure has little impact on the penetration of the liquid-phase spray for either geometrical orifice. Additionally, increasing the ambient temperature can reduce the penetration of liquid-phase spray, because an increase in temperature increases the rate of evaporation. The differences in steady liquid-phase penetration between circular and elliptical sprays decrease as the ambient temperature... [more]
Enhancing CO2 Hydrogenation to Methane by Ni-Based Catalyst with V Species Using 3D-mesoporous KIT-6 as Support
Hongxia Cao, Wenyuan Wang, Tianlei Cui, Hongyan Wang, Guang Zhu, Xiangkun Ren
April 25, 2023 (v1)
Keywords: 3D-mesoporous, CO2 methanation, KIT-6, Ni-based catalyst, V species
Using renewable H2 for CO2 hydrogenation to methane not only achieves CO2 utilization, but also mitigates the greenhouse effect. In this work, several Ni-based catalysts with V species using 3D-mesoporous KIT-6 (Korea Advanced Institute of Science and Technology, KIT) as support were prepared at different contents of NiO and V2O5. Small Ni nanoparticles with high dispersibility on 20Ni-0.5V/KIT-6 were identified by X-ray diffraction (XRD), TEM and hydrogen temperature-programmed desorption (H2-TPD) analysis, which promoted the production of more Ni active sites for enhancing catalytic activity for CO2 methanation. Moreover, TEM and hydrogen temperature-programmed reduction (H2-TPR) characterizations confirmed that a proper amount of Ni and V species was favorable to preserve the 3D-mesoporous structure and strengthen the interaction between active Ni and KIT-6. The synergistic effect between Ni and V could strengthen surface basicity to elevate the ability of CO2 activity on the 20Ni-0... [more]
The Application of Molten Salt Energy Storage to Advance the Transition from Coal to Green Energy Power Systems
Wojciech Kosman, Andrzej Rusin
April 25, 2023 (v1)
Keywords: Energy Storage, flexibility, renewable sources, steam turbine
The paper presents technical solutions for a power grid that undergoes the elimination of a significant number of coal-based power generating units. The purpose of the solutions is to adapt the existing machines with sufficient lifespans to the new operating conditions. In particular these include steam turbines. The steam turbines’ cycles may be extended with energy storage systems based on a molten salt. This allows to increase the flexibility of the power generating units while maintaining the largest possible efficiency of the power generation. The solutions presented here allow to connect the steam turbines cycles to renewable energy sources and reduce the overall number of the units that create the fundamental layer of the power grid. The analysis of the solutions involves numerical modeling. The paper describes the assumptions and the results of the modeling for chosen cases of the modernization. The researched considered a number of options that differed in the investment costs... [more]
Advanced Control of a Compensator Motor Driving a Variable Speed Diesel Generator with Rotating Stator
Mohammadjavad Mobarra, Bruno Tremblay, Miloud Rezkallah, Adrian Ilinca
April 25, 2023 (v1)
Keywords: digital signal processor (DSP), motor speed control algorithm, rotating stator concept, variable frequency drive, variable speed diesel generator
Variable speed generators can improve overall genset performance by allowing the diesel engine to reduce its speed at lower loads. In this project, a variable speed diesel generator (VSDG) uses a rotating stator driven by a compensator motor. At lower loads, the stator turns in the opposite direction of the rotor, a process that can be used for purposes like maintaining a fixed relative speed between the two components of a generator. This allows the diesel engine to turn at a lower speed (same as the rotor) and to increase its efficiency. The present research addresses the control of the compensator motor driving the generator’s stator using a variable-frequency drive that adapts the speed to its optimal value according to the load. The performance of the proposed control strategy was tested using a Freescale microcontroller card programmed in C-code to determine the appropriate voltage for the variable-frequency drive. The control algorithm uses a real-time application implemented on... [more]
Low Voltage Battery Management System with Internal Adaptive Charger and Fuzzy Logic Controller
Omer Faruk Goksu, Ahmet Yigit Arabul, Revna Acar Vural
April 25, 2023 (v1)
Keywords: battery chargers, battery management systems, fuzzy logic control
Lithium ion (Li-Ion) and lithium polymer (Li-Po) batteries need to be used within certain voltage/current limits. Failure to observe these limits may result in damage to the battery. In this work, we propose a low voltage battery management system (LV-BMS) that balances the processes of the battery cells in the battery pack and the activating-deactivating of cells by guaranteeing that the operation is within these limits. The system operates autonomously and provides energy from the internal battery. It has a modular structure and the software is designed to control the charging and discharging of eight battery cells at most. A STM32F103 microcontroller is used for system control. The fuzzy logic controller (FLC) is used to set the discharge voltage limit to prevent damage to the battery cells, shorten the settlement time and create a specialized design for charge control. The proposed structure enables solar panel or power supplies with different voltage values between 5 V and 8 V to... [more]
Energy Consumption Reduction of a Chiller Plant by Adding Evaporative Pads to Decrease Condensation Temperature
Francisco J. Rey Martínez, Julio F. San José Alonso, Eloy Velasco Gómez, Ana Tejero González, Paula M Esquivias, Javier M. Rey Hernández
April 25, 2023 (v1)
Keywords: adiabatic condenser, air cooled chiller, energy savings, equivalent carbon dioxide emissions, evaporative cooling pad
The high energy consumption of cooling systems justifies the need for strategies to increase the efficiency of the facilities, in order to reduce the related CO2 emissions. This study aims to improve the performance and reduce the energy consumption of an 8.6 MW air cooled chiller. This installed capacity is biased due to the screw compressors, of 2.98 Energy Efficiency Ratio (EER) at full load (characteristics provided by the manufacturer). The chiller unit has been modified by placing evaporating cooling pads before the condensing coils. The chiller has been monitored for three months, recording over 544,322 measurements (5 min-step data), with and without the evaporative cooling pads, to assess the performance. Data comparison has been done by selecting two days (with and without evaporative panels) with the same health care load and temperatures. Implementing the proposed strategy yields an improvement in the European Seasonal Energy Efficiency Ratio (ESEER) from 3.69 to 4.83, whil... [more]
Dynamics for Sustainable Nuclear Buildup Based on LWR and FBR Technologies and Its Impact on CO2 Emission Reduction
Boris Crnobrnja, Krešimir Trontl, Dubravko Pevec, Mario Matijević
April 25, 2023 (v1)
Keywords: CO2 emission reduction, fast breeder reactor, light water reactor, plutonium resources, uranium resources
In recent years, most of the growth in electricity demand is covered by renewable and nuclear energy sources. However, electricity generation in fossil-fired power plants is also increasing resulting in the increase of CO2 emissions. Nuclear energy has to be considered as one of the available tools to accomplish CO2 emission reduction in electricity sector. Light water reactors (LWR) are currently the dominant nuclear technology but their intensive application in long-term period is constrained by available uranium fuel resources. Fast breeder reactors’ (FBR) technology is not used on a larger scale. Plutonium resources are limited, but do have the potential of stronger buildup if light water reactors, as the source of plutonium, are used on a larger scale. The appropriate dynamics for LWR/FBR buildup till the end of the 21st century is developed under assumptions of different LWR life times, and different uranium fuel resources available. The possible CO2 emission reduction is calcula... [more]
Effect of HPT on the First Hydrogenation of LaNi5 Metal Hydride
Renato Belli Strozi, Julia Ivanisenko, Natalia Koudriachova, Jacques Huot
April 25, 2023 (v1)
Keywords: AB5 alloys, high-pressure torsion, hydrogen storage, LaNi5
This paper reports the effect of high-pressure torsion (HPT) on the first hydrogenation of LaNi5. We found that, for loose powder, reduction of particle size has an effect of increasing the incubation time and decreasing the hydrogen capacity. A higher amount of HPT turns only marginally reduce the incubation time but has no effect on hydrogen capacity. In all cases, the first dehydrogenation and subsequent hydrogenation have the same kinetics, irrespective of the particle size or number of HPT turns. Therefore, for LaNi5, HPT has a beneficial effect only for the first hydrogenation.
Thermodynamic Analysis of the Effect of Green Hydrogen Addition to a Fuel Mixture on the Steam Methane Reforming Process
Robert Kaczmarczyk
April 25, 2023 (v1)
Keywords: carbon deposition, equilibrium characteristics, green hydrogen, parametric equation formalism, steam reforming of methane
Steam methane (CH4−H2O) reforming in the presence of a catalyst, usually nickel, is the most common technology for generating synthesis gas as a feedstock in chemical synthesis and a source of pure H2 and CO. What is essential from the perspective of further gas use is the parameter describing a ratio of equilibrium concentration of hydrogen to carbon monoxide (H/C=xH2/xCO). The parameter is determined by operating temperature and the initial ratio of steam concentration to methane SC=xH2O0/xCH40. In this paper, the author presents a thermodynamic analysis of the effect of green hydrogen addition to a fuel mixture on the steam methane reforming process of gaseous phase (CH4/H2)−H2O. The thermodynamic analysis of conversion of hydrogen-enriched methane (CH4/H2)−H2O has been performed using parametric equation formalism, allowing for determining the equilibrium composition of the process in progress. A thermodynamic condition of carbon precipitation in methane reforming (CH4/H2) with the... [more]
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