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Showing records 207 to 231 of 310. [First] Page: 1 6 7 8 9 10 11 12 13 14 Last
A Review on Experimental Studies Investigating the Effect of Hydrogen Supplementation in CI Diesel Engines—The Case of HYMAR
Charalambos Frantzis, Theodoros Zannis, Petros G. Savva, Elias Ar. Yfantis
February 27, 2023 (v1)
Keywords: compression ignition engines, decarbonization, Hydrogen, internal combustion engines, marine diesel engines, maritime alternative fuels
Hydrogen supplementation in diesel Compression Ignition (CI) engines is gaining more attention, since it is considered as a feasible solution to tackle the challenges that are related to the emission regulations that will be applied in the forthcoming years. Such a solution is very attractive because it requires only limited modifications to the existing technology of internal combustion CI engines. To this end, numerous work on the investigation of an engine’s performance and the effects of emissions when hydrogen is supplied in the engine’s cylinders has been completed by researchers. However, contradictory results were found among these studies regarding the efficiency of the engine and the emission characteristics achieved compared to the diesel-only operation. The different conclusions might be attributed to the different characteristics and technology level of the engines that were utilized, as well as on the chosen operational parameters. This paper aims to present an overview o... [more]
CFD Study of Dual Fuel Combustion in a Research Diesel Engine Fueled by Hydrogen
Maria Cristina Cameretti, Roberta De Robbio, Ezio Mancaruso, Marco Palomba
February 27, 2023 (v1)
Keywords: combustion modeling, Computational Fluid Dynamics, diesel engine, dual fuel, Hydrogen
Superior fuel economy, higher torque and durability have led to the diesel engine being widely used in a variety of fields of application, such as road transport, agricultural vehicles, earth moving machines and marine propulsion, as well as fixed installations for electrical power generation. However, diesel engines are plagued by high emissions of nitrogen oxides (NOx), particulate matter (PM) and carbon dioxide when conventional fuel is used. One possible solution is to use low-carbon gaseous fuel alongside diesel fuel by operating in a dual-fuel (DF) configuration, as this system provides a low implementation cost alternative for the improvement of combustion efficiency in the conventional diesel engine. An initial step in this direction involved the replacement of diesel fuel with natural gas. However, the consequent high levels of unburned hydrocarbons produced due to non-optimized engines led to a shift to carbon-free fuels, such as hydrogen. Hydrogen can be injected into the in... [more]
A Perspective on Decarbonizing Mobility: An All-Electrification vs. an All-Hydrogenization Venue
Anton Manakhov, Maxim Orlov, Mustafa Babiker, Abdulaziz S. Al-Qasim
February 27, 2023 (v1)
Subject: Environment
Keywords: circular economy, climate change, cost analysis, Hydrogen, the levelized cost of hydrogen (LCOH)
The growing demand for low-carbon fuel is predicted by ultimate goals to fit the carbon neutrality by 2050 in many countries and regions including the European Union. According to the International Energy Agency, the CO2 emissions related to transportation stand for around 30% of total annual emissions, and so, the decarbonization of the mobility sector has the highest priority. In this work, we attempt to evaluate the expected demand for low-carbon fuels, including blue and green hydrogen, and low-carbon electricity in order to compare the available and required capacities of low-carbon fuels and electricity. According to our calculations based on the figures from 2020, the transition toward H2 mobility would require an amount of hydrogen equal to 366 million tons/annum, and by 2035, this requirement will increase up to 422 million tons/annum, which is several times larger than the existing H2 production capacities. We have estimated the volume of the carbon capture and storage facili... [more]
Safe Ventilation Methods against Leaks in Hydrogen Fuel Cell Rooms in Homes
Hyon Wook Ji, Hongcheol Lee, Inju Hwang, Heela Jang
February 27, 2023 (v1)
Keywords: enclosure, experiments, fuel cell room, Hydrogen, hydrogen concentration, hydrogen leak, shutoff valve, ventilation
Hydrogen, which has a high energy density and does not emit pollutants, is considered an alternative energy source to replace fossil fuels. Herein, we report an experimental study on hydrogen leaks and ventilation methods for preventing damage caused by leaks from hydrogen fuel cell rooms in homes, among various uses of hydrogen. This experiment was conducted in a temporary space with a volume of 11.484 m3. The supplied pressure, leak-hole size, and leakage amount were adjusted as the experimental conditions. The resulting hydrogen concentrations, which changed according to the operation of the ventilation openings, ventilation fan, and supplied shutoff valve, were measured. The experimental results showed that the reductions in the hydrogen concentration due to the shutoff valve were the most significant. The maximum hydrogen concentration could be reduced by 80% or more if it is 100 times that of the leakage volume or higher. The shutoff valve, ventilation fan, and ventilation openin... [more]
Sector Coupling and Migration towards Carbon-Neutral Power Systems
Minjae Son, Minsoo Kim, Hongseok Kim
February 27, 2023 (v1)
Keywords: electricity, gas, heat, Hydrogen, Renewable and Sustainable Energy, sector coupling
There is increasing interest in migrating to a carbon-neutral power system that relies on renewable energy due to concerns about greenhouse gas emissions, energy shortages, and global warming. However, the increasing share of renewable energy has added volatility and uncertainty to power system operations. Introducing new devices and using flexible resources may help solve the problem, but expanding the domain of the problem can be another solution. Sector coupling, which integrates production, consumption, conversion, and storage by connecting various energy domains, could potentially meet the needs of each energy sector. It can also reduce the generation of surplus energy and unnecessary carbon emissions. As a result, sector coupling, an integrated energy system, increases the acceptance of renewable energy in the traditional power system and makes it carbon neutral. However, difficulties in large-scale integration, low conversion efficiency and economic feasibility remain obstacles.... [more]
Dry Reforming of Methane Using a Swirl-Induced Plasma Discharge Reactor
R. Bharathi Raja, Anusha C. Halageri, R. Sankar, Ramanujam Sarathi, Ravikrishnan Vinu
February 27, 2023 (v1)
Keywords: dry reforming of methane, Hydrogen, non-thermal plasma, point-plane electrode discharge reactor, Syngas
This study reports the dry reforming of methane (DRM) using non-thermal plasma in a swirl-induced point-plane electrode discharge reactor to produce syngas. This reactor geometry facilitates better mixing of the reactant gases in the plasma region, thus increasing the residence time and conversion of the reactants. The effect of varying flow rates and compositions of CO2/CH4 (v%/v%) on conversion was studied. A high-voltage AC power input of 50 W and 70 W at a frequency of 19 kHz was provided. The voltage−current characteristics with respect to time were studied. The results show that with an increase in the flow rate of the gas mixture from 0.5 to 2 LPM the conversion of both CO2 and CH4 decreases, while an increase in the concentration of CO2 or CH4 (from 25 to 75%) increases the conversion of the respective reactant. The products, viz. syngas (CO and H2), C2 hydrocarbons, and solid carbon, were characterized and quantified. The maximum total conversion of 44% was obtained for a CO2:... [more]
Semi-Systematic Literature Review on the Contribution of Hydrogen to Universal Access to Energy in the Rationale of Sustainable Development Goal Target 7.1
Nikolas Schöne, Boris Heinz
February 27, 2023 (v1)
Subject: Environment
Keywords: clean cooking, electrification, Hydrogen, semi-systematic review, Sustainable Development Goal 7
As part of the United Nations’ (UN) Sustainable Development Goal 7 (SDG7), SDG target 7.1 recognizes universal electrification and the provision of clean cooking fuel as two fundamental challenges for global society. Faltering progress toward SDG target 7.1 calls for innovative technologies to stimulate advancements. Hydrogen has been proposed as a versatile energy carrier to be applied in both pillars of SDG target 7.1: electrification and clean cooking. This paper conducts a semi-systematic literature review to provide the status quo of research on the application of hydrogen in the rationale of SDG 7.1, covering the technical integration pathways, as well as the key economic, environmental, and social aspects of its use. We identify decisive factors for the future development of hydrogen use in the rationale of SDG target 7.1 and, by complementing our analysis with insights from the related literature, propose future avenues of research. The literature on electrification proposes th... [more]
Energy and Exergy Analysis of a Geothermal Sourced Multigeneration System for Sustainable City
Sheikh Muhammad Ali Haider, Tahir Abdul Hussain Ratlamwala, Khurram Kamal, Fahad Alqahtani, Mohammed Alkahtani, Emad Mohammad, Moath Alatefi
February 27, 2023 (v1)
Keywords: geothermal, Hydrogen, multigeneration system, power, renewable
The issue of depleting fossil fuels has emphasized the use of renewable energy. Multigeneration systems fueled by renewables such as geothermal, biomass, solar, etc., have proven to be cutting-edge technologies for the production of different valuable by-products. This study proposes a multigeneration system using a geothermal source of energy. The main outputs include power, space heating, cooling, fresh and hot water, dry air, and hydrogen. The system includes a regenerative Rankine cycle, a double effect absorption cycle and a double flash desalination cycle. A significant amount of electrical power, hydrogen and fresh water is generated, which can be used for commercial or domestic purposes. The power output is 103 MW. The thermal efficiency is 24.42%, while energetic and exergetic efficiencies are 54.22% and 38.96%, respectively. The COPen is found to be 1.836, and the COPex is found to be 1.678. The hydrogen and fresh water are produced at a rate of 0.1266 kg/s and 37.6 kg/s, res... [more]
Techno-Economic Analysis of Hydrogen Storage Technologies for Railway Engineering: A Review
Zhan Xu, Ning Zhao, Stuart Hillmansen, Clive Roberts, Yan Yan
February 27, 2023 (v1)
Keywords: Hydrogen, railway engineering, storage technology, Technoeconomic Analysis
According to the specific requirements of railway engineering, a techno-economic comparison for onboard hydrogen storage technologies is conducted to discuss their feasibility and potentials for hydrogen-powered hybrid trains. Physical storage methods, including compressed hydrogen (CH2), liquid hydrogen (LH2), and cryo-compressed hydrogen (CcH2), and material-based (chemical) storage methods, such as ammonia, liquid organic hydrogen carriages (LOHCs), and metal hydrides, are carefully discussed in terms of their operational conditions, energy capacity, and economic costs. CH2 technology is the most mature now but its storage density cannot reach the final target, which is the same problem for intermetallic compounds. In contrast, LH2, CcH2, and complex hydrides are attractive for their high storage density. Nevertheless, the harsh working conditions of complex hydrides hinder their vehicular application. Ammonia has advantages in energy capacity, utilisation efficiency and cost, espec... [more]
Microorganisms as New Sources of Energy
Jasminka Talapko, Domagoj Talapko, Anita Matić, Ivana Škrlec
February 27, 2023 (v1)
Subject: Biosystems
Keywords: bioenergy, biomass waste, Hydrogen, microorganisms, renewable energy sources
The use of fossil energy sources has a negative impact on the economic and socio-political stability of specific regions and countries, causing environmental changes due to the emission of greenhouse gases. Moreover, the stocks of mineral energy are limited, causing the demand for new types and forms of energy. Biomass is a renewable energy source and represents an alternative to fossil energy sources. Microorganisms produce energy from the substrate and biomass, i.e., from substances in the microenvironment, to maintain their metabolism and life. However, specialized microorganisms also produce specific metabolites under almost abiotic circumstances that often do not have the immediate task of sustaining their own lives. This paper presents the action of biogenic and biogenic−thermogenic microorganisms, which produce methane, alcohols, lipids, triglycerides, and hydrogen, thus often creating renewable energy from waste biomass. Furthermore, some microorganisms acquire new or improved... [more]
Batteries and Hydrogen Storage: Technical Analysis and Commercial Revision to Select the Best Option
José Manuel Andújar, Francisca Segura, Jesús Rey, Francisco José Vivas
February 27, 2023 (v1)
Keywords: battery, energy capacity, Energy Storage, gravimetric and volumetric density, Hydrogen, hydrogen storage method, mathematical model, technical comparison
This paper aims to analyse two energy storage methods—batteries and hydrogen storage technologies—that in some cases are treated as complementary technologies, but in other ones they are considered opposed technologies. A detailed technical description of each technology will allow to understand the evolution of batteries and hydrogen storage technologies: batteries looking for higher energy capacity and lower maintenance, while hydrogen storage technologies pursuing better volumetric and gravimetric densities. Additionally, as energy storage systems, a mathematical model is required to know the state of charge of the system. For this purpose, a mathematical model is proposed for conventional batteries, for compressed hydrogen tanks, for liquid hydrogen storage and for metal hydride tanks, which makes it possible to integrate energy storage systems into management strategies that aim to solve the energy balance in plants based on hybrid energy storage systems. From the technical point... [more]
Energy Storage Solutions for Offshore Applications
Yessica Arellano-Prieto, Elvia Chavez-Panduro, Pierluigi Salvo Rossi, Francesco Finotti
February 27, 2023 (v1)
Keywords: ammonia, Batteries, CAES, decarbonisation, Energy Storage, flywheel, Hydrogen, offshore, supercapacitor
Increased renewable energy production and storage is a key pillar of net-zero emission. The expected growth in the exploitation of offshore renewable energy sources, e.g., wind, provides an opportunity for decarbonising offshore assets and mitigating anthropogenic climate change, which requires developing and using efficient and reliable energy storage solutions offshore. The present work reviews energy storage systems with a potential for offshore environments and discusses the opportunities for their deployment. The capabilities of the storage solutions are examined and mapped based on the available literature. Selected technologies with the largest potential for offshore deployment are thoroughly analysed. A landscape of technologies for both short- and long-term storage is presented as an opportunity to repurpose offshore assets that are difficult to decarbonise.
Economic Analysis on Hydrogen Pipeline Infrastructure Establishment Scenarios: Case Study of South Korea
Heeyeon Lee, Sanghun Lee
February 27, 2023 (v1)
Keywords: case study, economic analysis, Hydrogen, infrastructure, pipeline
South Korea has a plan to realize a hydrogen economy, and it is essential to establish a main hydrogen pipeline for hydrogen transport. This study develops a cost estimation model applicable to the construction of hydrogen pipelines and conducts an economic analysis to evaluate various scenarios for hydrogen pipeline construction. As a result, the cost of modifying an existing natural gas to a hydrogen pipeline is the lowest, however, there are issues with the safety of the modified hydrogen pipes from natural gas and the necessity of the existing natural gas pipelines. In the case of a short-distance hydrogen pipeline, the cost is about 1.8 times that of the existing natural gas pipeline modification, but it is considered a transitional scenario before the construction of the main hydrogen pipeline nationwide. Lastly, in the case of long-distance main hydrogen pipeline construction, it takes about 3.7 times as much cost as natural gas pipeline modification, however it has the advantag... [more]
Transition to Low-Carbon Hydrogen Energy System in the UAE: Sector Efficiency and Hydrogen Energy Production Efficiency Analysis
Mustapha D. Ibrahim, Fatima A. S. Binofai, Maha O. A. Mohamad
February 27, 2023 (v1)
Subject: Environment
Keywords: data envelopment analysis, efficiency, Hydrogen, sector coupling, UAE
To provide an effective energy transition, hydrogen is required to decarbonize the hard-to-abate industries. As a case study, this paper provides a holistic view of the hydrogen energy transition in the United Arab Emirates (UAE). By utilizing the directional distance function undesirable data envelopment analysis model, the energy, economic, and environmental efficiency of UAE sectors are estimated from 2001 to 2020 to prioritize hydrogen sector coupling. Green hydrogen production efficiency is analyzed from 2020 to 2050. The UAE should prioritize the industry and transportation sectors, with average efficiency scores of 0.7 and 0.74. The decomposition of efficiency into pure technical efficiency and scale efficiency suggests policies and strategies should target upscaling the UAE’s low-carbon hydrogen production capacity to expedite short-term and overall production efficiency. The findings of this study can guide strategies and policies for the UAE’s low-carbon hydrogen transition.... [more]
Market Opportunities in Portugal for the Water-and-Waste Sector Using Sludge Gasification
Octávio Alves, Bruno Garcia, Bruna Rijo, Gonçalo Lourinho, Catarina Nobre
February 27, 2023 (v1)
Keywords: biosynthetic natural gas, combined heat and power, gasification, Hydrogen, market analysis, sewage sludge
The water-and-waste sector has shown a marked interest in innovative management practices for dewatered sludge. The need to manage increased sludge volumes at rising disposal costs, coupled with the recognition of the potential for on-site energy production, have been the key drivers for this recent appeal. With the current political view supporting the development of a renewable-gas industry in Portugal, renewable gases are considered an attractive solution for dewatered-sludge valorization. Moreover, investment in renewable-gas supply chains would help the industry to mature to a level at which the technology and market are rapidly established. Recognizing this interest, dewatered-sludge gasification was selected as a possible valorization pathway, with the potential for hydrogen and bio-SNG production, as well as decentralized heat and power. This document identifies the market opportunities for the establishment of sewage-sludge gasification in Portugal. The analysis starts with a... [more]
Effect on Diesel Engine Performance Parameters Using Hydrogen and Oxygen Produced on Demand
Robson do Carmelo Santos Barreiros, Elias Amancio Siqueira-Filho, Alesson Itallo Ribeiro Dias Silva, Flávio Wilson Barreiros De Oliveira, Priscilla Bernardo Mendonça Barreiros, Mirna Dimenstein, Leonie Asfora Sarubbo, Rosa Lúcia Martins dos Santos, Vanias De Araújo Júnior
February 27, 2023 (v1)
Keywords: combustion behavior, fuel consumption, gas emission, greenhouse effect, Hydrogen, Renewable and Sustainable Energy
Hydrogen is seen as a future energy carrier since its chemical compounds make up a large part of the Earth’s surface. This study sought to analyze the impact related to the inclusion of hydrogen and oxygen gases produced on demand by an alkaline electrolyzer to the engine added directly through the fuel intake line. For this purpose, performance parameters were monitored, such as liquid fuel consumption and greenhouse gas emissions, and correlated to any effect observed on the engine’s power output and combustion behavior. A 58 kVA nominal power motor-generator was used, coupled with a resistive load bank (20 kW), where two fuel configurations were tested (diesel injection only and a mixture of diesel, hydrogen and oxygen) and compared. A total of 42 tests were performed considering both the admission gases into the fuel intake line and also diesel supply only for baseline. A substantial decrease in fuel consumption was observed (7.59%) when the blend configuration was used despite a d... [more]
The Role of Hydrogen in the Visegrad Group Approach to Energy Transition
Ewelina Kochanek
February 27, 2023 (v1)
Subject: Environment
Keywords: energy security, energy transition, Hydrogen, hydrogen economy, hydrogen strategy, Visegrad Group
Hydrogen is an energy carrier in which hopes are placed for an easier achievement of climate neutrality. Together with electrification, energy efficiency development, and RES, hydrogen is expected to enable the ambitious energy goals of the European Green Deal. Hence, the aim of the article is to query the development of the hydrogen economy in the Visegrad Group countries (V4). The study considers six diagnostic features: sources of hydrogen production, hydrogen legislation, financial mechanisms, objectives included in the hydrogen strategy, environmental impact of H2, and costs of green hydrogen investments. The analysis also allowed to indicate the role that hydrogen will play in the energy transition process of the V4 countries. The analysis shows that the V4 countries have similar approaches to the development of the hydrogen market, but the hydrogen strategies published by each of the Visegrad countries are not the same. Each document sets goals based on the hydrogen production t... [more]
The Effect of Hydrogen Addition on the Pollutant Emissions of a Marine Internal Combustion Engine Genset
George Mallouppas, Elias A. Yfantis, Charalambos Frantzis, Theodoros Zannis, Petros G. Savva
February 27, 2023 (v1)
Keywords: decarbonization, emissions, Hydrogen, marine internal combustion engines, maritime fuels
Hydrogen, as a maritime fuel, is one of the solutions that will assist the shipping sector in addressing the challenges regarding decarbonization, taking into consideration the targets set for 2030 and 2050. The extensive utilization of hydrogen requires massive production of green hydrogen and the development of proper infrastructure to support a sustainable supply chain. An alternative solution is based on the on-board production of hydrogen, where production units are installed on-board the vessel. Along these lines, the HYMAR project aims to test the utilization of a hydrogen production unit for on-board use. The article deals with the use of hydrogen as a fuel for internal combustion engines, taking into consideration reports from literature and the preliminary results of the HYMAR project, focusing on the environmental impact and the reduction in emissions. Experimental investigation on a marine auxiliary engine for power generation, under the HYMAR project, leads to promising re... [more]
Investigation of PEM Fuel Cell Characteristics in Steady and Dynamic Operation Modes
Alexey Loskutov, Andrey Kurkin, Andrey Shalukho, Ivan Lipuzhin, Rustam Bedretdinov
February 27, 2023 (v1)
Keywords: control system, efficiency, fuel cell, hybrid energy complex, Hydrogen, PEMFC
The article is devoted to the problem of proton-exchange membrane fuel cells (PEMFCs) integration into power supply systems. A hybrid energy complex (HEC) based on PEMFCs and lithium iron phosphate batteries can be used as a reliable energy source. It is necessary to properly determine the PEMFC characteristics in order to develop a PEMFC-based HEC prototype and its control algorithms. This paper presents a 1 kW PEMFC’s test results in steady and dynamic modes. The dependences of the average hydrogen consumption per 1 min, the volume of hydrogen for the generation of 1 kWh, the PEMFC efficiency on the load current were obtained and an analysis of these dependences for steady operation modes was performed. A range of load changes beyond which the efficiency of the PEMFC significantly decreased and it was recommended to switch to the joint operation of the PEMFCs and batteries (or only batteries) was established. Diagrams of the PEMFC output voltage during the dynamic changes in loads ar... [more]
Non-Thermal Plasma Technology for CO2 Conversion—An Overview of the Most Relevant Experimental Results and Kinetic Models
Vera Marcantonio, Marcello De Falco, Enrico Bocci
February 24, 2023 (v1)
Keywords: biomass gasification, Carbon Dioxide Capture, Hydrogen, kinetic models, NTP, plasma reactor
Global warming, along with increasing global energy demands, has led to the need for a sustainable and low-carbon-based energy economy. In addition to renewable energy technologies, such as biomass, solar, hydro, and wind, another possible strategy to mitigate climate change is the capture/conversion and recycling of CO2. In recent years, many methods for both CO2 capture (mainly adsorption, absorption, and membrane) and conversion (many electrolysis, catalyst, and plasma) have been investigated. Conversion technology is less studied but seems to be very promising. Within that, non-thermal plasma technology has received much interest because it works at low temperatures and atmospheric pressure, and there is no need for high temperature and high electricity consumption, which are typical of the catalyst and electrolysis conversion processes, respectively. Therefore, in order to optimize this emerging technology, simulative kinetic models have been developed with the aim of maximizing b... [more]
Blowout Prediction on a Salt Cavern Selected for a Hydrogen Storage Pilot
Hippolyte Djizanne, Carlos Murillo Rueda, Benoit Brouard, Pierre Bérest, Grégoire Hévin
February 24, 2023 (v1)
Keywords: blowout, flash fire, Hydrogen, jet fire, numerical modelling, salt caverns, thermodynamics, UVCE
To prevent climate change, Europe and the world must shift to low-carbon and renewable energies. Hydrogen, as an energy vector, provides viable solutions for replacing polluting and carbon-emitting fossil fuels. Gaseous hydrogen can be stored underground and coupled with existing natural gas pipe networks. Salt cavern storage is the best suited technology to meet the challenges of new energy systems. Hydrogen storage caverns are currently operated in the UK and Texas. A preliminary risk analysis dedicated to underground hydrogen salt caverns highlighted the importance of containment losses (leaks) and the formation of gas clouds following blowouts, whose ignition may generate dangerous phenomena such as jet fires, unconfined vapor cloud explosions (UVCEs), or flashfires. A blowout is not a frequent accident in gas storage caverns. A safety valve is often set at a 30 m depth below ground level; it is automatically triggered following a pressure drop at the wellhead. Nevertheless, a blow... [more]
Screening of Nickel and Platinum Catalysts for Glycerol Conversion to Gas Products in Hydrothermal Media
Carine T. Alves, Jude A. Onwudili
February 24, 2023 (v1)
Subject: Materials
Keywords: glycerol, heterogeneous catalysis, Hydrogen, hydrothermal reforming, propane
The production of low-carbon gaseous fuels from biomass has the potential to reduce greenhouse gas emissions and promote energy sustainability, stability and affordability around the world. Glycerol, a large-volume by-product of biodiesel production, is a potential feedstock for the production of low-carbon energy vectors. In this present work, an aqueous solution of pure glycerol was reacted under hydrothermal conditions using a total of 10 types of heterogeneous catalysts to evaluate its conversion to gas products (hydrogen, methane, CO, CO2 and C2−C4 hydrocarbon gases). Two bimetallic Ni-Fe and Ni-Cu catalysts, three Pt-based catalysts and physical mixtures of the five catalysts were tested. The reactions were carried out in a batch reactor for 1 h reaction time, using a 9:1 mass ratio of water/glycerol (10 wt%) and the reaction temperatures ranged between 250−350 °C using and without using 1 g of catalyst. The effects of the catalysts and reaction conditions on the conversion of gl... [more]
Overview of the Hydrogen Production by Plasma-Driven Solution Electrolysis
Sergii Bespalko, Jerzy Mizeraczyk
February 24, 2023 (v1)
Keywords: contact glow-discharge electrolysis (CGDE), electrolytic solution, Hydrogen, hydrogen production, hydrogen production energy yield, hydrogen production rate, plasma electrolysis, plasma-driven solution electrolysis (PDSE)
This paper reviews the progress in applying the plasma-driven solution electrolysis (PDSE), which is also referred to as the contact glow-discharge electrolysis (CGDE) or plasma electrolysis, for hydrogen production. The physicochemical processes responsible for the formation of PDSE and effects occurring at the discharge electrode in the cathodic and anodic regimes of the PDSE operation are described. The influence of the PDSE process parameters, especially the discharge polarity, magnitude of the applied voltage, type and concentration of the typical electrolytic solutions (K2CO3, Na2CO3, KOH, NaOH, H2SO4), presence of organic additives (CH3OH, C2H5OH, CH3COOH), temperature of the electrolytic solution, the active length and immersion depth of the discharge electrode into the electrolytic solution, on the energy efficiency (%), energy yield (g(H2)/kWh), and hydrogen production rate (g(H2)/h) is presented and discussed. This analysis showed that in the cathodic regime of PDSE, the hyd... [more]
Experimental Study and Optimisation of a Non-Conventional Ignition System for Reciprocating Engines Operation with Hydrogen−Methane Blends, Syngas, and Biogas
Luigi De Simio, Sabato Iannaccone, Massimo Masi, Paolo Gobbato
February 24, 2023 (v1)
Keywords: biogas, Hydrogen, ignition energy, spark duration, spark intensity, Syngas
The paper deals with the experimental study of a medium-load spark ignition engine under operation with different fuel mixtures among those deemed as promising for the transition towards carbon-free energy systems. In particular, the performance of a non-conventional ignition system, which permits the variation of the ignition energy, the spark intensity and duration, was studied fuelling the engine with 60−40% hydrogen−methane blends, three real syngas mixtures and one biogas. The paper is aimed to find the optimal ignition timing for minimum specific fuel consumption and the best setup of the ignition system for each of the fuel mixtures considered. To this end, a series of steady-state tests were performed at the dynamometer by varying the parameters of the ignition system and running the engine with surrogate hydrogen−methane−nitrogen mixtures that permit the simulation of hydrogen−methane blends, real syngas, and biogas. The results quantify the increase of spark advance associate... [more]
Green Hydrogen Production Technologies from Ammonia Cracking
Yousefi Rizi Hossein Ali, Donghoon Shin
February 24, 2023 (v1)
Subject: Materials
Keywords: ammonia, catalyst, cracking, Hydrogen
The rising technology of green hydrogen supply systems is expected to be on the horizon. Hydrogen is a clean and renewable energy source with the highest energy content by weight among the fuels and contains about six times more energy than ammonia. Meanwhile, ammonia is the most popular substance as a green hydrogen carrier because it does not carry carbon, and the total hydrogen content of ammonia is higher than other fuels and is thus suitable to convert to hydrogen. There are several pathways for hydrogen production. The considered aspects herein include hydrogen production technologies, pathways based on the raw material and energy sources, and different scales. Hydrogen can be produced from ammonia through several technologies, such as electrochemical, photocatalytic and thermochemical processes, that can be used at production plants and fueling stations, taking into consideration the conversion efficiency, reactors, catalysts and their related economics. The commercial process i... [more]
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