Search results
1 – 10 of over 6000The strategy doubles Germany’s domestic hydrogen production target, shifts its approach to low-carbon hydrogen and pledges other measures to establish a domestic hydrogen market…
Details
DOI: 10.1108/OXAN-DB281110
ISSN: 2633-304X
Keywords
Geographic
Topical
The shortcomings of hydrogen as a green energy source.
Details
DOI: 10.1108/OXAN-DB272066
ISSN: 2633-304X
Keywords
Geographic
Topical
Xingyang Chen, Linlin Ma, Haoping Xie, Fengting Zhao, Yufeng Ye and Lin Zhang
The purpose of this paper is to present a crack initiation mechanism of the external hydrogen effect on type 304 stainless steel, as well as on fatigue crack propagation in the…
Abstract
Purpose
The purpose of this paper is to present a crack initiation mechanism of the external hydrogen effect on type 304 stainless steel, as well as on fatigue crack propagation in the presence of hydrogen gas.
Design/methodology/approach
The effects of external hydrogen on hydrogen-assisted crack initiation in type 304 stainless steel were discussed by performing fatigue crack growth rate and fatigue life tests in 5 MPa argon and hydrogen.
Findings
Hydrogen can reduce the incubation period of fatigue crack initiation of smooth fatigue specimens and greatly promote the fatigue crack growth rate during the subsequent fatigue cycle. During the fatigue cycle, hydrogen invades into matrix through the intrusion and extrusion and segregates at the boundaries of α′ martensite and austenite. As the fatigue cycle increased, hydrogen-induced cracks would initiate along the slip bands. The crack initiation progress would greatly accelerate in the presence of hydrogen.
Originality/value
To the best of the authors’ knowledge, this paper is an original work carried out by the authors on the hydrogen environment embrittlement of type 304 stainless steel. The effects of external hydrogen and argon were compared to provide understanding on the hydrogen-assisted crack initiation behaviors during cycle loading.
Details
Keywords
This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the…
Abstract
Purpose
This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the evaluation. The TOPSIS method was used to evaluate the best generation technology.
Design/methodology/approach
The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation are CO2 emissions, NOX emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost.
Findings
The results drawn from the analysis in technology wise are as follows: natural gas fuelled solid oxide fuel cells>natural gas combined cycle>natural gas fuelled phosphoric acid fuel cells>natural gas internal combustion engine>hydrogen fuelled solid oxide fuel cells>hydrogen internal combustion engines>hydrogen combustion turbines>hydrogen fuelled phosphoric acid fuel cells> and natural gas turbine. It shows that the natural gas fuelled solid oxide fuel cells are the best technology available among all the available technology considering the seven criteria such as service life, electricity cost, O&M costs, capital cost, NOX emissions, CO2 emissions and efficiency of the plant.
Research limitations/implications
The most dominant electricity generation technology proved to be the natural gas fuelled solid oxide fuel cells which ranked in the first place among nine alternatives. The research is helpful to evaluate the different alternatives.
Practical implications
The research is helpful to evaluate the different alternatives and can be extended in all the spares of technologies.
Originality/value
The research was the original one. Nine energy generation options were evaluated with regard to seven criteria. The energy generation options were the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation were efficiency, CO2 emissions, NOX emissions, capital cost, O&M costs, electricity cost and service life.
Details
Keywords
Abstract
Purpose
This paper aims to verify the inhibition of the hydrogen permeation effect of the coating and to quantitatively and qualitatively characterize the coating-induced stress.
Design/methodology/approach
By means of slow strain rate tensile testing (SSRT) in humid air, thickness measurement, fracture morphology, cross-section morphology and surface morphology, hydrogen content measurements, flow stress difference method.
Findings
The results demonstrate that the mechanism of the inhibition of hydrogen embrittlement by the coating is mainly attributed to the repression of hydrogen permeation and the additional coating-induced compressive stress.
Originality/value
It is proven that the micro-arc oxidation (MAO) coating does inhibit hydrogen entry into the alloy, and the stress induced by the MAO coating is compressive stress, which can restrain the hydrogen embrittlement of the alloy. Therefore, the mechanism of the inhibition of hydrogen embrittlement is dominated by the mechanisms of both hydrogen permeation inhibition and coating-induced stress.
Details
Keywords
Fan Bao, Kaiyu Zhang, Zhengrong Zhou, Wenli Zhang, Xiao Cai and Lin Zhang
The purpose of this paper is to demonstrate the effect of δ-ferrite on the susceptibility to hydrogen embrittlement of type 304 stainless steel in hydrogen gas environment.
Abstract
Purpose
The purpose of this paper is to demonstrate the effect of δ-ferrite on the susceptibility to hydrogen embrittlement of type 304 stainless steel in hydrogen gas environment.
Design/methodology/approach
The mechanical properties of as-received and solution-treated specimens were investigated by the test of tensile and fatigue crack growth (FCG) in 5 MPa argon and hydrogen.
Findings
The presence of δ-ferrite reduced the relative elongation and the relative reduction area (H2/Ar) of 304 stainless steel, indicating that δ-ferrite increased the susceptibility of hydrogen embrittlement in 304 stainless steel. Moreover, δ-ferrite promoted the fatigue crack initiation and propagation at the interface between δ-ferrite and austenite. The FCG tests were used to investigate the effect of δ-ferrite on the FCG rate in hydrogen gas environment, and it was found that δ-ferrite accelerated the FCG rate, which was attributed to rapid diffusion and accumulation of hydrogen around the fatigue crack tip through δ-ferrite in high-pressure hydrogen gas environment.
Originality/value
The dependence of the susceptibility to hydrogen embrittlement on δ-ferrite was first investigated in type 304 steel in hydrogen environment with high pressures, which provided the basis for the design and development of a high strength, hydrogen embrittle-resistant austenitic stainless steel.
Details
Keywords
Production offers flexibility: hydrogen can be made in multiple locations -- increasing geopolitical diversification -- using renewable electricity, nuclear power and fossil fuels…
Details
DOI: 10.1108/OXAN-DB270889
ISSN: 2633-304X
Keywords
Geographic
Topical
Gang Wang, Zihan Wang, Yue Zhang, GuangTao Xu, MingHao Zhao and Yanmin Li
The purpose of this paper is to find a new method to evaluate the hydrogen embrittlement performance of heterogeneous materials and thin film materials.
Abstract
Purpose
The purpose of this paper is to find a new method to evaluate the hydrogen embrittlement performance of heterogeneous materials and thin film materials.
Design/methodology/approach
The changes of hydrogen embrittlement properties of steel were studied by electrochemical hydrogen charging test and scratch test. The microstructure and properties of the alloy were analyzed by hardness tester, scanning electron microscope and three-dimensional morphology. The fracture toughness before and after hydrogen charging was calculated based on the scratch method.
Findings
The results showed that the hydrogen-induced hardening phenomenon occurs in the material after hydrogen charging. The scratch depth and width increased after hydrogen charging. The fracture toughness obtained by the scratch method showed that hydrogen reduces the fracture toughness of the material. The comparison error of fracture toughness calculated by indentation method was less than 5%.
Originality/value
The results show that the scratch method can evaluate the hydrogen embrittlement performance of the material. This method provides a possibility to evaluate the hydrogen embrittlement of thin-film and heterogeneous materials.
Details
Keywords
Gang Wang, Mian Wang, ZiHan Wang, GuangTao Xu, MingHao Zhao and Lingxiao Li
The purpose of this paper is to assess the hydrogen embrittlement sensitivity of carbon gradient heterostructure materials and to verify the reliability of the scratch method.
Abstract
Purpose
The purpose of this paper is to assess the hydrogen embrittlement sensitivity of carbon gradient heterostructure materials and to verify the reliability of the scratch method.
Design/methodology/approach
The surface-modified layer of 18CrNiMo7-6 alloy steel was delaminated to study its hydrogen embrittlement characteristics via hydrogen permeation, electrochemical hydrogen charging and scratch experiments.
Findings
The results showed that the diffusion coefficients of hydrogen in the surface and matrix layers are 3.28 × 10−7 and 16.67 × 10−7 cm2/s, respectively. The diffusible-hydrogen concentration of the material increases with increasing hydrogen-charging current density. For a given hydrogen-charging current density, the diffusible-hydrogen concentration gradually decreases with increasing depth in the surface-modified layer. Fracture toughness decreases with increasing diffusible-hydrogen concentration, so the susceptibility to hydrogen embrittlement decreases with increasing depth in the surface-modified layer.
Originality/value
The reliability of the scratch method in evaluating the fracture toughness of the surface-modified layer material is verified. An empirical formula is given for fracture toughness as a function of diffused-hydrogen concentration.
Details
Keywords
Sidhartha Harichandan and Sanjay Kumar Kar
The purpose of this study is to explore the determinants influencing industrial adoption of green hydrogen amidst the global transition towards sustainability. Recognizing green…
Abstract
Purpose
The purpose of this study is to explore the determinants influencing industrial adoption of green hydrogen amidst the global transition towards sustainability. Recognizing green hydrogen as a pivotal clean energy alternative for industrial applications is critical for understanding its potential integration into sustainable practices.
Design/methodology/approach
This research examines the impact of factors such as innovativeness, perceived ease of use, user comfort, optimism and governmental policies on the industrial intention towards green hydrogen usage. Using responses from 227 Indian industry professionals and conducting analysis via the SmartPLS software, the study reveals a discernible discomfort among industrial workers pertaining to the daily application of green hydrogen.
Findings
The research presents an array of policy recommendations for stakeholders. Emphasized strategies include the introduction of green hydrogen certificates, sustainable public procurement mechanisms, tax incentives, green labelling protocols and the establishment of a dedicated hydrogen skill development council, all of which can significantly influence the trajectory of green hydrogen adoption within the industrial sector.
Originality/value
This research synthesizes various elements, from industry perception and challenges to policy implications, presenting a holistic view of green hydrogen’s potential role in industry decarbonization and SDG realization. In essence, this study deepens not only the empirical understanding but also pioneers fresh theoretical frameworks, setting a precedent for subsequent academic endeavours.
Details