Publications

The aim of the work is a numerical estimation of the conditional probability of damage to the mine personnel during an accidental explosion of a hydrogen-air mixture. The methodology for determining the parameters of the gas-dynamic process of the explosion of a hydrogen-air cloud in an open and closed space taking into account chemical interaction and space clutter is presented. A computational method based on a probit analysis for determining the damage probability fields of a person exposed to the explosion shock wave has been developed. To automate the computational process the tabular dependence “probit-function-damage probability” is replaced by a piecewise cubic spline. Numerical studies of the influence of the drift working space clutter by an electric locomotive on the distribution of the overpressure of the gaseous medium and the conditional probability of the eardrums rupture and lethal damage to personnel in the accidental zone of the coal mine have been carried out. It was obtained that the closed nature of the working space and its blockage significantly changes the shape and size of the danger zone and requires consideration by an expert at the stage of deciding on the safety level at the mine. The scientific novelty of the method proposed in the work is in taking into account in the mathematical model of the movement of a multi-component chemically reacting gas mixture the effect of compressibility of flow complex terrain (space clutter with equipment) three-dimensional nature of the gas-air mixture dispersion process. The model allows obtaining the space-time distributions of the shock-impulse load of the blast wave that is necessary for determining the non-stationary three-dimensional fields of the conditional probability of damage to the staff on the basis of probit analysis. The developed computational method allows analyzing and forecasting in time and space the conditional probability of damage of varying degrees of severity of personnel who are exposed to an explosive shock wave as an indicator of the safety level of a coal mine.

The modern steelmaker of advanced high-strength steels has always been challenged with the conflicting targets of increased strength while maintaining or improving ductility. These new steels help the transportation sector including the automotive sector to achieve the goals of increased passenger safety and reduced emissions. With increasing tensile strengths certain steels exhibit an increased sensitivity towards hydrogen embrittlement (HE). The ability to characterize the material's sensitivity in an as-delivered condition has been developed and accepted (SEP1970) but the complexity of the stress states that can induce an embrittlement together with the wide range of applications for high-strength steels make the development of a standardized test for HE under in-service conditions extremely challenging. Some proposals for evaluating the material's sensitivity give an advantage to materials with a low starting ductility. Despite this newly developed materials can have a higher original elongation with only a moderate reduction in elongation due to hydrogen. This work presents a characterization of new materials and their sensitivity towards HE.

This article is part of the themed issue ‘The challenges of hydrogen and metals’.

Link to document download on Royal Society Website 

The presented work is dedicated to evaluation of strain and fatigue behaviour of the ferrite-pearlite low-alloyed pipeline steels under known hydrogen concentration in a bulk of metal. Tensile test results have shown on the existence of some characteristic value of the hydrogen concentration CH at which the mechanism of hydrogen influence changes namely: below this value the enhanced plasticity (decreasing of the yield stress value) takes place and above – the hydrogen embrittlement occurs. The ambiguous relationship between fatigue crack growth rate and hydrogen concentration CH in the bulk of steels under their cyclic loading in hydrogen-contained environments has been found. There is a certain CH value at which the crack growth resistance of steel increases and the diagram of fatigue crack growth rate shifts to higher values of stress intensity factor. The generalised diagram of hydrogen concentration effect on strength behaviour of low-alloyed ferrite-pearlite pipeline steels is presented and discussed with the aim of evaluation of different mechanisms of hydrogen effect conditions of their realization and possible co-existence.

The influence of isothermal aging at 620 °C in combination with subsequent electrochemical hydrogen charging at room-temperature was studied on quenched-and-tempered T92/TP316H martensitic/austenitic weldments in terms of their room-temperature tensile properties and fracture behavior. Hydrogen charging of the weldments did not significantly affect their strength properties; however it resulted in considerable deterioration of their plastic properties along with significant impact on their fracture characteristics and failure localization. The hydrogen embrittlement plays a dominant role in degradation of the plastic properties of the weldments already in their initial material state i.e. before thermal aging. After thermal aging and subsequent hydrogen charging mutual superposition of thermal and hydrogen embrittlement phenomena had led to clearly observable effects on the welds deformation and fracture processes. The measure of hydrogen embrittlement was clearly lowered for thermally aged material state since the contribution of thermal embrittlement to overall degradation of the weldments has dominated. The majority of failures of the weldments after hydrogen charging occurred in the vicinity of T92 BM/Ni weld metal (WM) fusion zone; mostly along the Type-II boundary in Ni-based weld metal. Thus regardless of aging exposure the most critical failure regions of the investigated weldments after hydrogen charging and tensile straining at room temperature are the T92 BM/Ni WM fusion boundary and Type-II boundary acting like preferential microstructural sites for hydrogen embrittling effects accumulation

Realizing the hydrogen economy in Japan entails a risk assessment of its domestic hydrogen supply especially hydrogen transport by road. The first step of the risk assessment is to characterize the hydrogen transport accidents from different energy carriers. However it is difficult to characterize the accidents because hydrogen transport systems have not been fully implemented in Japan. The aim of this study is to characterize the hydrogen transport accidents from different energy carriers in Japan. We studied three major energy carriers namely compressed hydrogen liquefied hydrogen and liquid organic hydride. The accident networks based on network theory were constructed to capture the comprehensive accident processes and quantitatively characterized the hydrogen transport accidents from different energy carriers. The results clarified the differences and similarities in the accident process amongst the energy carriers. Furthermore key accident events were identified. This study contributes to the development of comprehensive hydrogen transport accident scenarios for risk assessment.

Although the UK has done a great job of decarbonising electricity generation to get to net zero we need to tackle harder-to-decarbonise sectors like heat transport and industry. Decarbonised gas – biogases hydrogen and the deployment of carbon capture usage and storage (CCUS) – can make our manufacturing more sustainable minimise disruption to families and deliver negative emissions.

Developing the capability to produce hydrogen at scale is one of the key challenges in the race to meet the UK’s ambitious net zero targets. Using the East Neuk of Fife - with its abundant on- and offshore renewables resource and well-developed electricity and gas networks – as a test bed we investigated the use of surplus electricity generated by renewables to produce green hydrogen which could then be used to heat homes and businesses carbon-free.

Aims

The study focused on answering a number of important questions around bringing power-to-hydrogen to Fife including:

How much low-cost low-carbon electricity would be available to a power-to-hydrogen operator in Fife and how much hydrogen could be produced today and in 2040? How much hydrogen storage would be required to meet demand under three end-use cases: injection into the natural gas grid; use in a dedicated hydrogen grid for heating; and use as transport fuel for a small fleet of vehicles? What if any network upgrades could be avoided by implementing power-to-hydrogen? Which hydrogen end-use markets would be most attractive for a power-to-hydrogen operator? What are the regulatory legislative or market barriers to be overcome to realise large-scale deployment of power-to-hydrogen?

The study

Our expert researchers used a high-level model of the European electricity system and established wholesale prices generation volumes by generation type and constrained generation in Fife. Considering both the present day and a 2040 picture based on National Grid’s Two Degrees Future Energy Scenarios our team explored a number of configurations of power generation and hydrogen end-use to assess the value associated with producing hydrogen.

Alongside this modelling our team conducted a comprehensive review of power-to-hydrogen legislation and regulation and reports and academic papers to identify the current characteristics and direction of the sector observe where most progress had been made and identify lessons learned.

This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.

Core of the Power-to-Gas (PtG) concept is the utilization of renewable electricity to produce hydrogen via water electrolysis. This hydrogen can be used directly as final energy carrier or can be converted to e.g. methane synthesis gas liquid fuels electricity or chemicals. To integrate PtG into energy systems technical demonstration and systems integration is of mayor importance. In total 128 PtG research and demonstration projects are realized or already finished in Europe to analyze these issues by May 2018. Key of the review is the identification and assessment of relevant projects regarding their field of application applied processes and technologies for electrolysis type of methanation capacity location and year of commissioning. So far main application for PtX is the injection of hydrogen or methane into the natural gas grid for storing electricity from variable renewable energy sources. Producing fuels for transport is another important application of PtX. In future PtX gets more important for refineries to lower the carbon food print of the products.

Composite materials consisting of metal and metal oxide phases are being researched intensively for application in various energy conversion and storage technologies. In these applications composites are often expected to operate under redox conditions at elevated temperature. The understanding of the dynamics of composite phase and morphology evolution during redox cycling is still very limited yet critical to maximising performance and increasing durability. Here we track the microstructural evolution of a single composite particle over 200 redox cycles for hydrogen production by chemical looping using multi-length scale X-ray computed tomography. We show that redox cycling triggers a centrifugal redispersion of the metal phase and a centripetal clustering of porosity both seemingly driven by the asymmetric nature of oxygen exchange in composites. We show that initially the particle develops a large amount of internal porosity which boosts activity but on the long term this facilitates structural and compositional reorganisation and eventually degradation. We also correlate the microstructural data with phase and activity analysis to identify structure-property correlations which not only provide valuable insight into the evolution of composite materials under redox conditions but also for the design of new composite materials with enhanced durability.

Experimental research on performance and emissions of engine fuelled with low calorific value gas blended with hydrogen was carried out and indicated thermal efficiency engine torque indicator diagram pressure rise rate and emissions with different hydrogen ratios were also analyzed. Experimental results show that with the increase of hydrogen fraction and CNG fraction in mixtures the indicated thermal efficiency increased. The engine power output is influenced by both low calorific value and hydrogen fractions. With the increase of hydrogen fraction in mixtures HC emissions decrease CO and NOx emissions increase. An engine operating on lean-burn low calorific value gas blended with hydrogen is favourable for getting lower emissions.

The influence of the previous electrolytic hydrogenation on the micromechanical properties and tribological behavior of the surface layers of iron and carbon steels has been studied. The concentrations of diffusion-moving and residual hydrogen in steels are determined depending on the carbon content. It is shown that the amount of sorbed hydrogen is determined by the density of dislocations and the relative volume of cementite. After desorption of diffusion-moving hydrogen the microhardness increases and materials plasticity decreases. The change of these characteristics decreases with the increase of carbon content in the steels. Internal stresses increase and redistribute under hydrogen desorption. Fragmentation of ferrite and perlite occurs as a result of electrolytic hydrogenation. Ferrite is characterized by the structure fragmentation and change of the crystallographic orientation of planes. The perlite structure shows the crushing of cementite plates and their destruction. The influence of hydrogen desorption on the microhardness of structural components of ferrite-perlite steels is shown. Large scattering of microhardness is found in perlite due to different diffusion rates of hydrogen because of the unequally oriented cementite plates. It was found that the tendency of materials to blister formation is reduced with the increase of carbon content. The influence of hydrogen on the tribological behaviour of steels under dry and boundary friction has been studied. It is shown that hydrogen desorption intensifies the materials wear. After hydrogen desorption tribological behaviour is determined by the adhesion interaction between the contacting pairs.