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This Meeting Report summarises the findings of a two-day workshop in April 2007 at the Culham Science Centre and Worcester College Oxford which explored the potential for large-scale Hydrogen production through methods other than electrolysis.<br/>Operating at the cusp of research and policy-making the UK Energy Research Centre's mission is to be the UK's pre-eminent centre of research and source of authoritative information and leadership on sustainable energy systems. The Centre takes a whole systems approach to energy research incorporating economics engineering and the physical environmental and social sciences while developing and maintaining the means to enable cohesive research in energy. A key supporting function of UKERC is the Meeting Place based in Oxford which aims to bring together members of the UK energy community and overseas experts from different disciplines to learn identify problems develop solutions and further the energy debate.

Comparison of Computational Fluid Dynamics (CFD) predictions with measurements is presented for cryo-compressed hydrogen vertical jets. The stagnation conditions of the experiments are characteristic of unintended leaks from pipe systems that connect cryogenic hydrogen storage tanks and could be encountered at a fuel cell refuelling station. Jets with pressure up to 5 bar and temperatures just above the saturation liquid temperature were examined. Comparisons are made to the centerline mass fraction and temperature decay rates the radial profiles of mass fraction and the contours of volume fraction. Two notional nozzle approaches are tested to model the under-expanded jet that was formed in the tests with pressures above 2 bar. In both approaches the mass and momentum balance from the throat to the notional nozzle are solved while the temperature at the notional nozzle was assumed equal to the nozzle temperature in the first approach and was calculated by an energy balance in the second approach. The two approaches gave identical results. Satisfactory agreement with the measurements was found in terms of centerline mass fraction and temperature. However for test with 3 and 4 bar release the concentration was overpredicted. Furthermore a wider radial spread was observed in the predictions possibly revealing higher degree of diffusion using the k-ε turbulence model. An integral model for cryogenic jets was also developed and provided good results. Finally a test simulation was performed with an ambient temperature jet and compared to the cold jet showing that warm jets decay faster than cold jets.

The final session of the meeting consisted of a discussion panel to propose future directions for research in the field of hydrogen embrittlement and the potential impact of this research on public policy.

This article is a transcription of the recorded discussion of ‘Hydrogen Embrittlement: Future Directions’ at the Royal Society Scientific Discussion Meeting Challenges of Hydrogen and Metals Jan 16th–18th 2017. The text is approved by the contributors. H.L. transcribed the session and drafted the manuscript. Y.C. assisted in the preparation of the manuscript.

Link to document download on Royal Society Website 

The objective of this work was to assess the suitability of a synthetic Cu-based oxygen carrier in a continuous pilot plant for the production of blue and green hydrogen through the autothermal Chemical Looping Reforming (CLRa). In CLRa methane is converted to a H2 + CO mixture through partial oxidation and reforming reactions in the fuel reactor. The degree of the partial oxidation of methane was defined by controlling the oxygen flow in the air reactor. Steam was used as reforming gas in natural gas to produce blue H2 but the existing CO2 in biogas was the reforming gas to produce green H2. Operating at 950 ◦C in the fuel and air reactors CH4 conversion and H2 yield parameters were 96 % and 2.60 mol of H2 per mole of CH4 respectively. These experimental results were close to the theoretical values that could be achieved in the CLRa process. Furthermore the physico-chemical characterization of the samples extracted from the pilot plant throughout the experimental campaign revealed that the Cu-based oxygen carrier maintained its mechanical integrity and chemical stability under harsh operating conditions. Therefore it can be concluded that Cu-based oxygen carriers can be considered a promising alternative to Ni-based materials for the production of blue and green hydrogen through the CLRa process.

Energy from hydrogen is an appropriate technological choice in the context of sustainable development. The opportunities offered by the use of energy from hydrogen also represent a significant challenge for mobile technologies and daily life. Nevertheless despite a significant amount of research and information regarding the benefits of hydrogen energy it creates considerable controversy in many countries. Globally there is a lack of understanding about the production process of hydrogen energy and the benefits it provides which leads to concerns regarding the consistency of its use. In this study an original questionnaire was used as a research tool to determine the opinions of inhabitants of countries in which hydrogen energy is underutilized and where the infrastructure for hydrogen energy is underdeveloped. Respondents presented their attitude to ecology and indicated their knowledge regarding the operation of hydrogen energy and the use of hydrogen fuel. The results indicate that society is not convinced that the safety levels for energy derived from hydrogen are adequate. It can be concluded that knowledge about hydrogen as an energy source and the production safety and storage methods of hydrogen is very low. Negative attitudes to hydrogen energy can be an important barrier in the development of this energy in many countries.

The reliable supplies of electricity and hydrogen required for 100% renewable energy systems have been found to be achievable by utilisation of a mix of different resources and storage technologies. In this paper more demanding parameter conditions than hitherto considered are used in measurement of the reliability of variable renewable energy resources. The defined conditions require that supply of baseload electricity (BLEL) and baseload hydrogen (BLH2) occurs solely using cost-optimised configurations of variable photovoltaic solar power onshore wind energy and balancing technologies. The global scenario modelling is based on hourly weather data in a 0.45° × 0.45° spatial resolution. Simulations are conducted for Onsite and Coastal Scenarios from 2020 to 2050 in 10-year time-steps. The results show that for 7% weighted average cost of capital Onsite BLEL can be generated at less than 119 54 41 and 33 €/MWhel in 2020 2030 2040 and 2050 respectively across the best sites with a maximum 20000 TWh annual cumulative generation potential. Up to 20000 TWhH2HHV Onsite BLH2 can be produced at less than 66 48 40 and 35 €/MWhH2HHV in 2020 2030 2040 and 2050 respectively. A partially flexible electricity demand at 8000 FLh could significantly reduce the costs of electricity supply in the studied scenario. Along with battery storage power-to-hydrogen-to-power is found to have a major role in supply of BLEL beyond 2030 as both a daily and seasonal balancing solution. Batteries are not expected to have a significant role in the provision of electricity to water electrolysers.

With downward trends in Australian equipment manufacturing there are increased numbers of overseas designed manufactured and certified hydrogen systems being introduced into Australia. In parallel there are also opportunities for hydrogen and its carriers to be exported to overseas. Certainty of reputable codes and standards is important to meet regulatory requirements and community safety expectations locally and overseas.

This paper is a progress report of Hydrogen Mobility Australia’s (HMA) Technical Committee on mapping the regulatory codes and standards (RCS) gaps in Australia and establishing a pathway together with Standards Australia and Commonwealth and State Governments. This paper will discuss the benefits of the pathway covering the areas of:

• Safety – Enable Australia to implement consensual rules to minimise avoidable risks to persons and goods to an acceptable level
• Environment – Ensure protection of the environment from unacceptable damage due to the operation and effects of products processes and services linked to hydrogen
• Elimination of barriers to trade – Provide consistency between international jurisdictions enabling streamlined entry of hydrogen related equipment from overseas
• Upskilling of Australian industry participants – Gain useful learnings from countries more advanced in their progress in implementing ISO standards and hydrogen sector development

This paper is jointly prepared by representatives of HMA Technical Committee and Department of Energy and Mining South Australian Government. The paper also highlights the initiatives of Commonwealth and State Governments to advance the hydrogen economy.

Liquid hydrogen is increasingly being used as a delivery and storage medium for stations that provide compressed gaseous hydrogen for fuel cell electric vehicles. In efforts to provide scientific justification for separation distances for liquid hydrogen infrastructure in fire codes the dispersion characteristics of cryogenic hydrogen jets (50–64 K) from high aspect ratio nozzles have been measured at 3 and 5 barabs stagnation pressures. These nozzles are more characteristic of unintended leaks which would be expected to be cracks rather than conventional round nozzles. Spontaneous Raman scattering was used to measure the concentration and temperature field along the major and minor axes. Within the field of interrogation the axis-switching phenomena was not observed but rather a self-similar Gaussian-profile flow regime similar to room temperature or cryogenic hydrogen releases through round nozzles. The concentration decay rate and half-widths for the planar cryogenic jets were found to be nominally equivalent to that of round nozzle cryogenic hydrogen jets indicating a similar flammable envelope. The results from these experiments will be used to validate models for cryogenic hydrogen dispersion that will be used for simulations of alternative scenarios and quantitative risk assessment

Emissions from natural gas combustion and use are the largest source of greenhouse gas (GHG) emissions in the UK. The use of hydrogen in place of natural gas in principle offers a potential route to long term widespread decarbonisation of gas distribution networks as shown by the Leeds City Gate (‘H21’) study.1 The purpose of considering conversion to hydrogen is to deliver widespread carbon abatement across the UK at lower cost than alternative decarbonisation strategies.<br/>The Government is to finalise and publish the long-awaited ‘Clean Growth Plan’ along with an Industrial Strategy White Paper in Autumn 2017. Conversion from natural gas to hydrogen potentially on an incremental basis would likely represent a major opportunity for new industrial growth. This might be through the longer term stability or potential expansion of existing (newly decarbonised) energy intensive industry or through business opportunities and growth created from new technologies developed to facilitate the transition to hydrogen as the UK becomes a global leader and major exporter of equipment and skills. Job creation and the resulting gross value added (GVA) to the economy could therefore be significant in delivery of the goals of the Industrial Strategy Challenge Fund (ISCF).<br/>The core requirement is to supply low carbon hydrogen in bulk matching production to distribution network demand at an affordable cost. The H21 study concluded that to do so reliably hydrogen is best produced by reducing natural gas in steam methane reformers (SMRs) fitted with Carbon Capture and Storage (CCS). The study proposed that the considerable inter-seasonal and daily fluctuations in network demand can be managed by storing hydrogen in underground salt formations. It concluded that the SMRs with associated carbon dioxide (CO2) capture should be located near to where CO2 transport and storage infrastructure was likely to be created and noted that candidate locations for this are Teesside Humberside Grangemouth and the Liverpool-Manchester (L-M) area. Two of these Humberside and the L-M area are within the Cadent Gas Ltd (‘Cadent’) network and are also industrial ‘clusters’ with significant populations.<br/>The work reported here builds upon the approach proposed in the H21 project by focussing on defining ‘low carbon’ hydrogen supply and distribution systems in Humberside and the L-M area at a system scale sufficient to supply a large city.2 Both the Humber and L-M clusters are close to salt deposits which are suitable for both daily and inter-seasonal storage of hydrogen (for initial or expanded projects). Furthermore new large-scale gas Combined Cycle Gas Turbine (CCGT) plants widely assumed as likely anchor projects for CCS infrastructure have been consented in both cluster areas confirming that they are both strong candidates as locations for the first CCS clusters and hence as locations for a hydrogen supply system.

Shipping accounts for about 3% of global CO2 emissions. In order to achieve the target set by the Paris Agreement IMO introduced their GHG strategy. This strategy envisages 50% emission reduction from international shipping by 2050 compared with 2008. This target cannot be fulfilled if conventional fuels are used. Amongst others hydrogen is considered to be one of the strong candidates as a zero-emissions fuel. Yet concerns around the safety of its storage and usage have been formulated and need to be addressed. “Safety” in this article is defined as the control of recognized hazards to achieve an acceptable level of risk. This article aims to propose a new way of comparing two systems with regard to their safety. Since safety cannot be directly measured fuzzy set theory is used to compare linguistic terms such as “safer”. This method is proposed to be used during the alternative design approach. This approach is necessary for deviations from IMO rules for example when hydrogen should be used in shipping. Additionally the properties of hydrogen that can pose a hazard such as its wide flammability range are identified.

Following the unprecedented Covid-19 outbreak currently unfolding Hydrogen Europe is publishing its latest paper: "Post COVID-19 and the Hydrogen Sector - A Hydrogen Europe Analysis"<br/><br/>On the long-term climate and environmental challenges remain the major threat to our planet and to humanity as a whole.  The economic crisis following the Covid-19 pandemic may cause a significant delay to the adoption and commercial roll-out of clean hydrogen. It may even permanently endanger the capacity of the clean hydrogen sector to take-up its role as the missing link in the energy transition.<br/><br/>A swift decisive and coordinated action is necessary to address the risks and at least dampen the negative impact that they may have on the deployment of clean hydrogen technologies and on our transition to a net carbon yet powerful and wealthy economy.<br/><br/>Our document outlines the need for and rationale behind rapid action as a result of the Covid-19 impact. Please find here below a short summary of what you will find in it:<br/><br/>Is there a need to take action? – describing why the current pandemic will result in significantly jeopardising the hydrogen sector if no action is taken.<br/><br/>Why should action be taken? – underlining the importance of the hydrogen sector to EU’s decarbonisation efforts as well as its long-term potential to support sustainable economic growth of the EU.  <br/><br/>What can be done? – outlining several potential options for supporting the industry starting from most obvious monetary support but including also no less important policy actions that can be taken to restore investors’ confidence.<br/><br/>How much will it cost? – containing an estimation of the value of the monetary support needed in order to retain the high skilled workforce and the sector’s investment portfolio followed by an estimation of what will be the impact of the action.

Transition metal carbides are a class of materials widely known for both their interesting physical properties and catalytic activity. In this work we have used plane-wave DFT methods to study the interaction with increasing amounts of molecular hydrogen on the low-index surfaces of four major carbides – TiC VC ZrC and NbC. Adsorption is found to be generally exothermic and occurs predominantly on the surface carbon atoms. We identify trends over the carbides and their surfaces for the energetics of the adsorption as a function of their electronic and geometrical characteristics. An ab initio thermodynamics formalism is used to study the properties of the slabs as the hydrogen coverage is increased.

The energy approach for determining the durability of structural elements at high temperature creep and hydrogen activity was proposed. It has been shown that the approach significantly simplifies research compared with the known ones. Approbation of the approach was carried out on the example of determining the indicators of durability of the Bridgman sample under conditions of creep and different levels of hydrogenation of the metal. It was shown that with an increase of hydrogen concentration in the metal from 2 to 10 ppm the durability of the test sample decreased from 22 to 58%.

The present research focuses on the investigation of an in situ hydrogen charging effect during Crack Tip Opening Displacement testing (CTOD) on the fracture toughness properties of X65 pipeline steel. This grade of steel belongs to the broader category of High Strength Low Alloy Steels (HSLA) and its microstructure consists of equiaxed ferritic and bainitic grains with a low volume fraction of degenerated pearlite islands. The studied X65 steel specimens were extracted from pipes with 19.15 mm wall thickness. The fracture toughness parameters were determined after imposing the fatigue pre-cracked specimens on air on a specific electrolytic cell under a slow strain rate bending loading (according to ASTM G147-98 BS7448 and ISO12135 standards). Concerning the results of this study in the first phase the hydrogen cations’ penetration depth the diffusion coefficient of molecular and atomic hydrogen and the surficial density of blisters were determined. Next the characteristic parameters related to fracture toughness (such as J KQ CTODel CTODpl) were calculated by the aid of the Force-Crack Mouth Open Displacement curves and the relevant analytical equations.

Currently the periodic inspection of composite tanks is typically achieved via hydrostatic test combined with internal and external visual inspections. Acoustic emission (AE) technology demonstrates a promising non destructive testing method for damage mode identification and damage assessment. This study focuses on AE signals characteristics and evolution behaviours for used 70 MPa Type IV hydrogen storage tanks during hydrostatic burst tests. AE-based tensile tests for epoxy resin specimen and carbon fiber tow were implemented to obtain characteristics of matrix cracking and fiber breakage. Then broadband AE sensors were used to capture AE signals during multi-step loading tests and hydrostatic burst tests. K-means ++ algorithm and wavelet packet transform are performed to cluster AE signals and verify the validity. Combining with tensile tests three clusters are manifested via matrix cracking fiber/matrix debonding and fiber breakage according to amplitude duration counts and absolute energy. The number of three clustering signals increases with the increase of pressure showing accumulated and aggravated damage. The sudden appearance of a large number of fiber breakage signals during hydrostatic burst tests suggests that the composite tank structure is becoming mechanically unstable namely the impending burst failure of the tank.

Gas switching reforming (GSR) is a promising technology for natural gas reforming with inherent CO₂ capture. Like conventional steam methane reforming (SMR) GSR can be integrated with CO₂ -gas shift and pressure swing adsorption units for pure hydrogen production. The resulting GSR-H2 process concept was techno-economically assessed in this study. Results showed that GSR-H2 can achieve 96% CO₂ capture at a CO₂ avoidance cost of 15 $/ton (including CO₂ transport and storage). Most components of the GSR-H2 process are proven technologies but long-term oxygen carrier stability presents an important technical uncertainty that can adversely affect competitiveness when the material lifetime drops below one year. Relative to the SMR benchmark GSR-H2 replaces some fuel consumption with electricity consumption making it more suitable to regions with higher natural gas prices and lower electricity prices. Some minor alterations to the process configuration can adjust the balance between fuel and electricity consumption to match local market conditions. The most attractive commercialization pathway for the GSR-H2 technology is initial construction without CO2 capture followed by simple retrofitting for CO₂ capture when CO₂ taxes rise and CO₂ transport and storage infrastructure becomes available. These features make the GSR-H2 technology robust to almost any future energy market scenario.

Efficient energy production and consumption are fundamental points for reducing carbon emissions that influence climate change. Alternative resources such as renewable energy sources (RESs) used in electricity grids could reduce the environmental impact. Since RESs are inherently unreliable during the last decades the scientific community addressed research efforts to their integration with the main grid by means of properly designed energy storage systems (ESSs). In order to highlight the best performance from these hybrid systems proper design and operations are essential. The purpose of this paper is to present a so-called model predictive controller (MPC) for the optimal operations of grid-connected wind farms with hydrogen-based ESSs and local loads. Such MPC has been designed to take into account the operating and economical costs of the ESS the local load demand and the participation to the electricity market and further it enforces the fulfillment of the physical and the system's dynamics constraints. The dynamics of the hydrogen-based ESS have been modeled by means of the mixed-logic dynamic (MLD) framework in order to capture different behaviors according to the possible operating modes. The purpose is to provide a controller able to cope both with all the main physical and operating constraints of a hydrogen-based storage system including the switching among different modes such as ON OFF STAND-BY and at the same time reduce the management costs and increase the equipment lifesaving. The case study for this paper is a plant under development in the north Norway. Numerical analysis on the related plant data shows the effectiveness of the proposed strategy which manages the plant and commits the equipment so as to preserve the given constraints and save them from unnecessary commutation cycles.

As the world’s largest integrated energy and chemicals company Saudi Aramco continues to invest in technologies and innovative business models to enable the sustainable use of hydrocarbon resources across the value chain.  In this podcast David Ledesma discusses with Yasser Mufti Vice President Strategy & Market Analysis Saudi Aramco about Saudi Aramco’s perspectives on hydrogen its opportunities and challenges. This wide-ranging interview discusses Saudi Aramco’s investment in new technologies and the sustainable use of its hydrocarbon resources before addressing the role of hydrogen in achieving a low emissions economy possible business models and the barriers to achieving hydrogen’s growth. The podcast then moves on to discuss ammonia carbon capture utilisation and storage finishing up with a forward-looking perspective on the vision for Saudi Aramco asking how will the company look in 2050 and specifically whether it will still be a hydrocarbon company?

The podcast can be found on their website

Laser-induced nuclear processes in ultra-dense hydrogen H(0) give ejection of bunches of mesons similar to known baryon annihilation processes. This process was recently described as useful for relativistic interstellar travel (Holmlid and Zeiner-Gundersen 2020) and more precise experimental results exist now. The mesons are identified from their known decay time constants at rest as slow charged kaons slow neutral long-lived kaons and slow charged pions. Other observed time constants are interpreted as relativistically dilated decays for fast mesons of the same three types with kinetic energy up to 100 MeV for the kaons. Mouns are observed with kinetic energy of >100 MeV as decay products from the mesons. These particle energies are much too high to be due to nuclear fusion in hydrogen and the only known process which can give such energies is baryon annihilation. A model of the annihilation process starting with two protons or two neutrons gives good agreement with the observed meson types and their masses and kinetic energies thus now giving the complete energetics of the process. The process works with both D(0) and p(0). The efficiency from mass (of two baryons) to useful energy is 46% (contrary to 0.3% for T + D fusion) and the main non-recoverable energy loss is to neutrinos. Neutrons are not formed or ejected so this is an aneutronic process. The energy which can be extracted from ordinary hydrogen is 11.4 TWh per kg. This annihilation method is well suited for small and medium energy applications in the kW to MW range but scaling-up to GW power stations requires further development. It is unlikely that this energy production method can be used for weapons since there is no ignition or chain reaction.

Objectives

The aim of this review is to establish which available literature may be of use as part of the HSE funded project which will investigate spontaneous ignition of accidental hydrogen releases (JR02071). It will identify  phenomena that have the potential to cause spontaneous ignition of releases of pressured hydrogen and identify literature that may be of use when formulating the experimental program.

Main Findings

The identification of important work that shows conclusive evidence of spontaneous ignition of hydrogen due to the failure of a boundary layer.

The Government’s recently published ‘Road to Zero’ strategy sets out objectives to electrify cars and reduce emissions from heavy goods vehicles (HGVs) through policies such as ending the sale of diesel and petrol cars and subsidising electric charging infrastructure. The CCC response to the strategy however stated that the proposed measures do not go far enough. New Government policies combined with action from industry will be required for mobility related carbon reduction targets to be met.<br/>Hydrogen has been identified by the Government and CCC as one potential solution. The CCC report on a possible future hydrogen economy recognises that in particular hydrogen may have an important role to play for long distance journeys and heavy goods transport. This view was echoed further in the recent CCC ‘Net Zero’ report.<br/>Cadent’s HyNet project will produce low carbon hydrogen through reformation of natural gas combined with carbon capture utilisation and storage (CCUS). HyNet has primarily been designed to supply low carbon heat to industry and a blend of hydrogen to Cadent’s existing natural gas network but also provides the opportunity to supply low cost hydrogen for mobility. The HyMotion project has considered the relative merits of such an approach modelled potential demand scenarios and sought to determine technical and commercial solutions to enable deployment.<br/>Hydrogen fuel cell electric vehicles (FCEVs) share powertrain technologies with battery electric vehicles (BEVs) but the roll-out of BEVs is currently ahead of FCEVs. This is largely due to a lack of low cost low carbon bulk hydrogen production and refuelling infrastructure both of which HyNet seeks to address.

Bamboo-like nitrogen-doped carbon nanotubes (N-CNTs) were used to synthesize supported palladium catalysts (0.2–2 wt.%) for hydrogen production via gas phase formic acid decomposition. The beneficial role of nitrogen centers of N-CNTs in the formation of active isolated palladium ions and dispersed palladium nanoparticles was demonstrated. It was shown that although the surface layers of N-CNTs are enriched with graphitic nitrogen palladium first interacts with accessible pyridinic centers of N-CNTs to form stable isolated palladium ions. The activity of Pd/N-CNTs catalysts is determined by the ionic capacity of N-CNTs and dispersion of metallic nanoparticles stabilized on the nitrogen centers. The maximum activity was observed for the 0.2% Pd/N-CNTs catalyst consisting of isolated palladium ions. A ten-fold increase in the concentration of supported palladium increased the contribution of metallic nanoparticles with a mean size of 1.3 nm and decreased the reaction rate by only a factor of 1.4.

Hydrogen when based on renewable electricity can play a key role in the transition towards CO2-neutral industrial production since its use as an energy carrier as well as a feedstock in various industrial process routes is promising. At the same time a large-scale roll-out of hydrogen for industrial use would entail substantial impacts on the energy system which can only be assessed if the regional distribution of future hydrogen demand is considered. Here we assess the technical potential of hydrogen-based technologies for energy-intensive industries in Germany. The site-specific and process-specific bottom-up calculation considers 615 individual plants at 367 sites and results in a total potential hydrogen demand of 326 TWh/a. The results are available as an open dataset. Using hydrogen for non-energy-intensive sectors as well increases the potential hydrogen demand to between 482 and 534 TWh/a for Germany - based on today’s industrial structure and production output. This assumes that fossil fuels are almost completely replaced by hydrogen for process heating and feedstocks. The resulting hydrogen demand is very unevenly distributed: a few sites account for the majority of the overall potential and similarly the bulk of demand is concentrated in a few regions with steel and chemical clusters.

The current requirements for composite cylinders are still based on an arbitrary approach derived from the behaviour of metal structures that the designed burst pressure should be at least 2.5 times the maximum in-service pressure. This could lead to an over-designed composite cylinder for which the weight saving would be less than optimum. Moreover predicting the lifetime of composite cylinders is a challenging task due to their anisotropic characteristics. A federal research institute in Germany (BAM) has proposed a minimum load-cycle requirement that mitigates this issue by using a MonteCarlo analysis of the burst test results. To enrich this study more experiments are required however they are normally limited by the necessity of long duration testing times (loading rate and number of cylinders) and the design (stacking sequence of the composite layer). A multi-scale model incorporating the micromechanical behaviour of composite structures has been developed at Mines ParisTech. The model has shown similar behaviour to that of composite cylinders under different loading rates. This indicates that the model could assist the Monte-Carlo analysis study. An evaluation of the multi-scale model therefore has been carried out to determine its limitations in predicting lifetimes of composite cylinders. The evaluation starts with the comparison of burst pressures with type IV composite cylinders under different loading rates. A μCT-Scan of a type IV cylinder has been carried out at the University of Southampton. The produced images were analysed using the Fast-Fourier Transform (FFT) technique to determine the configuration of the composite layers which is required by the model. Finally the time dependent effect studied by using the multi scale model has been described. In the long-term this study can be used to conduct a parametric study for creating more efficient design of type IV cylinders.

This paper presents an optimization modeling approach to support strategic planning for designing hydrogen supply chain (HSC) networks. The energy source for hydrogen production is proposed to be electricity generated at Mexican sugar factories. This study considers the utilization of existing infrastructure in strategic areas of the country which brings several advantages in terms of possible solutions. This study aims to evaluate the economic and environmental implications of using biomass wastes for energy generation and its integration to the national energy grid where the problem is addressed as a mixed-integer linear program (MILP) adopting maximization of annual profit and minimization of greenhouse gas emissions as optimization criteria. Input data is provided by sugar companies and the national transport and energy information platform and were represented by probability distributions to consider variability in key parameters. Independent solutions show similarities in terms of resource utilization while also significant differences regarding economic and environmental indicators. Multi-objective optimization was performed by a genetic algorithm (GA). The optimal HSC network configuration is selected using a multi-criteria decision technique i.e. TOPSIS. An uncertainty analysis is performed and main economic indicators are estimated by investment assessment. Main results show the trade-off interactions between the HSC elements and optimization criteria. The average internal rate of return (IRR) is estimated to be 21.5% and average payback period is 5.02 years.