Publications
Framing Policy on Low Emissions Vehicles in Terms of Economic Gains: Might the Most Straightforward Gain be Delivered by Supply Chain Activity to Support Refuelling?
May 2018
Publication
A core theme of the UK Government's new Industrial Strategy is exploiting opportunities for domestic supply chain development. This extends to a special ‘Automotive Sector Deal’ that focuses on the shift to low emissions vehicles (LEVs). Here attention is on electric vehicle and battery production and innovation. In this paper we argue that a more straightforward gain in terms of framing policy around potential economic benefits may be made through supply chain activity to support refuelling of battery/hydrogen vehicles. We set this in the context of LEV refuelling supply chains potentially replicating the strength of domestic upstream linkages observed in the UK electricity and/or gas industries. We use input-output multiplier analysis to deconstruct and assess the structure of these supply chains relative to that of more import-intensive petrol and diesel supply. A crucial multiplier result is that for every £1million of spending on electricity (or gas) 8 full-time equivalent jobs are supported throughout the UK. This compares to less than 3 in the case of petrol/diesel supply. Moreover the importance of service industries becomes apparent with 67% of indirect and induced supply chain employment to support electricity generation being located in services industries. The comparable figure for GDP is 42%.
HyP SA – Our safety story
Sep 2019
Publication
Australian Gas Infrastructure Group’s (AGIG’s) vision is to be the leading gas infrastructure business in Australia this means delivering for our customers being a good employer and being sustainably cost efficient. Establishing and developing a hydrogen industry is a key pathway for us to achieve our vision.
In South Australia AGIG is pioneering the introduction of hydrogen into its existing gas distribution networks through the Hydrogen Park South Australia (HyP SA) project. With safety our top priority we would like to give an overview of the safety considerations of our site our network methodology and the development of new safety procedures and culture regarding the production handling and reticulation of a 5% hydrogen blend.
We will cover three themes each having a safety story that is specific to the Australian context and to the project’s success:
The Production Plant and Site
Project site safety known hazards and risk mitigation electrical protection safety procedures lighting and security. Hydrogen storage filling and transportation.
The Network
Securing the network for an isolated safe demonstration footprint. Gas network and hydrogen safety considerations why 5%? Emergency procedures and crew training. New safety regulations blended networks. How does hydrogen perform in a blended gas with respect to leaks? How safe is the existing network and what sensors and controls are we using.
The Home
Introducing blended gas to existing homes. Appliance safety and failure mode analysis. Community engagement and education on a 5% renewable hydrogen gas blend and use in the home
.
We aim to give a comprehensive overview of delivering a safe demonstration network for the HyP SA project in terms of the three main ecosystems that the hydrogen will be present our learnings so far and the development of the safety methodologies that will be applied in the industry in the future.
In South Australia AGIG is pioneering the introduction of hydrogen into its existing gas distribution networks through the Hydrogen Park South Australia (HyP SA) project. With safety our top priority we would like to give an overview of the safety considerations of our site our network methodology and the development of new safety procedures and culture regarding the production handling and reticulation of a 5% hydrogen blend.
We will cover three themes each having a safety story that is specific to the Australian context and to the project’s success:
The Production Plant and Site
Project site safety known hazards and risk mitigation electrical protection safety procedures lighting and security. Hydrogen storage filling and transportation.
The Network
Securing the network for an isolated safe demonstration footprint. Gas network and hydrogen safety considerations why 5%? Emergency procedures and crew training. New safety regulations blended networks. How does hydrogen perform in a blended gas with respect to leaks? How safe is the existing network and what sensors and controls are we using.
The Home
Introducing blended gas to existing homes. Appliance safety and failure mode analysis. Community engagement and education on a 5% renewable hydrogen gas blend and use in the home
.
We aim to give a comprehensive overview of delivering a safe demonstration network for the HyP SA project in terms of the three main ecosystems that the hydrogen will be present our learnings so far and the development of the safety methodologies that will be applied in the industry in the future.
Simulation of Hydrogen Dispersion under Cryogenic Release Conditions
Sep 2013
Publication
The use of hydrogen as fuel should always be accompanied by a safety assessment in case of an accidental release. To evaluate the potential hazards in a spill accident both experiments and simulations are performed. In the present work the CFD code ADREA-HF is used to simulate the liquefied hydrogen (LH2) spill experiments (test 5 6 7) conducted by the Health and Safety Laboratory (HSL). In these tests LH2 was spilled at a fixed rate of 60lt/min in several directions and for several durations. The factors that influence the vapor dispersion under cryogenic release conditions that were examined in this study are: the air humidity the wind direction and the slip effect of droplets formed by both the cryogenic liquid and the condensation of air humidity. The numerical results were compared with the experimental measurements and the effect of each abovementioned factors in the vapor dispersion is being discussed.
Safe Hydrogen Fuel Handling and Use for Efficient Implementation – SH2IFT
Sep 2019
Publication
The SH2IFT project combines social and technical scientific methods to address knowledge gaps regarding safe handling and use of gaseous and liquid hydrogen. Theoretical approaches will be complemented by fire and explosion experiments with emphasis on topics of strategic importance to Norway such as tunnel safety maritime applications etc. Experiments include Rapid Phase Transition Boiling Liquid Expanding Vapour Explosion and jet fires. This paper gives an overview of the project and preliminary results.
Membrane Based Purification of Hydrogen System (MEMPHYS)
Feb 2019
Publication
A hydrogen purification system based on the technology of the electrochemical hydrogen compression and purification is introduced. This system is developed within the scope of the project MEMPHYS. Therefore the project its targets and the different work stages are presented. The technology of the electrochemical purification and the state of the art of hydrogen purification are described. Early measurements in the project have been carried out and the results are shown and discussed. The ability of the technology to recover hydrogen from a gas mixture can be recognized and an outlook into further optimizations shows the future potential. A big advantage is the simultaneous compression of the purified hydrogen up to 200 bar therefore facilitating the transportation and storage.
Chitosan Flocculation Associated with Biofilms of C. Saccharolyticus and C. Owensensis Enhances Biomass Retention in a CSTR
Jun 2021
Publication
Cell immobilization and co-culture techniques have gained attention due to its potential to obtain high volumetric hydrogen productivities (QH2). Chitosan retained biomass in the fermentation of co-cultures of Caldicellulosiruptor saccharolyticus and C. owensensis efficiently up to a maximum dilution rate (D) of 0.9 h−1. Without chitosan wash out of the co-culture occurred earlier accompanied with approximately 50% drop in QH2 (D > 0.4 h−1). However butyl rubber did not show as much potential as carrier material; it did neither improve QH2 nor biomass retention in continuous culture. The population dynamics revealed that C. owensensis was the dominant species (95%) in the presence of chitosan whereas C. saccharolyticus was the predominant (99%) during cultivation without chitosan. In contrast the co-culture with rubber as carrier maintained the relative population ratios around 1:1. This study highlighted chitosan as an effective potential carrier for immobilization thereby paving the way for cost – effective hydrogen production.
Delivering a Safe, Viable Hydrogen Economy in Australia
Sep 2019
Publication
At Woodside Energy Ltd (Woodside) safety is built into everything we do and progressing hydrogen opportunities is no exception. This paper will present information from the macro level of process safety for hydrogen at a plant level through to the consumer experience. Examples of the benefits of an integrated process safety approach will be used from Woodside’s experience pioneering the liquefied natural gas industry in Australia.<br/>This paper will underscore the reasons why Australia needs to adopt robust safety standards for hydrogen as quickly as possible in order to advance the hydrogen economy across all sectors. Focus areas requiring attention during development of standards and potential mechanisms to close will be proposed. Establishing a hydrogen economy in Australia could lower carbon emissions stabilise power grids increase renewable energy penetration and create jobs. Developing Australian standards that are fully aligned with international standards will facilitate Australia taking a leading role in the global hydrogen economy.
Homogeneous and Inhomogeneous Hydrogen Deflagrations in 25 m3 Enclosure
Sep 2019
Publication
Explosion venting is a frequently used measure to mitigate the consequence of gas deflagrations in closed environments. Despite the effort to predict the vent area needed to achieved the protection through engineering formulas and CFD tools work has still to be done to reliably predict the outcome of a vented gas explosion. Most of available data derived from experimental campaigns performed in the past involved homogeneous conditions while especially in the case of a very buoyant gas such as hydrogen the most probable scenario that can follow and unintended release in a closed environment foresee the ignition of a stratified inhomogeneous mixture. University of Pisa performed experimental tests in a 25 m3 facility in homogeneous and inhomogeneous conditions. The present paper is aimed to share the results of hydrogen dispersion and deflagration tests and discuss the comparison of maximum peak overpressure generated in the two scenarios. Description of the experimental set-up includes all the details deemed necessary to reproduce the phenomenon with a CFD tool.
Dependency of Equivalence Ratio on Hydrogen Cylindrical Detonation Induced by Direct Initiation
Sep 2011
Publication
A hydrogen fuel is expected to expand its demand in the future. However hydrogen has to be treated with enough caution because of wide combustible conditions and easiness to ignite. Detonation accidents are caused in hydrogen gas such as the explosion accident in Fukushima first nuclear plant (2011). Therefore it is necessary to comprehend initiation conditions of detonation to prevent its detonation explosion. In the present study cylindrical detonation induced by direct initiation is simulated to understand the dependency of equivalence ratios in hydrogen-oxygen mixture. The several detailed kinetic models are compared to select the most appropriate model for detonation in a wide range of equivalence ratios. The Petersen-Hanson model is used in the present study due to the best agreement among the other models. In the numerical results of cylindrical detonation induced by direct initiation a cellular structure which is similar to the experimental smoked foil record is observed. The local pressure is up to 12 MPa under the condition at the standard state. The ignition process of cylindrical detonation has two stages. At the first stage the normalized cell width /L1/2 at each equivalence ratio increases linearly. At the second stage cell bifurcations appear due to a generation of new transverse waves. It is observed that a transverse wave transforms to a transverse detonation at the end of the first stage and after that some disturbance is developed to be a new transverse wave at the beginning of the second stage.
Experimental Results on The Dispersion of Buoyant Gas in a Full Scale Garage from a Complex Source
Sep 2009
Publication
The lack of experimental data on hydrogen dispersion led to the experimental project DRIVE (Experimental Data for Hydrogen Automotive Risks Assessment for the validation of numerical tools and for the Edition of guidelines) that involves the CEA (French Atomic Energy Commission) the National Institute of Industrial Environment and Risks (INERIS) the French car manufacturer PSA PEUGEOT CITROËN and the Research Institute on Out of Equilibrium Phenomena (IRPHE). The CEA has developed an experimental setup named GARAGE in order to analyze the condition of formation of an explosive atmosphere in an enclosure. This is a full scale facility in which a real car can be parked. Hydrogen releases were simulated with helium which volume fraction was measured with mini-katharometers. These thermal conductivity probes allow spatial and time volume fraction variations measurements. We present experimental results on the dispersion of helium in the enclosure due to releases in a typical car. The tested parameters are the location of the source (engine bottom of the car storage) and the flow rate. Emphasis is put on the influence of these parameters on the time evolution of the volume fraction in the enclosure as well as on the vertical distribution of helium.
Experiments on the Distribution of Concentration Due to Buoyant Gas Low Flow Rate Release in an Enclosure.
Sep 2009
Publication
Hydrogen energy based vehicles or power generators are expected to come into widespread use in the near future. Safety information is of major importance to support the successful public acceptance of hydrogen as an energy carrier. One of the most important issues in terms of safety is the use of such system in closed area such as a private garage in which a fuel cell car may be parked. This kind of situation leads to the fundamental problem of the dispersion of hydrogen due to a simple vertical source in an enclosure. Many numerical and experimental studies have already been conducted on this problem showing the formation of a stably stratified distribution of concentration. Most of them consider the cases of accidental situation in which the flow rate is relatively important (of the order of 10Nl/min to 100Nl/min). We present a set of experiments conducted on a full scale facility of the size of a typical private garage with helium as a model gas for hydrogen. In this study we focus on the low flow rates that can be characteristic of chronic leaks that may not be detected by security devices of the system (of the order of 0.1Nl/min to 10Nl/min). The facility allows changing natural ventilation conditions and experiments have been conducted from the tightest which is less than 0.01ACH to that typical of a real garage say of the order of 0.1ACH.
Influence of Hydrogen-Based Storage Systems on Self-Consumption and Self-Sufficiency of Residential Photovoltaic Systems
Aug 2015
Publication
This paper analyzes the behavior of residential solar-powered electrical energy storage systems. For this purpose a simulation model based on MATLAB/Simulink is developed. Investigating both short-time and seasonal hydrogen-based storage systems simulations on the basis of real weather data are processed on a timescale of 15 min for a consideration period of 3 years. A sensitivity analysis is conducted in order to identify the most important system parameters concerning the proportion of consumption and the degree of self-sufficiency. Therefore the influences of storage capacity and of storage efficiencies are discussed. A short-time storage system can increase the proportion of consumption by up to 35 percentage points compared to a self-consumption system without storage. However the seasonal storing system uses almost the entire energy produced by the photovoltaic (PV) system (nearly 100% self-consumption). Thereby the energy drawn from the grid can be reduced and a degree of self-sufficiency of about 90% is achieved. Based on these findings some scenarios to reach self-sufficiency are analyzed. The results show that full self-sufficiency will be possible with a seasonal hydrogen-based storage system if PV area and initial storage level are appropriate.
Numerical Modelling of Hydrogen Deflagration Dynamics in Enclosed Space
Sep 2009
Publication
A three-dimensional mathematical model of gaseous hydrogen deflagration in the enclosed space is developed. The process is described by the system of gas dynamics differential equations. Thermodynamic parameters of the mixture and its components are defined as functions of the local temperature and mixture composition. The concentration changes of the fuel and combustion products are determined using conservation laws taking into account rates of component disappearance and formation and turbulent diffusion. It is assumed that the chemical reaction takes place only in the volume where the fuel concentration is within the limits of inflammability. The mathematical model is validated during an intercomparison test to predict deflagration of a large-scale hydrogen-air mixture in open atmosphere. An algorithm of numerical solution based on the Godunov method is developed. A computer system of engineering analysis of gas-dynamic processes of hydrogen-air mixture formation and combustion in enclosed space with natural ventilation is created. It allows predicting the history of the changes of overpressure temperature concentrations of hydrogen and combustion products and other thermogasdynamic parameters of the mixture in space. This prognosis can be used to estimate dangerous zones of destruction and recommend some safety measures.
Laser Powder Bed Fusion of WE43 in Hydrogen-argon-gas Atmosphere
Sep 2020
Publication
Growing demand for individual and especially complex parts with emphasis on biomedical or lightweight applications enhances the importance of laser powder bed fusion. Magnesium alloys offer both biocompatibility and low density but feature a very high melting point of oxide layers while the evaporation temperature of pure magnesium is much lower. This impedes adequate part quality and process reproducibility. To weaken this oxide layer and enhance processability a 2 %-hydrogen-argon-gas atmosphere was investigated. A machine system was modified to the use of the novel inert gas to determine the influence of gas atmosphere on hollow cuboids and solid cubes. While processing a 20.3 % decrease in structure width and 20.6 % reduction in standard deviation of the cuboids was determined. There was no significate influence on relative density of solid cubes although eight of the ten highest density specimen were fabricated with the hydrogen addition.
Cyclic Voltammetry of a Cobaloxime Catalyst
Jul 2019
Publication
<br/>Cyclic Voltammetry Measurements performed on a Cobaloxime Catalyst designed for photochemical hydrogen production.
The Battle between Battery and Fuel Cell Powered Electric Vehicles: A BWM Approach
Oct 2017
Publication
The transition to a more sustainable personal transportation sector requires the widespread adoption of electric vehicles. However a dominant design has not yet emerged and a standards battle is being fought between battery and hydrogen fuel cell powered electric vehicles. The aim of this paper is to analyze which factors are most likely to influence the outcome of this battle thereby reducing the uncertainty in the industry regarding investment decisions in either of these technologies. We examine the relevant factors for standard dominance and apply a multi-criteria decision-making method best worst method to determine the relative importance of these factors. The results indicate that the key factors include technological superiority compatibility and brand reputation and credibility. Our findings show that battery powered electric vehicles have a greater chance of winning the standards battle. This study contributes to theory by providing further empirical evidence that the outcome of standards battles can be explained and predicted by applying factors for standard success. We conclude that technology dominance in the automotive industry is mostly driven by technological characteristics and characteristics of the format supporter.
Determination of Distribution Function Used in Monte Carlo Simulation on Safety Analysis of Hydrogen Vessels
Sep 2019
Publication
The test data of static burst strength and load cycle strength of composite pressure vessels are often described by GAUSSian normal or WEIBULL distribution function to perform safety analyses. The goodness of assumed distribution function plays a significant role in the inferential statistics to predict the population properties by using limited test data. Often GAUSSian and WEIBULL probability nets are empirical methods used to validate the distribution function; Anderson-Darling and Kolmogorov-Smirnov tests are the mostly favorable approaches for Goodness of Fit. However the different approaches used to determine the parameters of distribution function lead mostly to different conclusions for safety assessments.<br/>In this study six different methods are investigated to show the variations on the rates for accepting the composite pressure vessels according to GTR No. 13 life test procedure. The six methods are: a) Norm- Log based method b) Least squares regression c) Weighted least squares regression d) A linear approach based on good linear unbiased estimators e) Maximum likelihood estimation and f) The method of moments estimation. In addition various approaches of ranking function are considered. In the study Monte Carlo simulations are conducted to generate basic populations based on the distribution functions which are determined using different methods. Then the samples are extracted randomly from a population and evaluated to obtain acceptance rate. Here the “populations” and “samples” are corresponding to the burst strength or load cycle strength of the pressure vessels made from composite material and a plastic liner (type 4) for the storage of hydrogen. To the end the results are discussed and the best reliable methods are proposed.
Mesh-Independent Large-Eddy Simulation with Anisotropic Adaptive Mesh Refinement for Hydrogen Deflagration Prediction in Closed Vessels
Sep 2019
Publication
The use of high-fidelity simulation methods based on large-eddy simulation (LES) are proving useful for understanding and mitigating the safety hazards associated with hydrogen releases from nuclear power plants. However accurate modelling of turbulent premixed hydrogen flames via LES can require very high resolution to capture both the large-scale turbulence and its interaction with the flame fronts. Standard meshing strategies can result in impractically high computational costs especially for the thin fronts of hydrogen flames. For these reasons the use of a recently formulated integral length scale approximation (ILSA) subfilter-scale model in combination with an efficient anisotropic block-based adaptive mesh refinement (AMR) technique is proposed and examined herein for performing LES of turbulent premixed hydrogen flames. The anisotropic AMR method allows dynamic and solution-dependent resolution of flame fronts and the grid-independent properties of the ILSA model ensure that numerical errors associated with implicitly-filtered LES techniques in regions with varying resolution are avoided. The combined approach has the potential to allow formally converged LES solutions (direct numerical simulation results are typically reached in the limit of very fine meshes with standard subgrid models). The proposed LES methodology is applied to combustion simulations of lean premixed hydrogen-air mixtures within closed vessels: a problem relevant to hydrogen safety applications in nuclear facilities. A progress variable-based method with a multi-phenomena burning velocity model is used as the combustion model. The present simulation results are compared to the available experiment data for several previously studied THAI vessel cases and the capabilities of the proposed LES approach are assessed.
Multi-objective Optimal Configurations of a Membrane Reactor for Steam Methane Reforming
Nov 2021
Publication
The combination of traditional reactor and permeable membrane is beneficial to increase the production rate of the target product. How to design a high efficiency and energy saving membrane reactor is one of the key problems to be solved urgently. This paper utilizes finite-time thermodynamics and nonlinear programming to solve the optimal configurations of the membrane reactor of steam methane reforming (MR-SMR) for two optimization objectives that is heat exchange rate minimization and power consumption minimization. The exterior wall temperature and fixed hydrogen production rate are regarded as the control variable and constraint respectively. The results indicate that the hydrogen production rate and heat exchange rate in MR-SMR are increased by 108.58% and 58.42% respectively while the power consumption is reduced by 33.44% compared with those in the traditional reactor under the same condition. Compared with the results in reference reactor (MR-SMR obtained with initial values) the heat exchange rate is reduced by 1.40% by optimizing the exterior wall temperature and the power consumption is reduced by 5.10% by optimizing the exterior wall temperature and molar flow rate of sweep gas. The optimal distributions of exterior wall temperatures in the optimal reactors of minimum heat exchange rate and power consumption have a theoretical guiding significance for the thermal design of the membrane reactors.
Heading for Hydrogen - The Oil and Gas Industry’s Outlook for Hydrogen, From Ambition to Reality
May 2020
Publication
The future of hydrogen energy is wrapped up with the future of natural gas renewable energy and carbon capture and storage (CCS). This yields useful synergies but also political economic and technical complexity. Nevertheless our survey of more than 1000 senior oil and gas professionals suggests a more certain future for hydrogen and that the time is right to begin scaling the hydrogen economy.
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