United Kingdom

The large eddy simulation (LES) model developed at the University of Ulster has been applied to simulate releases of 5.11 m3 liquefied hydrogen (LH2) in open atmosphere and gaseous hydrogen (GH2) in 20-m3 closed vessel. The simulations of a spill of liquefied hydrogen confirmed the advantage of LES application to reproduce experimentally observed eddy structure of hydrogen-air cloud. The inclination angle of simulated cloud is close to experimentally reported 300. The processes of two phase hydrogen release and heat transfer were simplified by inflow of gaseous hydrogen with temperature 20 K equal to boiling point. It is shown that difference in inflow conditions geometry and grid resolution affects simulation results. It is suggested that phenomenon of air condensationevaporation in the cloud in temperature range 20-90 K should be accounted for in future. The simulations reproduced well experimental data on GH2 release and transport in 20-m3 vessel during 250 min including a phenomenon of hydrogen concentration growth at the bottom of the vessel. Higher experimental hydrogen concentration at the bottom is assumed to be due to non-uniformity of temperature of vessel walls generating additional convection. The comparison of convective and diffusion terms in Navie-Stokes equations has revealed that a value of convective term is more than order of magnitude prevail over a value of turbulent diffusion term. It is assumed that the hydrogen transport to the bottom of the vessel is driven by the remaining chaotic flow velocities superimposed on stratified hydrogen concentration field. Further experiments and simulations with higher accuracy have to be performed to confirm this phenomenon. It has been demonstrated that hydrogen-air mixture became stratified in about 1 min after release was completed. However one-dimensional models are seen not capable to reproduce slow transport of hydrogen during long period of time characteristic for scenarios such as leakage in a garage.

HyDeploy is a pioneering hydrogen energy project designed to help reduce UK CO2 emissions and reach the Government’s net zero target for 2050.

As the first ever live demonstration of hydrogen in homes HyDeploy aims to prove that blending up to 20% volume of hydrogen with natural gas is a safe and greener alternative to the gas we use now.  It is  providing evidence on how customers don’t have to change their cooking or heating appliances to take the blend which means less disruption and cost for them.

Hydrogen induced cracking behaviour of O&G nickel alloy 625+ (UNS N07716) was investigated. Deuterium was introduced electrochemically into samples by cathodic polarisation (3.5 wt.% NaCl.D₂O) under different mechanical conditions. Subsequently deuterium distributions were mapped using NanoSIMS. Deuterium was used as an isotopic tracer instead of hydrogen to avoid the detection of hydrogen artefacts. Complimentary image analysis using scanning electron microscopy (SEM) and low voltage energy dispersive X-ray (EDX) allowed the identification of microstructural features corresponding to deuterium enrichments. The results provided experimental evidence of enrichments at dislocation slip bands (DSB) twin boundary and grain boundary features that include σ precipitates.

Decarbonisation should be very much on the radar of new LNG projects currently taking FID commissioning around 2024-25 and planning to operate up to 2050. The LNG community needs to replace an `advocacy’ message – based on the generality of emissions from combustion of natural gas being lower than from other fossil fuels – with certified data on carbon and methane emissions from specific elements of the value chain for individual projects. As carbon reduction targets tighten over the coming decade LNG cargoes which do not have value chain emissions certified by accredited authorities or which fail to meet defined emission levels run the risk of progressively being deemed to have a lower commercial value and eventually being excluded from jurisdictions with the strictest standards. There will be no place in this process for confidentiality; nothing less than complete transparency of data and methodologies will be acceptable.<br/>In relation to affordability prospects for new projects look much better than they did three years ago. Cost estimates for most new projects suggest that they will be able to deliver profitably to most established and anticipated import markets at or below the wholesale prices prevailing in those markets over the past decade although affordability in south Asian countries may be challenging. But new projects need to factor in costs related to future decarbonisation requirements in both exporting and importing countries. To the extent that LNG suppliers can meet standards through relatively low-cost offsets – forest projects low-cost biogas and biomethane – this may not greatly impact their commercial viability. However any requirement to transform methane into hydrogen with CCS in either the exporting or importing country would substantially impact project economics and the affordability of LNG relative to other energy choices.

Road transport is recognized as having a negative impact on the environment. Policy has focused on replacement of the internal combustion engine (ICE) with less polluting forms of technology including battery electric and fuel cell electric powertrains. However progress is slow and both battery and fuel cell based vehicles face considerable commercialization challenges. To understand these challenges a review of current electric battery and fuel cell electric technologies is presented. Based on this review this paper proposes a battery electric vehicle (BEV) where components are sized to take into account the majority of user requirements with the remainder catered for by a trailer-based demountable intelligent fuel cell range extender. The proposed design can extend the range by more than 50% for small BEVs and 25% for large BEVs (the extended range of vehicles over 250 miles) reducing cost and increasing efficiency for the BEV. It enables BEV manufacturers to design their vehicle battery for the most common journeys decreases charging time to provide convenience and flexibility to the drivers. Adopting a rent and drop business model reduces the demand on the raw materials bridging the gap in the amount of charging (refueling) stations and extending the lifespan for the battery pack.

The European Commission have just stated that hydrogen would play a major role in the economic recovery of post-COVID-19 EU countries. Hydrogen is recognised as one of the key players in a fossil fuel-free world in decades to come. However commercially practiced pathways to hydrogen production todays are associated with a considerable amount of carbon emissions. The Paris Climate Change Agreement has set out plans for an international commitment to reduce carbon emissions within the forthcoming decades. A sustainable hydrogen future would only be achievable if hydrogen production is “designed” to capture such emissions. Today nearly 98% of global hydrogen production relies on the utilisation of fossil fuels. Among these steam methane reforming (SMR) boasts the biggest share of nearly 3 50% of the global generation. SMR processes correspond to a significant amount of carbon emissions at various points throughout the process. Despite the dark side of the SMR processes they are projected to play a major role in hydrogen production by the first half of this century. This that a sustainable yet clean short/medium-term hydrogen production is only possible by devising a plan to efficiently capture this co-produced carbon as stated in the latest International Energy Agency (IEA) reports. Here we have carried out an in-depth technical review of the processes employed in sorption-enhanced steam methane reforming (SE-SMR) an emerging technology in low-carbon SMR for combined carbon capture and hydrogen production. This paper aims to provide an in-depth review on two key challenging elements of SE-SMR i.e. the advancements in catalysts/adsorbents preparation and current approaches in process synthesis and optimisation including the employment of artificial intelligence in SE-SMR processes. To the best of the authors‟ knowledge there is a clear gap in the literature where the above areas have been scrutinised in a systematic and coherent fashion. The gap is even more pronounced in the application of AI in SE-SMR technologies. As a result this work aims to fill this gap within the scientific literature.

Since the UK’s Net Zero greenhouse gas emissions target was set in 2019 organisations across the energy systems community have released pathways on how we might get there – which end-use technologies are deployed across each sector of demand how our fossil fuel-based energy supply would be transferred to low carbon vectors and to what extent society must change the way it demands energy services. This paper presents a comparative analysis between seven published Net Zero pathways for the UK energy system collected from Energy Systems Catapult National Grid ESO Centre for Alternative Technology and the Climate Change Committee. The key findings reported are that (i) pathways that rely on less stringent behavioural changes require more ambitious technology development (and vice versa); (ii) electricity generation will increase by 51-160% to facilitate large-scale fuel-switching in heating and transport the vast majority of which is likely to be generated from variable renewable sources; (iii) hydrogen is an important energy vector in meeting Net Zero for all pathways providing 100-591 TWh annually by 2050 though the growth in demand is heavily dependent on the extent to which it is used in supplying heating and transport demand. This paper also presents a re-visited analysis of the potential renewable electricity generation resource in the UK. It was found that the resource for renewable electricity generation outstrips the UK’s projected 2050 electricity demand by a factor 12-20 depending on the pathway. As made clear in all seven pathways large-scale deployment of flexibility and storage is required to match this abundant resource to our energy demand.

An independent report by the CCUS Cost Challenge Taskforce setting out the industry’s view on how best to progress carbon capture usage and storage (CCUS) in the UK in order to enable the UK to have the option of deploying CCUS at scale during the 2030s subject to costs coming down sufficiently.

Numerical experiments are performed to understand different regimes of hydrogen non-premixed combustion in an enclosure with passive ventilation through one horizontal or vertical vent located at the top of a wall. The Reynolds averaged Navier–Stokes (RANS) computational fluid dynamics (CFD) model with a reduced chemical reaction mechanism is described in detail. The model is based on the renormalization group (RNG) k-ε turbulence model the eddy dissipation concept (EDC) model for simulation of combustion coupled with the 18-step reduced chemical mechanism (8 species) and the in-situ adaptive tabulation (ISAT) algorithm that accelerates the reacting flow calculations by two to three orders of magnitude. The analysis of temperature and species (hydroxyl hydrogen oxygen water) concentrations in time as well as the velocity through the vent shed a light on regimes and dynamics of indoor hydrogen fires. A well-ventilated fire is simulated in the enclosure at a lower release flow rate and complete combustion of hydrogen within the enclosure. Fire becomes under-ventilated at higher release flow rates with two different modes observed. The first mode is the external flame stabilised at the enclosure vent at moderate release rates and the second mode is the self-extinction of combustion inside and outside the enclosure at higher hydrogen release rates. The simulations demonstrated a complex reacting flow dynamics in the enclosure that leads to formation of the external flame or the self-extinction. The air intake into the enclosure at later stages of the process through the whole vent area is a characteristic feature of the self-extinction regime. This air intake is due to faster cooling of hot combustion products by sustained colder hydrogen leak compared to the generation of hot products by the ceasing chemical reactions inside the enclosure and hydrogen supply. In general an increase of hydrogen sustained release flow rate will change fire regime from the well-ventilated combustion within the enclosure through the external flame stabilised at the vent and finally to the self-extinction of combustion throughout the domain.

The heat and buildings strategy sets out the government’s plan to significantly cut carbon emissions from the UK’s 30 million homes and workplaces in a simple low-cost and green way whilst ensuring this remains affordable and fair for households across the country. Like the transition to electric vehicles this will be a gradual transition which will start by incentivizing consumers and driving down costs.<br/>There are about 30 million buildings in the UK. Heating these buildings contributes to almost a quarter of all UK emissions. Addressing the carbon emissions produced in heating and powering our homes workplaces and public buildings can not only save money on energy bills and improve lives but can support up to 240000 skilled green jobs by 2035 boosting the economic recovery levelling up across the country and ensuring we build back better.<br/>The heat and buildings strategy builds on the commitments made in Clean growth: transforming heating our Energy white paper and the Prime Minister’s 10 point plan. This strategy aims to provide a clear direction of travel for the 2020s set out the strategic decisions that need to be taken this decade and demonstrate how we plan to meet our carbon targets and remain on track for net zero by 2050.

The turbine-combined free-piston engine generator (TCFPEG) is a hybrid machine generating both mechanical work from the gas turbine and electricity from the linear electric generator for battery charging. In the present study the system performance of the designed TCFPEG system is predicted using a validated numerical model. A parametric analysis is undertaken based on the influence of the engine load valve timing the number of linear generators adopted and different fuels on the system performance. It is found that when linear electric generators are connected with the free-piston gas turbine the bottom dead centre the peak piston velocity and engine operation frequency are all reduced. Very minimal difference on the in-cylinder pressure and the compressor pressure is observed while the peak pressure in the bounce chamber is reduced. When coupled with a linear electric generator the system efficiency can be improved to nearly 50% by optimising engine load and the number of the linear generators adopted in the TCFPEG system. The system is able to be operated with different fuels as the piston is not limited by a mechanical system; the output power and system efficiency are highest when hydrogen is used as the fuel.

Hydrogen dispersion in stagnant environment resulting from blowdown of a vessel storing the gas at cryogenic temperature is simulated using different CFD codes and modelling strategies. The simulations are based on the DISCHA experiments that were carried out by Karlsruhe Institute of Technology (KIT) and Pro-Science (PS). The selected test for the current study involves hydrogen release from a 2.815 dm3 volume tank with an initial pressure of 200 barg and temperature 80 K. During the release the hydrogen pressure in the tank gradually decreased. A total of about 139 gr hydrogen is released through a 4 mm diameter. The temperature time series and the temperature decay rate of the minimum value predicted by the different codes are compared with each other and with the experimentally measured ones. Recommendations for future experimental setup and for modeling approaches for similar releases are provided based on the present analysis. The work is carried out within the EU-funded project PRESLHY.

Existing studies of financing efficiency concentrate on capital structure and a single external environment or internal management characteristic. Few of the studies include the internal and external financing environments at the same time for hydrogen energy industry financing efficiency. This paper used the data envelopment analysis (DEA) model and the Malmquist index to measure the financing efficiency of 70 hydrogen energy listed enterprises in China from 2014 to 2020 from both static and dynamic perspectives. Then a tobit model was constructed to explore the influence of external environment and internal factors on the financing efficiency. The contributions of this paper are studying the internal and external financing environments and integrating financing cost efficiency and capital allocation efficiency into the financing efficiency of hydrogen energy enterprises. The results show that firstly the financing efficiency of China’s hydrogen energy listed enterprises showed an upward trend during the years 2014–2020. Secondly China’s hydrogen energy enterprises mainly gather in the eastern coastal areas and their financing efficiency is more than that in western areas. Thirdly the regional economic development level enterprise scale financing structure capital utilization efficiency and profitability have significant effects on the financing efficiency. These results can promote the achievement of “carbon neutrality” in China.

Clean renewable energy for Chinese cities is a priority in air quality improvement. This paper describes the recent Chinese advances in Polymer Electrolyte Membrane (PEM) hydrogen-fuel-cell-battery vehicles including buses and trucks. Following the 2016 Chinese government plan for new energy vehicles bus production in Foshan has now overtaken that in the EU USA and Japan combined. Hydrogen infrastructure requires much advance to catch up but numbers of filling stations are now increasing rapidly in the large cities. A particular benefit in China is the large number of battery manufacturing companies which fit well into the energy storage plan for hybrid fuel cell buses. The first city to manufacture thousands of PEM-battery hybrid buses is Foshan where the Feichi (Allenbus) company has built a new factory next to a novel fuel cell production line capable of producing 500 MW of fuel cell units per year. Hundreds of these buses are running on local Foshan routes this year while production of city delivery trucks has also been substantial. Results for energy consumption of these vehicles are presented and fitted to the Coulomb theory previously delineated.

The thermal management system architectures proposed for hydrogen-powered propulsion technologies are critically reviewed and assessed. The objectives of this paper are to determine the system-level shortcomings and to recognise the remaining challenges and research questions that need to be sorted out in order to enable this disruptive technology to be utilised by propulsion system manufacturers. Initially a scientometrics based co-word analysis is conducted to identify the milestones for the literature review as well as to illustrate the connections between relevant ideas by considering the patterns of co-occurrence of words. Then a historical review of the proposed embodiments and concepts dating back to 1995 is followed. Next feasible thermal management system architectures are classified into three distinct classes and its components are discussed. These architectures are further extended and adapted for the application of hydrogen-powered fuel cells in aviation. This climaxes with the assessment of the available evidence to verify the reasons why no hydrogen-powered propulsion thermal management system architecture has yet been approved for commercial production. Finally the remaining research challenges are identified through a systematic examination of the critical areas in thermal management systems for application to hydrogen-powered air vehicles’ engine cooling. The proposed solutions are discussed from weight cost complexity and impact points of view by a system-level assessment of the critical areas in the field.

The thermochemical water‐splitting method is a promising technology for efficiently con verting renewable thermal energy sources into green hydrogen. This technique is primarily based on recirculating an active material capable of experiencing multiple reduction‐oxidation (redox) steps through an integrated cycle to convert water into separate streams of hydrogen and oxygen. The thermochemical cycles are divided into two main categories according to their operating temperatures namely low‐temperature cycles (<1100 °C) and high‐temperature cycles (<1100 °C). The copper chlorine cycle offers relatively higher efficiency and lower costs for hydrogen production among the low‐temperature processes. In contrast the zinc oxide and ferrite cycles show great potential for developing large‐scale high‐temperature cycles. Although several challenges such as energy storage capacity durability cost‐effectiveness etc. should be addressed before scaling up these technologies into commercial plants for hydrogen production. This review critically examines various aspects of the most promising thermochemical water‐splitting cycles with a particular focus on their capabilities to produce green hydrogen with high performance redox pairs stability and the technology maturity and readiness for commercial use.

According to the UK’s Committee on Climate Change the economically efficient achievement of Government’s legally-binding carbon-reduction target will require full decarbonisation of all heat in buildings and the decarbonisation of most industrial heat over the next 20 to 30 years (BEIS 2018). This goliath task is not unprecedented. Indeed the scale of this transition is similar to the UK’s former transition from coal to natural gas heating. Albeit the rate of transition away from natural gas will certainly need to be greater than the rate of the transition toward natural gas to achieve net zero greenhouse gas emissions by 2050.<br/><br/>At present Government’s commitment stands in sharp contrast with its inaction on heat decarbonisation to date. Under pressure to progress this agenda Government has charged the Clean Heat Directorate with the task of outlining the process for determining the UK’s long-term heat policy framework to be published in the ‘Roadmap for policy on heat decarbonisation’ in the summer of 2020 (BEIS 2017). This report resulting from one of six EPSRC-funded secondments is designed to support early thinking on the roadmap by answering the research question: How can ‘Transitions’ research informs the roadmap for governing the UK’s heating transition?<br/><br/>‘Transitions’ research is an interdisciplinary field of study within the Social Sciences and Humanities that investigates the co-evolution of social and technological systems (such as the UK heating system) and the dynamics by which fundamental change in these systems occur. To investigate what insights this area of research may hold for the governance of the UK’s heat transition a systematic literature review was conducted focusing specifically on past and ongoing heat transitions across Europe.<br/><br/>The review uncovered learnings about the role of path dependency; power and politics; complexity; cross-sector interactions; multi-level governance; and intermediaries in shaping non-linear transitions toward renewable heat. This report illustrates each learning with real-world examples from case studies undertaken by Transitions researchers and concludes with a long list of policy and process-oriented governance recommendations for the UK Government.

Hydrogen storage in nanoporous materials has been attracting a great deal of attention in recent years as high gravimetric H2 capacities exceeding 10 wt% in some cases can be achieved at 77 K using materials with particularly high surface areas. However volumetric capacities at low temperatures and both gravimetric and volumetric capacities at ambient temperature need to be improved before such adsorbents become practically viable. This article therefore discusses approaches to increasing the gravimetric and volumetric hydrogen storage capacities of nanoporous materials and maximizing the usable capacity of a material between the upper storage and delivery pressures. In addition recent advances in machine learning and data science provide an opportunity to apply this technology to the search for new materials for hydrogen storage. The large number of possible component combinations and substitutions in various porous materials including Metal-Organic Frameworks (MOFs) is ideally suited to a machine learning approach; so this is also discussed together with some new material types that could prove useful in the future for hydrogen storage applications.

In this work we present the experimental results obtained from hydrogen fuelled spark-ignited dual piston free-piston engine generator (FPEG) prototype operated in two-stroke and four-stroke mode. The FPEG testing was successfully conducted at 3.7 compression ratio engine speed between 5 Hz and 11 Hz and with different equivalence ratios. The FPEG technical details experimental set-up and operational control are explained in detail. Performance indicators show that both equivalence ratio and engine speed affect the engine operation characteristics. For every set of specified FPEG parameters appropriate range of equivalence ratio is recommended to prevent unwanted disturbance to electric generator operation. Both two-stroke and four-stroke cycle mode were tested and the results showed different combustion characteristics with the two thermodynamic cycles. Four-stroke cycle mode could operate with indicated thermal efficiency gain up to 13.2% compared with the two-stroke cycle.

The bioanode is important for a microbial electrolysis cell (MEC) and its robustness to maintain its catalytic activity affects the performance of the whole system. Bioanodes enriched at a potential of +0.2 V (vs. standard hydrogen electrode) were able to sustain their oxidation activity when the anode potential was varied from -0.3 up to +1.0 V. Chronoamperometric test revealed that the bioanode produced peak current density of 0.36 A/m2 and 0.37 A/m2 at applied potential 0 and +0.6 V respectively. Meanwhile hydrogen production at the biocathode was proportional to the applied potential in the range from -0.5 to  -1.0 V. The highest production rate was 7.4 L H2/(m2 cathode area)/day at -1.0 V cathode potential. A limited current output at the bioanode could halt the biocathode capability to generate hydrogen. Therefore maximum applied potential that can be applied to the biocathode was calculated as -0.84 V without overloading the bioanode.

Engineering tools for calculation of hazard distances for cryogenic hydrogen jets are currently missing. This study aims at the development of validated correlations for calculation of hazard distances for cryogenic unignited releases and jet fires. The experiments performed by Sandia National Laboratories (SNL) on jets from storage temperature in the range 46-295 K and pressure up to 6 bar abs are used to expand the validation domain of the correlations. The Ulster’s under-expanded jet theory is applied to calculate parameters at the real nozzle exit. The similarity law for concentration decay in momentum-dominated jets is shown to be capable to reproduce experimental data of SNL on 9 unignited cryogenic releases. The accuracy of the similarity law to predict experimentally measured axial concentration decay improves with the increase of the release diameter. This is thought due to decrease of the effect of friction and minor losses for large release orifices. The dimensionless flame length correlation is applied to analyse 30 cryogenic jet fire tests. The deviation of calculated flame length from measured in experiments is mostly within acceptable accuracy for engineering correlations 20% similarly to releases from storage and equipment at atmospheric temperatures. It is concluded that the similarity law and the dimensionless flame correlation can be used as universal engineering tools for calculation of hazard distances for hydrogen releases at any storage temperature including cryogenic.

Hydrogen fuelling in the US is unattended activity although this precedent is not without several challenges that have been addressed in the past decade. This paper provides the recent history and the generic safety case which has established this precedent for hydrogen. The paper also explores the longer history of unattended gasoline fuelling and attempts to help place hydrogen fuelling into the longer history of fuelling personal vehicles.

The Prime Minister’s Ten Point Plan has set out the measures that will help ensure the UK is at the forefront of this revolution just as we led the first over two centuries ago. As nations move out of the shadow of coronavirus and confront the challenge of climate change with renewed vigour markets for new green products and services will spring up round the world. Taking action now will help ensure not just that we end our contribution to climate change by achieving our target of net zero emissions. It will help position UK companies and our world class research base to seize the business opportunities which flow from it creating jobs and wealth for our country.

Following on from the Ten Point Plan and the National Infrastructure Strategy the Energy White Paper provides further clarity on the Prime Minister’s measures and puts in place a strategy for the wider energy system that:

• Transforms energy building a cleaner greener future for our country our people and our planet 
• Supports a green recovery growing our economy supporting thousands of green jobs across the country in new green industries and leveraging new green export opportunities
• Creates a fair deal for consumers protecting the fuel poor providing opportunities to save money on bills giving us warmer more comfortable homes and balancing investment against bill impacts.

The 30 integrated steel plants operating in the European Union (EU) are among the largest single-point CO₂ emitters in the region. The deployment of bioenergy with carbon capture and storage (bio-CCS) could significantly reduce their emission intensities. In detail the results demonstrate that CO₂ emission reduction targets of up to 20% can be met entirely by biomass deployment. A slow CCS technology introduction on top of biomass deployment is expected as the requirement for emission reduction increases further. Bio-CCS could then be a key technology particularly in terms of meeting targets above 50% with CO₂ avoidance costs ranging between €60 and €100 tCO2−1 at full-scale deployment. The future of bio-CCS and its utilisation on a larger scale would therefore only be viable if such CO₂ avoidance cost were to become economically appealing. Small and medium plants in particular would economically benefit from sharing CO₂ pipeline networks. CO₂ transport however makes a relatively small contribution to the total CO₂ avoidance cost. In the future the role of bio-CCS in the European iron and steelmaking industry will also be influenced by non-economic conditions such as regulations public acceptance realistic CO₂ storage capacity and the progress of other mitigation technologies.

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.