United Kingdom

A model has been derived for the magnesium hydrogenation reaction at conditions close to equilibrium. The reaction mechanism involves an adsorption element where the model is an extension of the Langmuir adsorption model. The concept of site availability (σs) is introduced whereby it has the capability to reduce the reaction rate. To improve representation of σs an adaptable semi-empirical equation has been developed. Supplement to the surface reaction a rate equation has been derived considering resistance effects. It was found that close to equilibrium surface resistance dominated the reaction.

This paper presents the optimal design and operation of integrated wind-hydrogen-electricity networks using the general mixed integer linear programming energy network model STeMES (Samsatli and Samsatli 2015). The network comprises: wind turbines; electrolysers fuel cells compressors and expanders; pressurised vessels and underground storage for hydrogen storage; hydrogen pipelines and electricity overhead/underground transmission lines; and fuelling stations and distribution pipelines.<br/>The spatial distribution and temporal variability of energy demands and wind availability were considered in detail in the model. The suitable sites for wind turbines were identified using GIS by applying a total of 10 technical and environmental constraints (buffer distances from urban areas rivers roads airports woodland and so on) and used to determine the maximum number of new wind turbines that can be installed in each zone.<br/>The objective is the minimisation of the total cost of the network subject to satisfying all of the demands of the domestic transport sector in Great Britain. The model simultaneously determines the optimal number size and location of each technology whether to transmit the energy as electricity or hydrogen the structure of the transmission network the hourly operation of each technology and so on. The cost of distribution was estimated from the number of fuelling stations and length of the distribution pipelines which were determined from the demand density at the 1 km level.<br/>Results indicate that all of Britain's domestic transport demand can be met by on-shore wind through appropriately designed and operated hydrogen-electricity networks. Within the set of technologies considered the optimal solution is: to build a hydrogen pipeline network in the south of England and Wales; to supply the Midlands and Greater London with hydrogen from the pipeline network alone; to use Humbly Grove underground storage for seasonal storage and pressurised vessels at different locations for hourly balancing as well as seasonal storage; for Northern Wales Northern England and Scotland to be self-sufficient generating and storing all of the hydrogen locally. These results may change with the inclusion of more technologies such as electricity storage and electric vehicles.

Across Europe permitted blend levels of hydrogen blending into the gas grid are appreciably higher than that currently permitted in the UK up to 12% mol/mol compared with 0.1% mol/mol. Whilst there is some routine blending undertaking – typically power to gas applications three major projects have been undertaken to demonstrate operation of a gas distribution network at higher blend levels of hydrogen.<br/>A Dutch project was completed in 2011 which demonstrated successful operation into a network with new appliances at 20% mol/mol. A German project was completed in 2015 which demonstrated successful operation into an existing gas network with existing appliances at their permitted level of 10% mol/mol. In France an extensive programme is underway to inject hydrogen into a network at 20% mol/mol due to commence injection in 2018.<br/>Each of these projects undertook extensive pre-trial activities and operational data was collected during the Dutch and German trials. The programme of pre-trial work for the French project was particularly extensive and mirrored the work done by HyDeploy. This led to a permit being granted for the French project at 20% mol/mol with injection into the network imminent.<br/>The HyDeploy team has engaged with each of the project teams who have been very co-operative; this has enabled scientific sharing of best practice. In all cases the projects were successful. The participants in the Dutch project were particularly keen to have been able to undertake a similar trial to HyDeploy; a larger trial into existing appliances. However political changes in Holland have precluded that at this time such progress was not limited by technical findings from the work.<br/>A high level overview of the projects and the data provided is summarised in this report. More detailed information is referenced and covered in more detail where required in the appropriate individual topic reports supporting the Exemption.<br/>Click on supplements tab to view the other documents from this report

Hydrogen has been identified as a potential energy vector to decarbonise the transport and chemical sectors and achieve global greenhouse gas reduction targets. Despite ongoing efforts hydrogen technologies are often assessed focusing on their global warming potential while overlooking other impacts or at most including additional metrics that are not easily interpretable. Herein a wide range of alternative technologies have been assessed to determine the total cost of hydrogen production by coupling life-cycle assessments with an economic evaluation of the environmental externalities of production. By including monetised values of environmental impacts on human health ecosystem quality and resources on top of the levelised cost of hydrogen production an estimation of the “real” total cost of hydrogen was obtained to transparently rank the alternative technologies. The study herein covers steam methane reforming (SMR) coal and biomass gasification methane pyrolysis and electrolysis from renewable and nuclear technologies. Monetised externalities are found to represent a significant percentage of the total cost ultimately altering the standard ranking of technologies. SMR coupled with carbon capture and storage emerges as the cheapest option followed by methane pyrolysis and water electrolysis from wind and nuclear. The obtained results identify the “real” ranges for the cost of hydrogen compared to SMR (business as usual) by including environmental externalities thereby helping to pinpoint critical barriers for emerging and competing technologies to SMR.

Fuel cells as clean power sources are very attractive for the maritime sector which is committed to sustainability and reducing greenhouse gas and atmospheric pollutant emissions from ships. This paper presents a technological review on fuel cell power systems for maritime applications from the past two decades. The available fuels including hydrogen ammonia renewable methane and methanol for fuel cells under the context of sustainable maritime transportation and their pre-processing technologies are analyzed. Proton exchange membrane molten carbonate and solid oxide fuel cells are found to be the most promising options for maritime applications once energy efficiency power capacity and sensitivity to fuel impurities are considered. The types layouts and characteristics of fuel cell modules are summarized based on the existing applications in particular industrial or residential sectors. The various research and demonstration projects of fuel cell power systems in the maritime industry are reviewed and the challenges with regard to power capacity safety reliability durability operability and costs are analyzed. Currently power capacity costs and lifetime of the fuel cell stack are the primary barriers. Coupling with batteries modularization mass production and optimized operating and control strategies are all important pathways to improve the performance of fuel cell power systems.

Low-carbon hydrogen has the potential to play a significant role in tackling climate change and poor air quality. This policy briefing considers how hydrogen could be produced at a useful scale to power vehicles heat homes and supply industrial processes.

Four groups of hydrogen production technologies are examined:

Thermochemical Routes to Hydrogen

These methods typically use heat and fossil fuels. Steam methane reforming is the dominant commercial technology and currently produces hydrogen on a large scale but is not currently low carbon. Carbon capture is therefore essential with this process. Innovative technology developments may also help and research is underway. Alternative thermal methods of creating hydrogen indicate biomass gasification has potential. Other techniques at a low technology readiness level include separation of hydrogen from hydrocarbons using microwaves.

Electrolytic Routes to Hydrogen

Electrolytic hydrogen production also known as electrolysis splits water into hydrogen and oxygen using electricity in an electrolysis cell. Electrolysis produces pure hydrogen which is ideal for low temperature fuel cells for example in electric vehicles. Commercial electrolysers are on the market and have been in use for many years. Further technology developments will enable new generation electrolysers to be commercially competitive when used at scale with fluctuating renewable energy sources.

Biological Routes to Hydrogen

Biological routes usually involve the conversion of biomass to hydrogen and other valuable end products using microbial processes. Methods such as anaerobic digestion are feasible now at a laboratory and small pilot scale. This technology may prove to have additional or greater impact and value as route for the production of high value chemicals within a biorefinery concept.

Solar to Fuels Routes to Hydrogen

A number of experimental techniques have been reported the most developed of which is ‘solar to fuels’ - a suite of technologies that typically split water into hydrogen and oxygen using solar energy. These methods have close parallels with the process of photosynthesis and are often referred to as ‘artificial photosynthesis’ processes. The research is promising though views are divided on its ultimate utility. Competition for space will always limit the scale up of solar to fuels.

The briefing concludes that steam methane reforming and electrolysis are the most likely technologies to be deployed to produce low-carbon hydrogen at volume in the near to mid-term providing that the challenges of high levels of carbon capture (for steam methane reforming) and cost reduction and renewable energy sources (for electrolysis) can be overcome.

Hydrogen has potential applications across our future energy systems due particularly to its relatively high energy weight ratio and because it is emission-free at the point of use. Hydrogen is also abundant and versatile in the sense that it could be produced from a variety of primary energy sources and chemical substances including water and used to deliver power in a variety of applications including fuel cell combined heat and power technologies. As a chemical feedstock hydrogen has been used for several decades and such expertise could be fed back into the relatively new areas of utilising hydrogen to meet growing energy demands.<br/>The UK interest in hydrogen is also growing with various industrial academic and governmental organisations investigating how hydrogen could be part of a diverse portfolio of options for a low carbon future. While hydrogen as an alternative fuel is yet to command mass-appeal in the UK energy market IGEM believes hydrogen is capable of allowing us to use the wide range of primary energy sources at our disposal in a much greener and sustainable way.<br/>IGEM also sees hydrogen playing a small but key role in the gas industry whereby excess renewable energy is used to generate hydrogen which is then injected into the gas grid for widespread distribution and consumption. Various studies suggest admixtures containing up to 10 – 50%v/v hydrogen could be safely administered into the existing natural gas infrastructure. However IGEM understands that this would currently not be permissible under the Gas Safety (Management) Regulations (GS(M)R) for gas conveyance here in the UK. Also proper assessments of the risks associated with adding hydrogen to natural gas streams will need to be performed so that such systems can be managed effectively.<br/>IGEM has also identified a need for standards that cover the safety requirements of hydrogen technologies particularly those pertaining to installations in commercial or domestic environments. IGEM also recommend that the technical measures used to determine separation distances for hydrogen installations particularly refuelling stations are re-assessed through a systematic identification and control of potential sources of ignition.<br/>Hydrogen has the potential to be a significant fuel of the future and part of a diverse portfolio of energy options capable of meeting growing energy needs. This report therefore seeks to demonstrate how hydrogen could be a potential option for energy storage and power generation in a diverse energy system. It also aims to inform the readers on the current state of hydrogen here in the UK and abroad. This report has been assembled for IGEM members interested bodies and the general public.

In the framework of the EU-funded project HyTunnel-CS an inter-comparison among partners CFD simulations  has  been  carried  out.  The simulations  are  based  on  experiments  conducted   within  the project by Pro-Science and involve hydrogen release inside a safety vessel testing different ventilation configurations. The different ventilation configurations that were tested are co-flow counter-flow and cross-flow.  In the  current  study  co-flow  and  counter-flow  tests   along  with  the  no  ventilation  test (m'  = S g/s  d = 4 mm ) are simulated with the aim to validate available and well-known CFD codes against  such  applications  and  to  provide   recommendations  on  modeling  strategies. Special  focus  is given on modeling the velocity field produced by the fan during the experiments. The computational results are compared with the experimental results and a discussion follows regarding the efficiency of each ventilation configuration.

Introduction of hydrogen into the UK gas main has been reviewed in terms of how materials within the Keele G3 gas distribution network (G3 GDN) on the Keele University network may be affected by contact with natural gas (NG):hydrogen blends up to a limit of 20 % mol/mol hydrogen.<br/>This work has formed part of the supporting evidence for a 1 year hydrogen blending trial on the Keele G3 GDN coordinated by the HyDeploy consortium (formed of representatives of Cadent Northern Gas Networks ITM Power Progressive Energy HSL and Keele University).<br/>A wide range of materials were identified and assessed via a combination of literature review and practical test programmes. No significant changes to material properties in terms of accelerated material degradation or predicted efficiency of gas confinement were identified which would cause concern for the year-long trial at Keele.<br/>It can be concluded that materials on the Keele G3 GDN should be acceptable to provide a safe operating network the HyDeploy demonstrator project up to a level of 20 % mol/mol hydrogen.<br/>Check the supplements tab for the other documents in this report

There is no inherent property of hydrogen that makes it unsuitable for metering at distribution or transmission pressures. Towns gas containing large percentages of hydrogen was used for many years in the UK and continues to be in use in Hong Kong and Singapore. Many manufacturers sell their ordinary mechanical gas meters as suitable for hydrogen in a laboratory or industrial situation; unfortunately lack of demand has meant that none of these meters seem to have certified under appropriate metering regulations for gaseous hydrogen (e.g. the Measuring Instruments Directive)<br/>Some of the more sophisticated modern inferential meters (e.g. thermal or ultrasonic) currently designed specifically for natural gas (or LPG if suitably calibrated) are likely to unsuitable for repurposing directly to hydrogen but none of the problems appear fundamental or insuperable. The largest potential hurdle probably surrounds the physical size of current meters. A hydrogen appliance will consume about 3.3 more hydrogen than natural gas (on a volumetric basis) and using traditional designs this would have been measured through a meter probably too large to fit within an existing meter box. Unless unsolved such an increase in size would add materially to any hydrogen re-purposing programme.<br/>The meter trade thus need to be challenged to come up with a hydrogen meter that is the same physical size as a natural gas meter on a power rating basis (i.e. in kW). Ultrasonic and thermal mass meters should be included in the necessary Research and Development programme.<br/>A meter test programme is suggested that will provide evidence to meter manufacturers that the metering of hydrogen is not inherently difficult and thus convince them to make the necessary investments and/or approach the GDNO’s for assistance with such a programme.