United Kingdom

The clean hydrogen in the prioritized value chain platform could provide energy incentives and reduce environmental impacts. In the current study strengths weaknesses opportunities and threats (SWOT) analysis has been successfully applied to the clean hydrogen value chain in different sectors to determine Japan’s clean hydrogen value chain’s strengths weaknesses opportunities and threats as a case study. Japan was chosen as a case study since we believe that it is the only pioneer country in that chain with a national strategy investments and current projects which make it unique in this way. The analyses include evaluations of clean energy development power supply chains regional energy planning and renewable energy development including the internal and external elements that may influence the growth of the hydrogen economy in Japan. The ability of Japan to produce and use large quantities of clean hydrogen at a price that is competitive with fossil fuels is critical to the country’s future success. The implementation of an efficient carbon tax and carbon pricing is also necessary for cost parity. There will be an increasing demand for global policy coordination and inter-industry cooperation. The results obtained from this research will be a suitable model for other countries to be aware of the strengths weaknesses opportunities and threats in this field in order to make proper decisions according to their infrastructures potentials economies and socio-political states in that field.

Previously suggested options to achieve carbon neutrality involve the use of fossil fuels with carbon capture or exploiting biomass as sources of energy. Industrial high-temperature heating could possibly exploit electrical heating or combustion using hydrogen. However it is difficult to replace all the current coal or natural gas furnaces with these options for chemical industry. In this work a method that integrates solid oxide electrolysis cells (SOEC) and H2–O2 combustion is proposed and the related parameters are modelled to analyze their impacts. There is no waste heat and waste emissions in the proposed option and all substances are recycled. Unlike previous research the heat required for SOEC operation is generated from H2 combustion. The best working condition is under thermoneutral voltage and the highest electricity-to-thermal efficiency that can be achieved is 86.88% under a current density of 12000 A/m2 and operating temperature of 750 ◦C. Ohmic overpotential has the greatest effect on electricity consumption and the anode activation overpotential is the second most important option. Increasing combustion product temperature cannot significantly improve thermal efficiency but can raise the available maximum thermal energy.

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.

Europe’s low-carbon energy policy favors a greater use of fuel cells and technologies based on hydrogen used as a fuel. Hydrogen delivered at the hydrogen refueling station must be compliant with requirements stated in different standards. Currently the quality control process is performed by offline analysis of the hydrogen fuel. It is however beneficial to continuously monitor at least some of the contaminants onsite using chemical sensors. For hydrogen quality control with regard to contaminants high sensitivity integration parameters and low cost are the most important requirements. In this study we have reviewed the existing sensor technologies to detect contaminants in hydrogen then discussed the implementation of sensors at a hydrogen refueling stations described the state-of-art in protocols to perform assessment of these sensor technologies and finally identified the gaps and needs in these areas. It was clear that sensors are not yet commercially available for all gaseous contaminants mentioned in ISO14687:2019. The development of standardized testing protocols is required to go hand in hand with the development of chemical sensors for this application following a similar approach to the one undertaken for air sensors.

Liquid hydrogen (LH2) has the potential to form part of the UK energy strategy in the future and therefore could see widespread use due to the relatively high energy density when compared to other renewable energy sources. To study the feasibility of this the European Fuel Cells and Hydrogen Joint Undertaking (FCH JU) funded project PRESLHY undertook pre-normative research for the safe use of cryogenic LH2 in non-industrial settings. Several key scenarios were identified as knowledge gaps and both theoretical and experimental studies were conducted to provide insight into these scenarios. This included experiments studying the effect of congestion on an ignited hydrogen plume that develops from a release of LH2; this paper describes the objectives experimental setup and a summary of the results from these activities. Characterisation of the LH2 release hydrogen concentration and temperatures measurements within the resulting gas cloud was undertaken along with pressure measurements both within the cloud and further afield. Various release conditions and congestion levels were studied. Results showed that at high levels of congestion increased overpressures occurred with the higher flow rates studied including one high order event. Data generated from these experiments is being taken forward to generate and validate theoretical models ultimately to contribute to the development of regulations codes and standards (RCS) for LH2."

By considering the weight penalty of batteries on payload and total vehicle weight this paper shows that almost all forms of land-based transport may be served by battery electric vehicles (BEV) with acceptable cost and driving range. Only long-distance road freight is unsuitable for battery electrification. The paper models the future Indian electricity grid supplied entirely by low-carbon forms of generation to quantify the additional solar PV power required to supply energy for transport. Hydrogen produced by water electrolysis for use as a fuel for road freight provides an inter-seasonal energy store that accommodates variations in renewable energy supply. The advantages and disadvantages are considered of midday electric vehicle charging vs. overnight charging considering the temporal variations in supply of renewable energy and demand for transport services. There appears to be little to choose between these two options in terms of total system costs. The result is an energy scenario for decarbonized surface transport in India based on renewable energy that is possible realistically achievable and affordable in a time frame of year 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.

IGEM/SR/23 (“Venting of natural gas”) provides recommendations for the conceptual design operation and safety aspects of permanent temporary and emergency venting of natural gas. The document was originally developed many years ago and the current edition dates to 1995. The document is due to be reviewed and updated for application to natural gas but the aim of this study is not to review the applicability of the document for natural gas but to assess the possible impact of 100% hydrogen on specific aspects of the existing guidance.<br/>A key element of the guidance concerns the safe dispersion distances for natural gas as vents are intended to provide a means of safely dispersing gas in the atmosphere without ignition. Guidance on safe dispersion distances for venting are provided in Section 6.6 accompanied by graphs showing the relationship between the mass flow rate through the vent and the safe (horizontal) dispersion distance. Details of the model used to predict the dispersion distances are given in Appendix 1. However for dispersion the guidance in IGEM/SR/23 has been superseded by similar guidance on hazard distances for unignited releases in IGEM/SR/25 (“Hazardous area classification of natural gas installations”) [2]. A comprehensive review of the applicability of IGEM/SR/25 to hydrogen is already underway for the LTS Futures project and is not duplicated here.<br/>However IGEM/SR/23 contains guidance on other important aspects relevant to the safe design and operation of vents which are not addressed elsewhere in the IGEM suite of standards; in particular guidance on hazard ranges for thermal radiation (in the event of an unplanned ignition of the venting gas) and noise.<br/>The main aim of this report is to assess the potential impact of replacing natural gas with 100% hydrogen on the guidance in IGEM/SR/23 concerned with thermal hazards with a secondary objective of assessing the available information to comment on the possible influence of hydrogen on noise.

The H21 National Innovation Competition project is examining the feasibility of repurposing the existing GB natural gas distribution network for transporting 100% hydrogen. It aims to undertake an experimental testing programme that will provide the necessary data to quantify the comparative risk between a 100% hydrogen network and the natural gas network. The first phase of the project focuses on leakage testing of a strategic set of assets that have been removed from service which provide a representative sample of assets across the network. This paper presents the work undertaken for Phase 1A (background testing) where HSE and industry partners have tested a range of natural gas pipework assets of varying size material age and pressure-rating in a new bespoke open-air testing facility at the HSE Science and Research Centre Buxton. The assets have been pressurised with hydrogen and then methane and the leakage rate from the assets measured in both cases. The main finding of this work is that the assets tested which leak hydrogen also leak methane. None of the assets were found to leak hydrogen but not methane. In addition repair techniques that were effective at stopping methane leaks were also effective at stopping hydrogen leaks. The data from the experiments have been interpreted to obtain a range of leakage ratios between the two gases for releases under different conditions. This has been compared to the predicted ratio of hydrogen to methane volumetric leak rates for laminar (1.2:1) and turbulent (2.9:1) releases and good agreement was observed.

Current standard practice at wastewater treatment plants (WWTPs) involves the recycling of digestate liquor produced from the anaerobic digestion of sludge back into the treatment process. However a significant amount of energy is required to enable biological breakdown of ammonia present in the liquor. This biological processing also results in the emission of damaging quantities of greenhouse gases making diversion of liquor and recovery of ammonia a noteworthy option for improving the sustainability of wastewater treatment. This study presents a novel process which combines ammonia recovery from diverted digestate liquor for use (alongside biomethane) in a solid oxide fuel cell (SOFC) system for implementation at WWTPs. Aspen Plus V.8.8 and numerical steady state models have been developed using data from a WWTP in West Yorkshire (UK) as a reference facility (750000p.e.). Aspen Plus simulations demonstrate an ability to recover 82% of ammoniacal nitrogen present in digestate liquor produced at the WWTP. The recovery process uses a series of stripping absorption and flash separation units where water is recovered alongside ammonia. This facilitates effective internal steam methane as a case of study has the potential to make significant impacts energetically and environmentally; findings suggest the treatment facility could transform from a net consumer of electricity to a net producer. The SOFC has been demonstrated to run at an electrical efficiency of 48% with NH3 contributing 4.6% of its power output. It has also been demonstrated that 3.5 kg CO2e per person served by the WWTP could be mitigated a year due to a combination of emissions savings by diversion of ammonia from biological processing and lifecycle emissions associated with the lack of reliance on grid electricity.