Hydrogen Blending

The Aberdeen Vision Project could deliver CO2 savings of 1.5MtCO2/y compared with natural gas. A dedicated pipeline from St Fergus to Aberdeen would enable the phased transfer of the Aberdeen regional gas distribution system to 20% then 100% hydrogen.

The study has demonstrated that 2% hydrogen can be injected into the National Transmission System (NTS) at St Fergus and its distribution through the system into the gas distribution network. Due to unique regional attributes the Aberdeen region could lead the UK in the conversion to largescale clean hydrogen. A 200MW hydrogen generation plant is planned to suit 2% blend into the NTS followed by a build out to supply the Aberdeen gas networks and to enable low cost hydrogen transport applications.

This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.

A key element in the safe operation of a modern gas distribution system is gas detection. The addition of hydrogen to natural gas will alter the characteristics of the fuel and therefore its impact on gas detection must be considered. It is important that gas detectors remain sufficiently sensitive to the presence of hydrogen and natural gas mixtures and that they do not lead to false readings. This paper presents analyses of work performed as part of the Office for Gas and Energy Markets (OFGEM) funded HyDeploy project on the response of various natural gas industry detectors to blended mixtures up to 20 volume percent (vol%) of hydrogen in natural gas. The scope of the detectors under test included survey instruments and personal monitors that are used in the gas industry. Four blend ratios were analysed (0 10 15 and 20 vol% hydrogen in natural gas). The laboratory testing undertaken investigated the following:

• Flammable response to blends in the ppm range (0-0.2 vol%);
• Flammable response to blends in the lower explosion limit range (0.2-5 vol%);
• Flammable response to blends in the volume percent range (5-100 vol%);
• Oxygen response to blends in the volume percent range (0-25 vol%); and
• Carbon monoxide response to blends in the ppm range (0-1000 ppm).

Catalytic and thermal conductivity based flammable detectors in the volume percent range are as expected affected in the form of a relative increase in output. All of the carbon monoxide detectors tested were found to be cross-sensitive to hydrogen in the blended mixtures tested at levels which have the potential to cause false alarms at current permissible leakage rates. In summary a number of measurement ranges across multiple detectors commonly used in the gas industry have been found to be cross-sensitive to hydrogen in natural gas blends to differing degrees. This required the HyDeploy project to select alternative instruments for the purpose of gas detection as part of the trial. This paper relates to the preparatory work to introduce hydrogen into the Keele closed network.

The main goal of the project is to enable the wide adoption of H2NG (hydrogen in natural gas) blends by closing knowledge gaps regarding technical impacts on residential and commercial gas appliances. The project consortium will identify and recommend appropriate codes and standards that should be adapted to answer the needs and develop a strategy for addressing the challenges for new and existing appliances.<br/>This deliverable on market segmentation is part of work package 2 and provides a quantitative segmentation of the gas appliance market in terms of appliance population numbers. It therefore prepares the project partners to perform the subsequent selection of the most representative product types to be tested in the laboratories of the THyGA partners.<br/>The classification is developed to categorise appliances installed in the field based on available statistics calculation methods and estimations. As a result appliance populations are provided for each technology segment that draw a representative picture of the installed end-use appliances within the European Union in 2020.

Hydrogen is increasingly receiving a primary role as an energy vector in ensuring the achievement of the European decarbonization goals by 2050. In fact Hydrogen could be produced also by electrolysis of water using renewable sources such as photovoltaic and wind power being able to perform the energy storage function as well as through injection into natural gas infrastructures. However hydrogen injection directly impacts thermodynamic properties of the gas itself such as density calorific value Wobbe index sound speed etc. Consequently this practice leads to changes in metrological behavior especially in terms of volume and gas quality measurements. In this paper the authors present an overview on the impact of hydrogen injection in natural gas measurements. In particular the changes in thermodynamic properties of the gas mixtures with different H2 contents have been evaluated and the effects on the accuracy of volume conversion at standard conditions have been investigated both on the theoretical point of view and experimentally. To this end the authors present and discuss the effect of H2 injection in gas networks on static ultrasonic domestic gas meters both from a theoretical and an experimental point of view. Experimental tests demonstrated that ultrasonic gas meters are not significantly affected by H2 injection up to about 10%.

The addition of hydrogen to natural gas for heating and cooking is being considered as a route to reducing carbon emissions in the United Kingdom (UK). The HyDeploy programme (hereafter referred to as HyDeploy) aims to demonstrate that hydrogen can be added to the natural gas supply without compromising public safety or appliance performance. This paper relates to the preparatory work for hydrogen injection on a live site at Keele University closed network comprising domestic premises multi-occupancy buildings and light commercial premises. The project is based around the injection of up to 20 %mol/mol hydrogen into mains natural gas at pressures below 2 barg. Work streams addressed during the pre-trial preparation included; assessment of material interaction with hydrogen blends for all distribution system components and appliances; understanding of gas appliance behaviour; review of: gas detection systems fire and explosion considerations routine and emergency procedural considerations; and the design of a new hydrogen injection grid entry unit. This paper describes the safety and regulatory challenges that were encountered during preparation of the project including obtaining the necessary regulatory permissions to blend hydrogen gas.

In this paper the effects of hydrogen blending radio and EGR rate on combustion and emission characteristics of a PFI gasoline engine with hydrogen direct-injection have been investigated by numerical modelling methods using a new generation of CFD simulation software CONVERGE. Results showed that compared with original engine hydrogen direct-injection PFI gasoline engine had a better performance on combustion characteristics but it also had a disadvantage of increasing NOx emissions. With the increase of hydrogen blending radio combustion duration shortened and CA50 advanced and was closer to TDC. And CO and THC emissions decreased however NOx emission increased. The variations of the combustion and emission characteristics followed by the increase of the EGR rate were exactly the opposite to the change of hydrogen blending radio. Considering both the combustion and emission characteristics using moderate EGR rate (15%~20%) under high hydrogen blending radio (15%~20%) condition can realize the simultaneous improvement of combustion and emission performance.

Fast depletion of fossil fuels and their detrimental effect to the environment is demanding an urgent need of alternative fuels for meeting sustainable energy demand with minimum environmental impact.  Expert studies indicate hydrogen is one of the most promising energy carriers for the future due to its superior combustion qualities and availability. The use of hydrogen in spark ignition internal combustion engine may be part of an integrated solution to the problem of depletion of fossil fuels and pollution of the environment. The broader flammability limits and fast flame propagation velocity of hydrogen ensures complete combustion of fuel and allows engine to be operated at lean ranges. Lean burn operation comparatively maintains NOx CO and HC emissions at a very low level. In the present work oxyhydrogen (HHO) gas is produced in leak proof plexiglass reactor by electrolysis of water using potassium hydroxide as electrolyte.  The HHO gas generator is attached to a spark ignition engine currently operating on the road without any modifications of the engine. The HHO gas produced is then added to the air which is being drawn into the engine.  Experiments were conducted on a 4-stroke single cylinder natural air cooled spark ignition engine to determine total fuel consumption specific fuel consumption air fuel ratio brake power and brake thermal efficiency and emissions CO CO₂ O2 NOx HC at different loads with and without addition of HHO gas to gasoline for lower speeds ranging from 700 rpm to 1500 rpm. Also mileage tests were conducted to find the speed at which the fuel consumption is optimum.

The HyDeploy Project seeks to address a key issue for UK customers: how to reduce the carbon they emit in heating their homes. The UK has a world class gas grid delivering heat conveniently and safely to over 83% of homes. Emissions could be reduced by lowering the carbon content of gas through blending with hydrogen. Compared with solutions such as heat pumps this means that customers would not need disruptive and expensive changes in their homes. This Network Innovation Competition (NIC) funded project seeks to establish the level of hydrogen that can be safely blended with natural gas for transport and use in a UK network.

Under its Smart Energy Network Demonstration innovation programme Keele University is establishing its electricity and gas networks as facilities to drive forward innovation in the energy sector. The objective of HyDeploy is to trial natural gas blended with potentially up to 20% volume of hydrogen in a part of the Keele gas network. Before any hydrogen can be blended with natural gas in the network the percentage of hydrogen to be delivered must be approved by the Health and Safety Executive (HSE). It must be satisfied that the approved blended gas will be as safe to use as normal gas. Any approval will be given as an exemption to the Gas Safety (Management) Regulations. These regulations ensure the safe use and management of gas through the gas network in the UK. The evidence presented to the HSE comprises critically appraised literature combined with the results from a specifically commissioned experimental and testing programme. Based on engagement with all local customers this includes detailed safety checks on the network appliances and installations at Keele. Subject to approval by the HSE the hydrogen production and grid injection units will be installed and an extensive trial programme of blending will be undertaken. If hydrogen were blended at 20% volume with natural gas across the UK it would save around 6 million tonnes of carbon dioxide emissions every year the equivalent of taking 2.5 million cars off the road.

This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.

The HyDeploy project seeks to address a key issue for UK customers: how to reduce the carbon they emit in heating their homes. The UK has a world class gas grid delivering heat conveniently and safely to over 83% of homes. Emissions can be reduced by lowering the carbon content of gas through blending with hydrogen. This delivers carbon savings without customers requiring disruptive and expensive changes in their homes. It also provides the platform for deeper carbon savings by enabling wider adoption of hydrogen across the energy system.

This Network Innovation Competition (NIC) funded project seeks to establish the level of hydrogen that can be safely blended with natural gas for transport and use in a UK network. Under its smart energy network innovation demonstration programme Keele University is establishing its electricity and gas networks as facilities to drive forward innovation in the energy sector. The objective of HyDeploy is to trial natural gas blended with 20%mol of hydrogen in a part of the Keele gas network. Before any hydrogen can be blended with natural gas in the network the percentage of hydrogen to be delivered must be approved by the Health and Safety Executive (HSE). It must be satisfied that the approved blended gas will be as safe to use as normal gas. Such approval is provided as an Exemption to the Gas Safety (Management) Regulations. These regulations ensure the safe use and management of gas through the gas network in the UK. Following such approval hydrogen production and grid injection units are to be installed and an extensive trial programme undertaken. Blending hydrogen at 20%mol with natural gas across the UK would save around 6 million tonnes of carbon dioxide emissions every year the equivalent of removing 2.5 million cars from the road.

This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.

The HyDeploy project is the UK’s first practical project to demonstrate that hydrogen can be safely blended into the natural-gas distribution system without requiring changes to appliances and the associated disruption. The project is funded under Ofgem’s Network Innovation Competition and is a collaboration between Cadent Gas Northern Gas Networks Progressive Energy Ltd Keele University (Keele) Health & Safety Laboratory and ITM Power. Cadent and Northern Gas Networks are the Gas Distribution Network sponsors of the project. Keele University is the host site providing the gas-distribution network which will receive the hydrogen blend. Keele University is the largest campus university in the UK. Health & Safety Laboratory provides the scientific laboratories and experimental expertise. ITM Power provides the electrolyser that produces the hydrogen. Progressive Energy Ltd is the project developer and project manager. HyDeploy is structured into three distinct phases. The first is an extensive technical programme to establish the necessary detailed evidence base in support of an application to the Health & Safety Executive for Exemption to Schedule 3 of the Gas Safety (Management) Regulations (GS(M)R) to permit the injection of hydrogen at 20 mol%. This is required to allow hydrogen to be blended into a natural-gas supply above the current British limit of 0.1 mol%.



The second phase comprises the construction of the electrolyser and grid entry unit along with the necessary piping and valves to allow hydrogen to be mixed and injected into the Keele University gas-distribution network and to ensure all necessary training of operatives is conducted before injection. The third phase is the trial itself which is due to start in the summer of 2019 and last around 10 months. The trial phase also provides an opportunity to undertake further experimental activities related to the operational network to support the pathway to full deployment of blended gas. The outcome of HyDeploy is principally developing the initial evidence base that hydrogen can be blended into a UK operational natural-gas network without disruption to customers and without prejudicing the safety of end users. If deployed at scale hydrogen blending at 20 mol% would unlock 29 TWh pa of decarbonized heat and provide a route map for deeper savings. The equivalent carbon savings of a national roll-out of a 20-mol% hydrogen blend would be to remove 2.5 million cars from the road.



HyDeploy is a seminal UK project for the decarbonization of the gas grid via hydrogen deployment and will provide the first stepping stone for setting technical operational and regulatory precedents of the hydrogen vector.