Project Summary
In a hydrogen future, additional gas storage will be required to meet increasing demand and futureproof against evolving green applications of hydrogen and its hydrides.
PATCH will provide the future hydrogen system with an economic and safe long-term storage solution for hydrogen, which is imperative in removing Britain's dependence on natural gas.
PATCH will provide a synergetic solution, leveraging industrial by-products for chemical hydride production, storage, regeneration, and network injection. Using waste energy/gases from industry and excess renewable electricity, to produce chemical hydrides, helping deliver Britain's net zero commitments by 2050.
Innovation Justification
PATCH will develop a bespoke chemical process plant, integrating hydride production, storage, regeneration and network injection. Direct network injection is a novel application of hydride storage which has not been previously assessed.
Utilising industrial waste heat, gases, and curtailment adds further innovation to the overall solution. The range of hydrides that are expected to be viable for this network application will allow PATCH to be paired with multiple industry sectors, creating optimal value and scalability.
Hydride storage provides a safe and economical long-term storage alternative to other hydrogen vectors. Hydrides can be stored near to standard temperatures and pressures, whilst also having a high percentage of recoverable hydrogen compared to vectors such as MOFs. Hydrides can also rapidly regenerate to hydrogen thus enhancing network resilience during periods of high demand, which many other hydrogen storage vectors cannot deliver. Combining these innovations within a single system represents a novel step change for hydride storage.
PATCH will build on previous research that demonstrates the use of hydrides as a hydrogen storage vector. Examples include ammonia as a maritime fuel or toluene as storage for transportation. However, these processes are unique to the industries they supply and require centralised infrastructure.
PATCH will assess GDN use cases and bridge the knowledge gap to apply these processes to industry coupled production plants.
During Discovery: System TRL will develop from 2 to 3, with qualitative studies completed.
IRL will develop from IRL 1 to IRL3, ensuring GDN compatibility. CRL will be at 3, with some elements of 4 considered (regulatory landscape).
The Beta phase will deliver a demonstrator hydride storage plant, directly fulfilling SIF objectives related to technical designs of long-term hydrogen storage.
This project is not appropriate for business-as-usual funding due to: Technical risks associated with integrating multiple novel technology aspects; Regulatory constraints preventing GDNs from owning/operating process facilities e.g. a PATCH demonstrator.
A publicly funded project is appropriate to since it has not yet been determined whether GDN or commercially operated storage is appropriate. Demonstrating technical viability will provide the evidence required to seek external funding for further development and network implementation.
MOFs for hydrogen storage were disregarded within this project as they have been extensively researched and are considered less innovative. Downselection to a single hydride for detailed development was considered but this would narrow the diversification of industrial coupling options and potentially reduce the number of viable use cases.
Impacts and Benefits
GDNs currently use linepack flexibility to ensure that natural gas is available to consumers on demand. Without the provision of additional storage, the lower volumetric density of hydrogen would reduce network resilience. Storage within GDNs is an option, alongside alternative storage options outside of the network.
Metrics that can be used to report on storage solutions include:
- Energy storage requirements (MW/annum)
- Volumetric storage density (kg/m3)
- Storage cost effectiveness (£/MW)
Environmental
Solving the issue of network storage is a key enabler to a hydrogen future and therefore will indirectly reduce CO2 emissions. Industrial gas consumption (which represents 23% of UK gas consumption - Reference - HyNTS: Hydrogen in the NTS) is a key initial focus of developing a hydrogen future. Industrial decarbonisation will save over 100 million tonnes of CO2 per year, and hydrogen storage is a key enabler to unlocking this.
Revenues
Coupling PATCH with renewable electricity generators that would otherwise be curtailed provides a route to maximise utilisation of renewables and provide generators with enhanced revenue streams, supporting the business cases for new low carbon renewable investments. The energy demands for PATCH, which may be sourced from curtailment pathways, could provide tens of millions of pounds of additional revenues per year. It is not yet understood whether these benefits could be passed on to energy consumers.
The use of industry byproducts (waste heat, chemicals) in the production ofchemical hydrides will provide new revenue streams for these industries, also supporting a direct reduction in their environmental impact. The value of these revenues has not yet been evaluated.
New to Market
The option of storage of hydrogen outside of GDNs could create new to market opportunities for the provision of production, storage and regeneration capability by commercial organisations (owners & operators).
Benefits Realisation
This project has not yet been delivered and therefore no benefits have yet been realised.
Impacts and benefits
The benefit of PATCH to end users is that we have explored the use of ammonia and methanol as long term hydrogen storage mediums connected to a future gas network. The main conclusion that we identified were:
· The future of gas distribution networks and hydrogen usage is not clear and there is a wide range of possibilities, therefore, any detail around the application of hydride storage in a potential network has been difficult to define beyond high level storage capacities.
· The technology readiness level (TRL) of hydride to hydrogen processes examined are low. Methanol to hydrogen would require use of carbon capture and storage (CCS) which has not been deployed commercially yet in the UK.
· Overall process efficiencies for the system from hydrogen to hydride to hydrogen are low (Ammonia ~40%, Methanol ~47%).
· Using the hydrides converted from hydrogen directly in chemicals or as sustainable fuels is more energy efficient than turning them back into hydrogen.
· Any storage site of appreciable capacity would need to be upper tier COMAH (Control of Major Accident Hazards) sites and so would be limited geographically.
· The CBA showed that the cost of ammonia PATCH storage is more expensive than compressed hydrogen storage in salt caverns, with methanol PATCH storage being more expensive still.
· Therefore, it is not appropriate to take this further through the SIF process as there is not a suitable path to demonstration of the PATCH concept.
Different configurations of using ammonia and methanol are being explored by others where the advantages of the energy density of the hydrides can be exploited more than the static storage identified in PATCH. These projects normally include transport of the hydride over significant distances or use of the hydride directly as a sustainable fuel.
