Electrolysers can be scaled to meet a variety of input and output ranges, ranging in size from small industrial plants installed in shipping containers to large-scale centralised production facilities that can produce and deliver hydrogen by trucks or connected to pipelines.
Large scale Hydrogen electrolysers are also expected to form a key part of current and future renewable energy installations so that surplus electricity can be used to produce hydrogen that can then be stored and repurposed for future use as national energy demands require. Due to the versatility of the Vertex range, a venting solution can be provided to suit any electrolyser installation.
Battery Energy Storage Systems (BESS) represent a significant part of the shift towards a more sustainable and green energy future. BESS units can be employed in a variety of situations, ranging from temporary, standby and “off-grid” applications to larger, permanent installations. However, along with the obvious attractions of this growing technology, there is a need to fully assess the safety concerns of operating large scale BESS buildings and containerised installations, particularly the associated risk of fire and explosions.
NFPA 855[1], the Standard for the Installation of Stationary Energy Storage Systems, calls for explosion control in the form of either explosion prevention in accordance with NFPA 69[2] or deflagration venting in accordance with NFPA 68[3]. There are also jurisdictions that require both preventative measures and venting protection. Insurance companies also look favourably at installations with multiple levels of control as they help protect the assets being insured. To meet legislation, protect people and assets, look no further than Rhino HySafe and its Vertex range which has been designed in accordance with NFPA 68.
Given the close proximity that hydrogen equipment will need to be to the general public, safe venting solutions will almost certainly be required in most applications, particularly on any electrolyser modules to be used. ISO 19880 which defines the minimum design, installation, commissioning, operation, inspection and maintenance requirements for gaseous hydrogen fuelling stations clearly states the need for venting in within any enclosures used. The Vertex range is ideally suited to such applications due to is modular design and , complete retention of the panel elements upon activation.
Larger road transport vehicles and trains are likely to be refuelled at their associated depots as it would not be safe to fill the hydrogen tank with passengers on board. Depots are typically congested spaces surrounded by houses and/or other commercial enterprises meaning once again, venting panels will be required.
Full scale dispersion tests by DnV at Spadeadam conducted in a purpose-built row of brick houses showed that the gas volume that leaks from a given orifice at a given discharge pressure was three times as high with hydrogen as it is with methane. Realistic leak trials in a mock-up kitchen led to explodable gas clouds of much greater concentration than was found with methane. Given the lower ignition energy of hydrogen (even moving about in nylon clothes is sufficient to set it off) the explosion risk is much increased.
It is not possible to mount the boilers on the outside of high-rise buildings on a one boiler per flat basis so mini district heating systems will likely be required. Boilers for this application are already being offered and a 250kw Boiler may suffice for a well-insulated building. These boilers will need an external facing room or free-standing boiler houses, again not big, as the boilers are quite compact. These boiler houses will require strong ventilation and explosion relief cladding to prevent development of structurally significant blast pressures and formation of projectiles. A smaller, single leaf version of the Vertex range would be ideal in such applications.
Compressors are needed to move and store hydrogen. The compressor technology doesn’t care about the “colour” of the hydrogen and how it is produced, it simply compresses according to the physics of a low mol-weight gas application. Compression is an essential component of the hydrogen value chain as it includes the gathering of hydrogen produced by electrolysers, steam methane or autothermal reformers (SMRs/ATRs), sending hydrogen through short or long-distance pipelines, compressing hydrogen to the pressure levels required by vehicle fuelling stations, liquefaction for vessel transport facilities, and feeding it into gas turbines or other downstream and petrochemical processes.
Many of these installations which currently operate on methane, have explosion suppressors and no vent panels, although some older units in the UK do have roof relief panels. The scope of the required modifications to configure a gas turbine to operate on hydrogen depends on the initial configuration of the gas turbine and the overall balance of plant, as well as the desired hydrogen concentration in the fuel. What is known however is that the requirement for explosion relief panels on hydrogen compressor enclosures and that the Rhino Vertex panels are ideally suited.
Ships are beginning to be powered by liquid hydrogen although uptake is slow. One reason is that current levels of hydrogen production have not yet reached a scale that can sufficiently service the shipping industry. Accepting that this hurdle can be overcome given the investment being pledged for such purposes, there is then much debate surrounding the best way of using hydrogen to power vessels.
Hydrogen can either be burnt in an internal combustion engine, as the world’s first passenger vessel Hydroville is currently doing or Hydrogen can also be used in a fuel cell. Both approaches have their advantages and disadvantages. Hydrogen is often used as a catch-all term for synthetic fuels, but many experts believe another option is better for the industry: using the green hydrogen to make green ammonia, another fuel which can be either combusted or used in a fuel cell.
Ammonia is considered the most likely alternative to fossil fuels by most ship builders and fleet managers given the ease of retrofitting existing ships with this technology. It is well known today that anhydrous gaseous ammonia can form an explosive atmosphere when mixed with air. However, the flame speed and maximum rate of pressure rise are rather low. Given the results of the UFER explosion tests which showed that the vent panels were able to operate at relatively low-pressure rates, the Vertex panels could be an ideal candidate should vent panels become a requirement in these applications.
The switching and transformer stations that support offshore wind farms are currently protected from explosions due to short circuiting by SF6 gas protection bottles surrounding the live wires and insulators. SF6 is however likely to be banned soon under EU rules due to the gas having a greenhouse effect 24000 times higher than CO2 and the fact that detectable levels of leaked SF6 gas are now being found in the atmosphere.
Where SF6 gas is not used, severe explosions can occur and the transformer rooms will need vent panels. The explosions are caused due to arcing in oil and are the result of acetylene combustion which has similar explosion behaviour to hydrogen. Given the Vertex panels have been empirically tested in Hydrogen deflagration explosions, performance can be guaranteed in such applications.