As the need to decarbonise the transport system continues at a pace, the heavy-duty, off-highway, agriculture, construction, marine & aviation sectors are also needing to adapt to changing expectations on emissions.
The reliance on diesel, red-diesel, aviation fuel & HFO which currently gives these vehicles the option to run perpetually & often in harsh & or remote locations; is needing to change & change involves developing & or adopting alternative fuels.
Thus far, the alternatives for these industry heavy weights including electrification, do not often work in the context that these machines need to operate.
Therefore, Hydrogen is rapidly becoming a ‘go-to’ future fuel option for heavy-duty, off-highway, agriculture, construction, marine & aviation sectors. Despite the fact that most of the current Hydrogen produced is grey or blue Hydrogen, producing incredible amounts of CO2 in its production or requiring considerable CCS; the options for the heavy duty sectors on land, sea & air are currently limited.
One of the alternatives is Synthetic fuel. Synthetic fuels are being developed to add another alternative to the heavy-duty sectors decarbonisation race. One example of this is ZERO® Petroleum synthetic drop-in fuel.
Having completed a world record breaking flight in November 2021 in an Ikarus C42 microlight aircraft, the flight was the first step in a joint programme which aims ultimately to defossilise the entire fuel requirement of the RAF & eliminate CO2 emissions. (1)
Ammonia (NH3) is also being developed as an alternative to HFO in the marine sector, despite the inherent challenges ammonias instability can have when handled or stored incorrectly.
There, are still a handful of challenges that the marine industry must overcome before shipowners can safely use ammonia as fuel. These range from questions of risk & safety, to regulatory concerns & assessing all aspects of ammonia’s sustainability as a fuel. (2)
With aviation seeking alternative fuels in the synthetic market & marine researching the possibilities of Ammonia as an alternative fuel; heavy-duty, off-highway, agriculture & construction are forging ahead with research & development of Hydrogen based engines.
With a global focus on the adaptability of diesel ICE’s to run on Hydrogen, the global Hydrogen economy continues to grow & as the hydrogen economy grows, so do some of the risks.
An example of the lack of understanding around Hydrogen (H2) in use, was highlighted by James Mercer of Costain Construction at the recent Dolphin N2 team day held at the National Propulsion Showcase. Costain having run a construction site at net zero for two weeks using a combination of alternative fuels for machinery including H2, found some resistance from colleagues & contractors when it was explained that H2 would be kept onsite.
Every type of fuel has some degree of danger associated with it, whether it be a liquid, solid or gas there is always a risk of unexpected & dangerous combustion.
Safety protocols surrounding the use of any fuel focus on preventing situations where the three combustion factors—ignition source (spark or heat), oxidant (air), & fuel—are present.
Designing fuel systems with appropriate engineering controls & establishing appropriate guidelines to enable the safe handling & use of any fuel is imperative. These systems are designed for the safety of those involved from the production of the fuel to the end user. Failure to have correct protocols in place could be disastrous.
In the case of H2 a number of its properties make it safer to handle & use than some of the fuels commonly used today. Hydrogen is non-toxic for example & because H2 is much lighter than air, it dissipates rapidly when it is released, allowing for relatively rapid dispersal of the fuel in case of a leak. (3)
However, some of H2’s properties do require additional engineering controls to enable its safe use, particularly in how it is stored & contained ready for use.
In addition, H2 has a wide range of flammable concentrations in air & lower ignition energy than gasoline or natural gas, which means it can ignite more easily. Consequently, adequate ventilation & leak detection are important elements in the design of safe H2 systems. In addition, due to the fact that H2 burns with a nearly invisible flame, special flame detectors are required. (3)
Another safety & engineering consideration required in designing the use of H2 into a product, is that some metals can become brittle when exposed to hydrogen. Therefore, selecting appropriate materials is important in the design of safe hydrogen systems.
In addition to designing safety features into hydrogen systems, training in safe hydrogen handling practices is a key element for ensuring the safe use of hydrogen.
To ensure best practises are being built into H2 development, training companies are now offering H2 safety training to support the hydrogen economy.
One such example is the ‘Hydrogen Safety – Achieving Safe Net Zero’ webinar run by The Health & Safety Executive (HSE)
HSE’s research & consultancy is helping to produce the evidence base to underpin the regulations, codes & standards required to enable a safe net zero. (4)
Having worked in hydrogen safety since the early 2000s, HSE understand the safety protocols required in its use in transport & infrastructure applications. (4)
HSE scientists & engineers have published over 60 peer-reviewed journal & conference papers on hydrogen safety, contributing to past & current UK & international standards & enabling industry to safely deploy hydrogen technologies. (4)
Written & cited by Katy-Jane Mason for & on behalf of Dolphin N2