Quick guide to alternative fuels: Part 2
In Part 1 of this quick guide to alternative fuels we reviewed biodiesel and HVO options, with Part 2 reviewing synthetic fuels and liquid hydrogen.
Synthetic Fuels (E-Fuels)
Synthetic fuels, or e-fuels, are created through chemical processes that combine hydrogen with captured CO₂ to form liquid hydrocarbons. These fuels can be designed to mimic the properties of diesel.
Advantages
Because synthetic fuels use captured CO₂ in their production, they can theoretically be carbon-neutral if produced using renewable energy.
Synthetic diesel can be used in existing HGV engines, eliminating the need for costly vehicle modifications, and like conventional diesel, have a high energy density, making them well-suited for long-haul transport.
Disadvantages
One of the advantages of synthetic fuels is also a challenge: producing it in a carbon neutral way. The process for carbon capture and creating enough renewable energy for its production and supply is still to be perfected – and as a result they are far more expensive than traditional fuels. Also, synthetic fuels are still burnt, meaning there will always be emissions. The issue is whether you can make these fuels, at the very least, carbon neutral, or whether there will always be an environmental cost to their use. Allied to this problem is the development of infrastructure. The distribution and production of synthetic fuels are not yet widespread, limiting their availability.
Liquid Hydrogen
Liquid hydrogen is a zero-emission fuel that can be used in fuel cell vehicles, but also can be burned directly in internal combustion engines that have been built to use them.
Advantages
When used in internal combustion engines, hydrogen create trace elements of Co2 and NOx, only produce because of the involvement of ambient air and lubrication oils in the powertrain. For fuel cell vehicles, the only emissions are water.
Hydrogen is the most abundant element in the universe and can be produced from various sources, including water electrolysis and biomass. The hydrogen in internal combustion engines can be lower grade , or less pure, than that for fuel cells, so fuel created from other industrial processes might be usable.
Disadvantages
Hydrogen must be stored at extremely low temperatures (of over -250°C ) to remain in liquid form, which requires specialised infrastructure and tanks. There are high production costs too. Green hydrogen (produced via electrolysis using renewable energy, rather than blue or grey hydrogen, which are less sustainable) is still expensive compared to fossil fuels. As with any alternative fuel, there are issues around availability. Widespread adoption in significant volumes will require substantial investment in refuelling stations and hydrogen production facilities.
Conclusion
The transition to alternative fuels for HGVs is critical for reducing the transport sector’s carbon footprint. Synthetic fuels and liquid hydrogen can present longer-term solutions with significant environmental benefits, if some of the problems associated with them can be solved.
With such a range of alternative fuels available, it’s important to be aware of what fuels could suit your fleet’s needs and/or adopt the right vehicles into your HGV fleet.