22/09/2023
The transportation sector continues to remain under pressure to seek out new ways of reducing reliance on conventional fossil fuels and reducing CO2 emissions.
In the automotive sector, there has been a particular focus on electric vehicles (EVs), whether in the form of battery electric vehicles (BEVs) or hybrid electric vehicles (HEVs). However, the batteries required for BEVs and HEVs do have drawbacks, including:
- The range of vehicles powered by batteries is limited by the lower specific energy of a battery compared to say gasoline or diesel;
- More investment will be needed in electric vehicle charging points to provide a nationwide charging infrastructure as comprehensive as the network of filling station forecourts across the UK;
- The manufacture of batteries currently relies on the mining and refining of lithium, which itself consumes significant amounts of energy and is associated with having a negative environmental impact;
- Heavy duty vehicles, such as long-distance lorries, are currently unsuited to solely being powered by electric batteries, with the battery mass required to provide a vehicle with a useful range making the payload capacity uneconomic.
In the aviation sector, research is ongoing into alternatives to the use of kerosene for powered flight. Previous articles have considered electrification and hydrogen as alternative “fuels” for use in powered flight. However, the specific energy of kerosene continues to make it a tough act to follow for any alternative fuel.
Electrification technology is developing rapidly, and at least some of the above issues are being addressed. However, there is space for additional fuel sources to replace fossil fuel derived gasoline / diesel / kerosene. eFuels represent one such alternative fuel source.
What are “eFuels”?
“eFuels” – also known as “electrofuels” – are synthetic fuels made by the combining of hydrogen and captured carbon dioxide (CO2) (or carbon monoxide (CO)). Ideally, the hydrogen is be obtained through processes powered by the use of sustainable electricity, such as electricity generated by solar, wind or tidal energy – essentially, electricity generated with a zero or near zero carbon footprint.
Overview of the processes for making an eFuel:
1. Hydrogen is extracted from water via electrolysis, with the electrolysis ideally powered by the use of sustainable electricity.
2. CO2 may be used which has previously been captured from industrial processes where it is a known by-product (for example, in the fabrication of steel). However, as mentioned below, direct air capture of CO2 is being looked at as a more sustainable source of CO2.
3. The hydrogen and CO2 are then synthesised to form a desired eFuel. The synthesis may be performed by a modified form of the Fischer-Tropsch process or methanol synthesis. The Fischer-Tropsch process dates from the 1920’s and is a series of chemical reactions for synthesising CO and hydrogen into liquid hydrocarbons, with the following being an example of a long expired patent for the technology.
What advantages do eFuels have in comparison to fossil fuel derived equivalents?
eFuels can be synthesised to form “drop-in” fuels which can be directly substituted for their fossil fuel derived equivalents (such as gasoline, diesel or kerosene), without requiring replacement of or extensive modification to existing engines. eFuels may also have the same or similar high energy density levels to their fossil fuel derived equivalents…and much higher energy density levels than currently obtainable with, say, lithium batteries.
eFuels have the potential to be cleaner than their fossil fuel derived equivalents, as they can be made without introducing compounds associated with poor emissions commonly found in fossil fuels, e.g. sulphur associated with emissions of sulphur dioxide.
The use of sustainable electricity and captured CO2 in the manufacture of eFuels gives eFuels the potential to be carbon neutral. This contrasts with the use of electricity generated from the burning of conventional fossil fuels (e.g. gas or coal), which introduces new CO2 into the atmosphere. Although the combustion of an eFuel would release CO2 back into the atmosphere, in an idealised scenario the amount of CO2 released would correspond to the amount of CO2 bound within the eFuel during its production. This provides the carbon-neutrality.
As eFuels have the same or similar physical characteristics to their fossil fuel derived equivalents, eFuels can be transported and handled using the same existing infrastructure. So, a ship or tanker lorry suitable for storing and conveying conventional liquid fossil fuels would be equally suitable for storing and conveying an eFuel equivalent. Further, garage filling stations used to refuel cars or lorries with gasoline / diesel and airport refuelling facilities for refuelling aircraft with kerosene would be equally suitable for use with equivalent eFuels.
In summary, when applied to the transportation sector, eFuels have the potential to make a significant contribution to making transportation more carbon neutral.
Obstacles to commercialisation:
So far, it all sounds good. So why aren’t eFuels spoken about more often in the mainstream media as being an alternative “fuel” to the use of batteries? Well, obstacles to the development and commercial success of eFuels are a mix of technical, commercial and legal / political issues. Some of these issues are discussed below:
Technical / Commercial
The electrolysis required to extract hydrogen from water for use in synthesising with CO2 is very energy intensive. This energy requirement is amplified when scaling up the technology to make sufficient quantities of eFuels to provide a commercially viable replacement to fossil fuel derived gasoline / diesel / kerosene. Without the ability to scale up the technology, eFuels are likely to be prohibitively expensive for many customers.
So, where solar or wind energy is relied upon as an energy source for generating sufficient electricity to power the electrolysis process, a geographical location is needed which can be relied upon to be very sunny or very windy. As the electrolysis relies upon water as a source of hydrogen, a location with a plentiful supply of water is also required. Therefore, coastal locations with plenty of wind and / or sun would seem ideal, as they would allow the extraction of hydrogen from sea water using electricity generated in a sustainable manner.
Legal / Political
These two issues are intertwined. Potential difficulties can be illustrated by taking a look at the different approaches adopted by the EU and the UK:
- EU: Up until earlier this year, the EU had planned to ban the sale of new internal combustion engine powered cars by 2035 without distinguishing between cars powered by petrol / diesel derived from fossil fuels and cars powered by eFuels. However, lobbying by the German and Italian governments resulted in the EU changing their position, with the ban now having an exemption for cars which run exclusively on carbon-neutral fuels. The wording of the exemption does seem to require the cars to be adapted to prevent them running on conventional fossil fuels.
- UK: Up very recently, the UK position was that the sale of new internal combustion engine powered cars was to be banned from 2030. However, the UK government has recently indicated that this deadline will now be relaxed to 2035. Nevertheless, there remains no indication of an exemption being provided for cars which run on eFuels.
Technical developments:
Research and Development into eFuels is ongoing worldwide. Two examples of projects relating to the development of eFuels are discussed below:
1. Pilot plant for manufacturing eFuels in Chile
Porsche, Siemens Energy, ExxonMobil and various other companies are involved in the ‘Haru Oni’ joint project to develop a pilot plant for the manufacture of eFuels in Punta Arenas, southern Chile.
The plant uses wind energy to generate electricity to power the electrolysis reactions needed to extract hydrogen from water. CO2 is drawn directly from the air by “direct air capture”. The hydrogen is synthesised with the CO2 to obtain e-methanol. The synthesised e-methanol can be used as a fuel in its own right, or converted via methanol-to-gasoline (MtG) synthesis into gasoline.
Punta Arenas is on the coast (providing plentiful access to water) and in a very windy location (ideal for generating electricity using wind energy). The pilot plant’s location near the port of Cabo Negro also allows for convenient transportation of manufactured eFuels.
At present, the pilot plant is focussed on producing synthetic gasoline.
2. Development of 100% synthetic aviation fuel and a Guinness World Record
Zero Petroleum (founded in 2020) is based in the UK and has been active in the development of eFuels for use in aircraft. Zero Petroleum have developed a proprietary variant of the Fischer-Tropsch process capable of producing synthetic petrol, diesel, or kerosene. Their fuels are made using CO2 captured from the atmosphere. One of Zero Petroleum’s co-founders is Paddy Lowe – perhaps better known for his career in Formula One motor racing.
In November 2021, Zero Petroleum achieved a Guiness World Record for the first flight powered solely by 100% synthetic fuel. Since July 2022, Zero Petroleum have been working with the Royal Air Force on scaling up the technology with a view to constructing a squadron scale manufacturing facility.
3. Relevant patents
The research and development into eFuels has been accompanied by an increase in the number of related patent filings. By way of example, this is a published patent application relating to a process for converting a feed stream containing CO2 to a product stream containing hydrocarbons. The process uses electrolysis to convert a feedstream containing water into a product stream containing hydrogen and oxygen, the electrolysis powered by electricity from “renewable or low carbon sources”. The process uses a reverse water gas shift step in which at least some of the hydrogen is reacted with a stream containing CO2 to produce a reverse water gas shift product stream containing CO. A hydrocarbon synthesis step is then used to react at least some of the hydrogen with a stream containing at least some of the reverse water gas shift product stream to make a hydrocarbon synthesis product stream.
Providing a source of CO2 for use in the manufacture of eFuels which does not rely upon the earlier introduction of new CO2 into the environment is an area ripe for research and development. Processes for extracting CO2 from the atmosphere are one way of achieving this goal. This is a published patent application relating to a process for producing a synthetic fuel including the extracting of CO2 from an atmospheric air flow using a sorbent material to form a recovered CO2 feed stream. Similarly, this is a published patent application relating to a CO2 capture unit having a number of adsorption units integrated into a rotatable frame.
Some thoughts for the future:
What form would an idealised eFuel production plant take? Well, an idealised scenario for an eFuel production plant might take the form of a hub in a coastal location with plentiful supplies of sun, wind or some other renewable energy source, the hub combining some or all of the following facilities:
- Power generating plant for generating electricity from renewable sources (for example, using solar, wind or tidal energy);
- CO2 capturing plant for capturing CO2 direct from the atmosphere;
- Electrolysis plant for extracting hydrogen from water (powered by the power generating plant discussed above);
- Plant for synthesising the hydrogen with the captured CO2 to form an eFuel;
- A port or railhead to allow transfer of manufactured eFuels to ships or rail tankers for onward transportation.
As the production of eFuels relies on plentiful supplies of water and sustainable electricity, this could provide economic opportunities to countries not usually associated with the production of fuels. For example, countries whose geography has afforded them plentiful supplies of sunshine and / or wind in a coastal location would seem ideal locations for eFuel production plants.
The challenges in developing processes for the production of eFuels for use in the transportation sector will provide opportunities for innovation and the development of valuable new intellectual property (IP). We at Reddie & Grose are very much looking forward to working with clients in protecting their IP to help them achieve their commercial and environmental goals.
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.
