While the challenges assailing the global aviation industry remain numerous, consisting of both long-standing issues, such as the lack of available talent, as well as present concerns over the world’s economy, one problem that continues to vex the sector lies with decarbonisation.
In less than a year from now, the International Air Transport Association’s (IATA) Carbon Offsetting Scheme for International Aviation (CORSIA) is set to go into effect. Once done, it will greatly impact how airlines operate in relation to the overall carbon footprint.
Designed as a global market-based measure to which IATA member airlines can utilise to oversee their respective carbon emissions, a key goal of the initiative is for the aviation industry to achieve carbon-neutral growth by 2020.
While this can be achieved through a variety of means, such as through the practice of carbon offsetting, a type of action by an organisation to compensate for their emissions by financing a reduction of emissions elsewhere, the real answer lies with sustainable fuels.
For over two decades, elements of the aviation sector have worked closely with researchers active within the energy space, to identify a viable, greener alternative to traditional jet fuel.
An estimated 160,000 passenger flights have taken to the air utilising a blend of sustainable and traditional jet fuel since biofuels were first certified for commercial travel in 2011.
Additionally, the advent of sustainable aviation fuel holds great potential in helping airlines meet their target of capping the growth of carbon emissions. Green alternatives may also prove instrumental in helping cut emissions to half of what they were back in 2005, by the year 2050.
It is this endeavour that now in 2019, the United Arab Emirates has thrown its hat into the ring.
During last month’s World Future Energy Summit (WFES) 2019, the Sustainable Bioenergy Research Consortium (SBRC), part of Khalifa University of Science and Technology, announced the successful flight of an Etihad Airways Boeing 787 that flew from Abu Dhabi to Amsterdam on sustainable fuel.
Though certainly not the first aircraft ever to fly using a mixed blend, the event marked the first instance a commercial aircraft flew utilising sustainable fuel produced in the UAE.
Following its formation back in 2011, the SBRC unveiled its pilot facility of the Seawater Energy and Agriculture System (SEAS) in 2016, which acts as a desert bionetwork designed to produce food and fuel from seawater supplies in arid land.
“SEAS is essentially comprised of three subsystems. The first one is an aquaculture farm, where we raise fish and shrimp. While these animals grow they generate waste and this waste goes into the water,” explains Dr Alejandro Ríos Galvan, director of the Sustainable Bioenergy Research Consortium (SBRC).
“We take this water full of waste, which acts as a liquid fertilizer and we use it to irrigate our second sub-system … This is where we grow our Salicornia, which is an oilseed plant … we harvest it and then we separate the seeds from the straw. We then take the seeds and crush them, extracting their oil.
“Then we put this oil through a refining process that is essentially very similar to the refining process of crude petroleum. We produce what is called synthetic paraffinic kerosene (SPK), which is an alternative fuel for the aviation industry. It can be blended in a particular pathway that this is certified, up to 50% with traditional fossil-based jet fuel.”
SEAS is based upon a techno-economic model in which the aquaculture farm and the nutrients it generates for halophytes, a term used to describe salt-tolerant plants, serve as the financial drivers of the system and enable it to be commercially viable.
Although Dr Galvan and his team oversaw the growth and cultivation of the Salicornia plants, the actual process of converting the oils into a useable fuel was achieved through the efforts of the Abu Dhabi National Oil Company (ADNOC), UOP-Honeywell, and the Abu Dhabi Vegetable Oil Company (ADVOC).
Other participating partners under the SBRC include Etihad Airways, ADNOC, Bauer Resources, Boeing, Safran and GE.
Located in the heart of Masdar City in Abu Dhabi, the SEAS pilot site consists of two hectares dedicated to the growth of Salicornia plants, of which two successful crops have been produced to date.
The fuel generated from these crops were used on the last month’s Etihad Airways Flight EY77.
“Even though we use the term alternative fuel, it is actually exactly the same specification of jet fuel. It has to meet very stringent requirements,” explains Linden Coppell, head of Sustainability at Etihad Airways.
“One of the things that some of these alternative fuels have shown though is that for some reason, for technical reasons that are difficult to explain, they are slightly cleaner than crude oil fuels. In a lot of places, crude oil is quite low quality. It needs a lot more refining.”
Coppell adds that the oils produced from the plants boast enhanced energy value over traditional aviation fuel.
“Some of these fuels are showing what we would say is a higher calorific value. You’re getting a bit more bang for your buck. A bit more energy out of every ton” says Coppell.
“So if we are flying an extra long-haul flight of 16 - 18 hours, one of the main things that may stop us from offering that flight is the range of the aircraft. If you want a full payload — passenger and cargo — it is then when you think about how much fuel you can carry … If you have a fuel type with higher energy content, it could potentially help airlines meet those ultra-long haul targets.”
Another key draw of utilising this type of sustainable fuel is the fact that it doesn’t require any type of modification — neither at the airport level nor with aircraft.
In the case of the former, the entity refining the oil would at most need to retool its facility. Once passed a certain stage where the mixture is combined with the regular jet fuel, the blend can simply be added directly to existing distribution systems at the airport.
Holding the viewpoint that current and future aircraft will be utilising the same propulsion for at least the next 20 – 30 years, the industry decided as a whole that modification of the aircraft was not economically feasible.
“We can’t have the luxury of having some aircraft that use one type of fuel and some another. So this fuel is completely mixable with regular fuel,” explains Coppell.
"If we arrive somewhere where there is alternative fuel available, we use that, but if we fly to another destination where there isn’t, we can just use regular jet fuel,” she adds.
While primarily focused on producing sustainable jet fuel, the project does hold potential for other segments. For starters, it presents a new opportunity to generate a new agriculture industry that uses salt water and desert land to grow halophytes. It also generates ancillary support services, such as the need for upstream and downstream industries.
Additionally, the oil extracted from the plants produce a significant amount of sugars, anti-oxidants, as well as bioactive agents. While research is currently exploring how properties can be best utilised, representatives from the cosmetics, pharmaceutical and nutraceutical industries have already reached out to the SBRC with interest in the project.
Despite the harsh conditions of the UAE’s environment, particularly with the waters of the Arabian Gulf that are 30% saltier than traditional sea water, the country was chosen to serve as a testbed for SEAS.
The reasoning behind this was that the success of the pilot site presents a viable case for replicating the system in different places around the world. This will be an absolute necessity in order to meet the demands of the entire world of aviation.
“If we are to reach scale — the scale that is needed to produce enough oil and enough biomass in order to supply the aviation market — we need hundreds of thousands of hectares and this will not happen exclusively in the UAE,” explains Dr Galvan.
“Our argument is that this system is actually amiable to many coastal deserts around the world and many arid regions that have access to brackish water,” he adds.
To this end, the SBRC is now set to expand the scale of SEAS up from the initial two hectares to a whopping 200. Explaining that by doing so, it helps to “unlock many of the necessary lessons that happen in order for you to do this at a large scale,” Dr Galvan shares that the organisation is already considering viable site locations for expansion.
While unable to share specifics, he expects that future expansions will likely be built on a coastal site and that it is the consortium’s intent for the site to be located in the UAE.