The bulk of Sustainable Aviation Fuel (SAF) used in aviation today is from feedstocks like animal fats, vegetable oils, and waste greases — collectively known as Hydrotreated Esters and Fatty Acids (HEFA).
But other technologies are being tested and promise to improve efficiency. One such alternative is power-to-liquid fuels (PtL or e-fuels). These synthetic liquid hydrocarbon fuels use renewable electricity to break water into hydrogen and oxygen and combine them with non-fossil carbon dioxide to produce fuels.
Neste is one of the innovators in the PtL research and development field. Jonathan Wood, VP of Global Commercial & Technical, Renewable Aviation at Neste, recently shared the potential of PtL for the future of aviation.
Twin and Turbine: Given the constraints on feedstock availability globally for SAF, what efforts is Neste focused on for e-fuels or power-to-liquid technology?
Jonathan Wood: In the short term, Neste plans to use green hydrogen to support the refinery processes sustainably. In the longer term, we also plan to use hydrogen as a raw material for e-fuels, further supporting our climate and sustainability goals.
The potential of technologies like PtL could be substantial. PtL is a complementary technology for future sustainable fuel production. We need breakthrough innovations and continued focus on research and technology development to provide the most cost-efficient and value-creating solutions possible for the future.
In 2022, Neste agreed to build an integrated Power-to-Liquids (e-fuels) demonstration facility at VTT Bioruukki Pilot Centre in Espoo, Finland, for CO2 capture, green hydrogen and e-fuels production.
In alignment with Neste’s ambition to reach carbon-neutral production by 2035, we are working on a 120-megawatt electrolyzer project to produce green hydrogen at our refinery in Porvoo, Finland. Neste has begun the introductory engineering phase of the project, and with an investment decision on track in 2024, green hydrogen production could start as soon as 2026.
In Rotterdam, Neste is setting up a demonstration unit for green hydrogen production — the world’s first multi-megawatt electrolyzer based on the innovative SOEC (solid oxide electrolysis cell) technology integrated into industrial production.
But we must be clear that PtL will not be feasible in meaningful quantities before 2030. We are also looking at other sources of sustainable feedstocks that could be lower cost and more quickly implemented at scale, such as novel vegetable oils, agricultural and forestry waste, municipal solid waste, and algae. These sustainable raw materials could be enough to independently meet future renewable aviation fuel needs. So, together with PtL, we can see a pipeline of feedstocks and associated production technologies to deliver on aviation’s net zero challenge.
The potential of technologies like PtL could be substantial. PtL is a complementary technology for future sustainable fuel production.
Jonathan Wood, VP of Global Commercial & Technical, Renewable Aviation at Neste
T&T: What are the challenges and opportunities associated with PtL technology, and what are the cost implications of using PtL technology?
JW: One of the challenges of PtL technology is that the production of synthetic fuels from green hydrogen and carbon dioxide has not been commercialized and is higher cost than alternatives. It requires new SAF production facilities, a significant increase in available renewable power on an ongoing continuous basis, and material sources of carbon.
HEFA-based SAF remains the most viable and scalable solution for the next ten years, using waste oils, fats, and other bio-based oils (e.g., novel vegetable oils and intermediate crops that do not cause land use change and help regenerate soil quality).
The other challenge is the lack of regulations that can encourage investment decisions to make this technology commercially available, given the level of capital expenditure is significantly higher than existing HEFA-based SAF projects. Supply support can come through investment incentives, while mandates for using renewable fuels, specifically for PtL-based SAF, support demand. In addition, we also need policies that ensure that the cost of carbon emissions is reflected equally in fossil fuel pricing. Currently, the cost comparison with SAF is not on a like-for-like basis.
As well as a significant increase in renewable power production capacity, we need the associated electric grids, pipelines and storage, and other infrastructure elements to be developed and maintained to meet the needs of the industry. Permitting processes also have to become quick and transparent.
To summarize, the government and industry must collaborate closely to make a positive business case for green hydrogen and PtL-based SAF, enabling deployment at scale from 2030 onwards.
T&T: What are the environmental benefits of using PtL technology?
JW: PtL has the potential to unlock new renewable feedstock pools beyond bio-based sustainable raw materials and reduce reliance on fossil fuels dug out of the ground.
We now know that increases in carbon in the atmosphere from fossil fuels have contributed to more than one degree (Celcius) of global warming compared to pre-industrial times. This increase in carbon could cause irreversible climate change if not addressed by curtailing the use of fossil fuels. The case for fast action is clear.
PtL needs hydrogen and carbon. Green hydrogen is generated without incremental emissions when using renewable power. The carbon required to make a renewable liquid fuel is the second challenge — bio-based carbon sources will continue to be required, ideally concentrated in locations close to the renewable power source for the green hydrogen. Direct air capture is a longer-term option, but once again, it requires significant additional amounts of renewable power and is higher cost given the low concentration of carbon in the atmosphere — but pilot plants are in development.
SAF-Specific Questions
T&T: How does Neste see PtL technology fitting into the future of SAF production?
JW: Neste expects that after 2030, industrial-scale volumes of PtL can become available. However, it will require time to scale up, and all independent studies indicate that it will be a significantly higher cost to produce than HEFA-based SAF. We see the future growth in the supply of SAF building on the foundation of HEFA-based production with other new technologies, including gasification+synthesis and alcohol-to-jet (ATJ), also playing a role. PtL will also play a big part in the future production of SAF.
T&T: What key partnerships has Neste formed to advance the development of SAF?
JW: No company can do it alone when it comes to energy transition. Neste relies on an ecosystem of partners to deliver sustainable products like SAF; these include customers, technology partners, and industry experts.
Moving toward 100% SAF: Neste has been collaborating with engine manufacturers, airlines, and other partners to test the viability of using 100% SAF in aircraft.
Projects: Airbus, Boeing, and recently Bell Textron made the Bell 505 the world’s first single-engine helicopter to fly on 100% SAF.
From grey to green infrastructure: We used pipelines that previously moved fossil fuels to deliver SAF to SFO. Last June, we delivered one batch of SAF from Texas to LGA New York using the Colonial Pipeline. Examples like these show the potential of leveraging what is often considered ‘grey infrastructure’ to fight climate change.
T&T: What are the research and development initiatives Neste is undertaking to improve the production of SAF?
JW: In addition to the PtL mentioned above, Neste is researching the potential of other sustainable future raw materials, making future renewable products from novel vegetable oils & oil-bearing plants on otherwise unused land, lignocellulosic feedstocks (i.e., agricultural and forestry waste), algae, and municipal solid waste.
T&T: What technological challenges does Neste face in producing SAF?
JW: Neste has been producing SAF since 2011. As it is compatible with the existing energy infrastructure, there are no technological challenges to produce and supply the fuel to the end users, i.e., airlines at airports. However, increasing availability to replace fossil jet fuel fully requires a massive investment, a ramp-up in production capacity and an increase in available sustainable feedstocks. This additional investment and feedstock cost means that SAF will be more expensive than fossil jet fuel (with its associated incremental carbon emissions) for some time.
The critical issue is ensuring sustainability and delivering a reduction in net greenhouse gas emissions. Neste has a strict supplier code of conduct, meaning that our suppliers should have the same commitment as us: conducting business to protect the environment, biodiversity, and human rights. If a supplier can’t meet this, we don’t do business with them.
