Last month, a report titled 'In-depth Insights: Sustainable Aviation Fuel (SAF) Promotional Path in the Chinese Market,' released by Roland Berger, revealed that Sustainable Aviation Fuel (SAF) is of great significance for emissions reduction in aviation and influences the global aviation industry's journey towards carbon neutrality. The aviation industry is widely recognized as a 'hard-to-reduce emissions' sector, but the report shows that Sustainable Aviation Fuel (SAF) is a commercial tool capable of reducing aviation travel emissions intensity in the near term.
There are many ways to achieve decarbonization goals in the aviation industry, including improving fuel efficiency, using Sustainable Aviation Fuel (SAF), carbon offsetting, adopting new power systems such as batteries and hybrid propulsion, and utilizing hydrogen, among others. Among these methods, the use of Sustainable Aviation Fuel is expected to be the primary decarbonization method for the next 30 years and the most direct way to directly apply to existing aircraft. According to Asia Jet Consulting, the global market size of SAF is expected to exceed 18 million tons by 2030, valued at several billion dollars.
Sustainable Aviation Fuel (SAF) is a direct liquid fuel substitute that, depending on the choice of raw materials and production processes, can reduce carbon emissions by up to 85% compared to traditional aviation fuel. SAF has characteristics of sustainability, including raw materials that do not compete with food crops or water supplies, do not cause deforestation or soil degradation, and allow for the recycling of carbon stored in biomass feedstocks. Currently, SAF is produced from resources such as forestry residues, agricultural waste, waste cooking oils, and municipal solid waste.
Four technology processes that are highly likely to attract industry attention and scale up
As of April 2023, the American Society for Testing and Materials has approved nine technology processes including HEFA, ATJ, and FT. The PtL process, which has enormous emission reduction potential and utilizes raw materials with long-term unlimited supply, is still pending approval.
The production routes of bio-based SAF shown in the above figure include SAF production through hydrogenation of oil, SAF production through bioethanol/bioethanol, SAF production through bio-syngas Fischer-Tropsch synthesis, and SAF production through direct air capture combined with electrolysis hydrogen synthesis, which are feasible technological routes globally.
Among the four technological routes, HEFA is currently the only mature route in commercial operation, which involves SAF production through hydrogenation of animal and plant oils. The main chemical reactions are as follows:
Liquid-phase reactions
Decarboxylation: R-COOH → R-H + CO2(g)
Decarbonylation: R-COOH → R'-H + CO(g) + H2O(g)
R-COOH + H2(g) → R'-H + CO(g) + H2O(g)
Hydrogenation: R'-COOH + 3H2(g) → R-CH3 + 2H2O(g)
where R is an unsaturated straight-chain alkyl group, and R' is a saturated straight-chain alkyl group.
Gas-phase reactions
Methanation: CO2 + H2 → CH4 + 2H2O
CO +3H2 CH4 + H20
Water-gas shift: CO + H2O → H2 + CO2
However, due to the scattered sources of raw materials (such as waste cooking oil) in the HEFA process, the high cost of collecting and processing waste cooking oil, and the lack of economic feasibility in further expanding production, the capacity growth is relatively weak. Sinopec has disclosed details of its independently developed and designed bio-coal-to-aviation-fuel process, with a brief process outline as follows:
This process can be scaled up to extract bio-coal from waste cooking oil and other kitchen waste oils. The production of bio-coal was first applied at China Petrochemical Corporation's Zhenhai Refining and Chemical Company, with an annual designed processing capacity of 100,000 tons. On one hand, the HEFA method involves a wide range of raw materials (mostly waste cooking oil, animal and vegetable fats), but they contain sulfur, chlorine, metallic elements, and a large amount of fatty acid impurities, all of which need to be removed one by one. On the other hand, the high oxygen content in waste cooking oil directly affects the activity and stability of the catalyst in the refining unit.
Coincidentally, the ATJ process has low procurement costs, but ethanol itself has a high oxygen content, requiring the removal of oxygen molecules during the refining process. A series of separation technologies from DODGEN will effectively address the purification challenges of both HEFA and ATJ processes, helping to boost the capacity of SAF and accelerate the commercialization process of SAF.
“DODGEN Distillation Technology"
According to YunDao Capital analysis: FT and ATJ, due to their wide range of raw material sources (agricultural and forestry waste, municipal solid waste, industrial waste, etc.) and low power consumption, are the new favorites of SAF producers in the near term, and are expected to gradually move from pilot lines to commercial operations.
The PtL route is constrained by expensive carbon capture technology and electrolytic hydrogen production, and commercialization is still far off. However, compared to traditional aviation fuel, it has the highest emission reduction efficiency and enormous potential. If policies are strengthened later on, it will become the most important technology route in the medium to long term.
In summary, the production of sustainable aviation fuel is still limited, and it cannot be guaranteed that end-users will always be able to obtain SAF through the existing supply chain network.
The potential for sustainable aviation fuel (SAF) production in China and the development process
China has an abundant supply of sustainable aviation fuel (SAF) raw materials, but innovative solutions are needed to establish the technological processes and expand production capacity.
In 2022, global SAF production doubled to approximately 300 million liters (240,000 tons), with announcements of potential SAF producers' projects rapidly increasing. Leading domestic and international industry giants such as Honeywell, ExxonMobil, Shell, Zhuangxin Wanfeng, Sinopec, TotalEnergies, BP, Neste, KBR, Chevron, Topsoe, and World Energy are strategically positioning themselves along the global SAF supply chain.
On November 14, 2023, China Energy Investment Corporation (CEIC) and Airbus signed a memorandum of understanding (MOU) to collaborate in the sustainable aviation fuel (SAF) industry chain and renewable energy supply, among other areas, to contribute jointly to the sustainable development of the aviation industry. According to the MOU, the two parties will collaborate on SAF fuel new technologies, production, certification, and promotion across the entire chain to build a SAF fuel industry chain that meets international standards, operates stably, and has sustainable development capabilities.
According to data, after nearly a year of development and industrial planning, the current planned/under-construction SAF project capacity in China is approximately 3.13 million tons per year.
Conclusion:
China has abundant raw materials available for sustainable aviation fuel (SAF), presenting enormous potential for sustainable development in the field of SAF. With the continuous growth in SAF demand, the commercialization process is accelerating, driving the continuous development of various technologies along the industry chain. DODGEN is willing to work together with relevant technology partners to promote the development of the SAF industry.
