Deep Insight: How Does China Take the Lead in the SAF Industry?
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Zhonglin International Group Date：12-11 3504 Belong to：Company Related
In 2021, the International Air Transport Association (IATA) approved the resolution for the global air transport industry to achieve net zero carbon emissions by 2050, making carbon reduction an important concern for aviation industry participants. Among numerous carbon reduction measures, sustainable aviation fuel (SAF) is the most critical technology, which is expected to contribute up to 65% of carbon reduction by 2050. SAF can reduce carbon emissions by up to 80%, while carbon emissions through other means (such as model optimization) can reduce by no more than 30%. Also, SAF is with high energy density, convenient refueling, as well as a maximum mixing ratio of 100%, few modification needs for engines, strong compatibility with fossil fuel infrastructure, and strong landing ability.
In 2022, global SAF production has doubled to approximately 300 million liters (240000 tons), and project announcements from potential SAF producers are rapidly increasing. The International Air Transport Association (IATA) predicts that the total production of renewable fuels will reach at least 69 billion liters (55 million tons) in 2028, with SAF being an important component.
1. SAF technical route
With rich raw material sources for SAF, there are various technical routes for producing it. As of 2021, a total of 9 technical routes have passed the ASTM (American Society for Testing and Materials) standard certification. But there are four processes with the clearest commercial prospects, namely the ester and fatty acid hydrogenation process (HEFA), Gas+Fischer Tropsch (FT or G+FT), Alcohol to Jet (AtJ), and the yet to be recognized but most promising electroconversion process (Power to Liquid, PtL).
From a global perspective, Europe and America are the main consumer markets and production locations for SAF, and the existing production capacity of European manufacturers is mainly based on the HEFA route; The new production capacity includes some G+FT, AtJ, and PtL routes. The United States mainly follows the AtJ route.
Among the major technological paths of SAF, HEFA has the highest short-term maturity and the largest landing capacity scale. However, due to the issue of raw material sources, the ramp up of production capacity is limited, making it difficult to cope with the explosive demand for SAF. However, there is still a transitional period of about 3 years. G+FT uses solid waste or steel plant exhaust gas as raw materials, with a wide range of sources and gradually maturing technology, which has cost advantages. It is currently a suitable path to balance cost and scale, and is in the window period of large-scale technology implementation.
The electric to liquid route (PtL) is a process of producing hydrogen gas through electrolysis of water, which is then synthesized with CO2 and converted into hydrocarbon fuel. At present, there are two synthesis paths for PtL fuel, namely the Fischer Tropsch synthesis method and the methanol synthesis method. This technology route is currently in its early stages and has not been included in the ASTM certification system. However, this route has significant carbon reduction potential, providing electricity for the electrolysis process through photovoltaic and wind energy, while utilizing CO2 captured from other sources, thus having good emission reduction benefits.
PtL, on the other hand, is most in line with the long-term carbon reduction spirit of the future due to the use of green carbon and green hydrogen. However, it is constrained by technological breakthroughs in green hydrogen electrolysis tanks (catalyst substitution, high-end membrane localization, and electrode plate improvement) and shipment volume limitations, as well as the cost of carbon dioxide capture technologies (DAC, BECCS, CCUS) that have not yet balanced the economic account. In the short term, it will still focus on demonstration, with a scale of 5-7 years away, But the core equipment in the industrial chain has the opportunity to sell overseas in the short term. In the future, with the further reduction of carbon capture and hydrogen production costs and the implementation of engineering, it is worth continuing to pay attention to scalable hydrogen production electrolysis tanks and DAC equipment in the short term to layout early projects.
2. Challenges to commercialize SAF
(1) High production cost
According to statistics from the International Commission on Clean Transportation (ICCT), the production cost of SAF is about 2-8 times that of aviation kerosene. Among them, even with the current relatively mature HEFA process, the lowest market price of the product is 1.9-2.8 times that of aviation kerosene, especially considering the urgent demand and competition from other industries for HEFA production raw materials such as soybean oil, palm oil, used edible oil, and palm fatty acid distillates. It is still very difficult to further reduce the cost of HEFA in the short term. Due to fuel costs accounting for 25% to 40% of the overall operating costs of the civil aviation industry, even if airlines are willing to purchase some SAF at higher prices to support their sustainable development, this is ultimately not a long-term solution. It is an urgent task to quickly reduce SAF to the same cost as aviation kerosene. Some fuel suppliers have noticed the potential utilization value of industrial waste gases rich in carbon monoxide and easily gasified urban solid waste, which are easier to obtain and much cheaper than agricultural biomass raw materials.
(2) Insufficient supply capacity
In 2019, the global aviation industry consumed approximately 360 billion liters of fuel, and it is expected to continue growing at an annualized rate of around 3% in the future. However, the current annual production of SAF is only 50 million liters, less than 0.02% of the total. Even without considering price issues, it is necessary to significantly increase SAF production capacity in the coming years to meet market demand. However, various certified SAF processes face more or less issues with the long-term availability of raw materials and large-scale production. The source of industrial waste and exhaust gas is extremely limited, and the production of other biomass raw materials requires a large amount of arable land and water resources. The most feasible long-term technological solution is to use the Fischer Tropsch method to synthesize industrial hydrogen (such as electrolysis) and atmospheric carbon dioxide into hydrocarbons for fuel production, but this will also bring about a huge gap in renewable electricity demand. In addition, the infrastructure system supporting SAF on a global scale is far from being formed. In order to enable traditional refineries to have integrated raw material processing capabilities, additional investment is essential. If SAF professional factories are to be expanded beyond the existing supply chain, corresponding pipeline transportation and packaging storage systems need to be constructed.
(3) Unclear component characteristics
To ensure the maximization of emission reduction potential, ideal SAF should not be mixed with any traditional fuel. However, due to the fact that most production technologies now only replicate the paraffin components represented by n-alkanes and isomers in aviation kerosene, the industry still lacks a comprehensive understanding of the performance characteristics of SAF to what extent it can reduce aviation kerosene, resulting in the mixing volume of SAF in commercial use being limited to less than 50%. Boeing's latest test shows that when using 100% HEFA fuel on Boeing 777 aircraft, seals that have not been in contact with the fuel before can achieve acceptable performance even without the need for aromatic hydrocarbon components. However, until sufficient chemical mechanism research and convincing experimental evidence are available, the industry remains cautious about whether cycloalkanes can replace aromatics in old aircraft/engine systems, Currently, ICAO has released SAF's Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) default Life Cycle Emissions (LCA), as shown in the table below. Based on this, it can be seen that there are significant differences in the LCA of SAF with different raw materials and processes. In order to allow SAF with different components from aviation kerosene to be used alone, future engine combustion systems may also be redesigned to maintain optimal operational performance.
(4) Tedious certification process
ASTM D4054 is the core standard operating procedure for uating new aviation fuels and fuel additives, aimed at ensuring the safe and reliable operation of aircraft using alternative aviation fuels. The entire test is led by the aviation OEM and is generally divided into four main steps, which is a iterative and rigorous uation process. This also leads to the current certification process for SAF taking 3-5 years, with a cost of over 5 million US dollars, and full process expenses of up to 10-15 million US dollars. The consumption of a large number of fuel samples is also a heavy burden for many emerging fuel suppliers. Reducing certification time and lowering certification costs is imperative. In January 2020, the ASTM D4054 Quick Certification Attachment was approved, but the maximum mixing ratio of SAF certified through this attachment is limited to below 10%. There is still much work to be done in the future. Of course, it should also be noted that although there is room to simplify the ASTM certification process, with the continuous advancement of technology, the requirements for SAF performance specifications will only be tightened rather than relaxed.
3. SAF updates globally
The EU is the first major global economy to propose a mandatory blending ratio target for SAF. To promote the use of SAF, Europe has launched a combination of tax cuts, mandatory use, and subsidies to accelerate the low-carbon transformation of aviation enterprises. The proportion of SAF used in airport aviation fuel is continuously increasing, striving to increase its proportion to over 2% of aviation fuel by 2025 and over 63% by 2050. At the same time, the European Parliament ETS voted to pass the "SAF allowances" resolution, which is mainly used to fund the research and development of low-carbon and zero carbon fuel technologies, as well as the promotion and application of SAF. The development of SAF allowances is considered by the industry to be an important measure in Europe to promote the large-scale production and use of SAF.
The US government has passed the Sustainable Aviation Fuel Act and the Sustainable Sky Act, providing tax breaks and subsidies for SAF production, and providing targeted funding for new technology development, supply chain construction, and more. In 2022, the US Department of Energy passed the Inflation Reduction Act, requiring SAF producers to reduce their greenhouse gas emissions over the entire lifecycle of fuel production by at least 50% compared to traditional fuels. In the same year, the US Department of Energy released a report titled "The Big Challenge of Sustainable Aviation Fuel," aimed at reducing costs, enhancing sustainability, and expanding production to achieve domestic sustainable aviation fuel production of 3 billion gallons per year. By 2030, greenhouse gas emissions will be reduced by at least 50% compared to using traditional fuels; By 2050, it is expected that aviation jet fuel usage will decrease by 100%, resulting in an annual decrease of 35 billion gallons.
According to the policies set by Europe and America, it is expected that SAF will account for 5% of the aviation fuel market by 2030. With the continuous expansion of other raw material sources, it is expected that by the mid-2030s, SAF will account for 20% of the aviation fuel market. In the short to medium term, fossil fuels and sustainable aviation fuels will coexist, but new technologies will gradually replace fossil fuels in the future.
Delta Air Lines aims to use SAF for 10% of its operations by the end of 2030. Delta has signed an agreement with SAF manufacturer Gevo to purchase approximately 284 million liters of SAF annually for seven consecutive years starting from mid-2026. At the same time, another company, DG Fuels, will establish a new SAF supply chain, supplying approximately 1.46 billion liters of SAF to Delta within seven years from the end of 2027. Emirates Airlines has recently committed to investing $200 million in developing advanced fuel and energy technology solutions. Internet giant Google recently announced its joining of one of the world's largest SAF projects, led by Global Business Travel and Shell Aviation. At present, airports such as Indira Gandhi International Airport in Delhi, Oslo Airport in Norway, Stockholm Airport in Sweden, Los Angeles Airport in the United States, and Seattle Airport have started supplying SAF. As shown in the table below, SAF production lines in Europe and America are competing for layout.
4. SAF updates domestically
(1) China Airlines SAF Flight Test
The research on SAF in China started not late. In 2011, the SAF, which was jointly promoted by Boeing and Air China, was successfully used for the first test flight of a passenger aircraft. However, due to the lack of policy subsidies, China's SAF industry is generally in the stage of knowledge reserves. Compared to over 400000 SAF test flights in the international aviation industry, China's number of test flights is also very small.
(2) Progress in China's SAF related policies
As a typical policy driven industry, the path and measures for China's development of SAF are not yet clear. Compared to the clear blending instructions and sustainable transportation fuel application goals in Europe and America, the legal policies and standard systems introduced by the Civil Aviation Administration and other relevant departments are also incomplete.
On July 12, 2023, the Aircraft Airworthiness Certification Department of the Civil Aviation Administration of China released industry standards "Sustainability Requirements for Aviation Alternative Fuel (Draft for Comments)" and "Test Method for Concentration of Toxic Gases Produced by Combustion of Non metallic Materials in Cabins (Draft for Comments)", which took an important step towards establishing China's SAF sustainable certification system. The sustainability standards for aviation alternative fuels that meet international requirements and meet China's national conditions are about to be released. In order to meet international standards and take into account the actual situation of domestic aviation alternative fuel development, promote industry development, and refer to ICAO standards, the Civil Aviation Administration of China has set a emission reduction threshold of 10%. After the establishment of the standard, it filled the domestic gap and provided an important technical foundation for guiding various stakeholders in the aviation fuel production and supply chain to carry out research and development applications, promoting the deep development of sustainable aviation fuels industry, and helping to achieve the dual carbon goals.
(3) SAF project capacity-domestically planned/under construction
At present, the commercialization of SAF in China is still in its early stages, and only two companies have put into production capacity, namely Sinopec Zhenhai Refining and Chemical Branch and Zhangjiagang Yigao Environmental Protection Investment Co., Ltd. The planned production capacity is about 150000 tons/year, and the production method is the HEFA process using waste oil as raw material. At present, the planned/under construction capacity of SAF projects in China is approximately 3.1302 million tons per year.
In July 2023, State Power Investment Tacheng signed a contract for the 1.2 million kilowatt wind power hydrogen synthesis green aviation kerosene project, marking the beginning of the era of green hydrogen synthesis green aviation kerosene in China. Subsequently, Yili Group signed contracts for green aviation fuel projects, including the Alashan Ulanbu and 3.5 million kilowatt integrated demonstration project for three-dimensional wind and solar hydrogen desertification control to produce aviation fuel, the Duerbert wind and solar hydrogen to produce aviation fuel project in Heilongjiang Province, the renewable green energy integration project of China Energy Construction Baicheng City, and the Bayan Zhuoer Luzhu Biomass Zero Carbon Industrial Park.
Since the beginning of this year, Honeywell has also announced the construction of a model project for sustainable aviation fuel production in North China in the Tianjin Port Free Trade Zone, and officially launched the use of ethanol to jet fuel process technology in China. This technology utilizes corn based, cellulose based, or sugar based ethanol raw materials to produce SAF, in order to solve the problem of insufficient supply of traditional SAF raw materials such as vegetable oil, animal fat, and gutter oil.
Spring Airlines and Airbus have signed a memorandum of understanding. Both sides will strengthen cooperation in the fields of civil aviation green and sustainable development, including promoting and applying SAF. COMAC has partnered with Boeing to conduct research on renewable aviation fuels, and the biofuels based on waste oils such as gutter oil have achieved good results in multiple tests. State Power Investment Corporation and Airbus have signed a letter of intent to cooperate in areas such as the sustainable aviation fuel (SAF) industry chain and renewable energy supply.
(4) Supply channel provider
From the perspective of the traditional aviation fuel industry chain in China, China Aviation Fuel Group Co., Ltd. (AVIC) is responsible for purchasing aviation fuel from oil producers and then supplying it uniformly to domestic airlines. China Aviation Fuel is currently the most important aviation fuel supply channel in mainland China, integrating procurement, transportation, storage, testing, sales, and refueling, responsible for over 95% of domestic aviation fuel supply. I have fully participated in the four SAF test flights in China and the aviation fuel supply of COMAC. I have also participated in the cooperation between the Guangzhou Institute of Energy of the Chinese Academy of Sciences and the Second Institute of Civil Aviation to carry out national and provincial level biological aviation fuel research and development projects. Although China Aviation Fuel has not yet provided large-scale SAF refueling services, the procurement, sales, and refueling processes of SAF in the future should be controlled by China Aviation Fuel.
5. How does China take the lead in SAF industry
Chinese automobile manufacturers will become the world's largest automobile exporter this year, mainly due to China's new energy vehicles having achieved "lead-taking" in the industrial chain, technology, and other aspects. So how does China do the same thing in SAF? We propose suggestions from the following aspects:
(1) Accelerate the improvement of China's SAF sustainable certification system, simplify airworthiness certification, and promote interoperability with international certification
At present, China has established a comprehensive airworthiness certification and verification system for alternative aviation fuels, and has conducted test flights and commercial route operations on multiple aircraft models. Accelerate the establishment of a calculation method for default lifecycle emissions of sustainable aviation fuels, and obtain recognition from ICAO, breaking the current situation of China's aviation alternative fuel sustainable certification and full lifecycle carbon emissions being subject to human constraints.
At present, the certification process for aviation alternative fuels in China is mainly based on the American ASTM-4054 certification process, which requires aviation alternative fuels to undergo fuel physical and chemical characteristics analysis, component testing, bench testing, and overall testing. The engines for overall testing are provided by the engine equipment manufacturer. However, there are three major issues with the existing certification process and platform in China's application: firstly, there are differences in the sensitivity of different models of engines to changes in alternative fuels, and the results of different engines used for aviation alternative fuel certification are difficult to reference each other. Under the existing process, fuel certification is limited to the engine model used during certification and cannot be extended, becoming a combination certification of "fuel engine" rather than a fuel license; Secondly, due to the fact that China's testing technology has not reached the international advanced level, it is difficult to measure all the required certification parameters for the whole machine test without dismantling the structure; Finally, for China, commercial large-scale engines started relatively late and are still in the development stage. The domestic commercial aviation market is dominated by foreign engines. Due to the special nature of fuel certification (such as uncertainty of engine damage, demand for component disassembly testing, high time and labor costs), foreign engine equipment manufacturers provide almost impossible engine products for certification when replacing fuel airworthiness certification in China's aviation industry.
To address the three major issues mentioned above, it is necessary to break the current state of "fuel engine" combination certification and establish scalable fuel certification standards with safety as the main focus; Design a targeted engine certification platform so that it can complete the measurement of required parameters while ensuring the matching and coupling of the entire machine; Establish a dedicated aviation engine and supporting platform for alternative fuel certification, breaking free from the constraints of foreign equipment manufacturers.
In addition, promoting the interoperability between China's airworthiness certification and sustainable certification systems and international certification systems can help simplify the certification process, shorten certification time, and facilitate SAF's "going out" and "bringing in".
(2) Make technological breakthroughs as soon as possible in the PtL electric-to-liquid conversion route of "green carbon+green hydrogen"
Even if everyone stops eating oil, the saved bio fuel can only meet 50% of the aviation industry's needs. The recycling system for gutter oil raw materials in China is not yet perfect, with a 5.6% recovery rate only one seventh that of the United States. Moreover, due to different dietary habits, China's "gutter oil" has high solid impurities, high moisture content, severe acidic decay, and high pre-treatment costs. Difficulty in collecting agricultural, forestry, and urban solid waste, unstable supply, and poor quality; Although sugar and starch raw materials have a large scale, there are situations of "competing with people for food" and "competing with food for land".
The PtL electric to liquid route can fully leverage China's advantages in new energy power infrastructure construction and equipment manufacturing. In theory, the raw materials used in the PtL electro-hydraulic conversion route only require hydrogen and CO2, and hydrogen can be produced by electrolyzing seawater with new energy. The raw materials come from a wide range of sources and there are no bottlenecks. Compared with traditional aviation kerosene, PtL aviation oil can achieve a maximum emission reduction of 99% -100% throughout its entire lifecycle, making it currently the technology route with the highest emission reduction ratio.
But this route involves capturing carbon dioxide and green hydrogen in the air, generating syngas through catalytic reactions, and further synthesizing SAF through Fischer Tropsch reactions. The core technical difficulty lies in the high production cost and cost reduction difficulties caused by the pre process of capturing carbon dioxide and green hydrogen in the air. With breakthroughs in production technology and equipment, this route will be able to achieve large-scale SAF mass production.
In 2022, Johnson&Fung announced the launch of a reverse water gas conversion technology called HyCOgenTM, aimed at converting captured CO2 and green H2 into sustainable aviation fuel (SAF). By combining HyCOgen technology with FTCANS Fischer Tropsch synthesis technology (developed in collaboration with BP), an integrated and scalable solution is provided for efficient and cost-effective production of renewable energy based SAF, which can be economically deployed in projects of various scales - from small-scale projects supplying hydrogen to world-class projects using multiple large electrolysis cell modules.
(3) SAF's raw material supply should be diversified and combined with environmental resource recycling
The supply of raw materials for SAF should be tailored to local conditions and adopt a diversified and multi-channel approach. Sichuan and Chongqing can use catering waste oil, the northwest desert can use waste gas, green electricity, and green hydrogen, the northeast and Xinjiang can use agricultural and forestry waste, and Hubei and Hunan can use bamboo. China's biomass resources are approximately 3.49 billion tons per year, mostly concentrated in the Northeast, Southwest, and Central regions. Approximately 460 million tons of standard coal can be used as energy, and China's biomass energy technology research and development is at the same level as international standards.
China ranks first in the world in terms of bamboo resources, area, and accumulation. It is also the largest bamboo industry in the world, with the highest production and trade volume of bamboo products. Compared with other plants, bamboo plants have the characteristics of multiple varieties, fast growth rate, strong regeneration ability, and sustainable utilization after a successful afforestation. At present, the utilization rate of bamboo processing in China is relatively low, less than 40%, resulting in a large amount of processing waste, which provides high-quality raw materials for biomass energy. Therefore, bamboo resources can be an important source of raw materials for producing aviation oil.
The integrated project of Alashan Ulanbu and 3.5 million kilowatt three-dimensional wind solar hydrogen desertification control to produce aviation fuel will couple green hydrogen with 700000 tons (dry basis) of synthetic gas from salix gasification to produce green aviation fuel; The overall plan for the Duerbert Wind and Solar Hydrogen to Aviation Fuel Project in Heilongjiang Province is "1.2GW of green electricity (wind power, photovoltaic)+green hydrogen+150000 tons of green aviation coal", utilizing biomass/urban solid waste as raw materials to comprehensively develop and implement integrated new energy hydrogen production and green aviation kerosene projects; Bayannur, Inner Mongolia, is building a biomass zero carbon industrial park based on the entire industry chain of bamboo, gathering projects such as wind, solar, green electricity, green hydrogen, green methanol, green aviation coal, and green fiber, fully leveraging the carbon absorption and fixation capabilities of bamboo, and achieving a negative carbon economy in the park. The above projects are tailored to local conditions and have achieved resource recycling. The government should provide support in terms of tax incentives, environmental subsidies, and encourage more such projects to be implemented.
(4) Policy support for R&D of new technologies such as alcohol to aviation fuel technology and all carbon bioconversion to produce bio-coal
Among the current renewable aviation fuel technologies certified by ASTM standards in the United States, alcohol based aviation fuel technology has received widespread attention from numerous giant enterprises in Europe and America. However, currently, alcohol based aviation fuel technology mainly synthesizes renewable aviation fuel components through ethanol gas-phase dehydration and ethylene multi-step polymerization hydrogenation isomerization. This technology requires multiple reaction units, high energy consumption, and high cost, and the temperature conditions required for different processes vary greatly. Energy management is difficult, and the available raw materials are also greatly limited. Professor Li Zhenglong further upgrades ethanol based renewable aviation fuel technology to reduce energy consumption and costs; By developing new biomass pretreatment technologies, the production cost of ethanol can be further reduced, and high-value utilization of lignin can be achieved, laying the foundation for low-cost preparation of ethanol and high-quality aviation oil from biomass. More importantly, through the integration of high-value utilization technologies such as methane, carbon dioxide, and synthetic gas, Professor Li Zhenglong's team has expanded the upstream raw materials of alcohol to aviation fuel technology to a variety of agricultural and forestry waste, organic solid waste, industrial waste gas, and carbon dioxide, providing the possibility and foundation for large-scale synthesis of renewable aviation fuel. This type of technology can achieve a combination of dispersion and concentration. By synthesizing alcohol intermediates through dispersion technology and transporting them to centralized large-scale aviation oil refineries, it can solve the problem of difficulty in large-scale storage and transportation of low-carbon resources such as biomass.
The research team of the School of Chemical Engineering at Xi'an Jiaotong University proposed in "Research Progress on the Manufacturing Route of Biogenic Aviation Coal by Bioconversion of Biogas from All Carbon Biogas" (Zhang Chenyue et al., 2023) that using biogas generated from anaerobic digestion of kitchen waste as raw material, using synthetic biology technology and biological manufacturing strategies, all carbon (CO2 and CH4) in it can be efficiently converted into Biogenic Aviation Coal (SAF). This manufacturing route utilizes photo autotrophic microorganisms and aerobic methanogenic bacteria to convert CO2 and CH4 respectively to synthesize bio fats, and then extracts and upgrades the fats to prepare SAF. By introducing the key enzymes and metabolic pathways of photo autotrophic microorganisms and aerobic methane loving bacteria, this paper summarizes the research progress of strain transformation strategies and fermentation process optimization in improving oil accumulation. After comparing the process characteristics of different bio oil pretreatment and upgrading processes, the economic feasibility and application scenarios of the relevant technologies were analyzed. Based on the combustion performance of SAF and its global warming potential in the production process, the technical feasibility of the SAF manufacturing route was discussed. Finally, with the help of technical and economic feasibility analysis, strategies to improve the economic efficiency of SAF manufacturing routes were proposed, providing reference for the commercial application of biotechnology in fuel production.
We need to fully support the research on aviation fuel new energy such as bio aviation oil in terms of policies, and plan, research, tackle and explore from the entire industry chain of technology, scientific research, production, use, and equipment.
(5) Encourage full industry chain linkage among oil manufacturers, suppliers, airlines and airports
The aviation industry's supply chain is relatively closed. Emerging SAF suppliers need to go through a long certification cycle and undergo extensive and multiple flight tests. On the one hand, SAF products bring entry opportunities for new players with technical capabilities; On the other hand, suppliers need to form partnerships with aviation industry players such as aircraft manufacturers, airlines, airports, and traditional aviation fuel manufacturers. For example, Neste collaborated with Boeing during the development and testing phase, and World Energy provided aircraft delivery fuel for Airbus. For new players, it is also possible to consider partnering with traditional fuel suppliers with strong industry relationships and resources to enter. In addition, the development of domestically produced aircraft brings new opportunities for Chinese aviation suppliers, and new players can strengthen research and development cooperation with Chinese OEMs.
Airports are important hubs in the aviation transportation chain, serving as the center of aircraft services and the main venue for aviation fuel supply. It is crucial for the promotion and application of SAF. Airport groups should lay out relevant capabilities as soon as possible to meet future market demands. At present, there are no domestic airports providing SAF refueling services for scheduled flights, and industrial cooperation mainly focuses on providing test flight venues. Airports can utilize their identity as SAF service providers to participate more deeply in technological upgrades and model innovation. SAF can continue to use traditional fuel facilities, and many airports are actively leveraging related infrastructure and optimizing supporting facilities. Some leading airports have comprehensively considered their own carbon neutrality goals and the fuel usage of base airlines, and have integrated SAF needs to centrally purchase from suppliers. Multiple leading airports have established subsidy programs to encourage local airlines to use SAF. The airport is also expected to share the benefits brought by the growth of new industries through deep participation in the SAF industry chain layout.
Airlines can seek cooperation upstream and downstream in the industry chain to stabilize SAF supply, achieve carbon neutrality, and reduce cost challenges. International leading airlines have conducted extensive practice. The airline has established close cooperative relationships with SAF suppliers through strategic investments, joint ventures, and other forms, occupying the first mover advantage in new energy. In addition, the additional costs brought by SAF applications are expected to be shared by end customers. For corporate customers, airlines can use SAF flights to assist customers in advancing their carbon neutrality goals. C-end consumers also have a high willingness to pay a premium. Based on Roland Berger's global research, most travelers are willing to pay a carbon reduction premium of about 5%. Airlines can further enhance the payment willingness of C-end consumers and alleviate the early cost pressure of SAF application by introducing SAF route mileage reward system and other measures.
SAF's product development cycle is long and costly, and in addition to the efforts of enterprises and industry players, policy assistance is also crucial. Clear SAF usage targets, implementation timelines and roadmaps, and guiding the establishment of industry standards can effectively enhance industry confidence and enhance the attractiveness of the SAF industry to social capital. In addition to regulation, direct government funding and investment are also important sources of funding for many research and development production institutions.
References
[1] Wang Xiangyu. Outlook on Sustainable Aviation Fuel Development. Aviation Power [J], 2022 (2): 24-28
[2] Zhang Chenyue, Ma Yingqun, Wang Xing, Fu Rongzhan, Huang Jiwei, Hua Xiufu, Fan Daidi, Fei Qiang. Research progress on the production route of bio aviation coal through full carbon bioconversion of biogas. Synthetic Biology [J]. 2023 (4): 1-13
[3] Yuan Sainan, Zhu Xiaofeng SAF - The Best Way to Reduce Emissions in Medium - and Short Term Civil Aviation. Large Aircraft [J]. 2023 (9): 14-20
[4] Born for Top Entrepreneurs. Cloud Point Daolin | Deep Research on China's Hydrogen Industry - SAF Special Study. Cloud Point Capital Official Account. 2023.08.08
[5] Biological basis Professor Li Zhenglong from Zhejiang University: Pioneer in the new generation of alcohol based renewable aviation fuel technology! Biobased Energy and Materials Public Account. 2023.11.20
[6] Liu Hua Smart Civil Aviation | Liu Hua: Airworthiness Approval for Sustainable Aviation Fuel. Civil Aviation Second Institute Official Account. May 27, 2023
[7] Energy Time Can reduce emissions by 80%! Why is sustainable aviation fuel lagging behind in development? https://baijiahao.baidu.com/s?id=1775440782525018228&wfr=spider&for=pc
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In 2022, global SAF production has doubled to approximately 300 million liters (240000 tons), and project announcements from potential SAF producers are rapidly increasing. The International Air Transport Association (IATA) predicts that the total production of renewable fuels will reach at least 69 billion liters (55 million tons) in 2028, with SAF being an important component.
1. SAF technical route
With rich raw material sources for SAF, there are various technical routes for producing it. As of 2021, a total of 9 technical routes have passed the ASTM (American Society for Testing and Materials) standard certification. But there are four processes with the clearest commercial prospects, namely the ester and fatty acid hydrogenation process (HEFA), Gas+Fischer Tropsch (FT or G+FT), Alcohol to Jet (AtJ), and the yet to be recognized but most promising electroconversion process (Power to Liquid, PtL).
From a global perspective, Europe and America are the main consumer markets and production locations for SAF, and the existing production capacity of European manufacturers is mainly based on the HEFA route; The new production capacity includes some G+FT, AtJ, and PtL routes. The United States mainly follows the AtJ route.
Among the major technological paths of SAF, HEFA has the highest short-term maturity and the largest landing capacity scale. However, due to the issue of raw material sources, the ramp up of production capacity is limited, making it difficult to cope with the explosive demand for SAF. However, there is still a transitional period of about 3 years. G+FT uses solid waste or steel plant exhaust gas as raw materials, with a wide range of sources and gradually maturing technology, which has cost advantages. It is currently a suitable path to balance cost and scale, and is in the window period of large-scale technology implementation.
The electric to liquid route (PtL) is a process of producing hydrogen gas through electrolysis of water, which is then synthesized with CO2 and converted into hydrocarbon fuel. At present, there are two synthesis paths for PtL fuel, namely the Fischer Tropsch synthesis method and the methanol synthesis method. This technology route is currently in its early stages and has not been included in the ASTM certification system. However, this route has significant carbon reduction potential, providing electricity for the electrolysis process through photovoltaic and wind energy, while utilizing CO2 captured from other sources, thus having good emission reduction benefits.
PtL, on the other hand, is most in line with the long-term carbon reduction spirit of the future due to the use of green carbon and green hydrogen. However, it is constrained by technological breakthroughs in green hydrogen electrolysis tanks (catalyst substitution, high-end membrane localization, and electrode plate improvement) and shipment volume limitations, as well as the cost of carbon dioxide capture technologies (DAC, BECCS, CCUS) that have not yet balanced the economic account. In the short term, it will still focus on demonstration, with a scale of 5-7 years away, But the core equipment in the industrial chain has the opportunity to sell overseas in the short term. In the future, with the further reduction of carbon capture and hydrogen production costs and the implementation of engineering, it is worth continuing to pay attention to scalable hydrogen production electrolysis tanks and DAC equipment in the short term to layout early projects.
2. Challenges to commercialize SAF
(1) High production cost
According to statistics from the International Commission on Clean Transportation (ICCT), the production cost of SAF is about 2-8 times that of aviation kerosene. Among them, even with the current relatively mature HEFA process, the lowest market price of the product is 1.9-2.8 times that of aviation kerosene, especially considering the urgent demand and competition from other industries for HEFA production raw materials such as soybean oil, palm oil, used edible oil, and palm fatty acid distillates. It is still very difficult to further reduce the cost of HEFA in the short term. Due to fuel costs accounting for 25% to 40% of the overall operating costs of the civil aviation industry, even if airlines are willing to purchase some SAF at higher prices to support their sustainable development, this is ultimately not a long-term solution. It is an urgent task to quickly reduce SAF to the same cost as aviation kerosene. Some fuel suppliers have noticed the potential utilization value of industrial waste gases rich in carbon monoxide and easily gasified urban solid waste, which are easier to obtain and much cheaper than agricultural biomass raw materials.
(2) Insufficient supply capacity
In 2019, the global aviation industry consumed approximately 360 billion liters of fuel, and it is expected to continue growing at an annualized rate of around 3% in the future. However, the current annual production of SAF is only 50 million liters, less than 0.02% of the total. Even without considering price issues, it is necessary to significantly increase SAF production capacity in the coming years to meet market demand. However, various certified SAF processes face more or less issues with the long-term availability of raw materials and large-scale production. The source of industrial waste and exhaust gas is extremely limited, and the production of other biomass raw materials requires a large amount of arable land and water resources. The most feasible long-term technological solution is to use the Fischer Tropsch method to synthesize industrial hydrogen (such as electrolysis) and atmospheric carbon dioxide into hydrocarbons for fuel production, but this will also bring about a huge gap in renewable electricity demand. In addition, the infrastructure system supporting SAF on a global scale is far from being formed. In order to enable traditional refineries to have integrated raw material processing capabilities, additional investment is essential. If SAF professional factories are to be expanded beyond the existing supply chain, corresponding pipeline transportation and packaging storage systems need to be constructed.
(3) Unclear component characteristics
To ensure the maximization of emission reduction potential, ideal SAF should not be mixed with any traditional fuel. However, due to the fact that most production technologies now only replicate the paraffin components represented by n-alkanes and isomers in aviation kerosene, the industry still lacks a comprehensive understanding of the performance characteristics of SAF to what extent it can reduce aviation kerosene, resulting in the mixing volume of SAF in commercial use being limited to less than 50%. Boeing's latest test shows that when using 100% HEFA fuel on Boeing 777 aircraft, seals that have not been in contact with the fuel before can achieve acceptable performance even without the need for aromatic hydrocarbon components. However, until sufficient chemical mechanism research and convincing experimental evidence are available, the industry remains cautious about whether cycloalkanes can replace aromatics in old aircraft/engine systems, Currently, ICAO has released SAF's Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) default Life Cycle Emissions (LCA), as shown in the table below. Based on this, it can be seen that there are significant differences in the LCA of SAF with different raw materials and processes. In order to allow SAF with different components from aviation kerosene to be used alone, future engine combustion systems may also be redesigned to maintain optimal operational performance.
(4) Tedious certification process
ASTM D4054 is the core standard operating procedure for uating new aviation fuels and fuel additives, aimed at ensuring the safe and reliable operation of aircraft using alternative aviation fuels. The entire test is led by the aviation OEM and is generally divided into four main steps, which is a iterative and rigorous uation process. This also leads to the current certification process for SAF taking 3-5 years, with a cost of over 5 million US dollars, and full process expenses of up to 10-15 million US dollars. The consumption of a large number of fuel samples is also a heavy burden for many emerging fuel suppliers. Reducing certification time and lowering certification costs is imperative. In January 2020, the ASTM D4054 Quick Certification Attachment was approved, but the maximum mixing ratio of SAF certified through this attachment is limited to below 10%. There is still much work to be done in the future. Of course, it should also be noted that although there is room to simplify the ASTM certification process, with the continuous advancement of technology, the requirements for SAF performance specifications will only be tightened rather than relaxed.
3. SAF updates globally
The EU is the first major global economy to propose a mandatory blending ratio target for SAF. To promote the use of SAF, Europe has launched a combination of tax cuts, mandatory use, and subsidies to accelerate the low-carbon transformation of aviation enterprises. The proportion of SAF used in airport aviation fuel is continuously increasing, striving to increase its proportion to over 2% of aviation fuel by 2025 and over 63% by 2050. At the same time, the European Parliament ETS voted to pass the "SAF allowances" resolution, which is mainly used to fund the research and development of low-carbon and zero carbon fuel technologies, as well as the promotion and application of SAF. The development of SAF allowances is considered by the industry to be an important measure in Europe to promote the large-scale production and use of SAF.
The US government has passed the Sustainable Aviation Fuel Act and the Sustainable Sky Act, providing tax breaks and subsidies for SAF production, and providing targeted funding for new technology development, supply chain construction, and more. In 2022, the US Department of Energy passed the Inflation Reduction Act, requiring SAF producers to reduce their greenhouse gas emissions over the entire lifecycle of fuel production by at least 50% compared to traditional fuels. In the same year, the US Department of Energy released a report titled "The Big Challenge of Sustainable Aviation Fuel," aimed at reducing costs, enhancing sustainability, and expanding production to achieve domestic sustainable aviation fuel production of 3 billion gallons per year. By 2030, greenhouse gas emissions will be reduced by at least 50% compared to using traditional fuels; By 2050, it is expected that aviation jet fuel usage will decrease by 100%, resulting in an annual decrease of 35 billion gallons.
According to the policies set by Europe and America, it is expected that SAF will account for 5% of the aviation fuel market by 2030. With the continuous expansion of other raw material sources, it is expected that by the mid-2030s, SAF will account for 20% of the aviation fuel market. In the short to medium term, fossil fuels and sustainable aviation fuels will coexist, but new technologies will gradually replace fossil fuels in the future.
Delta Air Lines aims to use SAF for 10% of its operations by the end of 2030. Delta has signed an agreement with SAF manufacturer Gevo to purchase approximately 284 million liters of SAF annually for seven consecutive years starting from mid-2026. At the same time, another company, DG Fuels, will establish a new SAF supply chain, supplying approximately 1.46 billion liters of SAF to Delta within seven years from the end of 2027. Emirates Airlines has recently committed to investing $200 million in developing advanced fuel and energy technology solutions. Internet giant Google recently announced its joining of one of the world's largest SAF projects, led by Global Business Travel and Shell Aviation. At present, airports such as Indira Gandhi International Airport in Delhi, Oslo Airport in Norway, Stockholm Airport in Sweden, Los Angeles Airport in the United States, and Seattle Airport have started supplying SAF. As shown in the table below, SAF production lines in Europe and America are competing for layout.
4. SAF updates domestically
(1) China Airlines SAF Flight Test
The research on SAF in China started not late. In 2011, the SAF, which was jointly promoted by Boeing and Air China, was successfully used for the first test flight of a passenger aircraft. However, due to the lack of policy subsidies, China's SAF industry is generally in the stage of knowledge reserves. Compared to over 400000 SAF test flights in the international aviation industry, China's number of test flights is also very small.
(2) Progress in China's SAF related policies
As a typical policy driven industry, the path and measures for China's development of SAF are not yet clear. Compared to the clear blending instructions and sustainable transportation fuel application goals in Europe and America, the legal policies and standard systems introduced by the Civil Aviation Administration and other relevant departments are also incomplete.
On July 12, 2023, the Aircraft Airworthiness Certification Department of the Civil Aviation Administration of China released industry standards "Sustainability Requirements for Aviation Alternative Fuel (Draft for Comments)" and "Test Method for Concentration of Toxic Gases Produced by Combustion of Non metallic Materials in Cabins (Draft for Comments)", which took an important step towards establishing China's SAF sustainable certification system. The sustainability standards for aviation alternative fuels that meet international requirements and meet China's national conditions are about to be released. In order to meet international standards and take into account the actual situation of domestic aviation alternative fuel development, promote industry development, and refer to ICAO standards, the Civil Aviation Administration of China has set a emission reduction threshold of 10%. After the establishment of the standard, it filled the domestic gap and provided an important technical foundation for guiding various stakeholders in the aviation fuel production and supply chain to carry out research and development applications, promoting the deep development of sustainable aviation fuels industry, and helping to achieve the dual carbon goals.
(3) SAF project capacity-domestically planned/under construction
At present, the commercialization of SAF in China is still in its early stages, and only two companies have put into production capacity, namely Sinopec Zhenhai Refining and Chemical Branch and Zhangjiagang Yigao Environmental Protection Investment Co., Ltd. The planned production capacity is about 150000 tons/year, and the production method is the HEFA process using waste oil as raw material. At present, the planned/under construction capacity of SAF projects in China is approximately 3.1302 million tons per year.
In July 2023, State Power Investment Tacheng signed a contract for the 1.2 million kilowatt wind power hydrogen synthesis green aviation kerosene project, marking the beginning of the era of green hydrogen synthesis green aviation kerosene in China. Subsequently, Yili Group signed contracts for green aviation fuel projects, including the Alashan Ulanbu and 3.5 million kilowatt integrated demonstration project for three-dimensional wind and solar hydrogen desertification control to produce aviation fuel, the Duerbert wind and solar hydrogen to produce aviation fuel project in Heilongjiang Province, the renewable green energy integration project of China Energy Construction Baicheng City, and the Bayan Zhuoer Luzhu Biomass Zero Carbon Industrial Park.
Since the beginning of this year, Honeywell has also announced the construction of a model project for sustainable aviation fuel production in North China in the Tianjin Port Free Trade Zone, and officially launched the use of ethanol to jet fuel process technology in China. This technology utilizes corn based, cellulose based, or sugar based ethanol raw materials to produce SAF, in order to solve the problem of insufficient supply of traditional SAF raw materials such as vegetable oil, animal fat, and gutter oil.
Spring Airlines and Airbus have signed a memorandum of understanding. Both sides will strengthen cooperation in the fields of civil aviation green and sustainable development, including promoting and applying SAF. COMAC has partnered with Boeing to conduct research on renewable aviation fuels, and the biofuels based on waste oils such as gutter oil have achieved good results in multiple tests. State Power Investment Corporation and Airbus have signed a letter of intent to cooperate in areas such as the sustainable aviation fuel (SAF) industry chain and renewable energy supply.
(4) Supply channel provider
From the perspective of the traditional aviation fuel industry chain in China, China Aviation Fuel Group Co., Ltd. (AVIC) is responsible for purchasing aviation fuel from oil producers and then supplying it uniformly to domestic airlines. China Aviation Fuel is currently the most important aviation fuel supply channel in mainland China, integrating procurement, transportation, storage, testing, sales, and refueling, responsible for over 95% of domestic aviation fuel supply. I have fully participated in the four SAF test flights in China and the aviation fuel supply of COMAC. I have also participated in the cooperation between the Guangzhou Institute of Energy of the Chinese Academy of Sciences and the Second Institute of Civil Aviation to carry out national and provincial level biological aviation fuel research and development projects. Although China Aviation Fuel has not yet provided large-scale SAF refueling services, the procurement, sales, and refueling processes of SAF in the future should be controlled by China Aviation Fuel.
5. How does China take the lead in SAF industry
Chinese automobile manufacturers will become the world's largest automobile exporter this year, mainly due to China's new energy vehicles having achieved "lead-taking" in the industrial chain, technology, and other aspects. So how does China do the same thing in SAF? We propose suggestions from the following aspects:
(1) Accelerate the improvement of China's SAF sustainable certification system, simplify airworthiness certification, and promote interoperability with international certification
At present, China has established a comprehensive airworthiness certification and verification system for alternative aviation fuels, and has conducted test flights and commercial route operations on multiple aircraft models. Accelerate the establishment of a calculation method for default lifecycle emissions of sustainable aviation fuels, and obtain recognition from ICAO, breaking the current situation of China's aviation alternative fuel sustainable certification and full lifecycle carbon emissions being subject to human constraints.
At present, the certification process for aviation alternative fuels in China is mainly based on the American ASTM-4054 certification process, which requires aviation alternative fuels to undergo fuel physical and chemical characteristics analysis, component testing, bench testing, and overall testing. The engines for overall testing are provided by the engine equipment manufacturer. However, there are three major issues with the existing certification process and platform in China's application: firstly, there are differences in the sensitivity of different models of engines to changes in alternative fuels, and the results of different engines used for aviation alternative fuel certification are difficult to reference each other. Under the existing process, fuel certification is limited to the engine model used during certification and cannot be extended, becoming a combination certification of "fuel engine" rather than a fuel license; Secondly, due to the fact that China's testing technology has not reached the international advanced level, it is difficult to measure all the required certification parameters for the whole machine test without dismantling the structure; Finally, for China, commercial large-scale engines started relatively late and are still in the development stage. The domestic commercial aviation market is dominated by foreign engines. Due to the special nature of fuel certification (such as uncertainty of engine damage, demand for component disassembly testing, high time and labor costs), foreign engine equipment manufacturers provide almost impossible engine products for certification when replacing fuel airworthiness certification in China's aviation industry.
To address the three major issues mentioned above, it is necessary to break the current state of "fuel engine" combination certification and establish scalable fuel certification standards with safety as the main focus; Design a targeted engine certification platform so that it can complete the measurement of required parameters while ensuring the matching and coupling of the entire machine; Establish a dedicated aviation engine and supporting platform for alternative fuel certification, breaking free from the constraints of foreign equipment manufacturers.
In addition, promoting the interoperability between China's airworthiness certification and sustainable certification systems and international certification systems can help simplify the certification process, shorten certification time, and facilitate SAF's "going out" and "bringing in".
(2) Make technological breakthroughs as soon as possible in the PtL electric-to-liquid conversion route of "green carbon+green hydrogen"
Even if everyone stops eating oil, the saved bio fuel can only meet 50% of the aviation industry's needs. The recycling system for gutter oil raw materials in China is not yet perfect, with a 5.6% recovery rate only one seventh that of the United States. Moreover, due to different dietary habits, China's "gutter oil" has high solid impurities, high moisture content, severe acidic decay, and high pre-treatment costs. Difficulty in collecting agricultural, forestry, and urban solid waste, unstable supply, and poor quality; Although sugar and starch raw materials have a large scale, there are situations of "competing with people for food" and "competing with food for land".
The PtL electric to liquid route can fully leverage China's advantages in new energy power infrastructure construction and equipment manufacturing. In theory, the raw materials used in the PtL electro-hydraulic conversion route only require hydrogen and CO2, and hydrogen can be produced by electrolyzing seawater with new energy. The raw materials come from a wide range of sources and there are no bottlenecks. Compared with traditional aviation kerosene, PtL aviation oil can achieve a maximum emission reduction of 99% -100% throughout its entire lifecycle, making it currently the technology route with the highest emission reduction ratio.
But this route involves capturing carbon dioxide and green hydrogen in the air, generating syngas through catalytic reactions, and further synthesizing SAF through Fischer Tropsch reactions. The core technical difficulty lies in the high production cost and cost reduction difficulties caused by the pre process of capturing carbon dioxide and green hydrogen in the air. With breakthroughs in production technology and equipment, this route will be able to achieve large-scale SAF mass production.
In 2022, Johnson&Fung announced the launch of a reverse water gas conversion technology called HyCOgenTM, aimed at converting captured CO2 and green H2 into sustainable aviation fuel (SAF). By combining HyCOgen technology with FTCANS Fischer Tropsch synthesis technology (developed in collaboration with BP), an integrated and scalable solution is provided for efficient and cost-effective production of renewable energy based SAF, which can be economically deployed in projects of various scales - from small-scale projects supplying hydrogen to world-class projects using multiple large electrolysis cell modules.
(3) SAF's raw material supply should be diversified and combined with environmental resource recycling
The supply of raw materials for SAF should be tailored to local conditions and adopt a diversified and multi-channel approach. Sichuan and Chongqing can use catering waste oil, the northwest desert can use waste gas, green electricity, and green hydrogen, the northeast and Xinjiang can use agricultural and forestry waste, and Hubei and Hunan can use bamboo. China's biomass resources are approximately 3.49 billion tons per year, mostly concentrated in the Northeast, Southwest, and Central regions. Approximately 460 million tons of standard coal can be used as energy, and China's biomass energy technology research and development is at the same level as international standards.
China ranks first in the world in terms of bamboo resources, area, and accumulation. It is also the largest bamboo industry in the world, with the highest production and trade volume of bamboo products. Compared with other plants, bamboo plants have the characteristics of multiple varieties, fast growth rate, strong regeneration ability, and sustainable utilization after a successful afforestation. At present, the utilization rate of bamboo processing in China is relatively low, less than 40%, resulting in a large amount of processing waste, which provides high-quality raw materials for biomass energy. Therefore, bamboo resources can be an important source of raw materials for producing aviation oil.
The integrated project of Alashan Ulanbu and 3.5 million kilowatt three-dimensional wind solar hydrogen desertification control to produce aviation fuel will couple green hydrogen with 700000 tons (dry basis) of synthetic gas from salix gasification to produce green aviation fuel; The overall plan for the Duerbert Wind and Solar Hydrogen to Aviation Fuel Project in Heilongjiang Province is "1.2GW of green electricity (wind power, photovoltaic)+green hydrogen+150000 tons of green aviation coal", utilizing biomass/urban solid waste as raw materials to comprehensively develop and implement integrated new energy hydrogen production and green aviation kerosene projects; Bayannur, Inner Mongolia, is building a biomass zero carbon industrial park based on the entire industry chain of bamboo, gathering projects such as wind, solar, green electricity, green hydrogen, green methanol, green aviation coal, and green fiber, fully leveraging the carbon absorption and fixation capabilities of bamboo, and achieving a negative carbon economy in the park. The above projects are tailored to local conditions and have achieved resource recycling. The government should provide support in terms of tax incentives, environmental subsidies, and encourage more such projects to be implemented.
(4) Policy support for R&D of new technologies such as alcohol to aviation fuel technology and all carbon bioconversion to produce bio-coal
Among the current renewable aviation fuel technologies certified by ASTM standards in the United States, alcohol based aviation fuel technology has received widespread attention from numerous giant enterprises in Europe and America. However, currently, alcohol based aviation fuel technology mainly synthesizes renewable aviation fuel components through ethanol gas-phase dehydration and ethylene multi-step polymerization hydrogenation isomerization. This technology requires multiple reaction units, high energy consumption, and high cost, and the temperature conditions required for different processes vary greatly. Energy management is difficult, and the available raw materials are also greatly limited. Professor Li Zhenglong further upgrades ethanol based renewable aviation fuel technology to reduce energy consumption and costs; By developing new biomass pretreatment technologies, the production cost of ethanol can be further reduced, and high-value utilization of lignin can be achieved, laying the foundation for low-cost preparation of ethanol and high-quality aviation oil from biomass. More importantly, through the integration of high-value utilization technologies such as methane, carbon dioxide, and synthetic gas, Professor Li Zhenglong's team has expanded the upstream raw materials of alcohol to aviation fuel technology to a variety of agricultural and forestry waste, organic solid waste, industrial waste gas, and carbon dioxide, providing the possibility and foundation for large-scale synthesis of renewable aviation fuel. This type of technology can achieve a combination of dispersion and concentration. By synthesizing alcohol intermediates through dispersion technology and transporting them to centralized large-scale aviation oil refineries, it can solve the problem of difficulty in large-scale storage and transportation of low-carbon resources such as biomass.
The research team of the School of Chemical Engineering at Xi'an Jiaotong University proposed in "Research Progress on the Manufacturing Route of Biogenic Aviation Coal by Bioconversion of Biogas from All Carbon Biogas" (Zhang Chenyue et al., 2023) that using biogas generated from anaerobic digestion of kitchen waste as raw material, using synthetic biology technology and biological manufacturing strategies, all carbon (CO2 and CH4) in it can be efficiently converted into Biogenic Aviation Coal (SAF). This manufacturing route utilizes photo autotrophic microorganisms and aerobic methanogenic bacteria to convert CO2 and CH4 respectively to synthesize bio fats, and then extracts and upgrades the fats to prepare SAF. By introducing the key enzymes and metabolic pathways of photo autotrophic microorganisms and aerobic methane loving bacteria, this paper summarizes the research progress of strain transformation strategies and fermentation process optimization in improving oil accumulation. After comparing the process characteristics of different bio oil pretreatment and upgrading processes, the economic feasibility and application scenarios of the relevant technologies were analyzed. Based on the combustion performance of SAF and its global warming potential in the production process, the technical feasibility of the SAF manufacturing route was discussed. Finally, with the help of technical and economic feasibility analysis, strategies to improve the economic efficiency of SAF manufacturing routes were proposed, providing reference for the commercial application of biotechnology in fuel production.
We need to fully support the research on aviation fuel new energy such as bio aviation oil in terms of policies, and plan, research, tackle and explore from the entire industry chain of technology, scientific research, production, use, and equipment.
(5) Encourage full industry chain linkage among oil manufacturers, suppliers, airlines and airports
The aviation industry's supply chain is relatively closed. Emerging SAF suppliers need to go through a long certification cycle and undergo extensive and multiple flight tests. On the one hand, SAF products bring entry opportunities for new players with technical capabilities; On the other hand, suppliers need to form partnerships with aviation industry players such as aircraft manufacturers, airlines, airports, and traditional aviation fuel manufacturers. For example, Neste collaborated with Boeing during the development and testing phase, and World Energy provided aircraft delivery fuel for Airbus. For new players, it is also possible to consider partnering with traditional fuel suppliers with strong industry relationships and resources to enter. In addition, the development of domestically produced aircraft brings new opportunities for Chinese aviation suppliers, and new players can strengthen research and development cooperation with Chinese OEMs.
Airports are important hubs in the aviation transportation chain, serving as the center of aircraft services and the main venue for aviation fuel supply. It is crucial for the promotion and application of SAF. Airport groups should lay out relevant capabilities as soon as possible to meet future market demands. At present, there are no domestic airports providing SAF refueling services for scheduled flights, and industrial cooperation mainly focuses on providing test flight venues. Airports can utilize their identity as SAF service providers to participate more deeply in technological upgrades and model innovation. SAF can continue to use traditional fuel facilities, and many airports are actively leveraging related infrastructure and optimizing supporting facilities. Some leading airports have comprehensively considered their own carbon neutrality goals and the fuel usage of base airlines, and have integrated SAF needs to centrally purchase from suppliers. Multiple leading airports have established subsidy programs to encourage local airlines to use SAF. The airport is also expected to share the benefits brought by the growth of new industries through deep participation in the SAF industry chain layout.
Airlines can seek cooperation upstream and downstream in the industry chain to stabilize SAF supply, achieve carbon neutrality, and reduce cost challenges. International leading airlines have conducted extensive practice. The airline has established close cooperative relationships with SAF suppliers through strategic investments, joint ventures, and other forms, occupying the first mover advantage in new energy. In addition, the additional costs brought by SAF applications are expected to be shared by end customers. For corporate customers, airlines can use SAF flights to assist customers in advancing their carbon neutrality goals. C-end consumers also have a high willingness to pay a premium. Based on Roland Berger's global research, most travelers are willing to pay a carbon reduction premium of about 5%. Airlines can further enhance the payment willingness of C-end consumers and alleviate the early cost pressure of SAF application by introducing SAF route mileage reward system and other measures.
SAF's product development cycle is long and costly, and in addition to the efforts of enterprises and industry players, policy assistance is also crucial. Clear SAF usage targets, implementation timelines and roadmaps, and guiding the establishment of industry standards can effectively enhance industry confidence and enhance the attractiveness of the SAF industry to social capital. In addition to regulation, direct government funding and investment are also important sources of funding for many research and development production institutions.
References
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