Current Feasible Technological Routes for SAF and the Enlightment for China's SAF Industry
From：
Zhonglin International Group Date：01-10 8296 Belong to：Company Related
Preface
Last year in September, the National Development and Reform Commission and the Civil Aviation Administration of China jointly held the launch ceremony for the pilot application of Sustainable Aviation Fuel (SAF), marking the progress of China's civil aviation industry towards a more environmentally friendly and low-carbon direction. Starting from September 19, 2024, 12 flights operated by Air China, China Eastern Airlines, and China Southern Airlines from Beijing Daxing, Chengdu Shuangliu, Zhengzhou Xinzheng, and Ningbo Lishe airports will be officially refueled with SAF. This major initiative by China once again focuses the public's attention on the sustainable development of the aviation industry in the future.
Compared to traditional aviation fuels, SAF can reduce carbon emissions by up to 80-85%. As one of the key areas for achieving the "dual carbon" goal in the transportation industry, the aviation industry is receiving increasing attention. Compared to other industries, the aviation industry has limited emission reduction plans and paths, making it difficult to reduce emissions and known as one of the "difficult emission reduction" areas. However, due to its high calorific value and zero emissions characteristics, the use of SAF does not require large-scale modifications to existing infrastructure, aircraft engines, and operational management systems, thereby significantly reducing emission reduction costs. Therefore, it brings new possibilities and prospects for reducing emissions in the aviation industry.
At present, companies from various countries around the world have laid out in the SAF related industry chain. In the eyes of the industry, China's SAF industry has a good development foundation and resource conditions. If fully utilized, China has enormous potential for SAF production and the ability to become the world's largest SAF supplier in the future. It is expected that by 2030, the demand for SAF in China will reach 3 million tons per year. However, at present, the domestic SAF supply and demand market is still in a very early stage, and the technical routes and commercialization are also uneven. This article will analyze the feasible technological routes and directions in the current SAF industry, and draw relevant insights for the future development trend of SAF in China.
The current feasible tech routes for SAF
At present, the preparation routes of SAF can be divided into alcohol to jet (ATJ), oil to jet (OTJ), gas to jet (GTJ), sugar to jet (STJ), and power to liquid (PTL) technologies.
I. Alcohol to Jet (ATJ)
ATJ technology involves two main steps: alcohol production and alcohol conversion. Alcohols are usually obtained through biological fermentation of sugars, starch hydrolysis fermentation, or conversion of lignocellulose. The second step is to convert alcohols into long-chain hydrocarbons, including alcohol dehydration, olefin oligomerization, middle distillate hydrogenation, and finally distillation to produce aviation kerosene. Ethanol, butanol, and isobutanol are commonly used as intermediate products in industry to convert biomass into fuel.
In the process of alcohol dehydration to produce olefins, the water resistance of the catalyst needs to be considered. For the oligomerization process, homogeneous or heterogeneous catalysts can be used. Common catalysts include Al2O3, transition metal oxides, zeolite catalysts, and heteropolyacid catalysts. Ethanol dehydration to produce ethylene is a mature process, while butanol dehydration, although not as mature as ethanol dehydration, requires lower temperature and pressure. The aviation kerosene prepared by oligomerization of different alcohols varies slightly. Dehydration and oligomerization of butanol yield compounds such as C8, C12, C16, while oligomerization of ethylene yields a wider range of compounds. The olefin obtained from oligomerization is hydrogenated to obtain saturated alkanes, and then distilled to obtain the final aviation kerosene.
II. Oil to Jet (OTJ)
The commonly used raw materials for OTJ (Oil to Jet) technology include vegetable oil, restaurant waste oil, algal oil, and pyrolysis oil. The main pathways of oil to aviation coal technology include ester and fatty acid hydrogenation (HEFA), catalytic water pyrolysis (CHJ), and pyrolysis.
HEFA (ester and fatty acid hydrogenation) is a process of hydroprocessing triglycerides, saturated and unsaturated fatty acids in vegetable oils, restaurant waste oils, and animal fats. The main product produced by HEFA is biodiesel, with bio aviation kerosene accounting for approximately 15% of the total product. The aviation kerosene prepared by HEFA has the advantages of high thermal stability, good cold flowability, high cetane number, and low exhaust emissions. However, low aromatic hydrocarbon content may lead to low fuel lubricity and fuel leakage issues.
Catalytic water pyrolysis (CHJ) uses algae or oil crops as raw materials, and converts fatty acid esters and fatty acids into synthetic kerosene containing aromatic hydrocarbons through hydrothermal treatment. Compared to HEFA, one advantage of CHJ is that it reduces hydrogen consumption by about 25%, and the resulting bio aviation coal not only contains alkanes, but also includes cycloalkanes and aromatics, which are more similar to traditional jet fuels. It has excellent combustion performance, low freezing point, and stability, and not only meets ASTM standards, but also military MTL standards.
III. Gas to Jet (GTJ)
GTJ refers to the conversion of biogas, natural gas, or synthetic gas into bio aviation fuel. The main GTJ methods include Fischer Tropsch process (FT) and gas fermentation method.
Fischer Tropsch synthesis (FT) technology is a process of producing liquid hydrocarbon fuels through synthesis gas. FT technology generates liquid fuels with high thermal stability, typically free of sulfur and nitrogen, through gasification and synthesis reactions of raw materials. In general, the conversion rate of Fischer Tropsch synthesis is about 10% -15%. In terms of carbon emissions, the greenhouse gas emissions from sustainable aviation coal produced using Fischer Tropsch synthesis are approximately 5.3-28.5 grams of carbon dioxide per megajoule, which is equivalent to achieving a carbon reduction of 67% -94% throughout the entire lifecycle of aviation fuel. However, due to the relatively low content of aromatic hydrocarbons, the energy density is relatively low, so further improvement and optimization are needed in the production process.
Gas fermentation process is a method of using microorganisms to convert synthesis gas into alcohols, and then preparing biofuels through ATJ process. This process can be achieved by gasifying biomass such as lignocellulose into syngas, which can then be used for fermentation to produce ethanol or butanol. Afterwards, these alcohols were converted into bio aviation kerosene using ATJ technology.
Its advantages include more flexible selection of raw materials, strong ability to handle various pollutants, high yield, and low operating costs. In addition, the biogas produced by the fermentation of lignocellulose can also be converted into biogenic aviation fuel by methane oxidizing bacteria. This method has greater potential compared to traditional biochemical or thermochemical pathways.
IV. Sugar to Jet (STJ)
Unlike ATJ, which ferments sugar into ethanol and then converts it into aviation fuel, sugars can be directly converted into hydrocarbon fuels through anaerobic fermentation. This process is called Direct Sugar to Hydrocarbons (DSHC) or Direct Fermentation Sugar to Aviation Coal (DFSTJ). In addition to this biochemical pathway, sugars can also be converted into jet fuel through thermochemical methods, such as aqueous phase reforming (APR).
The DSHC process includes six main steps: pretreatment and regulation, enzymatic hydrolysis, hydrolysate clarification, biotransformation, product purification, and hydroprocessing. The raw materials are similar to bioethanol, including sugarcane, sugar beets, corn, and pre treated lignocellulosic biomass. The fermentation process can be anaerobic or aerobic, and the products depend on the raw materials, fermentation process, and types of microorganisms.
Water phase reforming (APR) is a technology that converts soluble plant sugars into intermediates such as alcohols, ketones, aldehydes, acids, and furans, and further converts these intermediates into aviation kerosene. This process includes pretreatment and enzymatic hydrolysis of lignocellulosic biomass to obtain C5 and C6 sugars. Water soluble sugars are purified and concentrated, and solids and impurities that cannot be converted into soluble sugars are removed, improving the conversion efficiency of the reaction. The purified hydrolysate is converted into polyols or short chain oxygen-containing compounds through hydrogenation, and then undergoes aqueous phase reforming. Finally, the product is fractionated to obtain jet fuel. The unconverted solids, lignocellulose, and light alkanes generated during the APR process will be sent to the combustion chamber to provide thermal energy.
V. Power to Liquid (PTL)
PTL technology combines CO2, water, and renewable energy to produce SAF, which has characteristics similar to fossil jet fuels. The three main steps that make up this pathway are CO2 capture, hydrogen production (usually from water electrolysis), and hydrocarbon synthesis and regulation processes. The synthesis of hydrocarbons can be carried out through two different pathways: Fischer Tropsch (FT) synthesis or methanol synthesis for jet fuel; However, the performance of the FT process is superior to that of the methanol pathway, as the mixture containing 50% FT derived SAF and 50% conventional jet fuel has been certified by ASTM and can be put into use without modification.
Conclusion
Among the above technical routes, HEFA is currently the only mature route for commercialization, the most widely adopted process route in various countries, and the most commercially feasible production route in China. However, due to the shortage of raw materials and the fact that HEFA technology does not have the same decarbonization and emission reduction properties as ATJ and G+FT routes, it will gradually be replaced by ATJ, FT, PTL synthesis routes in the future.
Therefore, in the long run, there are three potential technological routes for development, namely gasification Fischer Tropsch synthesis (G+FT), alcohol to aviation kerosene (ATJ), and power synthesis fuel (PTL) technology.
According to statistics from the Rocky Mountain Institute, as of August 2023, the global announced production capacity for Fischer Tropsch synthesis has reached 1.36 million tons, mostly concentrated in North America and the United Kingdom. Only one North American startup, WasteFuel, plans to build a factory in the Philippines in Asia. Among them, Fulcrum Bioenergy in North America has officially entered commercial operation, and Enerkem in Canada is also under construction and is expected to start production in 2023.
In terms of alcohol based aviation coal, as of August 2023, the globally announced planned production capacity is approximately 960000 tons per year. Among them, only Gevo's small-scale demonstration project in the United States has been put into operation, while another American company LanzaJet is still under construction and is expected to start production in 2023. Except for Europe and America, only one Japanese company in Asia has announced that it will use alcohol to oil technology to produce SAF.
In terms of power synthetic fuels, based on the current level of technological development in various countries, synthetic fuels are still far from large-scale application. The current problems with synthetic fuels mainly manifest in three aspects: multiple production stages, limited process efficiency, and uneven technological maturity in each stage, resulting in high overall production costs for synthetic fuels. Although key technologies and equipment such as photovoltaics, wind power, and electrolyzers have achieved significant cost reductions in recent years, the price of synthetic fuels is still far behind traditional fuels.
Enlightment for China's SAF Industry
At present, the potential supply of catering waste oil in China exceeds 13 million tons per year. Although HEFA is currently the most important preparation technology adopted in China, there are challenges such as high export demand, scattered sources, and high collection and transportation costs. In the long run, it is not realistic to continue to follow the HEFA route. However, in terms of G+FT and ATJ, China currently lacks advantages and lacks technological reserves and research and development foundations; PTL is currently in the research and development stage. But China has accelerated the large-scale development of the green hydrogen industry, and in the long run, the prospects for PTL to accelerate commercialization and scale application are broad.
In the past two years, there have been frequent achievements in the field of PTL: State Power Investment Corporation has started the construction of a sustainable aviation coal demonstration project with an annual output of 10000 tons in Tacheng, Xinjiang in July 2023. On December 10, 2023, the Qiqihar Million Ton Hydrogen based Green Energy Base and Ten Thousand Ton Green Aviation Coal Demonstration Project was launched in the Laha Biotechnology and Chemical Pharmaceutical Industry Park in Nehe City. The project has a total investment of 42 billion yuan, covers an area of 162.9 hectares, plans to build 3.5 million kilowatts of off grid wind power, and is equipped with a 164000 ton/year hydrogen production system, which can achieve an annual output of 400000 tons of green aviation coal and 400000 tons of green methanol.
According to the above, based on the current situation, China has only accumulated certain knowledge in HEFA process and FT synthesis technology routes, and Chinese enterprises have no patent layout in ATJ route and PtL route, which have great emission reduction potential. As the country with the largest consumption and production of SAF today, the United States has the highest number of patent applications in various technological branches, and has an advantage and dominant position. For our country, in order to achieve the established goals, it is necessary to first formulate a long-term plan for SAF application, determine the SAF preparation process route that is in line with China's national conditions as our medium - and long-term development route, and provide strong support. We need to increase investment in small-scale, pilot, and industrial research on related improvement and alternative routes in order to achieve overtaking, help China's independent standard formulation, break through the constraints of international standards, and promote industrialization landing. Secondly, we also need to connect the innovation chain, industry chain, and funding chain of SAF, integrate innovation resources, vigorously promote the integration of industry, academia, and research in technological innovation and incentive mechanisms, in order to accelerate the application of SAF technology, reduce costs, and promote commercialization. Only in this way can we achieve the ambitious goal of becoming the world's largest producer and supplier of SAF in the long run.
Last year in September, the National Development and Reform Commission and the Civil Aviation Administration of China jointly held the launch ceremony for the pilot application of Sustainable Aviation Fuel (SAF), marking the progress of China's civil aviation industry towards a more environmentally friendly and low-carbon direction. Starting from September 19, 2024, 12 flights operated by Air China, China Eastern Airlines, and China Southern Airlines from Beijing Daxing, Chengdu Shuangliu, Zhengzhou Xinzheng, and Ningbo Lishe airports will be officially refueled with SAF. This major initiative by China once again focuses the public's attention on the sustainable development of the aviation industry in the future.
Compared to traditional aviation fuels, SAF can reduce carbon emissions by up to 80-85%. As one of the key areas for achieving the "dual carbon" goal in the transportation industry, the aviation industry is receiving increasing attention. Compared to other industries, the aviation industry has limited emission reduction plans and paths, making it difficult to reduce emissions and known as one of the "difficult emission reduction" areas. However, due to its high calorific value and zero emissions characteristics, the use of SAF does not require large-scale modifications to existing infrastructure, aircraft engines, and operational management systems, thereby significantly reducing emission reduction costs. Therefore, it brings new possibilities and prospects for reducing emissions in the aviation industry.
At present, companies from various countries around the world have laid out in the SAF related industry chain. In the eyes of the industry, China's SAF industry has a good development foundation and resource conditions. If fully utilized, China has enormous potential for SAF production and the ability to become the world's largest SAF supplier in the future. It is expected that by 2030, the demand for SAF in China will reach 3 million tons per year. However, at present, the domestic SAF supply and demand market is still in a very early stage, and the technical routes and commercialization are also uneven. This article will analyze the feasible technological routes and directions in the current SAF industry, and draw relevant insights for the future development trend of SAF in China.
The current feasible tech routes for SAF
At present, the preparation routes of SAF can be divided into alcohol to jet (ATJ), oil to jet (OTJ), gas to jet (GTJ), sugar to jet (STJ), and power to liquid (PTL) technologies.
I. Alcohol to Jet (ATJ)
ATJ technology involves two main steps: alcohol production and alcohol conversion. Alcohols are usually obtained through biological fermentation of sugars, starch hydrolysis fermentation, or conversion of lignocellulose. The second step is to convert alcohols into long-chain hydrocarbons, including alcohol dehydration, olefin oligomerization, middle distillate hydrogenation, and finally distillation to produce aviation kerosene. Ethanol, butanol, and isobutanol are commonly used as intermediate products in industry to convert biomass into fuel.
In the process of alcohol dehydration to produce olefins, the water resistance of the catalyst needs to be considered. For the oligomerization process, homogeneous or heterogeneous catalysts can be used. Common catalysts include Al2O3, transition metal oxides, zeolite catalysts, and heteropolyacid catalysts. Ethanol dehydration to produce ethylene is a mature process, while butanol dehydration, although not as mature as ethanol dehydration, requires lower temperature and pressure. The aviation kerosene prepared by oligomerization of different alcohols varies slightly. Dehydration and oligomerization of butanol yield compounds such as C8, C12, C16, while oligomerization of ethylene yields a wider range of compounds. The olefin obtained from oligomerization is hydrogenated to obtain saturated alkanes, and then distilled to obtain the final aviation kerosene.
II. Oil to Jet (OTJ)
The commonly used raw materials for OTJ (Oil to Jet) technology include vegetable oil, restaurant waste oil, algal oil, and pyrolysis oil. The main pathways of oil to aviation coal technology include ester and fatty acid hydrogenation (HEFA), catalytic water pyrolysis (CHJ), and pyrolysis.
HEFA (ester and fatty acid hydrogenation) is a process of hydroprocessing triglycerides, saturated and unsaturated fatty acids in vegetable oils, restaurant waste oils, and animal fats. The main product produced by HEFA is biodiesel, with bio aviation kerosene accounting for approximately 15% of the total product. The aviation kerosene prepared by HEFA has the advantages of high thermal stability, good cold flowability, high cetane number, and low exhaust emissions. However, low aromatic hydrocarbon content may lead to low fuel lubricity and fuel leakage issues.
Catalytic water pyrolysis (CHJ) uses algae or oil crops as raw materials, and converts fatty acid esters and fatty acids into synthetic kerosene containing aromatic hydrocarbons through hydrothermal treatment. Compared to HEFA, one advantage of CHJ is that it reduces hydrogen consumption by about 25%, and the resulting bio aviation coal not only contains alkanes, but also includes cycloalkanes and aromatics, which are more similar to traditional jet fuels. It has excellent combustion performance, low freezing point, and stability, and not only meets ASTM standards, but also military MTL standards.
III. Gas to Jet (GTJ)
GTJ refers to the conversion of biogas, natural gas, or synthetic gas into bio aviation fuel. The main GTJ methods include Fischer Tropsch process (FT) and gas fermentation method.
Fischer Tropsch synthesis (FT) technology is a process of producing liquid hydrocarbon fuels through synthesis gas. FT technology generates liquid fuels with high thermal stability, typically free of sulfur and nitrogen, through gasification and synthesis reactions of raw materials. In general, the conversion rate of Fischer Tropsch synthesis is about 10% -15%. In terms of carbon emissions, the greenhouse gas emissions from sustainable aviation coal produced using Fischer Tropsch synthesis are approximately 5.3-28.5 grams of carbon dioxide per megajoule, which is equivalent to achieving a carbon reduction of 67% -94% throughout the entire lifecycle of aviation fuel. However, due to the relatively low content of aromatic hydrocarbons, the energy density is relatively low, so further improvement and optimization are needed in the production process.
Gas fermentation process is a method of using microorganisms to convert synthesis gas into alcohols, and then preparing biofuels through ATJ process. This process can be achieved by gasifying biomass such as lignocellulose into syngas, which can then be used for fermentation to produce ethanol or butanol. Afterwards, these alcohols were converted into bio aviation kerosene using ATJ technology.
Its advantages include more flexible selection of raw materials, strong ability to handle various pollutants, high yield, and low operating costs. In addition, the biogas produced by the fermentation of lignocellulose can also be converted into biogenic aviation fuel by methane oxidizing bacteria. This method has greater potential compared to traditional biochemical or thermochemical pathways.
IV. Sugar to Jet (STJ)
Unlike ATJ, which ferments sugar into ethanol and then converts it into aviation fuel, sugars can be directly converted into hydrocarbon fuels through anaerobic fermentation. This process is called Direct Sugar to Hydrocarbons (DSHC) or Direct Fermentation Sugar to Aviation Coal (DFSTJ). In addition to this biochemical pathway, sugars can also be converted into jet fuel through thermochemical methods, such as aqueous phase reforming (APR).
The DSHC process includes six main steps: pretreatment and regulation, enzymatic hydrolysis, hydrolysate clarification, biotransformation, product purification, and hydroprocessing. The raw materials are similar to bioethanol, including sugarcane, sugar beets, corn, and pre treated lignocellulosic biomass. The fermentation process can be anaerobic or aerobic, and the products depend on the raw materials, fermentation process, and types of microorganisms.
Water phase reforming (APR) is a technology that converts soluble plant sugars into intermediates such as alcohols, ketones, aldehydes, acids, and furans, and further converts these intermediates into aviation kerosene. This process includes pretreatment and enzymatic hydrolysis of lignocellulosic biomass to obtain C5 and C6 sugars. Water soluble sugars are purified and concentrated, and solids and impurities that cannot be converted into soluble sugars are removed, improving the conversion efficiency of the reaction. The purified hydrolysate is converted into polyols or short chain oxygen-containing compounds through hydrogenation, and then undergoes aqueous phase reforming. Finally, the product is fractionated to obtain jet fuel. The unconverted solids, lignocellulose, and light alkanes generated during the APR process will be sent to the combustion chamber to provide thermal energy.
V. Power to Liquid (PTL)
PTL technology combines CO2, water, and renewable energy to produce SAF, which has characteristics similar to fossil jet fuels. The three main steps that make up this pathway are CO2 capture, hydrogen production (usually from water electrolysis), and hydrocarbon synthesis and regulation processes. The synthesis of hydrocarbons can be carried out through two different pathways: Fischer Tropsch (FT) synthesis or methanol synthesis for jet fuel; However, the performance of the FT process is superior to that of the methanol pathway, as the mixture containing 50% FT derived SAF and 50% conventional jet fuel has been certified by ASTM and can be put into use without modification.
Conclusion
Among the above technical routes, HEFA is currently the only mature route for commercialization, the most widely adopted process route in various countries, and the most commercially feasible production route in China. However, due to the shortage of raw materials and the fact that HEFA technology does not have the same decarbonization and emission reduction properties as ATJ and G+FT routes, it will gradually be replaced by ATJ, FT, PTL synthesis routes in the future.
Therefore, in the long run, there are three potential technological routes for development, namely gasification Fischer Tropsch synthesis (G+FT), alcohol to aviation kerosene (ATJ), and power synthesis fuel (PTL) technology.
According to statistics from the Rocky Mountain Institute, as of August 2023, the global announced production capacity for Fischer Tropsch synthesis has reached 1.36 million tons, mostly concentrated in North America and the United Kingdom. Only one North American startup, WasteFuel, plans to build a factory in the Philippines in Asia. Among them, Fulcrum Bioenergy in North America has officially entered commercial operation, and Enerkem in Canada is also under construction and is expected to start production in 2023.
In terms of alcohol based aviation coal, as of August 2023, the globally announced planned production capacity is approximately 960000 tons per year. Among them, only Gevo's small-scale demonstration project in the United States has been put into operation, while another American company LanzaJet is still under construction and is expected to start production in 2023. Except for Europe and America, only one Japanese company in Asia has announced that it will use alcohol to oil technology to produce SAF.
In terms of power synthetic fuels, based on the current level of technological development in various countries, synthetic fuels are still far from large-scale application. The current problems with synthetic fuels mainly manifest in three aspects: multiple production stages, limited process efficiency, and uneven technological maturity in each stage, resulting in high overall production costs for synthetic fuels. Although key technologies and equipment such as photovoltaics, wind power, and electrolyzers have achieved significant cost reductions in recent years, the price of synthetic fuels is still far behind traditional fuels.
Enlightment for China's SAF Industry
At present, the potential supply of catering waste oil in China exceeds 13 million tons per year. Although HEFA is currently the most important preparation technology adopted in China, there are challenges such as high export demand, scattered sources, and high collection and transportation costs. In the long run, it is not realistic to continue to follow the HEFA route. However, in terms of G+FT and ATJ, China currently lacks advantages and lacks technological reserves and research and development foundations; PTL is currently in the research and development stage. But China has accelerated the large-scale development of the green hydrogen industry, and in the long run, the prospects for PTL to accelerate commercialization and scale application are broad.
In the past two years, there have been frequent achievements in the field of PTL: State Power Investment Corporation has started the construction of a sustainable aviation coal demonstration project with an annual output of 10000 tons in Tacheng, Xinjiang in July 2023. On December 10, 2023, the Qiqihar Million Ton Hydrogen based Green Energy Base and Ten Thousand Ton Green Aviation Coal Demonstration Project was launched in the Laha Biotechnology and Chemical Pharmaceutical Industry Park in Nehe City. The project has a total investment of 42 billion yuan, covers an area of 162.9 hectares, plans to build 3.5 million kilowatts of off grid wind power, and is equipped with a 164000 ton/year hydrogen production system, which can achieve an annual output of 400000 tons of green aviation coal and 400000 tons of green methanol.
According to the above, based on the current situation, China has only accumulated certain knowledge in HEFA process and FT synthesis technology routes, and Chinese enterprises have no patent layout in ATJ route and PtL route, which have great emission reduction potential. As the country with the largest consumption and production of SAF today, the United States has the highest number of patent applications in various technological branches, and has an advantage and dominant position. For our country, in order to achieve the established goals, it is necessary to first formulate a long-term plan for SAF application, determine the SAF preparation process route that is in line with China's national conditions as our medium - and long-term development route, and provide strong support. We need to increase investment in small-scale, pilot, and industrial research on related improvement and alternative routes in order to achieve overtaking, help China's independent standard formulation, break through the constraints of international standards, and promote industrialization landing. Secondly, we also need to connect the innovation chain, industry chain, and funding chain of SAF, integrate innovation resources, vigorously promote the integration of industry, academia, and research in technological innovation and incentive mechanisms, in order to accelerate the application of SAF technology, reduce costs, and promote commercialization. Only in this way can we achieve the ambitious goal of becoming the world's largest producer and supplier of SAF in the long run.
Previous：Nothing
