During this time, Ma Longlong, the chief professor of the School of Energy and Environment at Southeast University, was a little busy. "The sustainable bio-aviation fuel we have developed is currently in the industrialization stage, and we plan to build a production line with an annual output of 10,000 tons by the end of this year. From the end of last year to now, nearly 10 companies have clearly expressed their intention to cooperate with us. "Doing research, looking at the venue, and talking about cooperation, Ma Longlong is very busy, but he is willing to do it. Carefully calculated, the world's leading new technology of refining sustainable bio-jet fuel from agricultural waste straw has been gaining momentum for 15 years, from laboratory to industrial production.
Huge carbon tax
The development of biomass aviation fuel is "ready to fly"
With the concept of environmental protection and sustainable development deeply rooted in the hearts of the people, traditional fossil fuels are facing substitution pressure, and bio-jet fuel as a sustainable alternative energy source has attracted the attention of various countries. In 2016, ICAO adopted the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). According to the resolution of the National Aviation Emission Reduction Market Mechanism, the increase in carbon emissions of international routes of airlines after 2020 needs to be offset by purchasing carbon allowances and other means. According to an institutional analysis, if this resolution is complied with, the total carbon trading expenditure of China's domestic airlines may reach 21 billion yuan by 2035. "To avoid such a huge aviation carbon tax, the alternative use of biomass jet fuel is currently the only measure that can significantly reduce emissions in the civil aviation industry. Ma Longlong said.
"From an academic point of view, biomass refers to a variety of organisms formed through photosynthesis, which covers a wide variety of species, such as crop waste, wood waste, and livestock manure. Our team focuses on lignocellulose, such as straw, grass, branches, etc. Ma Longlong told reporters that biomass resources are the only renewable resources that effectively replace petrochemical resources in an all-round way. As a source of heat supply, biomass fuels, like petroleum fuels, are mainly used in the three major areas of electricity, heating and transportation. Since biomass can be recycled as waste, biomass is used to produce energy, chemicals, and material products, which have zero-carbon and carbon-negative properties.
"Ground transportation and shipping can use electricity and hydrogen, but in aviation, there is currently no powertrain that can match the fuel system. Ma Longlong explained that the advantage of using biomass jet fuel is that it does not require aircraft and engine modifications, so it is also the best choice for carbon reduction in the aviation sector. However, the complex structure and low density of biomass raw materials make it difficult to utilize biomass. "Biomass fuels are not like petrochemical resources. Since the microstructure of petrochemical resources is clustered together, whether it is direct use or processing and refining treatment, the processing difficulty and cost are very low. However, considering the non-renewable nature of petrochemical resources and carbon tax policies, the development of biomass fuels is imperative. Ma Longlong said.
From scratch
The new path of "straw refining" leads the world
"Most of the traditional biomass fuel development encounters such bottlenecks, one is the limitation of raw materials, and the other is the usability of end products. "Before the Ma Longlong team, there had been attempts in the industry to refine bio-jet fuel from animal or vegetable fats and fats, but the path of "oil refining" did not go well. "Palm oil, gutter oil, tung oil, etc., because of the limited production, it is not possible to make biofuels. ”
If we do not use animal and vegetable fats and fats, can we replace them with straw, which has an annual output of more than 700 million tons on the mainland? This idea lingered in Malone Long's brain. However, before that, the world was also based on oil refining, and the field of straw refining was still blank. "Initially, we did combustion, vaporization, and degradation of biomass macromolecules. But in this process, from the pyrolysis point of view, part of the raw material becomes gas, and part of it becomes black oil, which is not the result we want. ”
After continuous experimental analysis, the team developed a three-element separation technology for separating hemicellulose, cellulose and lignin by solvent method, and then explored a new route for jet fuel refining technology by using the different structural differences of these three components. "In this route, the uvulinic acid and hemicellulose stripping products obtained from cellulose hydrolysis can be condensed and refined into sustainable bio-jet fuel, and furfural, like lignin, can be used as a raw material for different specialty fuels. Ma Longlong introduced that the carbon utilization rate of bio-jet fuel extracted by three-element separation technology is very high, and there are very few raw materials wasted in a set of processes. "The composition of the oil produced by this technical route is closer to that of petroleum-based jet fuel, with almost the same physical and chemical properties as petrochemical jet fuel. In addition, the direct cost of this technology is only 40% of that of biofuels with animal and vegetable fats and fats, which are currently popular. "The new path of straw refining has completely independent intellectual property rights, and the carbon emission reduction effect is better. Arguably, this new sustainable biofuel is an ideal jet fuel alternative.
Keep walking
A new era of green aviation fuel needs to be opened urgently
In 2017, the 100-ton bio-jet fuel pilot project was successfully launched in Yingkou, Liaoning Province. Ma Longlong said frankly that the pilot test is the key to promoting scientific research results from the laboratory to the production line, and during this period, the construction of a 100-ton unit is the most difficult part, "from the start of construction to the actual oil production took almost a year." Small-scale experiments in the laboratory are easy to control, but when it comes to industrial installations, processes, parameters, temperature conditions, etc., all change, and almost all processes need to be fine-tuned and need to be tried and tried. "At that time, we originally used the precious metal 'platinum' as a catalyst, but due to the cost, we went back to laboratory testing and eventually switched to the cheaper 'nickel'. ”
Ma Longlong said that the 100-ton pilot plant is still in use, but it will continue to expand production if it is to be finally marketed, and the team's goal is to obtain airworthiness certification. "Only aviation fuel that has obtained airworthiness certification can be sold internationally, and this certification process is very strict, and it has strict requirements for the production process, safety, and annual output of oil products. Ma Longlong said that if this year's annual output of 10,000 tons of production line can be successfully produced, then the annual output of the airworthiness certification evaluation index should be able to meet the standard.
"We are looking forward to a new era of sustainable bio-fuel, and we expect it to be a key force in the sustainable development of the global aviation industry. Ma Longlong revealed that the team is still working on process and technical improvements. In the past, about 1 ton of oil could be made from 10 tons of straw, but after replacing more suitable intermediates, about 1 ton of oil can be refined from less than 8 tons of straw, which saves a lot. "The pace of marketization cannot be stopped. This year's plan is to reach 10,000 tons per year, and there may be another 100,000 tons in the future, or more. ”
Xinhua Daily Intersection reporter Xie Shihan