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Do we really have sustainable aviation fuel?

by lcam84 5y ago

pjerem 5y ago
Of course not.
aero-glide2 5y ago
Its very expensive right now. Expect that to change
jillesvangurp 5y ago
There are several viable candidates. The reason this is hard are more related to a lack of infrastructure than fundamental technical issues. Producing vast amounts of fuel and putting the infrastructure in place to get it to airports around the world is a non trivial effort. Here's a list of things that could work: - Hydrogen has been used as rocket fuel and e.g. Airbus is working on adapting jet engines to burn it. Green hydrogen generated from wind/solar would be zero carbon and sustainable. It probably would not be that cheap though. It might also be interesting in combination with fuel cells. Airbus is working on that as well. Late 2030s are apparently what they are shooting for for this. - Methane, also used as a rocket fuel (e.g. SpaceX). There have been multiple attempts to use liquid gas as aviation fuel and if you use e.g. bio gas or synthesize it, it could be sustainable. I don't think there are a lot of companies working on this for aviation but it has definitely worked in the past as a fuel. Of course fossil supplies of methane are plentiful but not very sustainable. Synthesizing it would be similarly expensive as other synthetic fuels. - Ethanol (what boom is apparently proposing to use) is also suitable as a fuel. Corn based ethanol is of course controversial (i.e. only sustainable if you don't look at the production process with too much scrutiny) but there may also be ways to synthesize it in different ways as well. Currently mixing a portion of ethanol in fuels is a popular way for oil companies to green wash their business. Therefore, there's good reason to be wary of companies promoting its use. - Kerosene could feasibly be synthesized long term (just like a lot of other carbohydrates). Technology for that exists but there are a lot of scaling issues to solve. E.g. Shell is working on that. This would obviously be great for powering legacy planes for the foreseeable future. Planes produced today could fly well into the 2050s or beyond. So there is an obvious economic incentive to make that work. IMHO hydrogen is the most obvious path as there is a growing momentum to use it in many other applications and some serious effort to product it in sustainable ways. E.g. Airbus bringing planes to production in the late 2030s could inspire a lot of airports to start investing in related infrastructure. Relative to kerosene, it would be lot less polluting. Co2 is not the only issue associated with burning kerosene. Synthetic Kerosene might be a good second option. Everything else could work but seems less obvious right now.

Do we really have sustainable aviation fuel?

by lcam84 5y ago

Do we really have sustainable aviation fuel?

pjerem 5y ago

Of course not.

aero-glide2 5y ago

Its very expensive right now. Expect that to change

jillesvangurp 5y ago

There are several viable candidates. The reason this is hard are more related to a lack of infrastructure than fundamental technical issues. Producing vast amounts of fuel and putting the infrastructure in place to get it to airports around the world is a non trivial effort. Here's a list of things that could work: - Hydrogen has been used as rocket fuel and e.g. Airbus is working on adapting jet engines to burn it. Green hydrogen generated from wind/solar would be zero carbon and sustainable. It probably would not be that cheap though. It might also be interesting in combination with fuel cells. Airbus is working on that as well. Late 2030s are apparently what they are shooting for for this. - Methane, also used as a rocket fuel (e.g. SpaceX). There have been multiple attempts to use liquid gas as aviation fuel and if you use e.g. bio gas or synthesize it, it could be sustainable. I don't think there are a lot of companies working on this for aviation but it has definitely worked in the past as a fuel. Of course fossil supplies of methane are plentiful but not very sustainable. Synthesizing it would be similarly expensive as other synthetic fuels. - Ethanol (what boom is apparently proposing to use) is also suitable as a fuel. Corn based ethanol is of course controversial (i.e. only sustainable if you don't look at the production process with too much scrutiny) but there may also be ways to synthesize it in different ways as well. Currently mixing a portion of ethanol in fuels is a popular way for oil companies to green wash their business. Therefore, there's good reason to be wary of companies promoting its use. - Kerosene could feasibly be synthesized long term (just like a lot of other carbohydrates). Technology for that exists but there are a lot of scaling issues to solve. E.g. Shell is working on that. This would obviously be great for powering legacy planes for the foreseeable future. Planes produced today could fly well into the 2050s or beyond. So there is an obvious economic incentive to make that work. IMHO hydrogen is the most obvious path as there is a growing momentum to use it in many other applications and some serious effort to product it in sustainable ways. E.g. Airbus bringing planes to production in the late 2030s could inspire a lot of airports to start investing in related infrastructure. Relative to kerosene, it would be lot less polluting. Co2 is not the only issue associated with burning kerosene. Synthetic Kerosene might be a good second option. Everything else could work but seems less obvious right now.