At least it's hypothetically possible to create with less net carbon impact than fossil fuels. It still has a long way to go, but we've got to invest in things that aren't practical right now if we ever want aviation to decarbonize.
The most common method of making biodiesel that I know of involves fermenting farming byproducts, namely corn stalks and manure.
However, it still produces CO2 when it combusts.
Everything I have heard about sustainable jet fuel basically points to it being a pipe dream. Bio fuel is not effectively scalable and shows no hope of being so. Where synthetic fuel just increases the energy input per unit of fuel. Neither one addresses the fact that petroleum combust engines at a high altitude have a much greater impact than ones on the ground due to the fact that they inject particulates into the stratosphere. This needs to be placed in the bin as "clean coal"
It seems particulate matter was reducing the impact of increasing CO2. The rate of warming increased as countries around the world cleaned up their air.
There are a number of factors driving the acceleration of warming. While the world has made real progress in slowing down the growth of carbon dioxide and other greenhouse gas emissions, they have yet to peak and decline. And on top of this, we are reaping the results of what the climate scientist James Hansen calls our “Faustian bargain” with air pollution. For decades, air pollution from sulfur dioxide and other hazardous substances in fossil fuels has had a strong temporary cooling effect on our climate. But as countries around the world have begun to clean up the air, the cooling effect provided by these aerosols has fallen by around 30 percent since 2000. Aerosols have fallen even more in the past three years, after a decision to largely phase out sulfur in marine fuels in 2020. These reductions in pollution on top of continued increases in atmospheric greenhouse gas concentrations mean that we are encountering some of the unvarnished force of climate change for the first time.
Honestly not an expert on the effects of each part of global warming. I do know that NOx is a big by-product of high temp combustion(jet engines) NOx is a green house gas that is not affected by carbon capture and I believe that the rules about the effects of particulates and gas differ from the troposphere and the stratosphere.
Sorry to burst your bubble, but no matter how bad they are for the planet, planes aren't going anywhere. People will not stop flying, passenger numbers are increasing year by year. Finding climate friendly fuels is the only hope to fix this problem, cause it's not realistically going anywhere
If only the energy to create it was from nuclear power. But the way it is now and in the foreseeable future ... this is nonsense. You lose so much energy on the way, just use regular fuel instead. Use all of that energy in processes where it does not get wasted but saves much more CO2 instead.
There are ways to create biofuels that are much more environmentally friendly than hydrocarbon fuels, especially when starting from a waste product such as cooking oil or biomass from clearings that would otherwise be wasted.
Plus, it’s good to test out these not-yet-incredible sustainable fuels so that we can learn, improve, and wean off traditional hydrocarbon fuels.
While making it out of existing carbon compounds, of course, removes much of the energy needed, it is still a wasteful process. There are plenty of precesses where you can burn that fuel directly, with zero additional loses. We need to drive CO2 emissions down as fast as possible.
This is something that can be tackled in 30 years, when/if airplanes still need to burn fuel and other, lower hanging fruits are already gone.
What they are actually doing is trying to greewash airplanes.