Can we talk honestly about aviation biofuel?

[Evan]

I'm still trying to wrap my head around the claim that these are 'sustainable' aviation fuels. To begin with, our current rate of emissions is unsustainable, so anything that is merely neutral to the current rate is unsustainable. The only sustainable fuels would be those that actually reduce emissions to a sustainable level (and that's a large reduction).

Secondly, photosynthesis via plants and organisms is a carbon sink. It creates a captured reserve of carbon that will not return to the atmosphere. This is essential to a sustainable balance in the carbon cycle. If we burn ANYTHING, we are returning that carbon to the atmosphere, thus achieving, at best, a carbon neutral process, and, again, that is not sustainable.

SAF fuels also are derived from sources that may increase, or retain, the current levels of deforestation, which are unsustainable. Lufthansa uses a biofuel created by Neste Oil which is derived from reclaimed palm oil from the palm oil refining industry. That industry is unsustainable, therefore any feedstock for fuels that depends on that industry is unsustainable.

Boom is pushing ahead with its supersonic transport development (with UAL on board), claiming it is sustainable because it uses sustainble aviation fuel. That's nonsense. It is burning more fuel per seat/mile (much more) than needed in order to transport passengers in less time, which is not sustainable. They can claim that it uses less fuel than the Concorde, but neither design is at all sustainable.

Sustainability can be defined as anything the REDUCES our carbon output to levels that are in balance (or in deficit) with the carbon cycle and no longer contribute to increased climate warming. Carbon neutrality at this point is no longer sustainable. Minor reductions are no longer sustainable. And, by all means, diminished increases are most certainly not sustainable.

So how is SAF not just one big greenwashing scheme to greenlight growth in an already unsustainable industry? In fact, how is it more environmentally sustainable than fossil fuel? At least fossil fuel, which is most definitely NOT sustainable, doesn't also consume active photosynthesizing vegetation.

[Gabriel]

To begin with, our current rate of emissions is unsustainable, so anything that is merely neutral to the current rate is unsustainable. The only sustainable fuels would be those that actually reduce emissions to a sustainable level (and that's a large reduction).

Secondly, photosynthesis via plants and organisms is a carbon sink. It creates a captured reserve of carbon that will not return to the atmosphere. This is essential to a sustainable balance in the carbon cycle. If we burn ANYTHING, we are returning that carbon to the atmosphere, thus achieving, at best, a carbon neutral process, and, again, that is not sustainable.

Holly contradictions, Batman!

Carbon neutral is a HUGE reduction from fossil fuels emissions (in fact, it is an as-high reduction as you can reasonably obtain in a fuel), so it is sustainable by your own definition in the first paragraph. And suddenly, in the second paragraph a carbon neutral aviation fuel would not be sustainable.

If we could go carbon neutral in all activities, the crisis is over (unless we already reached a runaway trigger point that most think we have not).

[Evan]

Holly contradictions, Batman!

Carbon neutral is a HUGE reduction from fossil fuels emissions (in fact, it is an as-high reduction as you can reasonably obtain in a fuel), so it is sustainable by your own definition in the first paragraph. And suddenly, in the second paragraph a carbon neutral aviation fuel would not be sustainable.

Yes, but... no. Carbon neutral solutions do not lower the current level of greenhouse gasses in the atmosphere. They merely stop (or slow, in real world applications) raising them. But actually they don't even do this because... Add growth in consumption and biofuels require the creation of more recipricol carbon sequestration to remain neutral, which overtakes and supplants the native carbon sink that was previously there and NOT being consumed and converted back to carbon. Rain forests. Aquatic vegetation. Etc. And, since less natural resource is then absorbing carbon and simply retaining it (carbon sink) and more is recycling it to the atmosphere (carbon cycle), that translates to increased carbon imbalance in the atmosphere.

If we could go carbon neutral in all activities, the crisis is over (unless we already reached a runaway trigger point that most think we have not).

Assuming we haven't reached that point (which many question, due to complex causal chains and destructive momentum), that would be true. But it isn't the case and will not be the case, so we must have much more carbon sequestration than carbon emission to avoid environmental disaster. In other words, we need to leave natural carbon sinks alone, not repurpose them into a vast resource of neutral carbon cycles.

Do you follow?

[Evan]

For example, Neste's SAF depends on palm grove expansion, which is a major driver in the deforestation of native tropical canopies. The palms are then greatly inferior in terms of carbon sequestration to the forests they have replaced, so there is a net increase to the carbon imbalance right there. But then add the vast amount of sequestered carbon released from peat soils in the process. How is that sustainable? How is that even neutral?

You could argue (as Neste does) that the palm oils used are merely residual waste from palm oil production for other purposes, but that doesn't make it any less sustainable because it is parasitically dependent on industries which are most definitely unsustainable.

[Gabriel]

Have you gone vegan already?

[Gabriel]

You are starting to sound a lot like TeeVee now. I don't mean to leave it at that but I don't have time right now for the lengthy discussion.

[Gabriel]

There. That's all I will say (by now) because I already said it.

[Evan]

Have you gone vegan already?

My perfect solution is to move away from combustible fuels on the ground and leave them for the skies, where weight and volume per unit of energy is the issue. If we stopped using them for other purposes, we could burn all the jet A we need in a sustainable fashion.

What irks me is the BS of green washing. The first step toward saving the planet is to start being honest with each other. And, in all honesty, there is no way flying supersonic is going to be ‘sustainable’ in the current state of affairs. No matter what you are burning.

[3WE]

My perfect solution is to move away from combustible fuels on the ground and leave them for the skies, where weight and volume per unit of energy is the issue. If we stopped using them for other purposes, we could burn all the jet A we need in a sustainable fashion.

The imperfection is that the poor people of planet earth probably need your combustible fuels on the ground more than you elitists do to go visit Europe in shiny airplanes.

What irks me is the BS of green washing. The first step toward saving the planet is to start being honest with each other. And, in all honesty, there is no way flying supersonic is going to be ‘sustainable’ in the current state of affairs. No matter what you are burning.

I concur that the BS thing gets me. My biggie is Carbon Credits and carbon-neutral stuff. Microsoft pledges to be carbon neutral- So phugoid what?...you sit on your butt and type computer code. The local natural gas utility also pledged to be carbon neutral. EXCUSE ME??? Oh, nice, I'm the one making the CO2, but you pressurize the CH4 with solar power...WHATEVER.

"Be honest with each other" ROFLMAO...(Start with Microsoft and Spire gas).

3BS thoughts on biofuels. Like you said, energy/weight is a biggie, and planes might really need firewater instead of batteries.

I get your CONCEPT of electrifying ground transportation...and I had an interesting argument with Gabriel that I have plants that are good for making ethanol or vegetable oil.

We went in circles with him citing that the energy balance is garbage (how much fuel do we consume to make a bushel of corn). Aggies claim it's a bit positive in energy gain...but even if it's slightly negative- perhaps we grow soybeans with electric tractors AND USE THAT TO FUEL AIRPLANES FOR THE 1%.

Gabriel didn't like it that I was taking resources from cattle feed and Amazon forests to grow those beans. (I do not wish to dismiss his thoughts on that- a LOT OF THINGS will need to change).

The other circular argument was that Gabriel was going to simply make hydrocarbons out of electricity. That process is energy expensive to do in a plant (with reactors and tanks) AND energy expensive to do in a plant (with leaves and chlorophyll and the Z-scheme)...still, there's a nice simple beauty to throwing soybean seeeds out there, spraying glyphosate a couple times, watching them grow and squeezing a decent amount of oil out of the resulting crop.

Gabe and I also had an interesting argument- Pro-Ag people claim that making ethanol leaves you with corn meal that is just as nutritious to cows...I thought that "just as nutritious" might be an over statement...but that maybe there was some undigestible energy that can be "siphoned off". Then again, you can compost the cow manure and get some methane too...there's a lot of energy floating around in a lot of different chemical forms, and very little 100% of anything.

Again- the bottom line- Biofuels MIGHT be useful to fuel airplanes if fossil fuels run out...Gabe's chemical plant and my bio-plant both make energy expensive hydrocarbons...Electricity ==> gas in a brick and mortar plant or Electrically-supported farming ==> soybean oil. We are both researching ways to improve efficiencies- BUT I DON'T CLAIM A FREE LUNCH NOR A FAT, DUMB AND HAPPY UTOPIA...just a way to make hydrocarbon fuel for the 1%.

[LH-B744]

Ahm. This is a question which I should rather discuss with Alex, but, probably one of you can help me, too.

Is it good to have ten red bars, where I have not one? Alex has two red bars.

So, I assume that red bars are a good thing. One red bar for 100 good forum entries within one week?

That's definitely not something which I was good for since the year 2008.

I am rather the long haul, more nautical miles, less words. And I definitely LOVE HER:

https://www.jetphotos.com/photo/10638986

[3WE]

***Is it good to have ten red bars?***

I suppose it could be an activity index? Or how often you get quoted, or likes?

I liked several of your posts today to see if I could get you some red bars.

It is a curious question.

EDIT: You’ve got some bars now that I liked several posts. Edit edit: At first, it was only a few.

[Gabriel]

Congratulations. Now you have 10 bars, that's 2 more than me.

[3WE]

Congratulations. Now you have 10 bars, that's 2 more than me.

You're welcome, LH-B

[3WE]

I read a potentially biased factoid: Fossil fuels contain 5000% more energy per pound than our current batteries…

Maybe so, but I’m guessing that’s discussion worthy…combustion engines are about 30% efficient, so maybe the 5000% might be less when you talk useful energy…shoulder shrug.

[Not_Karl]

(...)combustion engines are about 30% efficient, so maybe the 5000% might be less when you talk useful energy…shoulder shrug.

And even less for people daily driving in 4WD mode.