Zero carbon emissions for major airline -- Do you think this is achievable? If so, how?

[tspear]

It is always funny to read the comments about how people forget. Politicians are now finding to their regret that the internet tends not to forget; and younger generations are much better at recall than old foggies like me, largely because they are willing to search and find it on the net

Anyway, electric flight should be viable for short range flights. You already have Cape Air and couple other short haul operators planning to switch to electric for flights under 200 miles which is a large percentage of their flights. Over the next thirty years, you would expect that the range and size will increase by a few percent every year.
Unless there is a major leap ahead in some sort of technology for energy storage, the only viable solutions remaining would be some sort of bio-fuel. Depending on the bio-mass you can either go one of two directions, bio-diesel which is largely based on the plant oil or ethanol which is based on the sugar/starches in the plants. Assuming I follow the states of both solutions, the ethanol based solutions are further ahead on the production side, likely by a few decades in terms of research. While bio-diesel is further ahead on testing and operating actual equipment with bio-diesel. It will be an interesting race to watch to get to the finish line.

Oh, for those advocating fuel cells, or other hydrogen solutions. They are just way to inefficient. The best fuel cell tech I have read upon converts roughly 50% of the hydrogen to electricity, the rest is heat. Then combine that with the weight and cost of pressure vessels... And the requirements the FAA will require on a large airliner. Yeah, I just do not see this technology working on a large scale.

Tim

 

[Pi1otguy]

My questions are:
1. Is a 100% reduction in carbon emissions possible for a major airline (assuming they don't shut down)?
2. If so, how?

1. Depends on the accountant.

2. Turbines can burn a wide variety of flammable liquids, technically if we ignore regs and wear issues. Plants can burn. There was a proof of concept flight years ago running a jet on algae based fuel.

In theory burning plants is nearly carbon neutral, especially algae fed power plant exhaust. That's gotta be 80% if you got a good accountant.

 

[GRG55]

I don't know if it's achievable, but betting against it being achieved is a bet against human ingenuity.
And historically that's been a poor odds wager.

 

[Salty]

I don't know if it's achievable, but betting against it being achieved is a bet against human ingenuity.
And historically that's been a poor odds wager.

Depends how you look at it. I could probably name two things we haven’t achieved for every one we have. I’ll start with flying cars, time travel, perpetual motion, and cold fusion.

 

[GRG55]

Depends how you look at it. I could probably name two things we haven’t achieved for every one we have. I’ll start with flying cars, time travel, perpetual motion, and cold fusion.

And if you want to run such a contest I bet all of the rest of us here can collectively name 100 things achieved for every one of yours not achieved. Without trying hard.

 

[Bob Noel]

people claiming that the internet never forgets are ignoring deletions of "fake news"

anyway, in the end entropy wins.

 

[Salty]

And if you want to run such a contest I bet all of the rest of us here can collectively name 100 things achieved for every one of yours not achieved. Without trying hard.

Not really. There a finite number of things we’ve achieved and an infinite number of things we haven’t. We haven’t travelled the speed of light. We haven’t travelled the speed of light +1. Etc

 

[PaulS]

They will become zero emission when dumbass leadership like this guy drives them out of business.

 

[eman1200]

...I bet all of the rest of us here can collectively name 100 things achieved.....

I have achieved total consciousness. so I got that goin' for me, which is nice.

 

[Lindberg]

I reviewed the rules, just in case. This is not a political post. It's a technical discussion prompted by a statement from the CEO of a major US airline.

I got an e-mail today (April 13, 2021) from United Airlines. Here is an excerpt:

"A note from our CEO, Scott Kirby.

This Earth Month, we have a lot to celebrate at United. We've committed to being 100% green by reducing our carbon emissions 100% by 2050 and have invested in ground-breaking technology to make our goal a reality. But there's still a long way to go. And today, we're launching an industry-first effort that has the potential to play a significant role in the global fight against climate change."
​

Reducing something by 100% eliminates it completely, so United is committed to eliminating all carbon emissions by 2050.

My questions are:
1. Is a 100% reduction in carbon emissions possible for a major airline (assuming they don't shut down)?
2. If so, how?

This email has zero to do with what will happen 30 years from now and is 100% about getting good PR and enviro cred today. If you asked United why they'd commit to something that's impossible, they'd say, "It may seem impossible today, but only by setting seemingly impossible goals and committing to them, will we change the world." If you ask them in 30 years why they didn't reach the goal (if the company still exists), they'll say, "We set lofty goals in the hopes of changing the world. The technology was not available to reach full carbon neutrality, but we're still committed to the environment."

In other words, the email was written by PR people, not engineers.

 

[Llewtrah381]

First, I think the algae answer is probably closest. Even though they’ve been working on it a while doesn’t mean it’s not imminent or possible. It’s definitely worth identifying a source of Jet-A/diesel from stuff that pulls CO2 out of the air to grow.

There was a time when LED flat screens were stupid expensive - now they’re the only game in town and inexpensive. So, today’s cost is not a measure of tomorrow’s feasibility.

Biodiesel clearly seems a smart way to go. Jet-A and diesel have far more energy density than batteries likely ever will, especially when you add in safety. Of course, small nuclear reactors are a consideration...

Second, this is capitalism at work. He wouldn’t be saying this publicly if it hurt shareholder value - similar to the earlier announcement about training plans. We internet peeps can anonymously say our opinions about his plans all we want but he has skin in the game - we don’t.

To me it’s pretty exciting that he - and other companies - appear to see options that are imminent and therefore possible to plan with and for.

 

[GRG55]

Not really. There a finite number of things we’ve achieved and an infinite number of things we haven’t. We haven’t travelled the speed of light. We haven’t travelled the speed of light +1. Etc

Ya, you're right. After all we're still trying to figure out "Why Aircraft Engines Quit?", "Do pilots still navigate?" and what's a negative tip. So there are many things left to achieve.

 

[farangutan]

Didn’t see anyone post this development. I think it’s a good transition technology until we figure out the next big thing.
https://www.sciencealert.com/researchers-find-way-to-pull-carbon-out-of-the-air-and-make-it-jet-fuel

 

[Everskyward]

Then there's this https://www.bbc.com/future/article/20210401-the-worlds-first-commercial-hydrogen-plane. Reminded me of Henning...

 

[Zeldman]

Already been done.

 

[chemgeek]

I reviewed the rules, just in case. This is not a political post. It's a technical discussion prompted by a statement from the CEO of a major US airline.

I got an e-mail today (April 13, 2021) from United Airlines. Here is an excerpt:

"A note from our CEO, Scott Kirby.

This Earth Month, we have a lot to celebrate at United. We've committed to being 100% green by reducing our carbon emissions 100% by 2050 and have invested in ground-breaking technology to make our goal a reality. But there's still a long way to go. And today, we're launching an industry-first effort that has the potential to play a significant role in the global fight against climate change."
​

Reducing something by 100% eliminates it completely, so United is committed to eliminating all carbon emissions by 2050.

My questions are:
1. Is a 100% reduction in carbon emissions possible for a major airline (assuming they don't shut down)?
2. If so, how?

They will have to buy carbon offsets. Which is kind of like a promising not to burn down a forest and then proudly claiming credit for saving the trees.

The reality is there is no current technology available to power a practical passenger airliner that does not directly or indirectly produce carbon emissions. At some point in the future it may be possible to deploy hydrogen-powered aircraft which will come closer to carbon-neutral, but even that hinges on the method of hydrogen production. The primary means of production of hydrogen now requires natural gas. And electrolysis requires an energy source, which would to a large extent utilize fossil fuels. Only solar, wind, tidal, and nuclear, for example, are truly carbon-neutral energy generators.

Electric anything is not really carbon-nuetral...yet. Electric vehicles simply increase the efficiency of fossil fuel energy capture, and move the carbon emissions to another location. Fossil fuel powered electrical generation is maybe double the efficiency of internal combustion.

 

[Palmpilot]

They will have to buy carbon offsets. Which is kind of like a promising not to burn down a forest and then proudly claiming credit for saving the trees.

The reality is there is no current technology available to power a practical passenger airliner that does not directly or indirectly produce carbon emissions. At some point in the future it may be possible to deploy hydrogen-powered aircraft which will come closer to carbon-neutral, but even that hinges on the method of hydrogen production. The primary means of production of hydrogen now requires natural gas. And electrolysis requires an energy source, which would to a large extent utilize fossil fuels. Only solar, wind, tidal, and nuclear, for example, are truly carbon-neutral energy generators.

Electric anything is not really carbon-nuetral...yet. Electric vehicles simply increase the efficiency of fossil fuel energy capture, and move the carbon emissions to another location. Fossil fuel powered electrical generation is maybe double the efficiency of internal combustion.

Thanks for that info.

How does the efficiency of electric motors compare to the efficiency of internal combustion? (Whatever power loss occurs in the motor would reduce the net efficiency of the end-to-end operation.)

 

[RyanB]

I could probably name two things we haven’t achieved for every one we have. I’ll start with flying cars, time travel, perpetual motion, and cold fusion.

I get what you’re saying, but relatively speaking, those things (besides flying cars to some degree) are science fiction and in absolute terms - not possible. Now, while I think this proposal by the United CEO is quite the stretch, it’s not impossible, but I can’t imagine true net zero emissions unless they can get off fossil fuel.

 

[SoonerAviator]

I'm just curious about how much of the flying population gives a flip about what eco-bs the airline is spouting? I'd wager that most people book airline tickets based off of price and schedule availability, then prior experience with airline staff/luggage policies. Waaayy down the list is whether they promise to be carbon-neutral at some point in the coming 3 decades, lol. If this is the best that United's marketing department can come up with, they have bigger problems than being carbon-neutral in 30 years.

 

[RyanB]

I'm just curious about how much of the flying population gives a flip about what eco-bs the airline is spouting? I'd wager that most people book airline tickets based off of price and schedule availability, then prior experience with airline staff/luggage policies. Waaayy down the list is whether they promise to be carbon-neutral at some point in the coming 3 decades, lol. If this is the best that United's marketing department can come up with, they have bigger problems than being carbon-neutral in 30 years.

I’d wager that most people in general aren’t concerned about being eco-friendly, which is really a shame and very troubling. I think the rationale behind this announcement, is to show that the company is more or less striving to do their part to better the environment; but you’re right, in the grand scheme of things, it’s very low priority for the flying public.

 

[farangutan]

Thanks for that info.

How does the efficiency of electric motors compare to the efficiency of internal combustion? (Whatever power loss occurs in the motor would reduce the net efficiency of the end-to-end operation.)

Electrical motors are way more efficient than ICE motors but the key problem is energy density for storage. A gallon of gas even with all of its losses has much more usable energy per pound than batteries.
I do have solar panels that could charge an EV car battery but it’s my understanding that it would take a significant portion of the lifetime of the solar panel generating electricity to offset the energy from fossil fuels used to make them.

 

[Cap'n Jack]

Yep. Hydrogen sucks from an energy density perspective. And any practical use would require cryogenic type storage and/or extremely strong (pressurized) containers. None of that stuff is light.

My realistic expectation is that aviation and maybe oceangoing ships will continue to use petrochemicals as their energy source. Maybe there are ways to be more efficient or have cleaner emissions, but high energy density is required in both cases. On the other hand, with better batteries, plus cleaner generation (I continue to pray that someone perfects controlled fusion, but as soon as that happens, the NIMBY's will line up 10 deep to prevent it near *their* house.), I think most manufacturing, residential, and ground transportation could be converted to something much cleaner than what we use today.

That probably solves 80-90% of the CO2 emission "problem".

Even cryogenic sucks with respect to energy density. I did the calculations when a fellow named Henning Heineman was pushing hydrogen in this forum a few years ago. There's some groups trying to adsorb hydrogen into various materials, but nothing noteworthy as yet- this gets you away from highly pressurized vessels. There's some interesting progress in batteries that may (or may not) pan out that would make electric 1 to 6 seat planes practical (or Harbor Air, since their routes are so short).

 

[172andyou]

Oh, for those advocating fuel cells, or other hydrogen solutions.

Nah, Henning has been gone for a long time.

 

[172andyou]

it’s my understanding that it would take a significant portion of the lifetime of the solar panel generating electricity to offset the energy from fossil fuels used to make them.

Depending on the panel it takes between 6 months and 2 years. Their lifespan is 25-30 years.

The entire industry went positive (meaning, all the energy consumed to make all the solar stuff ever, since the 1960's) about a decade ago. So it's been a net positive for a long time, and is also economically affordable now also. Much less expensive than coal and nuclear. Approximate parity with gas and oil. (All of which also take power to build, of course)

We still need to solve the storage problem, so we can power things at night, but peak loads are during the day anyway - so modern solar is a slam dunk and will continue to grow as technology continues to improve.

 

[Tarheelpilot]

I don't know if it's achievable, but betting against it being achieved is a bet against human ingenuity.
And historically that's been a poor odds wager.

Well if I thought they actually intended to do as they say and were willing to spend the $$ required then sure. I don’t think they are telling the truth. I think it’s just marketing.

 

[Lindberg]

I'm just curious about how much of the flying population gives a flip about what eco-bs the airline is spouting? I'd wager that most people book airline tickets based off of price and schedule availability, then prior experience with airline staff/luggage policies. Waaayy down the list is whether they promise to be carbon-neutral at some point in the coming 3 decades, lol. If this is the best that United's marketing department can come up with, they have bigger problems than being carbon-neutral in 30 years.

It cost United nothing to put out a press release, and there's no downside to making this statement. Plus, the target audience is likely more corporate than individuals.

 

[Lindberg]

First, I think the algae answer is probably closest. Even though they’ve been working on it a while doesn’t mean it’s not imminent or possible. It’s definitely worth identifying a source of Jet-A/diesel from stuff that pulls CO2 out of the air to grow.

There was a time when LED flat screens were stupid expensive - now they’re the only game in town and inexpensive. So, today’s cost is not a measure of tomorrow’s feasibility.

Biodiesel clearly seems a smart way to go. Jet-A and diesel have far more energy density than batteries likely ever will, especially when you add in safety.

Doesn't burning any of these things still emit carbon dioxide? So you still can't get to zero emissions that way.

 

[chemgeek]

Thanks for that info.

How does the efficiency of electric motors compare to the efficiency of internal combustion? (Whatever power loss occurs in the motor would reduce the net efficiency of the end-to-end operation.)

Electric motors are nearly 100% efficient. Long distance electrical transmission is 85+% efficient. Large electrical generation plants operate close to the Carnot efficiency for heat engines, and that is primarily a factor of the temperature of the generated steam. Current power plant technologies approach 40% efficiency in converting heat energy to electricity. Internal combustion engines top out at around 20%, so electric vehicles are demonstrably more efficient than internal combustion vehicles even accounting for the entire energy transmission chain. So it is worth doing from an energy conservation and environmental standpoint, even with the existing suite of power generation technologies. But electric vehicles are far from carbon-neutral, which is what much of the public perceives. Even my undergraduate STEM students hadn't thought this through very clearly until they encountered the underlying science in one or more classes. The non-science students at my university generally have no clue at all.

 

[X3 Skier]

People are talking as if the CEO was claiming carbon neutrality when the plain words were “reducing carbon emissions 100%. Unless the definition of emissions has somehow somewhere changed, that’s what comes out the tailpipe (or from wherever on the amazing zero carbon emissions gizmo propelling the aircraft).

Complete BS by the PR Dept mouthed by the CEO. But what isn’t?

Cheers

 

[Cap'n Jack]

Doesn't burning any of these things still emit carbon dioxide? So you still can't get to zero emissions that way.

Those things also take carbon dioxide from the air, or a process that emits it such as brewing beer. All the carbon you find in a tree or another plant came from the air.

 

[chemgeek]

I get what you’re saying, but relatively speaking, those things (besides flying cars to some degree) are science fiction and in absolute terms - not possible. Now, while I think this proposal by the United CEO is quite the stretch, it’s not impossible, but I can’t imagine true net zero emissions unless they can get off fossil fuel.

I think it is indeed impossible in the near term to achieve true carbon-neutral status in the air transport industry. (Carbon offsets, while well-intended, don't really address the core issue in a direct way.) The airline industry is one that has a negative environmental perception. I applaud them for paying attention, and making an effort to increase energy efficiency and lighten the environmental burden, but at least for now the claim to become carbon-neutral amounts to little more than "greenwashing."

 

[Llewtrah381]

Doesn't burning any of these things still emit carbon dioxide? So you still can't get to zero emissions that way.

But you can get to NET zero if you develop/use methods of capturing CO2 to the extent they offset the amount of CO2 produced by the jets, handling equipment, etc. I’m pretty sure that’s the goal here.

 

[X3 Skier]

But you can get to NET zero if you develop/use methods of capturing CO2 to the extent they offset the amount of CO2 produced by the jets, handling equipment, etc.

True.

Except that’s not what he said.

Cheers

 

[SoonerAviator]

It cost United nothing to put out a press release, and there's no downside to making this statement. Plus, the target audience is likely more corporate than individuals.

I didn't speak to cost, specifically. I'm just implying that if this is what their Marketing team spends their time prioritizing to push out to the press, they have bigger problems. Unless they think a bunch of corporations are just clamoring to say they "partner with United", it won't result in any increased business. It's just BS marketing-speak trying to pander to the flavor of the week.

 

[Ghery]

UA has been selling the "opportunity" to purchase carbon offsets with their tickets for several years now. I haven't given them any money for this "opportunity", nor will I, but for those who feel the need to "do something", feel free.

 

[midwestpa24]

UA has been selling the "opportunity" to purchase carbon offsets with their tickets for several years now. I haven't given them any money for this "opportunity", nor will I, but for those who feel the need to "do something", feel free.

I've only recently noticed airlines do that. They also tell you how many tons of CO2 your seat is creating. Last time I rented a car, they offered to sell carbon offsets. Sure sign me up for that voluntary tax. One that no one can tell you where the money actually goes.

 

[Tantalum]

I'm just curious about how much of the flying population gives a flip about what eco-bs the airline is spouting? I'd wager that most people book airline tickets based off of price and schedule availability, then prior experience with airline staff/luggage policies. Waaayy down the list is whether they promise to be carbon-neutral at some point in the coming 3 decades, lol. If this is the best that United's marketing department can come up with, they have bigger problems than being carbon-neutral in 30 years.

Agree. The average person generally dislikes the whole experience with flying so they go to orbits or one of the other sites and purchase some compromise of cheapest ticket and schedule that works for them

 

[Daleandee]

Electric vehicles simply increase the efficiency of fossil fuel energy capture, and move the carbon emissions to another location.

 

[Cap'n Jack]

Electric vehicles simply increase the efficiency of fossil fuel energy capture, and move the carbon emissions to another location.

Generally, that is true. It depends on where you live. Iowa and KS have some wind power, a lot of the northeast gets hydropower from Canada.

 

[Daleandee]

Generally, that is true. It depends on where you live. Iowa and KS have some wind power, a lot of the northeast gets hydropower from Canada.

Good point but it's difficult to connect a vehicle to a wind turbine or hydropower plant. The battery technology isn't there yet and the emissions from new battery technology seems to be quite costly.

Once in operation, electric cars certainly reduce your carbon footprint, but making the lithium-ion batteries could emit 74% more CO2 than for conventional cars.

https://www.industryweek.com/techno...acturing-them-leaves-massive-carbon-footprint