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

pburger

pburger

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Paul B.
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?
 
I'm guessing they meant a 50% reduction. If so, it's a shame that someone at that level of a major US corporation is that bad at math. If not, I'm wondering what "ground-breaking technology" they have invested in.
 
Breathing causes carbon emissions. Even dying causes carbon emissions. Being carbon neutral means never having existed, at least on this planet.
 
Salty said:
Breathing causes carbon emissions. Even dying causes carbon emissions. Being carbon neutral means never having existed, at least on this planet.
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Yeah, that’s completely wrong. But the thread will get locked in an hour so it’s not worth pursuing
 
Anything any CEO says/writes/etc. is questionable.

Unless they limit their routes to under 250 miles with electrically power airplanes, he’s smoking something that is illegal in several states. Maybe dirigibles powered by Compressed Air for long haul?

Cheers
 
They've given themselves 29 years...I'm assuming they caveat it internally that it is based on future technologies that don't currently exist.

A lot changed in the last 30 years of aviation. Could be that much or more change in the next 30. Plus, there's a lot of other equipment United has other than airplanes, that do have existing technologies to start making a dent in it, at least, so they can show progress right off the bat.
 
Is there a fuel without carbon emissions that could power an aircraft? (cold fusion? ZPMs? dilithium crystals?)

Is there some way to scrub the emissions to capture the carbon that would be otherwise emitted? At first blush, the energy requirements to capture all carbon emissions would be prohibitive.

edit: why couldn't we use existing technology to grab the carbon emissions and convert same to something useful or at least harmless? I don't mean something on the aircraft, but something on the ground scrubbing the stuff out of the air.
 
They are talking about 0 net emissions. So they will be reducing tailpipe emissions and then doing carbon capture and other offsets to reduce the net total to 0.

I know they aren't planning to do this, but in principle, they could fly B52s and spew black soot everywhere if they also had millions of acres of trees sucking CO2 out of the air.

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atbroome said:
United has been sending me quite a few emails recently. Oddly none of them seem to be about getting me from point A to point B safely and enjoyably.
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Me, too. And like you, none of them have dealt with getting me from point A to point B safely and enjoyably. But, given how little I've ridden the airlines in the last year I'm not surprised. They're too busy going woke.
 
Scrubbing is where my thoughts went. I don't believe electric will be feasible in 2050, but also don't expect to be around to know.

I suppose it is theoretically possible to build a scrubber in the exhaust which scavenges the CO2 out OR to switch to a fuel/additive which doesn't produce C02 in the first place. But I predict, if such a fuel exists, we'll have new problems when that exhaust gas upsets the "natural" balance.
 
JVerb said:
They've given themselves 29 years...
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Probably more than that. People can't remember what happened a few months ago so they certainly aren't going to remember that some CEO at United who is probably long gone claimed that they would be at zero emissions by 2050 when 2050 actually rolls around.

Perhaps something invented between now and then will make it possible or they'll pursue the carbon capture approach. Overall, I think making announcements like this is just the trendy thing to do so they'll give it a go to drum up more business, regardless if they have a plan to get it done or not.
 
Carbon credits is the most likely path. It is the least expensive, markets for credits already exist, will make people feel good about themselves for flying “green” United, and will certainly be a great PR achievement. People will pay almost anything to get that feel-good emotion of helping the plant and using “green power” which most people seem to define as only solar or wind; why else would people in the PNW pay for community solar and other solar projects when for example the Seattle area only has a 11-12% capacity factor? Battery technology is just simply too far off in the future as a source of energy necessary for commercial aviation. My former company is now testing a 1MW battery that cost over $2M and is hooked to a solar farm in an attempt to make solar more dependable as a base generation source. Large-scale battery testing is underway at a number of solar plants and wind farms across the country. However, theses batteries are huge and some use exotic chemical combinations that would likely never be approved by the FAA. Besides, we still haven’t solved the question of what happens if EVs really take off - where’s the energy going to come from to recharge and power those vehicles? Grids are already strained and the infrastructure is starting to simply fail in certain parts of the county because of their age, inefficiency and electrical loss, inability to construct new transmission systems and load limitations.
 
It is possible, most likely by developing and using an algae based biofuel. It's already possible to create biodiesel fuel from seed crops, but the amount produced per acre is too low and farmed crops require too much cultivation, land, and water to get the job done.
 
No. Ever notice the baggage loading gizmos are little diesels? The tugs pulling luggage carts? ALL THAT STUFF?

No chance.
 
FormerHangie said:
It is possible, most likely by developing and using an algae based biofuel. It's already possible to create biodiesel fuel from seed crops, but the amount produced per acre is too low and farmed crops require too much cultivation, land, and water to get the job done.
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Here's an article on use of biofuels in commercial aviation: https://www.iea.org/commentaries/are-aviation-biofuels-ready-for-take-off
Even the optimistic scenario suggests <20% usage by 2040 compared to Jet-A, plus the price isn't yet competitive. I suspect that aviation isn't a sector too amenable to minimizing carbon emissions. A passenger tax that pays for offsets is probably the simplest option.
 
“Reducing our carbon emissions 100%” certainly isn’t offsetting, it’s eliminating. His statement is a pipe dream.

Cheers
 
FormerHangie said:
It is possible, most likely by developing and using an algae based biofuel. It's already possible to create biodiesel fuel from seed crops, but the amount produced per acre is too low and farmed crops require too much cultivation, land, and water to get the job done.
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It may be possible some day, but they've been working at it since 2005. More work is needed to make algal biofuels feasible. Maybe a lot more work.
Tools said:
No. Ever notice the baggage loading gizmos are little diesels? The tugs pulling luggage carts? ALL THAT STUFF?

No chance.
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Maybe convert them to electric? Maybe the algal biofuel or something else will work out. Or maybe those don't belong to UAL, they belong to the airport so they don't count ;)
 
Nope. Company owned. And this stuff is ABUSED. And just sits and runs and runs and runs. Dripping oil, smoking, leaking fluids... completely unregulated and unmonitored.

Going all electric is technically possible, but probably not practically. The infrastructure to keep that many machines charged, wow...

Food for thought.
 
Algae are carbon based life forms, aren’t they? If so, what happens when you burn carbon? CO2 + plus other stuff.

Cheers
 
X3 Skier said:
Algae are carbon based life forms, aren’t they? If so, what happens when you burn carbon? CO2 + plus other stuff.

Cheers
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And when the algae grew it removed CO2 from the atmosphere. Hence zero net emissions (in theory).
 
Cap'n Jack said:
...Maybe convert them to electric?...
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In order for that to make their operation carbon-neutral, the electricity generation itself would have to be made carbon-neutral. Last time I looked, the lion's share of it was being produced with fossil fuels.
 
AlleyCat67 said:
And when the algae grew it removed CO2 from the atmosphere. Hence zero net emissions (in theory).
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He didn’t say zero net. The words were “Reducing our carbon emissions 100%”.

Expect a clarifying statement from the Chief Excrement Officer soon.

Cheers
 
Bob Noel said:
Is there a fuel without carbon emissions that could power an aircraft? (cold fusion? ZPMs? dilithium crystals?)

Is there some way to scrub the emissions to capture the carbon that would be otherwise emitted? At first blush, the energy requirements to capture all carbon emissions would be prohibitive.

edit: why couldn't we use existing technology to grab the carbon emissions and convert same to something useful or at least harmless? I don't mean something on the aircraft, but something on the ground scrubbing the stuff out of the air.
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Hydrogen is the solution to your first question. It burns cleanly. The problem is getting the H2. It takes more energy to break H2 free from other stuff than you get when you burn H2. So unless we get nuke fusion power or some other "free source" of non-carbon power, you're still generating naughty energy somewhere to create all that H2.

Same thing with CO2 scrubbers. You have to create/use energy to run them and the net is upside down.
 
Palmpilot said:
In order for that to make their operation carbon-neutral, the electricity generation itself would have to be made carbon-neutral. Last time I looked, the lion's share of it was being produced with fossil fuels.
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Agree, I was merely showing a direction, but that isn't necessarily the future.
kyleb said:
Hydrogen is the solution to your first question. It burns cleanly. The problem is getting the H2. It takes more energy to break H2 free from other stuff than you get when you burn H2. So unless we get nuke fusion power or some other "free source" of non-carbon power, you're still generating naughty energy somewhere to create all that H2.

Same thing with CO2 scrubbers. You have to create/use energy to run them and the net is upside down.
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Hydrogen is more of a medium for energy storage as someone pointed out to me some years ago in this forum. The other issue of hydrogen is rather poor energy density, even when used as a fuel cell. They've been looking at ways to improve that for some time now. Hydrogen as a fuel is best when attached to another atom, such as a carbon- the energy density becomes usable.
The energy of pretty much all fuels can be estimated by the amount of oxygen then consume, and uses a small amount of oxygen compared to the amount of hydrogen.
https://pubs.acs.org/doi/10.1021/acs.jchemed.5b00333
 
Cap'n Jack said:
The other issue of hydrogen is rather poor energy density, even when used as a fuel cell.
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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".
 
mondtster said:
Probably more than that. People can't remember what happened a few months ago so they certainly aren't going to remember that some CEO at United who is probably long gone claimed that they would be at zero emissions by 2050 when 2050 actually rolls around.

Perhaps something invented between now and then will make it possible or they'll pursue the carbon capture approach. Overall, I think making announcements like this is just the trendy thing to do so they'll give it a go to drum up more business, regardless if they have a plan to get it done or not.
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Exactly, it sounds good now. Plus knowing United they will have a fleet of vice presidents with impressive sounding titles (VP of Corporate Environmental Stewardship and Sustainability) making hefty salaries in charge of it. Lots of PowerPoint presentations and PR emails, but no real work. Fortunately, they will all be long gone before 2050 (deploy the golden parachute).
 
ColoPilot said:
Exactly, it sounds good now. Plus knowing United they will have a fleet of vice presidents with impressive sounding titles (VP of Corporate Environmental Stewardship and Sustainability) making hefty salaries in charge of it. Lots of PowerPoint presentations and PR emails, but no real work. Fortunately, they will all be long gone before 2050 (deploy the golden parachute).
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There's lots of goodwill to be earned all the way up to the moment you walk back the goal.
 
In case it hasn’t sunk in for someone, they aren’t talking about flying solar powered planes.

Nor nuclear powered planes. Maybe geothermal powered planes?
 
X3 Skier said:
Anything any CEO says/writes/etc. is questionable.

Unless they limit their routes to under 250 miles with electrically power airplanes, he’s smoking something that is illegal in several states. Maybe dirigibles powered by Compressed Air for long haul?

Cheers
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For which the lithium batteries do not come from mines and the electricity comes from unicorns.
 
It was posted up thread but I presume a lot of these carbon neutral and zero emissions stuff are more about offsetting their emissions by planting trees or trading carbon credits.. etc

Nothing inherently wrong with that. I appreciate the "leave no trace" policy when backpacking/camping/hiking.. no reason that shouldn't apply to day to day life, etc
 
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