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   Non-TechAirline Discussion Board


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To: Moonray who wrote (1657)10/27/2021 2:57:32 PM
From: TimF
2 Recommendations   of 1729
 
With the short time frame (a bit over two years to three years) and the small capacity it seems like a demonstration more than anything meaningful.

Hydrogen does have some serious advantages (in addition to what is probably the motivation, the fact that perfect burning of Hydrogen doesn't emit CO2). Its abundant in the universe, and in compounds (for example water) its abundant on Earth. It also has a lot of energy per weight.

But its difficult to handle and transport. Its density is very low. Store it as a gas and you need huge tanks. Store it as a liquid and it still needs tanks over three times as large as jet fuel or gasoline or diesel, and you also have to store it at more than 423 degrees below zero (or slightly higher with some pressure but still a cryogenic temperatures). Its escapes easily from containment so you lose some of it why you store it (even stored for use in the tank of a vehicle that's burning it) or transporting it. And when it escapes it can (depending on how its stored) cause en.wikipedia.org, or under some conditions en.wikipedia.org

Its low molecular and atomic weight and high energy to weight ratios do make it a good fuel for spacecraft (or it can be reaction mass for spacecraft that don't rely on burning it), and it has some other niche applications, but I don't think it will have any wide spread transportation use any time soon (spacecraft being a small enough proportion of transportation to not count as "wide spread").

Its use doesn't even necessarily reduce CO2 emissions because currently most hydrogen is generated from fossil fuels.

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To: TimF who wrote (1658)10/27/2021 3:25:25 PM
From: Moonray
   of 1729
 
You forgot to add that hydrogen has been tried on flights before,
some 85 years ago. You wouldn't have to show this video to a person
getting on a commercial flight more than once to allow many to change
their minds, rightly or wrongly.



o~~~ O

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To: Moonray who wrote (1659)10/27/2021 4:21:04 PM
From: TimF
1 Recommendation   of 1729
 
Hydrogen isn't necessarily more dangerous than other fuels. The issue with that accident was that the majority of the volume of the vehicle was fuel. Which isn't normally the case (except maybe with rockets, or with tankers transporting fuel).

And it wasn't even fuel they would burn to propel the airship forward. The Hindenburg had 4 diesel engines, which may have even been the cause of the fire (directly, or through their fuel being the source). There are other theories, such as static buildup, a lightning strike, or even sabotage.

I guess even if its just fuel (and not a lifting gas) the large storage space needed for hydrogen gas might reduce safety, it might be harder to properly isolate a very large tank from static or other threats. If your using liquid hydrogen then you have the possibility of failure of the cooling method for your cryogenic storage (although the tank would still be highly insulated, you wouldn't get a sudden shift to all gas, you would just have to vent some of the gas as it develops to avoid over-pressure)

OTOH hydrogen also has some safety advantages. Its lightness means it flows away in to the sky as it burns which usually causes less damage to things around it. It also normally produces a lot less harmful gases and smoke around the fire then conventional fuels (a perfect hydrogen/oxygen fire would just produce steam, so it would "no harmful gasses and smoke" but in the real world you have other objects and gasses around to burn).

Here is a video with some tests

Experimental Investigation of Liquid Hydrogen Hazards, 1960, Film Number 1

youtube.com

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To: Moonray who wrote (1659)10/27/2021 4:23:02 PM
From: Art Bechhoefer
   of 1729
 
The distance between Rotterdam and London, the two cities involved in the project, is about 100 miles. Even if hydrogen requires comparatively large storage tanks, the short distance makes hydrogen powered fuel cells practical, though probably at greater cost than, for example, a jet prop aircraft with some 19 passengers.

Art

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To: Moonray who wrote (1657)10/28/2021 9:05:40 AM
From: OldAIMGuy
1 Recommendation   of 1729
 
Hi M, Re: Hydrogen fueled aircraft....................

The problem isn't with the technology to use hydrogen to create motive power. The problem comes from creating a source of hydrogen that isn't impacting the environment to a worse degree than a carbon based fuel itself.

Sources of hydrogen are either hydrocarbon based or electrolysis based. Hydrocarbon based systems for generation hydrogen are endothermic (they use more energy than they create) and therefore not practical and also liberate CO². Electrolysis is just plain energy intensive no matter what the source.

It's tough to bypass the laws of thermodynamics!

Best wishes,
OAG Tom

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To: Moonray who wrote (1657)10/30/2021 12:33:23 AM
From: Stock Puppy
1 Recommendation   of 1729
 
Commercial flights that fly ‘entirely on hydrogen’ planned for 2024

o~~~ O



Sure that isn't a lot of hot air?

Oh wait ...

(Starts over)

Isn't it dangerous if some hydrogen gets into the air?
Then you'll get ... Hair!
.
.
Helium heard that joke - but Helium didn't react.
.
.
You didn't find that funny also?
You must not be hydrogen then.
after all, all the other elements are somewhat denser. (oooh!)

Therefore you need a real joke:
.
.
.
Two hydrogen atoms decide that they want to ride on the Large Hadron Collider.
]
They jump on a plane to Switzerland and sneak in while no one is looking. As they start to speed up one of them realizes that they have both lost their electrons. One mentions it to his friend who asks "Are you sure?"
]
His friend replied, "Yes, I'm positive." (ouch)
.
.
.
"Hydrogen Monoxide! Hydrogen Monoxide! Hydrogen Monoxide!" shouted Santa.
]
*Asking the Chemistry teacher to play Santa this year seemed to have backfired*

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From: Moonray10/31/2021 10:41:37 AM
2 Recommendations   of 1729
 
American Airlines cancels more than 1,200 flights amid weather and staffing issues

o~~~ O

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From: Moonray11/4/2021 9:59:13 PM
   of 1729
 
American Airlines delays employee vaccine mandate
deadline until 2022 after Biden postpones deadline

o~~~ O

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To: Moonray who wrote (1665)11/5/2021 11:47:44 AM
From: OldAIMGuy
   of 1729
 
Hi M,
I let 5% of my MESA shares go profitably this AM on a GTC Limit at $8.43. I'm still in a holding pattern on JETS between accumulation and distribution.

Best wishes,
OAG

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From: Sam11/5/2021 12:07:52 PM
   of 1729
 
The Market Is Rallying. But Airline Stocks Are Taking Off -- Barrons.com
Dow Jones Newswires November 05, 2021 10:49:00 AM ET

Travel stocks, including some of the biggest U.S. airlines, surged early Friday as positive sentiment swept across the sector.

The mood across markets was buoyed by strong earnings and news that Pfizer's (ticker: PFE) Covid-19 pill cut the risk of hospitalization or death by 89% in a trial of high-risk non-hospitalized patients. A better-than-expected October jobs report also helped.

Travel names led the way, with shares of American Airlines (AAL) and United Airlines (UAL) stock rising close to 5% and Delta Air Lines (DAL) climbing 6% in early trading. Southwest Airlines (LUV) and JetBlue Airways Corporation (JBLU) were also up more than 5%. Cruise operators also enjoyed gains, with Royal Caribbean Cruises (RCL) and Carnival Corporation (CCL) both moving 8% higher.

The sector was also boosted by earnings from Airbnb (ABNB) and Expedia (EXPE), which provided further signs that the rebound is gathering pace. Airbnb said it had its "strongest quarter ever" as the travel rebound, which began earlier this year, accelerated in the third quarter, while Expedia also beat expectations and struck an optimistic tone when it comes to the months ahead.

The U.S.-U.K. travel corridor will open up for Covid-19 vaccinated passengers from Monday, which could provide further impetus for airlines. The reopening will be a "pivotal moment" for the industry, British Airways owner IAG's (IAG) CEO Luis Gallego said early Friday.

Write to Callum Keown at callum.keown@dowjones.com



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