Note to NASA: Don't bring oxygen and matches to Titan...

[CFLarsen]

'Flammable' Titan covered in liquid gas

Saturn's moon Titan is covered by "dirty" ice ridges and seas of liquid natural gas, a team of scientists said on Friday after a week of research into data from the space probe Huygens.

"We've got a flammable world," said Toby Owen, an atmospheric scientist, at a news conference from European Space Agency offices in Paris monitored on NASA TV.

...

That surface, which scientists have said was the consistency of wet sand or even creme brulee, features ice rocks, channels, and abundant indications of liquid from rain.

"There's lots of evidence of fluid flow," said Marty Tomasko, the principal investigator for Huygens' on-board imaging instruments. While it does not rain every day on Titan, Tomasko and colleagues speculated there must be some sort of regular precipitation on the surface.

The methane can exist in liquid form on Titan's surface because it is so cold, -290 degrees Fahrenheit (-179 degrees Celsius). Methane is also a key component in Titan's atmosphere, along with nitrogen. But as opposed to the Earth, the atmosphere of Titan lacks oxygen, which is essential to fire.
Source (http://www.cnn.com/2005/TECH/space/01/21/space.titan.reut/index.html)

A flammable world. Reality always trumps fantasy!

[TillEulenspiegel]

Well I guess the "rain" doesn't produce lightining...

[Donks]

I always thought that natural gas and other fossil fuels came from, well, fossils. Seems I was mistaken.

[CFLarsen]

If you want wonders, turn to science.

[CurtC]

Originally posted by TillEulenspiegel
Well I guess the "rain" doesn't produce lightining...I don't think lightning would be a problem in the absence of oxygen. And I can't think of any reasons that lightning wouldn't happen there.

Originally posted by Donks
I always thought that natural gas and other fossil fuels came from, well, fossils. Seems I was mistaken.Methane is a very simple molecule - a carbon atom with four hydrogen atoms attached to it. This is the kind of molecule that can be made by non-life - get some carbon, get some hydrogen, and as long as there's no oxygen around, they just naturally attach to each other. The stuff we pump out of the ground has chains of carbon atoms attached to each other, with hydrogens attached as well. That's less likely, *especially* with the slut-molecule oxygen around.

[Johnny Pneumatic]

Maybe in a century or so we can use some of it to make plastics.

:Made on Titan: :D

[Donks]

Originally posted by CurtC
Methane is a very simple molecule - a carbon atom with four hydrogen atoms attached to it. This is the kind of molecule that can be made by non-life - get some carbon, get some hydrogen, and as long as there's no oxygen around, they just naturally attach to each other. The stuff we pump out of the ground has chains of carbon atoms attached to each other, with hydrogens attached as well. That's less likely, *especially* with the slut-molecule oxygen around.
Cool, thanks. You learn something new every day. Even if you had learnt it 10 years ago in chem class and you had forgotten it already. I think I should have paid a little more attention to class.

[SezMe]

If NASA starts to use corporate sponsorship (like, seemingly all the other branches are :( ) Bic is not likely to sponsor the next Titan mission. :D

[Art Vandelay]

"liquid gas"?

[MRC_Hans]

Originally posted by Art Vandelay
"liquid gas"? Yeah, that is, of course, semantically wrong. "Liquid methane", however, makes perfect sense.

Hans

[T'ai Chi]

Originally posted by CFLarsen
If you want wonders, turn to science.

Yup! Just don't confused the methods of science with the subjects of science..

[kookbreaker]

Originally posted by CurtC
I That's less likely, *especially* with the slut-molecule oxygen around.

I just quoted this becuase I love the phrase 'slut-molecule'.

:D

[CFLarsen]

Originally posted by jzs
Yup! Just don't confused the methods of science with the subjects of science..

I wasn't aware that I was.

[phildonnia]

I thought "flammable" meant "reacting exothermically with the earth's atmosphere", a most inappropriate and chauvinistic word to apply to another world.

The residents of Titan are, no doubt, amazed that earth's atmosphere is rich in a highly reactive substance, oxygen. "We've got a flammable world," they would say. It's hard to imagine how all that lightning doesn't ignite the atmosphere. Earthlings can sure be thankful that their oceans are not filled with liquid hydrocarbons.

I bet campers on Titan would have little backpacking stoves that run on compressed oxygen, which they would regard as a highly flammable substance.

[Dr. Imago]

But as opposed to the Earth, the atmosphere of Titan lacks oxygen, which is essential to fire.

Just wanted to point out that, to the best of my remembrance of basic chemistry, this is not "technically" correct. Another "oxidizer", i.e. an element in the same column as oxygen in the periodic table, that can support combusition is elemental sulfur gas.

IIRC, in the presence of a combustible substance, this gas is an excellent electron receptor and would render the combustible substance flammable. While earth's atmosphere at STP (along with the presence of oxygen which will always interfere with this reaction) would not allow the presence of pure sulfur gas in sufficient quantities to support combustion, we cannot discount this possibility on on other worlds.

Interestingly, one by-product ot "sulfurized" combustion in the absence of oxygen is H₂S, or hydrogen sulfide, which is also a contaiminant in natural gas and what gives rotten eggs their bad smell. (Remember, we are talking hypothetically about an atmosphere that has a nominal, if any, amount of molecular oxygen as a free gas.)

Any chemists, feel free to correct me if my memory is failing me. It's been a while since I've used that portion of my gray matter.

-TT

[pgwenthold]

Originally posted by ThirdTwin
Just wanted to point out that, to the best of my remembrance of basic chemistry, this is not "technically" correct. Another "oxidizer", i.e. an element in the same column as oxygen in the periodic table, that can support combusition is elemental sulfur gas.

IIRC, in the presence of a combustible substance, this gas is an excellent electron receptor and would render the combustible substance flammable. While earth's atmosphere at STP (along with the presence of oxygen which will always interfere with this reaction) would not allow the presence of pure sulfur gas in sufficient quantities to support combustion, we cannot discount this possibility on on other worlds.

Interestingly, one by-product ot "sulfurized" combustion in the absence of oxygen is H₂S, or hydrogen sulfide, which is also a contaiminant in natural gas and what gives rotten eggs their bad smell. (Remember, we are talking hypothetically about an atmosphere that has a nominal, if any, amount of molecular oxygen as a free gas.)

Any chemists, feel free to correct me if my memory is failing me. It's been a while since I've used that portion of my gray matter.

-TT

1) The stinky stuff in natural gas is methylsulfide, and it is added deliberately to natural gas to give it an odor. Granted, there are sulfides under ground, but they show up in stuff like ground water (Hot Sulfur Springs, CO, for example) and not in natural gas deposits.
2) As for sulfur as an oxidizer, you are correct that it can be (it is in the same column as O2, so it has similar reactivity). However, elemental S is solid at STP, even, and so the conditions in which methane is liquid, you aren't having a lot of gaseous S.

[c0rbin]

Originally posted by CFLarsen
If you want wonders, turn to science.

If you want wonders, turn to the universe.

If you want a process, turn to science.

Edited to refine:

If you want wonders, turn to the natural (as opposed to the "super-natural")

If you want process, turn to science.

[CFLarsen]

Originally posted by c0rbin
If you want wonders, turn to the universe.

If you want a process, turn to science.

Edited to refine:

If you want wonders, turn to the natural (as opposed to the "super-natural")

If you want process, turn to science.

Nope. The universe itself may produce awesome sights, but they only turn wondrous if we know what they are. And science is what tells us just that.

A wonder may be fantastic. But it becomes more than that, when you know what it really is.

[Beausoleil]

I recollect an old short story (Asimov?) where the i.d. of a murderer (on the Earth ) hinged on the gas cylinder he put a "match" to in order to start a fire. He chose the oxygen cylinder, showing that he was the Titan colonist. Back home it would have burnt in the methane atmosphere (as was thought at one point).

There is under the sun no new thing...

[c4ts]

Not only is it flammable, it rains all the time and is covered in custard.

And it's colder than hell.

[CFLarsen]

Originally posted by c4ts
Not only is it flammable, it rains all the time and is covered in custard.

And it's colder than hell.

I thought that was the UK.

[c4ts]

Originally posted by CFLarsen
I thought that was the UK.

And the next probe will find out if Titan is inhabited by toothless people and sheep.

[Larspeart]

Originally posted by phildonnia
I thought "flammable" meant "reacting exothermically with the earth's atmosphere", a most inappropriate and chauvinistic word to apply to another world.

The residents of Titan are, no doubt, amazed that earth's atmosphere is rich in a highly reactive substance, oxygen. "We've got a flammable world," they would say. It's hard to imagine how all that lightning doesn't ignite the atmosphere. Earthlings can sure be thankful that their oceans are not filled with liquid hydrocarbons.

I bet campers on Titan would have little backpacking stoves that run on compressed oxygen, which they would regard as a highly flammable substance.

That quote was both funny AND educational. Thanks!

[Dr. Imago]

Originally posted by pgwenthold
The stinky stuff in natural gas is methylsulfide, and it is added deliberately to natural gas to give it an odor.

Just to clarify, I wasn't specifically referring to the disclosing agent added to natural gas (which actually doesn't smell exactly like rotten eggs). But, there is, in fact, H₂S dissolved into natural gas that is removed from the ground, depending on the particular pocket it's taken from of course...

Hydrogen Sulfide (H2S) is a colorless gas that smells like rotten eggs (from the sulphur). Often referred to as "sewer gas," hydrogen sulfide is highly poisonous. Usually, the poisoning caused by hydrogen sulfide is though inhalation and has a toxicity similar to cyanide. It is found in petroleum and natural gas and is sometimes present in ground water. Natural gas can contain up to 28% hydrogen sulfide gas and may be considered an air pollutant when found near a natural gas production area or refinery.

http://www.h2ssafety.com/hydrogen_sulfide.htm

...the rotten egg smell that you are experiencing is most likely hydrogen sulfide (H2S) gas. Hydrogen sulfide gas is a natural product of decay, and in a residential setting, is most commonly a result of decomposition in septic or sewer systems. Some communities that have high concentrations of sulfur in their soil also tend to have detectable hydrogen sulfide in their water.

http://www.niehs.nih.gov/external/faq/eggs.htm

-TT

[Soapy Sam]

"1) The stinky stuff in natural gas is methylsulfide, and it is added deliberately to natural gas to give it an odor. Granted, there are sulfides under ground, but they show up in stuff like ground water (Hot Sulfur Springs, CO, for example) and not in natural gas deposits."- PGWenthold.

PGW-

Drat. Third Twin beat me to it.

H2S is a major hazard in the drilling industry. Removing H2S from oil and gas is a big cost. The stuff is both lethally toxic and highly corrosive.
It used to be separated mechanically and flared, which produced the (nearly as toxic) SO2. Go to any "sour" gas field in the world and you will see yellow hills- elemental sulphur removed from oil and gas.

[pgwenthold]

Originally posted by Soapy Sam
"1) The stinky stuff in natural gas is methylsulfide, and it is added deliberately to natural gas to give it an odor. Granted, there are sulfides under ground, but they show up in stuff like ground water (Hot Sulfur Springs, CO, for example) and not in natural gas deposits."- PGWenthold.

PGW-

Drat. Third Twin beat me to it.

H2S is a major hazard in the drilling industry. Removing H2S from oil and gas is a big cost. The stuff is both lethally toxic and highly corrosive.
It used to be separated mechanically and flared, which produced the (nearly as toxic) SO2. Go to any "sour" gas field in the world and you will see yellow hills- elemental sulphur removed from oil and gas.

OK, I'll take that correction, however I will also say that the smell of natural gas that you smell when there is a gas leak is not H2S but is methylsulfide that has been added intentionally (and the H2S has been removed)

Is that more correct?

[exarch]

Originally posted by Beausoleil
I recollect an old short story (Asimov?) where the i.d. of a murderer (on the Earth ) hinged on the gas cylinder he put a "match" to in order to start a fire. He chose the oxygen cylinder, showing that he was the Titan colonist. Back home it would have burnt in the methane atmosphere (as was thought at one point).

There is under the sun no new thing...Wouldn't oxigen burn just as well in a mostly nitrogen atmosphere like the earth's? It wouldn't exactly explode, but it sure would make your match burn a lot harder.

[CurtC]

Originally posted by pgwenthold
OK, I'll take that correction, however I will also say that the smell of natural gas that you smell when there is a gas leak is not H2S but is methylsulfide that has been added intentionally (and the H2S has been removed)When my dad was an eleven year old boy, he went to school about 15 miles away from New London, Texas. There was a leak in a natural gas pipe in the public school there, back before they put odorants in the gas. The basement of the school filled up with gas, and a spark blew up the whole school, killing pretty much all of the children who lived for several miles around. A whole generation in the area was completely wiped out. This event was what prompted the requirement that odorants be added to natural gas in the US.

[Skeptical Greg]

Originally posted by CurtC
When my dad was an eleven year old boy, he went to school about 15 miles away from New London, Texas. There was a leak in a natural gas pipe in the public school there, back before they put odorants in the gas. The basement of the school filled up with gas, and a spark blew up the whole school, killing pretty much all of the children who lived for several miles around. A whole generation in the area was completely wiped out. This event was what prompted the requirement that odorants be added to natural gas in the US.

Read all about it at:

TexasBob.com (http://www.texasbob.com/travel/tbt_london.html)


Probably a lot more than you really wanted to know about Texas...

<center>http://www.intergate.com/~gregorygatz/images/tex-flag1.gif <center>

[Terry]

Originally posted by exarch
Wouldn't oxigen burn just as well in a mostly nitrogen atmosphere like the earth's? It wouldn't exactly explode, but it sure would make your match burn a lot harder.

As I recall the story, the murderer put platinum black in the valve apparatus on top of the cylinder. Platinum black is finely divided platinum, which catalyses oxidation of hydrocarbons. Hence it would make a cylinder go bang if it was either the hydrocarbon in an oxygen atmosphere, or the oxygen in a hydrocarbon atmosphere. The detective found platinum black in the oxygen aparatus as well as the methane tank, and concluded that the miscreant was from the hydrocarbon world, and had made the obvious mistake (before going on to put the catalyst in the correct cylinder also).

--Terry.

[pgwenthold]

Originally posted by Terry
As I recall the story, the murderer put platinum black in the valve apparatus on top of the cylinder. Platinum black is finely divided platinum, which catalyses oxidation of hydrocarbons.

Hmmm, platinum is generally used as a reduction catalyst, not oxidation, although March says that it can be used to oxidize by dehydrogenation (the reverse of reduction).

March does have some catalysts for the oxidation of alkanes, but they are generally iron III based. Of course, chromium based reagents are good for the alkyl substituents on aromatic systems.

[Terry]

Originally posted by pgwenthold
Hmmm, platinum is generally used as a reduction catalyst, not oxidation, although March says that it can be used to oxidize by dehydrogenation (the reverse of reduction).

It is possible I remember wrong. I doubt that Asimov would have got the chemistry wrong, since that was his subject. Unless maybe he wanted to avoid telling people exactly how to blow up a chem lab...

After a spot of googling, it is possible the story in question is called "The Dust of Death" - anyone have it? I remember reading the collection it is commonly anthologised in, but it must have been at the library, since I don't have it on the shelf here.

--Terry.

[Soapy Sam]

Terry has it right-

In "The Dust of Death" (1957),Edmund Farley is working in a laboratory run by a man named Llewes.

Farley murders Llewes, by putting platinum black on a hydrogen cylinder , then spilling toluene on the floor so the air contains a highly explosive mixture. So the fuel is a mix of hydrogen and toluene vapour. The hydrogen will be ignited by the catalyst when the valve is opened. The 2 H2 + O2 flame will ignite the toluene vapour. Boom!
However, Farley , having just returned from six months fieldwork on Titan with it's methane and hydrogen, reducing atmosphere , mistakenly puts platinum black on an oxygen cylinder, before realising and correcting his mistake. After the explosion, the catalyst dust is found on both H2 and O2 cylinders.
Why would someone put the dust on the oxygen bottle? Because he is used to a methane atmosphere, where free oxygen would be thought of as the "explosive" gas.

I recall platinum black being used to light coal gas in a Victorian ghost story. Finely divided platinum dust will certainly ignite hydrogen and methane.

Exarch- Oxygen doesn't actually burn. What we call burning is the process of oxidation of a fuel. Oxidation is a type of chemical reaction which involves adding electrons. The electrons may come from many sources. Fluorine is an excellent oxidising agent. Iron bars will burn in fluorine. The commonest oxidant on Earth is simply atmospheric oxygen. Oxidation does not require a flame. Rusting is oxidation, as is much of our metabolism. Burning is just fast oxidation. An explosion is fast burning.

An oxide is a compound produced by oxidation. Water (H2O) is half burned hydrogen. Hydrogen peroxide (H2O2) is fully oxidised hydrogen.

Edit to add- PGW- yes, the smelly stuff is an additive. At least that's what the gas man said.