Mixing
How much hydrogen and oxygen can I add to an atmosphere before it explodes?
Clash Royale CLAN TAG#URR8PPP
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Hydrogen and oxygen gases can be combined to form water and a lot of heat. As with many exothermic reactions, the heat from this process can provide activation energy to the reaction of more H2 with more O2 in a runaway process commonly referred to as an explosion. I would like an atmosphere rich in both hydrogen and oxygen gases, but I don’t want it to explode. Well, I don’t want it to explode too much. Weather systems creating pockets of high pressure that spontaneously ignite, or lightning strikes resulting in exploding pockets of atmosphere sound awesome. What I need to avoid are planet-consuming runaway explosions that spectacularly scour the surface of the world of all life. A second consideration is that I would like this atmosphere to be breathable by humans.
How much hydrogen and oxygen can coexist in the atmosphere before apocalyptic runaway combustion becomes a possibility?
My current explanation for this world is that a biological or geological process constantly emits large amounts of hydrogen into the atmosphere but that constant small fires and explosions prevent it from accumulating to more dangerous levels. I’m trying to determine what level that is, where explosions are happening but there isn't a risk of extinction level events.
science-based atmosphere chemistry explosions
edited 2 hours ago
Mathaddict
1,590116
asked 2 hours ago
Mike Nichols
7,68152768
add a comment |Â
up vote
2
down vote
favorite
Hydrogen and oxygen gases can be combined to form water and a lot of heat. As with many exothermic reactions, the heat from this process can provide activation energy to the reaction of more H2 with more O2 in a runaway process commonly referred to as an explosion. I would like an atmosphere rich in both hydrogen and oxygen gases, but I don’t want it to explode. Well, I don’t want it to explode too much. Weather systems creating pockets of high pressure that spontaneously ignite, or lightning strikes resulting in exploding pockets of atmosphere sound awesome. What I need to avoid are planet-consuming runaway explosions that spectacularly scour the surface of the world of all life. A second consideration is that I would like this atmosphere to be breathable by humans.
How much hydrogen and oxygen can coexist in the atmosphere before apocalyptic runaway combustion becomes a possibility?
My current explanation for this world is that a biological or geological process constantly emits large amounts of hydrogen into the atmosphere but that constant small fires and explosions prevent it from accumulating to more dangerous levels. I’m trying to determine what level that is, where explosions are happening but there isn't a risk of extinction level events.
science-based atmosphere chemistry explosions
edited 2 hours ago
Mathaddict
1,590116
asked 2 hours ago
Mike Nichols
7,68152768
hydrogen gas and normal air can ignite at as low as 4% air; The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume
– Alexander
1 hour ago
add a comment |Â
up vote
2
down vote
favorite
up vote
2
down vote
favorite
Hydrogen and oxygen gases can be combined to form water and a lot of heat. As with many exothermic reactions, the heat from this process can provide activation energy to the reaction of more H2 with more O2 in a runaway process commonly referred to as an explosion. I would like an atmosphere rich in both hydrogen and oxygen gases, but I don’t want it to explode. Well, I don’t want it to explode too much. Weather systems creating pockets of high pressure that spontaneously ignite, or lightning strikes resulting in exploding pockets of atmosphere sound awesome. What I need to avoid are planet-consuming runaway explosions that spectacularly scour the surface of the world of all life. A second consideration is that I would like this atmosphere to be breathable by humans.
How much hydrogen and oxygen can coexist in the atmosphere before apocalyptic runaway combustion becomes a possibility?
My current explanation for this world is that a biological or geological process constantly emits large amounts of hydrogen into the atmosphere but that constant small fires and explosions prevent it from accumulating to more dangerous levels. I’m trying to determine what level that is, where explosions are happening but there isn't a risk of extinction level events.
science-based atmosphere chemistry explosions
edited 2 hours ago
Mathaddict
1,590116
asked 2 hours ago
Mike Nichols
7,68152768
Hydrogen and oxygen gases can be combined to form water and a lot of heat. As with many exothermic reactions, the heat from this process can provide activation energy to the reaction of more H2 with more O2 in a runaway process commonly referred to as an explosion. I would like an atmosphere rich in both hydrogen and oxygen gases, but I don’t want it to explode. Well, I don’t want it to explode too much. Weather systems creating pockets of high pressure that spontaneously ignite, or lightning strikes resulting in exploding pockets of atmosphere sound awesome. What I need to avoid are planet-consuming runaway explosions that spectacularly scour the surface of the world of all life. A second consideration is that I would like this atmosphere to be breathable by humans.
How much hydrogen and oxygen can coexist in the atmosphere before apocalyptic runaway combustion becomes a possibility?
My current explanation for this world is that a biological or geological process constantly emits large amounts of hydrogen into the atmosphere but that constant small fires and explosions prevent it from accumulating to more dangerous levels. I’m trying to determine what level that is, where explosions are happening but there isn't a risk of extinction level events.
science-based atmosphere chemistry explosions
science-based atmosphere chemistry explosions
edited 2 hours ago
Mathaddict
1,590116
asked 2 hours ago
Mike Nichols
7,68152768
edited 2 hours ago
Mathaddict
1,590116
asked 2 hours ago
Mike Nichols
7,68152768
edited 2 hours ago
Mathaddict
1,590116
edited 2 hours ago
Mathaddict
1,590116
edited 2 hours ago
Mathaddict
1,590116
1,590116
asked 2 hours ago
Mike Nichols
7,68152768
asked 2 hours ago
Mike Nichols
7,68152768
asked 2 hours ago
Mike Nichols
7,68152768
7,68152768
hydrogen gas and normal air can ignite at as low as 4% air; The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume
– Alexander
1 hour ago
add a comment |Â
hydrogen gas and normal air can ignite at as low as 4% air; The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume
– Alexander
1 hour ago
hydrogen gas and normal air can ignite at as low as 4% air; The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume
– Alexander
1 hour ago
hydrogen gas and normal air can ignite at as low as 4% air; The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume
– Alexander
1 hour ago
add a comment |Â
2 Answers
2
active
oldest
votes
up vote
5
down vote
Gaseous molecular hydrogen doesn't stick around; it escapes into space. The places where it doesn't do so are places with substantially more gravity than Earth (eg. gas giants).
The hydrogen that doesn't escape will react, but (for the most part) non-explosively, because hydrogen and oxygen will, left to their own devices, settle like oil and water, with the hydrogen in the upper atmosphere, either escaping, or undergoing UV excitation which breaks the hydrogen into atomic hydrogen, which will react with just about anything to form hydrides or salts.
If you had a uniform distribution of, say, 20% hydrogen by volume across the planet, then yes, a single spark would trigger a cataclysmic exothermic reaction. It would be loud. But there's no way such a distribution could remain mixed for any substantial period of time, and you'd need to continuously produce enormous quantities of hydrogen (assuming your planet is earthlike).
answered 1 hour ago
jdunlop
5,80611035
2
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
+ "it would be loud".
– Willk
14 mins ago
add a comment |Â
up vote
2
down vote
The explosive range for Hydrogen is 4% to 75%
This is really a question about stoichiometry. If your planet's air (without the Hydrogen) is roughly the same as the earth, then Hydrogen will start to burn (given an appropriate ignition source) at 4% Hydrogen by volume. If you get above 75%, then it's actually the oxygen you won't have enough of and you won't be able to burn again.
What we're talking about here is called the lower and upper explosive limits for a given gas, in this case Hydrogen.
The most explosive concentration is at about 35% hydrogen, this is when there is exactly twice the amount of hydrogen as there is oxygen, so neither of their concentrations are limiting. The reason it's not 42% (twice the 21% oxygen in air) is because the hydrogen displaces both the oxygen and the nitrogen.
edited 35 mins ago
Alexander
17.4k42969
answered 1 hour ago
Mathaddict
1,590116
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
5
down vote
Gaseous molecular hydrogen doesn't stick around; it escapes into space. The places where it doesn't do so are places with substantially more gravity than Earth (eg. gas giants).
The hydrogen that doesn't escape will react, but (for the most part) non-explosively, because hydrogen and oxygen will, left to their own devices, settle like oil and water, with the hydrogen in the upper atmosphere, either escaping, or undergoing UV excitation which breaks the hydrogen into atomic hydrogen, which will react with just about anything to form hydrides or salts.
If you had a uniform distribution of, say, 20% hydrogen by volume across the planet, then yes, a single spark would trigger a cataclysmic exothermic reaction. It would be loud. But there's no way such a distribution could remain mixed for any substantial period of time, and you'd need to continuously produce enormous quantities of hydrogen (assuming your planet is earthlike).
answered 1 hour ago
jdunlop
5,80611035
2
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
+ "it would be loud".
– Willk
14 mins ago
add a comment |Â
up vote
5
down vote
Gaseous molecular hydrogen doesn't stick around; it escapes into space. The places where it doesn't do so are places with substantially more gravity than Earth (eg. gas giants).
The hydrogen that doesn't escape will react, but (for the most part) non-explosively, because hydrogen and oxygen will, left to their own devices, settle like oil and water, with the hydrogen in the upper atmosphere, either escaping, or undergoing UV excitation which breaks the hydrogen into atomic hydrogen, which will react with just about anything to form hydrides or salts.
If you had a uniform distribution of, say, 20% hydrogen by volume across the planet, then yes, a single spark would trigger a cataclysmic exothermic reaction. It would be loud. But there's no way such a distribution could remain mixed for any substantial period of time, and you'd need to continuously produce enormous quantities of hydrogen (assuming your planet is earthlike).
answered 1 hour ago
jdunlop
5,80611035
2
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
+ "it would be loud".
– Willk
14 mins ago
add a comment |Â
up vote
5
down vote
up vote
5
down vote
Gaseous molecular hydrogen doesn't stick around; it escapes into space. The places where it doesn't do so are places with substantially more gravity than Earth (eg. gas giants).
The hydrogen that doesn't escape will react, but (for the most part) non-explosively, because hydrogen and oxygen will, left to their own devices, settle like oil and water, with the hydrogen in the upper atmosphere, either escaping, or undergoing UV excitation which breaks the hydrogen into atomic hydrogen, which will react with just about anything to form hydrides or salts.
If you had a uniform distribution of, say, 20% hydrogen by volume across the planet, then yes, a single spark would trigger a cataclysmic exothermic reaction. It would be loud. But there's no way such a distribution could remain mixed for any substantial period of time, and you'd need to continuously produce enormous quantities of hydrogen (assuming your planet is earthlike).
answered 1 hour ago
jdunlop
5,80611035
Gaseous molecular hydrogen doesn't stick around; it escapes into space. The places where it doesn't do so are places with substantially more gravity than Earth (eg. gas giants).
The hydrogen that doesn't escape will react, but (for the most part) non-explosively, because hydrogen and oxygen will, left to their own devices, settle like oil and water, with the hydrogen in the upper atmosphere, either escaping, or undergoing UV excitation which breaks the hydrogen into atomic hydrogen, which will react with just about anything to form hydrides or salts.
If you had a uniform distribution of, say, 20% hydrogen by volume across the planet, then yes, a single spark would trigger a cataclysmic exothermic reaction. It would be loud. But there's no way such a distribution could remain mixed for any substantial period of time, and you'd need to continuously produce enormous quantities of hydrogen (assuming your planet is earthlike).
answered 1 hour ago
jdunlop
5,80611035
answered 1 hour ago
jdunlop
5,80611035
answered 1 hour ago
jdunlop
5,80611035
answered 1 hour ago
jdunlop
5,80611035
5,80611035
2
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
+ "it would be loud".
– Willk
14 mins ago
add a comment |Â
2
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
+ "it would be loud".
– Willk
14 mins ago
2
2
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
+1, but also : on geological time scale hydrogen would oxidize non explosively. Would be hard to produce it fast enough to accumulate 20%
– Mołot
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
Would be hard to produce it fast enough to accumulate any substantial value - the Earth is not short on sources of ignition.
– jdunlop
1 hour ago
+ "it would be loud".
– Willk
14 mins ago
+ "it would be loud".
– Willk
14 mins ago
add a comment |Â
up vote
2
down vote
The explosive range for Hydrogen is 4% to 75%
This is really a question about stoichiometry. If your planet's air (without the Hydrogen) is roughly the same as the earth, then Hydrogen will start to burn (given an appropriate ignition source) at 4% Hydrogen by volume. If you get above 75%, then it's actually the oxygen you won't have enough of and you won't be able to burn again.
What we're talking about here is called the lower and upper explosive limits for a given gas, in this case Hydrogen.
The most explosive concentration is at about 35% hydrogen, this is when there is exactly twice the amount of hydrogen as there is oxygen, so neither of their concentrations are limiting. The reason it's not 42% (twice the 21% oxygen in air) is because the hydrogen displaces both the oxygen and the nitrogen.
edited 35 mins ago
Alexander
17.4k42969
answered 1 hour ago
Mathaddict
1,590116
add a comment |Â
up vote
2
down vote
The explosive range for Hydrogen is 4% to 75%
This is really a question about stoichiometry. If your planet's air (without the Hydrogen) is roughly the same as the earth, then Hydrogen will start to burn (given an appropriate ignition source) at 4% Hydrogen by volume. If you get above 75%, then it's actually the oxygen you won't have enough of and you won't be able to burn again.
What we're talking about here is called the lower and upper explosive limits for a given gas, in this case Hydrogen.
The most explosive concentration is at about 35% hydrogen, this is when there is exactly twice the amount of hydrogen as there is oxygen, so neither of their concentrations are limiting. The reason it's not 42% (twice the 21% oxygen in air) is because the hydrogen displaces both the oxygen and the nitrogen.
edited 35 mins ago
Alexander
17.4k42969
answered 1 hour ago
Mathaddict
1,590116
add a comment |Â
up vote
2
down vote
up vote
2
down vote
The explosive range for Hydrogen is 4% to 75%
This is really a question about stoichiometry. If your planet's air (without the Hydrogen) is roughly the same as the earth, then Hydrogen will start to burn (given an appropriate ignition source) at 4% Hydrogen by volume. If you get above 75%, then it's actually the oxygen you won't have enough of and you won't be able to burn again.
What we're talking about here is called the lower and upper explosive limits for a given gas, in this case Hydrogen.
The most explosive concentration is at about 35% hydrogen, this is when there is exactly twice the amount of hydrogen as there is oxygen, so neither of their concentrations are limiting. The reason it's not 42% (twice the 21% oxygen in air) is because the hydrogen displaces both the oxygen and the nitrogen.
edited 35 mins ago
Alexander
17.4k42969
answered 1 hour ago
Mathaddict
1,590116
The explosive range for Hydrogen is 4% to 75%
This is really a question about stoichiometry. If your planet's air (without the Hydrogen) is roughly the same as the earth, then Hydrogen will start to burn (given an appropriate ignition source) at 4% Hydrogen by volume. If you get above 75%, then it's actually the oxygen you won't have enough of and you won't be able to burn again.
What we're talking about here is called the lower and upper explosive limits for a given gas, in this case Hydrogen.
The most explosive concentration is at about 35% hydrogen, this is when there is exactly twice the amount of hydrogen as there is oxygen, so neither of their concentrations are limiting. The reason it's not 42% (twice the 21% oxygen in air) is because the hydrogen displaces both the oxygen and the nitrogen.
edited 35 mins ago
Alexander
17.4k42969
answered 1 hour ago
Mathaddict
1,590116
edited 35 mins ago
Alexander
17.4k42969
edited 35 mins ago
Alexander
17.4k42969
edited 35 mins ago
Alexander
17.4k42969
17.4k42969
answered 1 hour ago
Mathaddict
1,590116
answered 1 hour ago
Mathaddict
1,590116
answered 1 hour ago
Mathaddict
1,590116
1,590116
add a comment |Â
add a comment |Â
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hydrogen gas and normal air can ignite at as low as 4% air; The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume
– Alexander
1 hour ago