Separating Hydrogen and Natural Gas - Tilted Forum Project Discussion Community

BentNotTwisted · 08-28-2003, 09:50 AM

Is there a way to separate hydrogen from natural gas (CH4)? The reason I ask is there are a couple of guys who use this combination to produce synthetic diamonds, Link.
During the process carbon precipitates out of the gas to form diamond which leaves a mixture of more hydrogen and less natural gas than at the start. Separating the two would yield a byproduct of hydrogen which could then be sold. I dont know how much more hydrogen would be produced, I suppose it would be proportional to the size of the diamond being produced. Eventually the 'diamond growers' want to be able to make diamond wafers which could be cut up for semiconductors. At high production rates that could mean a great deal of hydrogen being produced.
Any ideas how to separate gases?

hobo · 08-28-2003, 10:11 AM

I'm not sure, but I know it would require a lot of energy to do. Growing diamonds for semiconductors is the future and I'm sure we'll be seeing that soon.

Lebell · 08-28-2003, 11:43 AM

From my limited knowledge, there are only a couple of ways to separate gases:

-a gas centrifuge
-a membrane that keeps the larger CH4 from passing but allows the H2 to pass
-a chemical combination process which targets one (but not the other) substance

yournamehere · 08-28-2003, 12:40 PM

Natural gas is (for now) the most common and cheapest source of pure hydrogen. The hydrogen is usually extracted using steam.

This is the problem with fuel cell cars - we'll still need natural gas to get the hydrogen fuel - so we're still using fossil fuels. Luckily, the US has a hefty supply of natural gas, and the biggest supplier - Russia - is currently on friendly terms with us.

The next breakthrough to really put us on the path to fuel cell vehicles will be when engineers can come up with a cheap (i.e. - solar powered) method of using electrolysis to separate hydrogen from water molecules.

RoadRage · 09-01-2003, 10:32 PM

A cryo plant could separate them. As you cool off natural gas, the larger fractions (butane and propane) would liquify first and be removed, then ethane, and finally methane. What's left would be a mixture mostly of hydrogen with some helium, neon, and argon.

I doubt this would be the cheapest method for this components, but this is one of the processes for separating larger hydrocarbons, like heptanes and octanes.

SaltPork · 09-02-2003, 10:47 AM

Try fire.

shakran · 09-02-2003, 08:07 PM

Quote:

Originally posted by yournamehere
Natural gas is (for now) the most common and cheapest source of pure hydrogen. The hydrogen is usually extracted using steam.

This is the problem with fuel cell cars - we'll still need natural gas to get the hydrogen fuel - so we're still using fossil fuels. Luckily, the US has a hefty supply of natural gas, and the biggest supplier - Russia - is currently on friendly terms with us.

The next breakthrough to really put us on the path to fuel cell vehicles will be when engineers can come up with a cheap (i.e. - solar powered) method of using electrolysis to separate hydrogen from water molecules.

Fuel cell vehicles are a load of crap. Even if we get hydrogen from a non-fossil fuel, we have the problem that hydrogen does not like to stay single. It bonds to other molecules at the drop of a hat. That means we have to separate the other molecule from the hydrogen, a process which takes a HELL of a lot of energy whether we do it with steam, electricity, or heat.

The simple fact is that hydrogen is an energy storage medium. That means you can use it to store energy you already have, but you'll lose some of that energy in the process - - -it's just like a battery. Meanwhile, the energy to crack the hydrogen from the other molecules is wasted, that energy was produced with coal, oil, or nuclear power, all of which pollute, yet enviro freaks who should know better are saying it's great for the environment because there are 0 emmissions from the tailpipe of a hydrogen car. They fail to see the fact that this is only true because the pollution is simply happening far away from the car, but it's still happening.

yournamehere · 09-03-2003, 03:03 PM

<b>shakran,</b>
You forgot the worst part - transporting it.
Currently, hydrogen is transported in its liquid state, in semi-trucks. To a lot of people, that's an accident waiting to happen.

To the idealist, using solar-powered electrolysis <i>on-site at the dispersal pump</i> to separate hydrogen atoms from the oxygen in water is the answer. Solar power is the one source of energy we can afford to waste - there's more of it around every day than we could possibly capture and use in a year.

Otherwise - yes - it's a pipe dream. Do the physics - we start with water, end up with water, and in the meantime, we have to power a 2-ton vehicle down the highway. That means a shitload of energy must be input somewhere in that process. To make it feasible, that energy must be "pretty damned cheap".

Granted - we're far from getting there at the present level of technology - but wait 'till Texas oilmen start seeing a profit in fuel cells - the technology will take off real quick - just you wait and see.

BentNotTwisted · 09-04-2003, 06:24 AM

Quote:

Originally posted by shakran
Fuel cell vehicles are a load of crap. Even if we get hydrogen from a non-fossil fuel, we have the problem that hydrogen does not like to stay single. It bonds to other molecules at the drop of a hat. That means we have to separate the other molecule from the hydrogen, a process which takes a HELL of a lot of energy whether we do it with steam, electricity, or heat.

The simple fact is that hydrogen is an energy storage medium. That means you can use it to store energy you already have, but you'll lose some of that energy in the process - - -it's just like a battery. Meanwhile, the energy to crack the hydrogen from the other molecules is wasted, that energy was produced with coal, oil, or nuclear power, all of which pollute, yet enviro freaks who should know better are saying it's great for the environment because there are 0 emmissions from the tailpipe of a hydrogen car. They fail to see the fact that this is only true because the pollution is simply happening far away from the car, but it's still happening.

This is way off topic, but I must address your comment. There is research going on at various universities to have bacteria turn biomass into hydrogen. Since the biomass comes from waste crops which were produced from solar energy the process would eliminate the use of hydrocarbons to produce hydrogen. Another option as mentioned by yournamehere is solar power. The sun puts out tremendous amounts of energy which could be harnessed to separate water into hydrogen and oxygen. There are many ways to produce hydrogen and not all of the involve using hydrocarbons or enriched uranium.

Quote:

Originally posted by yournamehere
You forgot the worst part - transporting it.
Currently, hydrogen is transported in its liquid state, in semi-trucks. To a lot of people, that's an accident waiting to happen.

Transportation options for hydrogen are also being researched. Some scientists believe they can make a material that will absorb hydrogen and store it in an inert state with only moderate pressure. When the pressure is released, the hydrogen is released from the material and becomes available for the fuel cell. It's still a long way off, but it's a step in the right direction.

shakran · 09-04-2003, 04:17 PM

Transporting:

Absolutely correct. That's usually one of my big arguments against this technology. How did I forget that! So yes, you're correct that the safest method of delivery would be the solar powered on-site electrolysis. BIG problem with this, however:

What do you do on a cloudy day? Or at night? Don't say batteries to store the solar energy - that's what the hydrogen is first off and second if we have backup batteries to convert when the sun's not out, then we have to worry about the enviornmental impact of making and burying enough batteries to do the job (this would be a LOT of batteries)

As for texas oilmen being the spark - -that's exactly why there's so much hubub over researching this idiocy in the first place. As I think I saw mentioned above, methane is a great source for hydrogen. Methane comes from oil wells. It's cheaper to get methane than it is to get oil. The oil barons would like nothing better than a conversion to fuel cell vehicles because they could get even more rich by selling the methane that costs them less to extract in the first place! Best of all, they're already sitting on a potential fortune in methane and they don't have to expend any capital to secure the rights to it since they already HAVE those rights.

The biomass idea seems plausible until you realize that once again you now have to transport the hydrogen, because no one would want a gas station that had a huge compost pile in its back yard.

As for the pressurized-inert-hydrogen. ..well, as you said this is VERY far off. Until we can do this reliably, AND produce the hydrogen without expending any renewable resources (we're talking decades here folks) it's pointless to go ga-ga over these cars.

Nitro · 09-05-2003, 01:34 AM

Quote:

BentNotTwisted:
"At high production rates that could mean a great deal of hydrogen being produced."

For every 16g of CH4 you put in you could get 44,8 litres of hydrogen (if you really crack it all). Electrolysis is easier!

Quote:

shakran:
"That means we have to separate the other molecule from the hydrogen, a process which takes a HELL of a lot of energy whether we do it with steam, electricity, or heat."

For 1m^3 of hydrogen it takes 4,5 kWh of electricity to produce it in a traditional way (steam, electricity, heat).
If you burn 1m^3 of hydrogen you get out ca. 3,3 kWh which leaves you with a "loss" of 1,2 kWh. If you compare this with electricity costs this would be something like 20 US cents lost.

Quote:

shakran:
"The simple fact is that hydrogen is an energy storage medium."

Totally true. It's not a primary energy source like natural gas it has to be produced prefferably with solar energy.

Quote:

shakran:
"As for the pressurized-inert-hydrogen. ..well, as you said this is VERY far off. "

No it's not. I did it in 2nd semester chemistry a few years ago. We did it with a kind of flintstone and pumped a few litres into a piece of the size of a toothpick. You have to warm it to get it out again.
The answer are metal-hydrides like FeTiH. You can put 30g hydrogen into a litre of this stuff which equals 336 litres of hydrogen under normal conditions.

Quote:

shakran:
"the safest method of delivery would be the solar powered on-site electrolysis. BIG problem with this,"

it's just a matter of size.

As for the transportation issue:
How about pipelines.
Brilliantly easy technology which is well researched and secure.
AirLiquide delivers hydrogen in pipelines in the US if you need it in large quantities.
Their german daughter has a whole network with hydrogen pipelines spanning 240km in the Rhine-Ruhr area (densly populated).
Running for many, many years - still no accidents.
Handling hydrogen is as dangerous as handling natural gas so the experience and technology to transport it is there.

Quote:

shakran:
"Fuel cell vehicles are a load of crap."

Not really. Fuel cells are more efficient at energy usage, just wait and see. At the moment it's only a question of space, power and heat to get them into a car.
In Europe they are already starting to put fuel cells into private homes to heat them and to provide them with power (no space problems in houses).

Scorpion23 · 09-22-2003, 04:52 PM

The theory behind selling the byproducts for extra money sounds good when you take a first look at it. But as stated earlier the diamond process would take a fairly large amount of energy. Depending on the setup of the reactor vessel it would probably be cheaper to use the byproducts as a fuel for heating the reaction.

BentNotTwisted · 09-23-2003, 06:24 AM

Quote:

Originally posted by Scorpion23
The theory behind selling the byproducts for extra money sounds good when you take a first look at it. But as stated earlier the diamond process would take a fairly large amount of energy. Depending on the setup of the reactor vessel it would probably be cheaper to use the byproducts as a fuel for heating the reaction.

Of course! I don't know why I didn't see that before. They can just use the byproduct as it is. Thanks Scorpion.

Noob · 10-03-2003, 12:18 AM

burn it
CH4 + 2O2 ---> 2H2O + CO2

collect the water condense it(or you could just get water from the sink) and split the water molecules with an electrolysis experiment youll get hydrogen at the cathode and oxygen at the anode

08-28-2003, 09:50 AM	#1 (permalink)
BentNotTwisted Optimistic Skeptic Location: Midway between a Beehive and Centennial	Separating Hydrogen and Natural Gas Is there a way to separate hydrogen from natural gas (CH4)? The reason I ask is there are a couple of guys who use this combination to produce synthetic diamonds, Link. During the process carbon precipitates out of the gas to form diamond which leaves a mixture of more hydrogen and less natural gas than at the start. Separating the two would yield a byproduct of hydrogen which could then be sold. I dont know how much more hydrogen would be produced, I suppose it would be proportional to the size of the diamond being produced. Eventually the 'diamond growers' want to be able to make diamond wafers which could be cut up for semiconductors. At high production rates that could mean a great deal of hydrogen being produced. Any ideas how to separate gases? __________________ IS THAT IT ???!!! Do you even know what 'it' is? When the last man dies for just words that he said... We Shall Be Free

08-28-2003, 11:43 AM	#3 (permalink)
Lebell Cracking the Whip Location: Sexymama's arms...	From my limited knowledge, there are only a couple of ways to separate gases: -a gas centrifuge -a membrane that keeps the larger CH4 from passing but allows the H2 to pass -a chemical combination process which targets one (but not the other) substance __________________ "Of all tyrannies, a tyranny exercised for the good of its victims may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end, for they do so with the approval of their own conscience." – C. S. Lewis The ONLY sponsors we have are YOU! Please Donate!

08-28-2003, 12:40 PM	#4 (permalink)
yournamehere Invisible Location: tentative, at best	Natural gas is (for now) the most common and cheapest source of pure hydrogen. The hydrogen is usually extracted using steam. This is the problem with fuel cell cars - we'll still need natural gas to get the hydrogen fuel - so we're still using fossil fuels. Luckily, the US has a hefty supply of natural gas, and the biggest supplier - Russia - is currently on friendly terms with us. The next breakthrough to really put us on the path to fuel cell vehicles will be when engineers can come up with a cheap (i.e. - solar powered) method of using electrolysis to separate hydrogen from water molecules. __________________ If you want to avoid 95% of internet spelling errors: "If your ridiculous pants are too loose, you're definitely going to lose them. Tell your two loser friends over there that they're going to lose theirs, too." It won't hurt your fashion sense, either.

09-01-2003, 10:32 PM	#5 (permalink)
RoadRage Stay off the sidewalk! Location: Oklahoma City, OK	A cryo plant could separate them. As you cool off natural gas, the larger fractions (butane and propane) would liquify first and be removed, then ethane, and finally methane. What's left would be a mixture mostly of hydrogen with some helium, neon, and argon. I doubt this would be the cheapest method for this components, but this is one of the processes for separating larger hydrocarbons, like heptanes and octanes. __________________ Join TFP Team SETI 43K workunits complete, 34 members, more of each needed.

09-02-2003, 10:47 AM	#6 (permalink)
SaltPork Everything's better with bacon Location: In your local grocer's freezer.	Try fire. __________________ It was like that when I got here....I swear.

08-28-2003, 10:11 AM	#2 (permalink)
hobo Archangel of Change	I'm not sure, but I know it would require a lot of energy to do. Growing diamonds for semiconductors is the future and I'm sure we'll be seeing that soon.

09-03-2003, 03:03 PM	#8 (permalink)
yournamehere Invisible Location: tentative, at best	<b>shakran,</b> You forgot the worst part - transporting it. Currently, hydrogen is transported in its liquid state, in semi-trucks. To a lot of people, that's an accident waiting to happen. To the idealist, using solar-powered electrolysis <i>on-site at the dispersal pump</i> to separate hydrogen atoms from the oxygen in water is the answer. Solar power is the one source of energy we can afford to waste - there's more of it around every day than we could possibly capture and use in a year. Otherwise - yes - it's a pipe dream. Do the physics - we start with water, end up with water, and in the meantime, we have to power a 2-ton vehicle down the highway. That means a shitload of energy must be input somewhere in that process. To make it feasible, that energy must be "pretty damned cheap". Granted - we're far from getting there at the present level of technology - but wait 'till Texas oilmen start seeing a profit in fuel cells - the technology will take off real quick - just you wait and see. __________________ If you want to avoid 95% of internet spelling errors: "If your ridiculous pants are too loose, you're definitely going to lose them. Tell your two loser friends over there that they're going to lose theirs, too." It won't hurt your fashion sense, either.

09-04-2003, 04:17 PM	#10 (permalink)
shakran Tone.	Transporting: Absolutely correct. That's usually one of my big arguments against this technology. How did I forget that! So yes, you're correct that the safest method of delivery would be the solar powered on-site electrolysis. BIG problem with this, however: What do you do on a cloudy day? Or at night? Don't say batteries to store the solar energy - that's what the hydrogen is first off and second if we have backup batteries to convert when the sun's not out, then we have to worry about the enviornmental impact of making and burying enough batteries to do the job (this would be a LOT of batteries) As for texas oilmen being the spark - -that's exactly why there's so much hubub over researching this idiocy in the first place. As I think I saw mentioned above, methane is a great source for hydrogen. Methane comes from oil wells. It's cheaper to get methane than it is to get oil. The oil barons would like nothing better than a conversion to fuel cell vehicles because they could get even more rich by selling the methane that costs them less to extract in the first place! Best of all, they're already sitting on a potential fortune in methane and they don't have to expend any capital to secure the rights to it since they already HAVE those rights. The biomass idea seems plausible until you realize that once again you now have to transport the hydrogen, because no one would want a gas station that had a huge compost pile in its back yard. As for the pressurized-inert-hydrogen. ..well, as you said this is VERY far off. Until we can do this reliably, AND produce the hydrogen without expending any renewable resources (we're talking decades here folks) it's pointless to go ga-ga over these cars.

09-22-2003, 04:52 PM	#12 (permalink)
Scorpion23 Psycho	The theory behind selling the byproducts for extra money sounds good when you take a first look at it. But as stated earlier the diamond process would take a fairly large amount of energy. Depending on the setup of the reactor vessel it would probably be cheaper to use the byproducts as a fuel for heating the reaction. __________________ "Empirically observed covariation is a necessary but not sufficient condition for causality" - Edward Tufte

10-03-2003, 12:18 AM	#14 (permalink)
Noob Upright	burn it CH4 + 2O2 ---> 2H2O + CO2 collect the water condense it(or you could just get water from the sink) and split the water molecules with an electrolysis experiment youll get hydrogen at the cathode and oxygen at the anode Last edited by Noob; 10-03-2003 at 12:22 AM..