I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Probably because we have ample supplies of methane to use down here?

But Elon ain’t coming back from Mars if he goes there.

roughbarked said:

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Probably because we have ample supplies of methane to use down here?

But Elon ain’t coming back from Mars if he goes there.

There are those who want to reduce the usage of fossil fuels.

I’m surprised you hadn’t heard about that.

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Probably because we have ample supplies of methane to use down here?

But Elon ain’t coming back from Mars if he goes there.

There are those who want to reduce the usage of fossil fuels.

I’m surprised you hadn’t heard about that.

Methane CH4. Hydrogen H2 No nasty carbon in hydrogen.

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Probably because we have ample supplies of methane to use down here?

But Elon ain’t coming back from Mars if he goes there.

There are those who want to reduce the usage of fossil fuels.

I’m surprised you hadn’t heard about that.

Oh I think I probably have.

Tamb said:

The Rev Dodgson said:

roughbarked said:

Probably because we have ample supplies of methane to use down here?

But Elon ain’t coming back from Mars if he goes there.

There are those who want to reduce the usage of fossil fuels.

I’m surprised you hadn’t heard about that.

Methane CH4. Hydrogen H2 No nasty carbon in hydrogen.

But H2 has several properties that make it more difficult to use than methane.

As long as the C is extracted from the atmosphere (or from emissions of CO2 producing processes), why not use it?

The Rev Dodgson said:

Tamb said:

The Rev Dodgson said:

There are those who want to reduce the usage of fossil fuels.

I’m surprised you hadn’t heard about that.

Methane CH4. Hydrogen H2 No nasty carbon in hydrogen.

But H2 has several properties that make it more difficult to use than methane.

As long as the C is extracted from the atmosphere (or from emissions of CO2 producing processes), why not use it?

Isn’t burning methane, cleaner than burning coal and oil?

who doesn’t love ethanol

SCIENCE said:

who doesn’t love ethanol

Teetotallers.

roughbarked said:

The Rev Dodgson said:

Tamb said:

Methane CH4. Hydrogen H2 No nasty carbon in hydrogen.

But H2 has several properties that make it more difficult to use than methane.

As long as the C is extracted from the atmosphere (or from emissions of CO2 producing processes), why not use it?

Isn’t burning methane, cleaner than burning coal and oil?

Yes it is.

Why do you ask?

The Rev Dodgson said:

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

How come you never hear stuff? I won’t presume to comment. :-)

I have heard quite a bit about green ammonia being easier to use for the same reasons you mention about Methane vs Hydrogen.

Witty Rejoinder said:

The Rev Dodgson said:

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

How come you never hear stuff? I won’t presume to comment. :-)

I have heard quite a bit about green ammonia being easier to use for the same reasons you mention about Methane vs Hydrogen.

Let me rephrase my question then:
How come we hear much more about hydrogen as an alternative fuel, rather than other fuels generated from non-fossil fuel sources?

The Rev Dodgson said:

Witty Rejoinder said:

The Rev Dodgson said:

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

How come you never hear stuff? I won’t presume to comment. :-)

I have heard quite a bit about green ammonia being easier to use for the same reasons you mention about Methane vs Hydrogen.

Let me rephrase my question then:
How come we hear much more about hydrogen as an alternative fuel, rather than other fuels generated from non-fossil fuel sources?

Cause of what you get when you set fire to it.

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

In fairness I do hear this talked about quite a bit, and indeed we’ve discussed it many times here.

dv said:

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

In fairness I do hear this talked about quite a bit, and indeed we’ve discussed it many times here.

See amended question.

The Rev Dodgson said:

Witty Rejoinder said:

The Rev Dodgson said:

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

How come you never hear stuff? I won’t presume to comment. :-)

I have heard quite a bit about green ammonia being easier to use for the same reasons you mention about Methane vs Hydrogen.

Let me rephrase my question then:
How come we hear much more about hydrogen as an alternative fuel, rather than other fuels generated from non-fossil fuel sources?

lobby pressure and vested interests

One of the reasons SpaceX is using methane is because it can be synthesised on Mars fairly easily. The other good reason is that it doesn’t leave carbon deposits in the various part of a rocket engine after shut-down, thus making it very much easier to re-start when desired. I think hydrogen/oxygen has a better ISP but it leaves the combustion chamber & injectors with crud on them that would have to be manually cleaned before starting the engine again.

What is an ISP?

SCIENCE said:

The Rev Dodgson said:

Witty Rejoinder said:

How come you never hear stuff? I won’t presume to comment. :-)

I have heard quite a bit about green ammonia being easier to use for the same reasons you mention about Methane vs Hydrogen.

Let me rephrase my question then:
How come we hear much more about hydrogen as an alternative fuel, rather than other fuels generated from non-fossil fuel sources?

lobby pressure and vested interests

Why are there more vested interests for hydrogen than methane?

The Rev Dodgson said:

What is an ISP?

Specific Impulse.
https://en.wikipedia.org/wiki/Specific_impulse

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

I see a way for Elon to save a lot of time.

It is easier to make green hydrogen than green methane: fewer steps, higher efficiency. This has to be weighed against the difficulties in storing and transporting bulk hydrogen.

They’ve detected methane on Mars haven’t they, wonder if that could be used

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Good question, I don’t know.

I have been thinking about this for some time as a pathway for biofuels. Use algae or seaweed as the feedstock. Pyrolysis as the first stage of processing, using concentrated solar thermal as the heat source. You end up with carbon, tars and syngas. The syngas can be converted into alkanes (including methane) using the Fischer-Tropsh process. This process has been around since the 1920s, so it shouldn’t be hard to do. Might even be able to improve it with a bit of tinkering using more modern catalyst materials. Anyway, this can take your biofuels and sunlight and convert it into a gas or liquid fuel that plugs right in as a fossil fuel replacement.

Then you have the charcoal and tars, which you might be able to do something useful with too.

party_pants said:

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Good question, I don’t know.

I have been thinking about this for some time as a pathway for biofuels. Use algae or seaweed as the feedstock. Pyrolysis as the first stage of processing, using concentrated solar thermal as the heat source. You end up with carbon, tars and syngas. The syngas can be converted into alkanes (including methane) using the Fischer-Tropsh process. This process has been around since the 1920s, so it shouldn’t be hard to do. Might even be able to improve it with a bit of tinkering using more modern catalyst materials. Anyway, this can take your biofuels and sunlight and convert it into a gas or liquid fuel that plugs right in as a fossil fuel replacement.

Then you have the charcoal and tars, which you might be able to do something useful with too.

Could the charcoal be used in agriculture or water filtering

Cymek said:

party_pants said:

The Rev Dodgson said:

I was reading on the electric Internet this morning that when Elon goes off to Mars he will spend his time converting CO2 and water into methane so he can come back again.

How come we never hear about people doing that here on Earth, but always proposals for “green” hydrogen?

Good question, I don’t know.

I have been thinking about this for some time as a pathway for biofuels. Use algae or seaweed as the feedstock. Pyrolysis as the first stage of processing, using concentrated solar thermal as the heat source. You end up with carbon, tars and syngas. The syngas can be converted into alkanes (including methane) using the Fischer-Tropsh process. This process has been around since the 1920s, so it shouldn’t be hard to do. Might even be able to improve it with a bit of tinkering using more modern catalyst materials. Anyway, this can take your biofuels and sunlight and convert it into a gas or liquid fuel that plugs right in as a fossil fuel replacement.

Then you have the charcoal and tars, which you might be able to do something useful with too.

Could the charcoal be used in agriculture or water filtering

Yeah. Adding it to the soil will make the process carbon negative. Or you could burn it in a conventional power station.

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

But H2 has several properties that make it more difficult to use than methane.

As long as the C is extracted from the atmosphere (or from emissions of CO2 producing processes), why not use it?

Isn’t burning methane, cleaner than burning coal and oil?

Yes it is.

Why do you ask?

Just checking on my brian cells.

Here’s one such project that started a few years ago. It’s a small trial.

https://arena.gov.au/blog/renewable-methane-southwest-queensland/

Renewable carbon neutral methane to be produced in south-west Queensland

https://en.wikipedia.org/wiki/Methanation

dv said:

Here’s one such project that started a few years ago. It’s a small trial.

https://arena.gov.au/blog/renewable-methane-southwest-queensland/

Renewable carbon neutral methane to be produced in south-west Queensland

Thanks, interesting.

https://en.wikipedia.org/wiki/Methanation

actually we remember recent times people would complain about how you couldn’t store renewables and also complain about how fuel drinking systems would be obsolete and we were saying just bloody use the renewables to make fuel and store it but damn

Methane fuel cells make a lot more sense than hydrogen fuel cells.

Much lower operating temperature, easier fuel storage, for starters.