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Started by barkis on Aug 24, 2021 10:32:04 PM
Blue Hydrogen

This apparently involves splitting methane into hydogen and carbon, the latter being released as CO2. Thhe idea is that the CO2 will be stored underground indefinitely. It's been suggested that even if this carbon storage works (and I don't know of anywhere it has) there will be large greenhouse gas emmisions.

If the carbon capture technology did work wouldn't it be easier to just burn the methane?

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Verdigris - 25 Aug 2021 16:14:15 (#1 of 58)

I strongly suspect this is being pushed by fossil fuel companies trying to keep their existing assets financially viable. On the other hand we are going to need a lot of hydrogen, at least for a transition period, for shipping, possibly aviation and heavy haulage. Presumably the CO2 can be put down into the depleted gas fields. They say hydrogen can be stored there (it's already being stored in old salt working) so CO2 should be easier, being a larger molecule.

tasselhoff - 25 Aug 2021 17:16:18 (#2 of 58)

Thhe idea is that the CO2 will be stored underground indefinitely

That's a load of bollocks for a start.

barkis - 25 Aug 2021 17:18:00 (#3 of 58)

If it relies on carbon storage why don't they just burn the gas?

tasselhoff - 25 Aug 2021 17:23:53 (#4 of 58)

Quite. It produces CO2 and water directly. Hydrogen just appears greener at the point of use, but is less efficient.

Verdigris - 25 Aug 2021 16:26:57 (#5 of 58)

That would be pretty much restricted to power stations, where you could capture the CO2. I think "green" hydrogen, produced by electrolysis by renewable electricity is going to be in short supply in the near to medium term.

tasselhoff - 25 Aug 2021 17:30:11 (#6 of 58)

What's the efficiency of turning CH4 into hydrogen?

looneytoon - 25 Aug 2021 17:50:32 (#7 of 58)

https://m.youtube.com/watch?v=qOntMxYA29U

Verdigris - 25 Aug 2021 17:10:07 (#8 of 58)

Hmmm! Baseball cap, probably American, do I risk losing 15 minutes of my life?

barkis - 25 Aug 2021 18:15:23 (#9 of 58)

Antipodean I think. I only watched a bit but there was a quite amusing response to someone who referred to his "annoying British accent".

Verdigris - 25 Aug 2021 17:17:47 (#10 of 58)

I suppose because Johnson and his mate Bamford, say hydrogen is the next big thing, alarm bells should ring.

bossab2 - 25 Aug 2021 18:29:13 (#11 of 58)

https://en.m.wikipedia.org/wiki/Heat_of_combustion

H2 has the greater heat of combustion.

But I dont know how much energy the process to produce it from methane consumes

( normally there are no energy free lunches )

tasselhoff - 25 Aug 2021 18:43:03 (#12 of 58)

And any H2 storage loses about 2% per day because it's so tiny.

looneytoon - 25 Aug 2021 18:46:26 (#13 of 58)

Taking fuel, CH4, heated in presence of steam to create H2 and CO2. So energy is used to turn fuel we already have into H2. So it is already a loss in efficiency. Then burning H2 in a nitrogen rich environment will not be clean as some oxides of nitrogen will be created.

Why not burn the fuel we have to create electricity to run things and capture carbon etc in a large industrial process?

tasselhoff - 25 Aug 2021 18:51:13 (#14 of 58)

Exactly. As mentioned upthread.

Verdigris - 25 Aug 2021 17:52:29 (#15 of 58)

Why not burn the fuel we have to create electricity to run things and capture carbon etc in a large industrial process?



Yes, as I said, upthread. As far as I can see CCS only works on a large scale, so power stations are about the only thing that fir the bill. Trouble is, the Tories (Cameron stamping out green crap?) binned CCS research, years ago, so we are probably nowhere near having a viable system available.

looneytoon - 25 Aug 2021 19:22:33 (#16 of 58)

My gas maintenance engineer was on about how we have to convert to H2 and everything else is just too expensive. I think this is what Blue Hydrogen is about - sowing seeds of disinformation

Verdigris - 25 Aug 2021 18:31:25 (#17 of 58)

I think there are a lot of situations where essentially keeping the gas-fired system going is the only reasonable stop-gap. Apartments, for example.

rejonked - 25 Aug 2021 18:50:05 (#18 of 58)

The gas companies have been lobbying really hard for hydrogen as a way to save their business. There are so many issues with it. Clearly a potential big role for green hydrogen in industry but heat pumps and district heating much more efficient for home heating and based on proven technology.

The only positive thing about hydrogen in the home is that it means less disruption - swapping out boilers and some appliances rather than doing the hard work of insulation and electrification.

Verdigris - 25 Aug 2021 18:56:33 (#19 of 58)

The only positive thing about hydrogen in the home is that it means less disruption - swapping out boilers and some appliances rather than doing the hard work of insulation and electrification.



Yes, a stop-gap of, say 20-30 years whilst you tackle the easier cases.

There are district borehole and heat pump schemes being done but in central London, for instance, you could end up drilling through Crossrail, which has troubles enough already!

AdonisBlue - 25 Aug 2021 20:02:24 (#20 of 58)

If you have to bury, huge by volume and weight, quantities of carbon why not instead bury far smaller quantities of radioactive waste and generate far more green energy that way?

Oh yeah because CND inextricably linked nuclear weapons and nuclear power for an entire generation in the UK. Meaning we have to wait for an entire generation to die off before we can start to properly reduce carbon emissions with the low carbon and super efficient nuclear power.

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