On Wednesday, 4 January 2017 17:36:45 UTC, wrote:
On Wednesday, 4 January 2017 16:11:09 UTC, harry wrote:
On Wednesday, 4 January 2017 13:33:31 UTC, tabby wrote:
On Wednesday, 4 January 2017 11:55:06 UTC, TimW wrote:
On 04/01/17 02:56, tabbypurr wrote:
On Wednesday, 4 January 2017 00:12:19 UTC, TimW wrote:
On 03/01/17 23:03, tabbypurr wrote:
[...]

Carbon capture has never made any sense even at the most basic level. But if it can rake in subsidies...

How could it not make sense?
I understand a method and technology has been elusive, but itmakes sense
at a basic level to take CO2 out of the atmosphere, no?
TW

Energy generation requires turning C into CO2 to generate heat. Going from CO2 back to any less oxidised form is merely reversing the process. It's like taking 2 steps forward then one back, you make less progress. And since the step back costs money and is not entirely efficient, the whole process ends up using more energy per kWh out, producing more CO2 per kWh out, and costing more. It just fails to make any sense.



This is the first time I have heard anyone suggest that 'Carbon Capture'
should involve converting CO2 to pure Carbon.

I didn't say back to C, I said back to any less oxidised form.

It would be an idiocy, but
I don't think it is any more than a straw man. I thought it was about
pumping CO2 underground into old mines or natural rock formations in
which you hoped it would stay put.

That's a hopeless approach, quite unrealistic. And achieves worse than nothing. The percentage of CO2 output one can bury is tiny, and guess what's required to do it... producing more CO2 to drive pumps etc. And of course putting it there temporarily does't achieve anything.


NT

I have heard warnings against deforestation on the grounds that tropical
forests capture large quantities of CO2, but that is a different matter,
and besides it is good sense for many reasons.

Tim W
Some carbon capture involves dissolving the CO2 in water.
This is done under high pressure.
The water is then pumped underground.
The CO2 then stays dissolved because it is under high pressure (all the other water on top of it.)
The problem is that it's hot down there.


How it works out as regards energy consumed toachieve this, have no idea.

There has been a few failed projects.

https://en.wikipedia.org/wiki/Carbon...e_CCS_projects

It takes energy to do it, and eenrgy to produce the equipment used to do it, transport the people involved etc etc. Energy comes from producing CO2, thus doing it produces more CO2 - not less. Now, CO2 isn't going to stay underground for ever, so what you've done is to add more CO2 to the atmosphere. Not just for no gain, but at significant cost.

It's the sort of thing that appeals to people with no grasp of basic engineering. It's the fashionable non-sense of the day and curries votes.


NT

CO2 remains dissolved in water for ever.
The higher the pressure, the more can be disolved.


Natural gas remained underground for millions of years with no leakage.
Why shouldn't CO2?

The questions revolve around the energy balance, not whether we can permanently "bury" it.