OT: Useful things to do with CO2

[Chris Hogg]

Costing the Earth, BBC R4, Wednesday 9.00PM

[ARW]

Ta,

[The Natural Philosopher]

Nonsensical solutions to non-existent problems...

...well that's practically a definition of socialism.

[Andy Burns]

And how much energy do these CO2->plastic or CO2->fuel processes take?

[The Natural Philosopher]

SOMEONE ALWAYS HAS TO SPOIL THE DREAM.

[Chris Hogg]

I did wonder whether some of the schemes weren't rather circular, a bit like perpetual motion, especially the reverse fuel cell one towards the end.

fuel > burn > electricity + CO2 electricity + CO2 + reverse fuel cell > fuel (but less of it, I assume) or so it seemed. I'd like to see the energy balance, the mass balance and the quantities potentially process able in a large installation and in what time.

[Tim Streater]

Well they could use intermittent renewables to power it. Then you would need an automated plant so if there was no wind for a few days, it wouldn't matter. But you'd still need to cost the overall plant in terms of payback time to see whether it was worth it.

[GB]

That looks like a perpetual motion machine.

[dennis]

We already do it using PLA plastics. We grow stuff and make PLA from the starch and then compost it back to CO2. Now to actually make a difference we need to stop recycling the PLA and leave the CO2 locked up so its time to be a litter lout. I reckon we could store a few tons at harry's place.

[Andy Burns]

I wrote that while listening to the programme reel of one after another research project to produce aggregate for concrete blocks, polycarbonate for plasticvs, fertiliser and fuel

To be fair, in the last few minutes it *did* say there was an energy cost to them all, the answer of course was to tax CO2 generating industries to subsidise the CO2 reversing industries.

[ARW]

You don't have to wonder about it.

It's complete bollocks

[Andy Burns]

Dell were banging on about making plastic from "thin air" for their packaging, with no mention of the energy required

[GB]

And how will they produce the energy required?

I suppose there's some sense in using "spare" electricity (eg at night time) to fix CO2, but the same electricity could also be used to pump water uphill, for example, to provide additional electricity at peak times.

[Chris Hogg]

Good question!

Bearing in mind that there will never be enough 'renewable' electricity at night to be 'spare'*, and that we don't have the topography for more than a little extra pumped storage over what we already have, neither of those options is open.

*except perhaps in Scotland on windy nights and if the tidal flow in the Pentland Firth is running strongly and the north-south interconnects aren't man enough to carry it, there might be a surplus up there, then build the CO2-gobblers in the Highlands.

[news]

A couple of the others were too in that they used other oxides from combustion to combine with CO2 to grow carbonates. If left exposed to air they would acquire the same CO2 over time like lime mortar does but they make a product with more utility in the process.

AJH

[Chris Hogg]

Some coal ash (fly ash) contains enough lime to be alkaline and will absorb some CO2, but I suspect not a lot. See Class C fly ash

I can't see it being viable to burn coal and then try and use the ash to absorb the CO2 produced, but I've not attempted to quantify it. Coal ash will be pretty variable depending on the source of the coal. Natural gas produces no ash anyway.

Wood ash, and other vegetable ashes, can be quite high in lime and other alkalis, so would also absorb CO2. No doubt the greenies would suggest that the ash from burning vast forests of wood could be used to absorb the CO2 from FF combustion, but without putting numbers to the idea it's impossible to judge its worth. Gut reaction says it's a total fantasy.

I look forward to the suggestion that we use lime to absorb all this nasty CO2! :-)

[news]

But that is essentially what was being discussed, making use of ash containing the oxides of alkaline metals. My point being they made more useful products than would otherwise have happened.

There are certain other volcanic rocks that will absorb CO2 to make carbonates but not generally exposed to the atmosphere.

As the americans have decided that increasing amounts of CO2 in the atmosphere will not affect them I doubt we will see any slow down in CO2 production for my remaining lifetime, nor is it likely to affect me directly.

AJH

[The Natural Philosopher]

The reported reaction from the green wankerati to Trumps victory is more or less subtexted as 'that's it chaps. Game over: we've been rumbled".

Climate change will doubtless continue up down or sideways, but the great Green scam will collapse.

This will probably be Trumps greatest legacy.

[Chris Hogg]

You've missed my point, which was that the majority of greens are not technically very savvy and wouldn't know that lime comes from calcining calcium carbonate (chalk, limestone etc) and driving off CO2 in the first place.

Peridotites and related rocks.

Most of those links are several years old. Has it gone quiet? If so, why?

The earth's mantle consists mostly of peridotite (the mantle is the layer below the crust). It occasionally gets pinched up through the crust when continents collide, forming what is known as an ophiolite structure. The Lizard peninsula in west Cornwall, close to where I live, is one such. Peridotites are not common, and weather rapidly in the atmosphere by absorption of water to form serpentine. See

Whether it would be practical to use them to absorb atmospheric CO2 in quantity and at a sufficient rate to make any difference at all would need to be demonstrated, but like a lot of these schemes, they're probably more efficient at getting grant money out of funding bodies than they are at actually working to any great effect in the real world.

All the efforts to reduce CO2 have so far had absolutely no effect on its continuing increase, as measured in Hawaii.

[news]

Yes I did, so basically we agree on this point.

AJH