The Oil Drum: Europe

If you could apply Carbon Capture and Storage (CCS) to the world's 2,000 largest fossil fuel power plants (about 90% of them coal) you would reduce world CO2 emissions by something like 25%.

I am assuming in this:

- that electric power production is c. 40% of world CO2 output

- that coal is about 7/8ths of that (coal is 1/2 US electric power output, and about 80-90% of CO2 output for the US electric power sector; it is c. 90% of Chinese electricity output, c. 80% I think of Indian, I can't remember the Russian fraction (about 20% I think), about 30% of Canadian, about 60% of Australian, 40% of German, 90% of Polish etc.

- that CCS, including the additional energy costs, would reduce total CO2 emission per plant by about 70%

(sorry for all the handwaiving, I haven't done a good model)

This would cost something between $100-200/tonne of carbon abated (might be as high as $300 or $81/tonne CO2).

Now it's likely that in the early stages, costs would be at the upper end, or beyond, what the IPCC estimates. The IGCC (Intermediate Gasification Combined Cycle) technology is relatively expensive and tricky, compared to Ultra-Critical pulverised coal technology.

The MIT coal study also shows that the technology pathway is not entirely clear: it's not certain that IGCC with CCS is better than conventional pulverised coal (PC) with CCS. We need to build the plants and find out.

As you point out, a systematic programme of improving building efficiency (c. 30% of greenhouse gas emissions) could sharply reduce the demand for electricity at the same time. It's entirely within current technology to double current building efficiency on average (new buildings, 80-90% better ie using 10% of the energy they do now; retrofitting buildings up to 50% better).

It's really quite sad, because that says we could reduce world CO2 emissions by 35-40%, simply by doing what we already know how to do, and by fully developing CCS technology. We could do that in 30 years (time to replace all power plants and bring all buildings up to standard).

By contrast, transport is much, much harder. There is a 'quick win' (US passenger vehicles) but after that, abatement costs per tonne of carbon are quite high.

(saving the rainforests is actually cheapest: as little as £10/tonne of carbon. Even cheaper is stuff like insulating your home or changing to CFLs, which have *positive* costs ie they *pay* you to do them)

Having watched the UK drown this summer (having nearly melted 2 summers ago) and watching Greece burn, and noting the continued disbelief in global warming in the US (and the prevalent belief that GW has something to do with Al Gore's political ambitions ie that it is a partisan issue) my conclusion is things really haven't gotten bad enough. Humans need much bigger threats to make them change their ways.

In 20 years time we'll be ready for these solutions. But we'll do everything to drag our heels in the meantime.

This week's Science Magazine (? couldn't find the cite, it might be Nature) has a debate between Sir Nicholas Stern and William Nordhaus. Nordhaus, the doyen of sceptical environmental economists, basically argues we should concentrate on economic growth, and making the future rich. Then they'll be rich enough to do something about global warming. He doesn't think our obligation runs any deeper than that, ie to do what we would normally have done.

The world, and the IPCC, as James Hansen points out in New Scientist this week, may be massively underestimating the risk of accelerated glacial melt.

Let's hope the earth's climate gives us that time to make up our minds to do something.

I've mounted a few desultory searches for the source of the efficiency loss numbers, and not found them.  How do we know, f'rex, that an IGCC plant would actually become less efficient than a PCC plant with recovery?

An IGCC plant could become far more efficient through the use of a few recent but simple technologies.  Take, for example, Acrion's CO2 Wash process.  This is a fractional distillation system designed to remove CO₂ and contaminants from landfill gas, but it would work equally well to remove CO₂, H₂S, COS, H₂O and the like from a syngas stream.  This leaves mainly H₂, CH₄ and CO.  This in turn could be fractionally distilled (a la air separation plants) to remove the hydrogen.  Carbon monoxide and methane go to solid-oxide fuel cells ($500/kW sometime soon), with the spent fuel gas sent to sequestration.  The air stream for the SOFC's is the combustion air for the gas turbine of an IGCC plant, heated by the hydrogen after exiting the SOFCs (to reach optimum turbine-inlet temperature).

I haven't taken this concept apart far enough to calculate a net efficiency for it, but my SWAG is it ought to be well over 50%.  Nearly all of the carbon, plus 99.9%+ of the sulfur and all the condensible pollutants such as mercury, will be removed from the combustion fuel stream in the two separation steps.  Energy supply for the separation is mostly as low-pressure steam to run the refrigeration system for the first distillation.

All we need is for the sub-$500/kW SOFC to come through, as Delphi and others have claimed they can do.  The rest is mostly re-plumbing a gas turbine.