Tuesday, July 15, 2008

Local problems with CO2 sequestration

Inside Business - 13/07/2008: Coal capture could be problematic

See the link for a short but interesting story on plans (and the initial pilot project) for CO2 sequestration in Australia.

Apparently, the current cost problem is more in the CO2 capture technology, not the storage.

I'll take their word for it, but I still assume that a major cost in the future will be getting the CO2 to the sequestration site. In this article they talk of using the Moomba area, which already has pipe in place which could be used for transporting the CO2. But for other areas, surely the transport costs are going to be huge.

I see that the trial Otway project will pump 100,000 tonnes of CO2 into the ground. Sounds quite a lot, but how much CO2 does Australian power generation generate each year? According to this BBC site: 205,000,000 tonnes. So the total Otway project (I am not sure over what period it runs) will remove about .048% of annual emissions.

See why I remain deeply sceptical about this as a concept?

UPDATE: here's a generally sceptical look at CO2 sequestration from the 7.30 Report earlier this year. (I missed it at the time.) I see that the 200 millions tonnes a year figure seems correct, but it will rise to perhaps 300 million by 2030. (!)

It just seems a hopeless task. Surely you would be better off giving high priority to decommissioning coal powered stations and replacing them with, well, virtually anything. (Natural gas as an interim, it emits much less. Then nuclear and solar.)

UPDATE 2: apparently, the government (and Martin Ferguson in particular) is a believer in sequestration. All to be revealed tomorrow, perhaps.

I also wonder how hard the government is looking at the possibility of using "algae reactors" to scrub CO2 from power stations? Here's an article from a 2006 CSIRO publication in which an American company argues that it has many advantages over sequestration.

The company is GreenFuel Technologies, and its FAQ section is worth reading. They estimate that, for an average American coal fired power station, you would need 3400 hectares of algal farms to get a 40% reduction in CO2. Sounds a hell of a lot, doesn't it? (A square kilometre is 100 hectares.) But then solar farms are not exactly small either. Maybe I would be aiming for less than 40% reduction....

Still, sequestration is not a walk in the park either, and at least algal farms have a potential product at the end which may help offset the cost. (It is also less energy intensive. You have to remember with CO2 sequestration, you have to use more energy just to get the CO2 out of the exhaust.)

UPDATE 3: Greenpeace put out a paper in May 2008 detailing why it is against sequestration. In the section on Australia, it says:
In Australia, CCS would lead, at best, to a 9% emissions reduction in 2030 and a cumulative emissions reduction from 2005 to 2030 of only 2.4%.[88] This is partly due to the lack of suitable storage locations. For example, in the Newcastle-Sydney-Wollongong area of New South Wales and at Port Augusta in South Australia, which together produce about 39% of Australia’s current net CO2 emissions from electricity generation, there are no identified storage sites within 500 km of the coal-fired power stations.[89] In comparison, a modest improvement in energy efficiency could – at zero or even negative cost – decrease emissions in 2030 by about the same amount, and cumulative emissions by twice as much.[90]
Well, they might just have a point.

No comments: