Australia’s coal industry takes public relations up a notch.
Did anybody else see the full page ad in The Age yesterday (Thursday 13th, I think it was page 7 or page 5) courtesy of the Australian Coal Association, telling us how wonderful CCS “clean coal” technology (i.e. carbon dioxide capture and geosequestration) is, and how it’s proven technology which is already in use, and how it’s going to solve all our problems with regards to anthropogenic CO2 emissions, and maintain active business as usual for the coal industry?
I don’t think so, personally.
You don’t see the ITER consortium taking out full-page page 5 ads in the major papers to promote their technology, do you? That option is about equally as mature and developed, and has just as much potential, if not more, for energy generation, and it’s far more environmentally sound.
I realise that, of course, those full-page newspaper spots must cost a pretty penny, so I did a little bit more investigation in the press.
THE coal industry feels unloved. Its polling tells it Australians have no idea what, if anything, it is doing to reduce its greenhouse gas emissions — and most say they’ve never heard of carbon capture and storage.
So the coalminers want to convert us. Today the Australian Coal Association launches a $1.5 million ad campaign — and a $1 million website — to tell us what it’s doing to develop what it calls “NewGenCoal”.
Association executive director Ralph Hillman predicted that carbon capture and storage would be commercially viable by 2017, and said the industry was investing $1 billion to ensure coal a future as a low-emission technology.
“CCS will work, and we’re investing in demonstrating these technologies,” Mr Hillman told journalists yesterday. “We’re working to implement them on a commercial scale by 2017.”
Back in Hugh Morgan’s day, the coal industry’s global warming strategy was to fund denialist groups. Not now: Mr Hillman said the industry saw climate change as real, and the association’s main goal was to drive the adoption of CCS to tackle it.
Coalminers now pay a voluntary levy of 20¢ for every tonne they mine into the Coal 21 Fund, raising $100 million to help finance CCS pilot plants and, in future, demonstration projects. These include:
* $68 million towards the $205 million trial of an oxyfuel post-combustion CCS system at the Callide power station in central Queensland, to be opened by Resources Minister Martin Ferguson tomorrow.
* $26 million towards a feasibility study to revive the collapsed ZeroGen project near Rockhampton.
* A proposed demonstration scale plant at Munmorah in NSW.
The Federal Government’s climate change adviser, Ross Garnaut, has criticised the industry’s effort as inadequate. In his final report last month, Professor Garnaut contrasted its research and development spending with the amounts paid by farmers out of a much lower revenue base. He said coalminers should beef up their R&D levies to $250 million a year to accelerate the adoption of CCS.
The International Energy Agency warned last month that CCS now costs between $US60 ($A90) and $US75 per tonne of emissions saved, way above the price of wind power or nuclear — and unless R&D efforts were radically stepped up, it might not be commercially viable until 2030.
There is no commercial coal-fired power station anywhere in the world at present which captures even 10% of its CO2 emissions.
The coal industry is quick to hold up their current, active CCS and “clean coal” enterprises as examples – but perhaps it’s worth looking at them a little more closely.
Firstly, we have the coal industry’s “clean coal” technology fund putting $68 million towards the $205 million trial of an oxyfuel post-combustion CCS system at the Callide power station in central Queensland. Where does the rest of the money come from? From state and federal governments, mostly, who are handing these projects lots of money in an effort to appear “clean and green”, and serious about mitigation of CO2 emissions, of course.
Oxyfuel combustion-and-CO2-capture involves the combustion of coal with virtually pure oxygen, rather than air, to fuel a power plant’s boiler. When the coal is burned in pure oxygen, the resulting exhaust gas is mostly CO2 (with a little bit of SO2 as usual, depending on sulfur content in the coal) instead of being mostly atmospheric nitrogen, with a smaller portion of CO2 as well as some SO2 and NO2 as is present when the coal is burned in air. A portion of the exhaust gas is recycled back into the boiler to regulate combustion and keep the oxy-fuel furnace from destroying itself.
Since the product of oxy-fuel combustion of coal is essentially pure CO2, (SO2 can be removed as usual via standard flue gas desulfurisation), the exhaust gas CO2 can be liquefied and sent straight to geosequestration, without the need to distil the CO2 from a mixture of other gases such as N2, hence making CO2 geosequestration easier to do.
Of course, the plant to produce pure oxygen, by compression and liquefaction of air followed by cryogenic distillation of pure O2, is required as part of the oxy-fuel combustion plant, and this is a non-trivial capital expense – and it also requires a reasonably significant energy input during operation.
However, the liquid oxygen produced (boiling at 90 K) can easily be used to liquefy the carbon dioxide output stream (boiling at 195 K), meaning that additional plant, and additional energy input, for the compression and liquefaction of the CO2 output is probably not required. It is claimed by the industry that oxyfuel combustion can be retrofitted to conventional coal power plants with relatively little modification.
There’s some more useful technical detail on the Callide oxyfuel project here. [PDF file, but it is not especially large.]
The graph on slide #4 is interesting, isn’t it – perhaps I’m misinterpreting it, but are Australia’s National Generators Forum really themselves predicting that nuclear energy will make up about 40% of Australia’s electricity supply by 2050, under a scenario achieving a 50% reduction in anthropogenic CO2 emission rates, over 2005 levels, by 2050? I’m surprised that they recognise, and indeed operate with the assumption, that nuclear energy will be the largest single technology on the electricity grid by 2050. Let’s hope that it actually plays out that way.
Then again, perhaps I’m not all that surprised – is there really any way that a 50% reduction in anthropogenic CO2 emission rates over 2005 levels by 2050 could actually be done, in the absence of a significant contribution from nuclear energy?
Back to the oxyfuel-CCS plant, anyway.
According to the table of data given in the above document, a typical 500 MW air-firing plant may have a gross electrical power output of 524 MW, a net electrical power output of 500 MW, and a net thermodynamic efficiency of 41%. Hence, the thermal power is 1278 MW. For the oxygen-firing plant, gross electrical power output is 633 MW, with a net thermodynamic efficiency of 34%, for the same net electrical power output of 500 MW. Hence, the thermal power is 1862 MW – an increase of 46% in the thermal power required from the boiler, and hence an increase of 46% in the amount of coal that needs to be mined, a 46% increase in mountaintop removal, and so forth.
At a net gas flow rate of 180 kg/s, which I assume is the exhaust gas output, from the oxyfuel plant, the 67% concentration of CO2 corresponds to a CO2 output of 868 g CO2 per kWh, or 10,420 tonnes per day (that is, ignoring any < 100% capacity factor, since a coal-fired plant should be operating with a high capacity factor, and I really have no idea what kind of capacity factor to expect from such a plant.)
The Australian coal industry’s efforts to develop and implement oxyfuel combustion with CO2 storage are currently at the demonstration phase. The Callide Oxyfuel Project team is assessing potential sites to the west of Biloela for carbon dioxide geosequestration and plans to select the final location in 2009.
The carbon dioxide will supposedly be transported in road tankers.
Road tankers? Seriously? Obviously that can not and does not work, for carbon dioxide geosequestration on any meaningful scale.
Let’s assume that the trucks leave the station, and travel, say, 50 km to the geoseqestration site. Assuming that the trucks travel at 100 km/h, and ignoring the time taken to load and unload the tankers, (obviously these assumptions are conservatively high to the point of being completely unrealistic) and assuming that one tanker holds 20 tonnes of liquid CO2, then you can move 20 tonnes per truck per hour. If you have, say, 22 tanker trucks, then you can transport the required 10,420 tonnes per day, if those 22 trucks are running non stop for 24 hours per day.
(Keep in mind that those trucks will almost certainly be running on fossil-fuelled, CO2 (and SO2) emitting engines…)
As the CSEnergy presentation notes, oxyfuel combustion, CO2 capture and geosequestration can reasonably be expected to increase the wholesale cost of electricity by between 50% and 75%.
The Callide oxyfuel project is not some important milestone in reducing Australia’s anthropogenic CO2 emissions. It is only a pilot-scale experiment designed to establish the design and operating costs for oxyfuel CCS plants, and to establish the capital and operating costs for these plants.
The project involves the refurbishment and retrofit of only one of the four 30 MW boilers are the currently-mothballed Callide A station, with the compression and purification of 100 tonnes of CO2 per day from a 20% side stream. That’s it – it’s only 30 MW of “clean coal” capacity.
How much CO2 is actually produced, and how much is actually being sent to geosequestration?
Assuming that the retrofitted 30 MW unit continues to operate with a capacity of 30 MW then, extrapolating the above numbers for the 500 MWe case, then the plant will be expected to produce about 625 tonnes of CO2 per day. If 20% of that CO2 is compressed and purified, then that’s 125 tonnes per day. OK, their quoted figures seem reasonable, so let’s work with that – 100 tonnes of CO2 compressed and purified per day. But only 50-75 tonnes per day of CO2 is transported and geosequestered.
To recapitulate: The plant will emit about 625 tonnes of CO2 per day, of which only 50-75 tonnes, 12 percent at the most, is geosequestered.
The atmospheric CO2 emissions intensity, then, is at best 764 gCO2/kWhe.
The Portland Wind Project under construction in Victoria has a nameplate capacity of 195 MW – which is over twice the energy output of the 30 MW Callide A unit, even when the lesser capacity factor of wind, at about 30% or so, is taken into account. At a cost of about 270 million dollars to construct the wind farm, which has zero carbon dioxide emissions, it is clear that even something as simple as wind energy, let alone nuclear, geothermal, solar thermal or anything else, is a far more economically attractive, and a far more environmentally attractive choice than the coal plant – and even typical wind farms generate far more energy than this pilot plant!
I really view “clean coal” in the same skeptical fashion that I treat anything else – such as solar photovoltaics or wind turbines – they can come back and sell their solutions, once they have a solution that realises actual generating capacity by the gigawatt, which can replace or retrofit existing coal-fired generators, with negligible, or essentially negligible greenhouse gas emissions. When the coal industry can capture and sequester all the carbon dioxide emissions from a conventionally sized coal-fired generator, economically, then I’m happy to reconsider the technology.
This plant is more expensive than nuclear, it’s more expensive than wind, and it’s probably more expensive than just about every low-emissions technology, with the possible exception of photovoltaics, it’s getting taxpayer money thrown at it, and it emits at least 764 gCO2/kWhe to the atmosphere.
That’s not “clean coal”; that’s… well, I won’t say what I think in polite company. I’ll leave it for you to think about.