Monday, April 02, 2007

Nuclear Powered Oil-Sands!

The subject of EROEI has raised its head in various of these postings - Energy Returned On Energy Invested. I have also referred to the oil-sands (tar-sands) of Alberta in Canada, which contain bitumen as is cracked into oil on a massive scale. I have referred too to the fact that it takes resources to extract resources, and that the production of oil from the "oil-sands" consumes enormous quantities of gas and water. It might be debated as to when "Peak gas" may arrive, an event which is projected to come within a decade or so after "Peak Oil", which is most likely already upon us. In consequence, another source of heat will be required if Canada is to continue producing oil from its massive reserves of oil sands, albeit at an EROEI of around just 3. For comparison, when the EROEI reaches 1, it takes as much energy to extract a resource as can be recovered in burning it. The EROEI for oil production from petroleum-wells stands currently at around 8 - a far cry from the EROEI of 100 that pertained in the early days of oil-exploration, when the famous "gushers" were struck in the US fields of "black gold".

To this end, it has been proposed to install nuclear reactors in Alberta, for the purpose of generating energy to produce oil from the tar-sands that are in abundance there and cover an area about the size of Florida. Canada produces 3.1 million barrels of oil a day, mostly from conventional sources, but over 1 million barrels worth come from the tar-sands - a figure which is set to triple within ten years. Canada is the world's seventh greatest oil producer and is the number one supplier to the United States. Not surprisingly, when the word "nuclear" is mentioned, hackles rise in some quarters, and the proposal has met with controversy from environmentalists. However, extracting oil from tar-sands is an extremely dirty process, and as noted, uses up large amounts of water and gas. Hence, the "nuclear option" is being promoted as the most environmentally friendly one.

Enhancing the status quo method of production means that demand for natural gas will increase by 1.1% a year through until the year 2030, by which time world gas supplies will probably have begun to wane. If Canada's oil-sands are costed among the oil reserves of the world, the nation would surpass Saudi in terms of the total amount of oil there. Venezuela also has enormous deposits of tar-sands, which might prove to be a major source of oil in the future. Canada is particularly fortunate in that it also has large reserves of uranium, and so a fertile collaboration between the nuclear and oil industries might be possible. It is true that generating nuclear power produces far less CO2 (probably around 20%) over the operational lifetime of the plant as compared with a coal or gas-fired power station, including the contributions from constructing the plant itself, mining, milling and processing its nuclear fuel and finally decommissioning the plant at the end of its life (as we will need to do in the UK with the current generation of 31 nuclear power stations by 2025).

The World Nuclear Association estimates that providing natural gas amounts to 60% of the operating costs for an oil-sands facility. However, the price of gas has jumped 6% in only the past week, and it seems almost certain that the cost of gas will increase over time, as its sources become more scarce. One major obstacle to the nuclear option is that the province of Alberta has never had any nuclear power, and to so install the technology would require the overall approval of the community there. The Canadian House of Commons' Committee on Natural Resources has issued a report entitled: "The Oil Sands: Toward Sustainable Development", which has put the project on hold, "until the repercussions of the process are fully known and understood". The report also expresses concerns about nuclear waste and whether "nuclear" can provide the necessary steam for the processing operations. The committee was also dissatisfied over the lack of information regarding exactly how many nuclear reactors would be needed - i.e. one or many large reactors, or perhaps a greater number of smaller installations.

There are two main processes involved in extracting oil from tar-sands. Firstly, the more shallow deposits are strip-mined, where earth is scraped back and giant shovels and trucks remove the desired material. This is then subjected to super-heated steam which loosens-up the tar-like bitumen, which is described as being like "molasses". Deep extraction methods have also been developed: Cyclic Steam Stimulation pipes high-pressure steam down to the heavy bitumen which is thus brought up to the surface. Another method which is becoming more popular is Steam Assisted Gravity Drainage, in which two parallel pipes are enplaced vertically and then project at an angle of 90 degrees. The top pipe is used to inject steam and the bottom one collects the bitumen and draws it to the surface. Both surface and deep extraction methods produce bitumen that requires subsequent intensive processing ("cracking") to recover oil from it. About half a barrel of oil is produced per tonne of tar-sands.

Several nuclear companies, led by Energy Alberta, are planning to bring two new nuclear reactors into operation to power the tar-sands operations by 2017.

Related reading.


Trinifar said...

Good post, Chris.

I just love that Canadian government report title: "The Oil Sands: Toward Sustainable Development." To me it's a bit of an oxymoron. How can any extraction of fossil-fuel be linked to sustainability in a meaningful way? Even if you could extract it sustainability, as soon as you burn it sustainability goes up the chimney so-to-speak.

Then add the whole idea of doing this with nuclear energy...!

At least they've put the project on hold.

Professor Chris Rhodes said...

I think the whole idea is a very messy business. However, as supplies of conventional petroleum begin to decline it might become a case of all being "fair in love and war"! Then wars and environmental destruction will be seen as a necessary evil.

Interesting how we use oil and gas to extract nuclear energy, isn't it...!