Boundary Dam Carbon Capture Project: A working CCS case study

Background

 Having divulged my thoughts on the geological viability of CCS and how to market CCS to the public over the last few weeks, I thought that this week I would present to you an in depth case study of CCS in action.

The Carbon Brief, though a little dated, provides a good overview of current CCS projects around the globe.

Figure 1: CCS projects around the globe. Just 3 of the 22 projects (in 2014) under construction or operational were working power stations.

Boundary Dam CCS Project

 The first example I encountered was the Boundary Dam CCS project in Canada, marketed by its owner, Saskpower, as "The world's first post combustion CO2 capture coal fired power station".

 The project, described in depth here constitutes:

• The regeneration of an ageing coal fired power unit into a more efficient, reliable generator of 115 megawatts of electricity per year.
• The capture of up to 90% of CO2 produced by the unit, reducing CO2 emissions by up to one million tonnes per year (the equivalent of 250,000 cars).
• Capture of other byproducts, such as SO2 and NOx, which are then sold to industry.

For further information, see this Department for energy and climate change blog here, and this rather self-indulgent and technical scientific paper by Karl Stephenne here. This (dry and corporate) youtube video from Saskpower also outlines the scheme well:

So far so good - coal is a cheap source of reliable electricity. With a 90% reduction in CO2 emissions, coal becomes a reliable, cheap and environmentally friendly source of electricity. However, there are caveats.

Destination of captured CO2

 The clue is in the name, carbon capture AND storage; Boundary Dam CCS project does the capturing well, but the storage? Not so much.

 "Most" of the captured CO2 is "transported by pipeline to nearby oilfields where it will be used for enhanced oil recovery (EOR)". 

So this project isn't CCS at all! It is merely a source of CO2 to fuel an oil extraction method that has existed for generations. 

Figure 2: Oil recovery at the nearby Weyburn oil field increased by ~250% when EOR methods were employed in the mid 2000's.

 Little data (probably purposefully) is available based on net CO2 emissions from CCS taking into account CO2 produced by extra crude production. So I thought i'd try for myself*:

• According to the US Energy Information Administration, ~170kg of CO2 is created from a barrel of oil (if converted into petrol and combusted).
• An extra ~15,000 barrels of oil a day was produced each day due to EOR at Weyburn oil field (at injection rates of 1,800,00 tonnes of CO2 per year).
• This equates to 475,000 extra barrels of oil produced a year based on 365 days a year production. 
• Post-combustion, this equates to 930,750,000kg of CO2 per year, or 930,750 tonnes, based on the US EIA's figure.
• The Boundary Dam project captures ~1,000,000 tonnes of CO2 per year. Assuming 'most' means ~90% then 900,000 tonnes of this is used for EOR. 
• ~1,800,000 tonnes of CO2 a year was injected at the Weyburn oil field. Boundary dam will contribute approximately half this amount (~900,000 tonnes) to EOR a year. 
• Based on this assumption, approximately 465,375 (930,750 / 2) tonnes of CO2 will be created per year from the combustion of oil produced from CO2 captured at Boundary Dam. 

 In short, this means that the Boundary Dam CCS project produces 115 Megawatts of electricity per year, with minimal (<10% of the norm) CO2 emissions. However, the project then effectively releases ~465,000 tonnes of CO2 per year from oil combustion.

Conclusions

 There are many assumptions in this rudimentary back of the envelope calculation, but what is clear is that there are distinct environmental benefits to CCS-EOR. Negative, or net zero emissions, are not attainable via this method. For this, highly efficient storage within geological formations would be required.

 But, we live in a world addicted to electricity, addicted to oil. There exists a whole different debate encompassing whether or not we should continue to use fossil fuels in the face of climate change. But, in a world unlikely to go teetotal anytime soon, projects such as this can help to drastically reduce, though not eradicate, CO2 emissions.

 Now, this line of argument ignores the nitty-gritty world of economics, of safety and of politics. My next post will explore these issues in relation to the Boundary Dam CCS project.

Until then...

*calculations based upon Weyburn oil field, an oilfield in the Boundary Dam region which underwent EOR in the mid 2000's. At the the time Weyburn was the largest CCS project in the world. Injection of CO2 into the Weyburn field was 1,800,000 tonnes per year.