Refrigeration could cool down the cost of carbon capture and storage
For years carbon capture and storage (CCS) has been considered a costly but necessary step in reducing emissions and protecting our environment. New research by Scandinavian research organization Sintef has found that refrigeration technology may reduce costs by up to 30 percent, increasing the potential for faster implementation.
“We were able to show that there are a number of important potential improvements to be made in the process,” says Sintef research scientist Kristin Jordal. “That said, cold CO2 capture turned out to be one of the most promising technologies.”
So how does it work? Refrigeration of flue gases from large power stations and industrial plants causes the CO2 compounds to condense into liquid form. This liquid can then be transported through pipelines, in tanks, or on boats. The research suggests that this could use less energy than approaches that use chemicals or advanced materials to extract CO2, and could potentially decrease the cost to transport the carbon.
“CO2 captured in liquid form can be loaded straight aboard a vessel and be transported to offshore storage sites before pipelines have been laid,” says Jordal. “If our findings open up the possibility of cold CO2 capture, they could help to bring forward the introduction of CO2 storage beneath the North Sea.”
Core participants in the “Cold CO2 Capture” project discuss their results. From the left; chief scientist Petter Nekså, research scientist Kristin Jordal and David Berstad, MSc, all of SINTEF Energy Research (Photo: SINTEF/Thor Nielsen)
Beneath the North Sea you’ll find what is known as the Sleipner field, an area where around 11 million tons of CO2 has been injected since 1996, according to the British Geological Survey. The area has the potential to hold an unimaginably large amount of CO2. The British Geological Survey estimates its pore-space volume at 6 x 1011 m3, where 1 percent of that space could hold 50 years worth of emissions from 20 coal-fired plants.
The looming concern is what happens if the CO2 leaks? If CO2 were to be absorbed into the water, it would increase the acidity, potentially damaging the eco-system. In the interest of monitoring the movement of CO2 there have been six 3D seismic surveys completed. The most recent was done in 2008, and all have shown that the CO2 has remained securely in the shale below the sea.
Proponents suggest that CCS would be able to minimize our carbon output and its effect on green house gasses. The Intergovernmental Panel on Climate Change (IPCC) has maintained in its latest report and summary released on April 13, that implementing CCS on a global level is an integral step in protecting our atmosphere. The IPCC asserts that in order to create a scenario in year 2100 where we are likely to keep temperature change below 3.8° F (2° C), which is in line with the pre-industrial levels, CCS will need to play a key role in reducing emissions globally by 25-55 percent compared with 2010 emission levels.
Sound too good to be true? It might just beUnfortunately, even in the ideal circumstances, CCS is not going to solve our climate challenges in the long term. Lets say CCS, as part of a portfolio of other emission-reducing technology, is successful in removing enough carbon in a timely manner to neutralize our species’ footprint. Eventually, there won’t be anywhere left to deposit the carbon. If we haven’t embraced renewable energy on a widespread scale by then, we’ll be back at square one.
And that’s only if the technology is in place in a timely manner. According to the Global CCS Institute, it can take 5-10 years to prepare a storage site for the collected carbon. This means that if a project commences today, it will be hard pressed to be storing carbon before 2020. As Kyle Sherer pointed out in his 2008 review of CCS, it was already questionable if there was enough time to effectively implement the technology six years ago, and today there are only 12 industrial scale CCS operations as opposed to the more than 2,300 coal-fired power plants identified by the IEA Clean Coal Centre.
The potential viability of refrigeration in CCS is an important step to overcoming cost and energy hurdles in the way of implementing carbon capture technology, but it will only be useful if companies and governments work together quickly to build the infrastructure required, so that researchers can move on to spending their time on more long-term solutions.