Sustainable Growth the Nordic Way
WEB MAGAZINE - May 2018
The Nordics can – and should – be the first carbon-negative region in the world
The Nordic region is at an advantage when it comes to emissions reductions. The number of electric vehicles per capita in Norway is higher than anywhere in the world; Denmark gets around 40% of its electricity from wind; Finland’s and Sweden’s vast forests provide an abundant resource for biofuels; and the Nordic region’s inter-connected electricity network offers opportunities to share clean energy across borders.
However, it is not enough to merely reduce emissions, we must actively take carbon out of the atmosphere, says Anders Lyngfelt, leader of the Negative-CO2 project, funded by Nordic Energy Research.
“If we are to meet the climate target of the Paris agreement, carbon dioxide emissions cannot exceed the ‘climate budget’. With today’s emissions, this budget will be spent in 20 years if we are to limit the global temperature increase to 2 degrees Celsius. It will be spent in just five years if we are to limit that increase to 1.5 degrees Celsius.”
It is therefore extremely unlikely that we can meet these targets without a system that removes carbon dioxide from the atmosphere. In other words, we need negative emissions.
Cleaning the air
There are several methods for negative emissions. Most are based on the principle that growing biomass (agricultural and forestry products) absorbs carbon dioxide from the atmosphere. Some methods, forest planting, bio-coke and altered farming methods, involve increasing the amount of carbon stored in forests and land. The problem with this form of storage is that it is not long-term, for example forests can burn down.
The Negative-CO2 project has developed a process where the CO2 produced from burning biomass fuel (for example wood chips from trees) can be efficiently captured and securely stored underground, thereby preventing the CO2 from ever being released into the atmosphere. This means that, as more trees are planted to replenish those used as fuel, more CO2 will be absorbed from the atmosphere and end up in underground bedrock, ultimately resulting in net negative emissions. The process, called Biogenic Carbon Capture and Storage (Bio-CCS), is the best of both worlds; it generates renewable energy, while also removing CO2 from the atmosphere and storing it in a secure way.
Professor Lyngfelt, explains the massive potential of negative CO2 technology being developed at his lab at Chalmers University of Technology:
“In Sweden, about 30 megatons per year of carbon dioxide is emitted from the use of biomass, and a high fraction can be captured to create negative emissions. This is comparable to Sweden’s domestic fossil carbon dioxide emissions of just over 40 megatons per year. In other words, Bio-CCS in combination with stopping fossil emissions, would enable Sweden to reduce its emissions by more than 150%. This means going from high emissions, to removing large amounts of CO2 from the atmosphere. In this way we take our responsibility for the ‘cleaning of the air’ that is needed.”
This method of removing carbon from the atmosphere is made possible by a process called chemical-looping combustion (CLC). Using the chemical-looping combustion method, CO2 is separated from other gases during the combustion process, which eliminates the need for costly and energy intensive CO2 separation later.
Technology soon to be semi-commercial
Whereas conventional combustors burn fuel with ambient air containing the needed oxygen (as well as a lot of nitrogen), CLC installations burn fuel with solid metal oxide particles. When the fuel reacts with these particles the oxygen is transferred to the fuel, resulting in the same combustion products as normal combustion, CO2 and water vapour. The important difference is that, in CLC, the combustion by-products leave the fuel reactor without any nitrogen, so when the gas is cooled, and the water vapour condenses, the result is an essentially pure CO2 stream.
Because a pure CO2 stream is much easier to capture than CO2 mixed with other gases, CLC is expected to have at least 50% lower energy penalty and cost than any other CO2 capture technology.
Another important aspect of the use of CLC is that it does not curtail production and economic growth, and even has the potential to support the growth of employment by helping to increase green jobs. Bio-CLC has many potential applications and its high efficiency relative to other carbon capture methods makes it an attractive option. The aim of the Negative-CO2 project is to take the technology to the next level in its development by upscaling it to a semi-commercial scale.
It is important to emphasise that negative emissions can never replace rapid reductions in fossil emissions. The availability of biomass is limited, so if we continue to release fossil carbon dioxide into the atmosphere, future negative emissions will not suffice. But if applied correctly, and in conjunction with emissions reductions in other areas, Bio-CCS could prove to be an essential component in solving the climate crisis.
Want to know more?
On 24 May, during Nordic Clean Energy Week 2018, the side event Sustainable Future Energy Systems: Smarter, Integrated & CO2-Negative will bring together experts from the cutting edge of sustainable energy research to discuss their vision for Nordic energy systems. These experts specialise in different fields, ranging from transport, to electricity grids and to carbon capture, and will present solutions for creating smarter, integrated and CO2-negative energy systems. Using these solutions together will give us the best chance of reaching our climate and energy goals, and re-affirm the Nordics as world-leaders in the fight against climate change.
Other topics that will be discussed at the event include:
Integrated & flexible energy systems
Skills for the energy transition
Speeding up the intro of E-mobility
Sustainable Horizons for Heating & Cooling
Picture 1: Jon Flobrant/Unsplash
Picture 2: Misha Jamsek/nordicenergy.org