It’s both the most abundant fossil fuel in the world, with global reserves estimated to last for roughly three centuries, and the most economic energy source.
Yet the word ‘coal’ is associated with pollution and emissions, including carbon dioxide, that are responsible for the greatest contributions to global heating of any resource. As a result, there has been much discussion about the fuel’s position in the energy mix—while many voices have advocated for methods to facilitate a cleaner production, transportation, and usage of coal.
In fact, there’s now a new term with which we should all become familiar: “clean coal”.
What is clean coal?
According to the International Energy Agency (IEA), clean coal is the name for coal that is used with efficient combustion processes and reduced emissions.
It is something to which the US Department of Energy (DOE) is paying an increasing amount of attention, as it pivots position and outlines several clean coal technology programmes. But the truth is that the DOE, in collaboration with many other countries, has promoted clean coal technologies for the last three decades.
What are the current clean coal technologies?
Some of the types of technologies that are being undertaken to clean this dirty and problematic energy are broadly categorized by the IEA into four main areas:
- Coal upgrading – which consist of established applications involving the washing and drying of coal with the effect of emissions reduction.
- Efficiency improvements at existing power plants – and this is characterised by equipment upgrading and monitoring the performance and testing of these equipment.
- Investing in advanced technologies – this consist of R&D in supercritical and ultra-supercritical technologies.
- Near zero emission technologies – which is mainly the carbon capture and storage technologies (CCS – the permanent storage of carbon dioxide)
What are the main impacts of these approaches on carbon emissions?
These approaches have proven to influence carbon dioxide emission reductions according to the IEA:
- Coal upgrading has up to 5% reduction while efficiency improvements in power plants contribute up to 22%.
- Advanced technologies are estimated to reduce emissions by 25% while near-zero emissions technologies could achieve almost a 99% drop in emissions.
Figure 1: CO2 emission reductions using clean coal technologies.
These positive results have also been reported by the DOE, which cites more efficient coal production processes and eco-friendly technologies as some of the achievements of clean coal technologies.
The role of coal in meeting the global energy demand.
In this context, there is a pressing question: why is the use of coal being encouraged when the dangers associated with this energy source are undisputed?
- Economic benefits. Supporters of coal—mainly in developing countries—tend to cite the economic benefits of using coal.
- Convenience. Some proponents argue that the convenience of coal for electricity generation far outweighs their alternatives when put under comparison.
- Long lead time of alternatives suggests we might be reliant on coal for some time.
- Concerns surrounding future energy supply and energy security make coal an attractive option.
When considering its well-known environmental impacts, the continued usage of coal is concerning. This is where clean coal technologies come in:
- With energy security considered a long-term focus for many countries, creating a balanced and diversified energy mix is necessary.
- This can be achieved in the short term with a mix of fossil, nuclear and renewable energy sources.
So, does clean coal have a place in the decarbonisation debate?
To answer the question whether clean coal has a place in the decarbonization debate we need to check the roadmap to net zero by 2050.
The route to net zero by 2050 drawn by the IEA, presents coal as part of the energy mix. However, its role is significantly reduced as shown in Figure 2 below:
- Coal is significantly phased out in the net zero by 2050
- According to the IEA, all unabated coal plants must be phased out by 2030 in advanced economies and by 2040 in all economies.
- The position of coal can only be permitted with some form of abatement technologies. Beyond 2040, the only type of coal acceptable by 2050 is clean coal.
- CCS, which currently has proven to reduce emissions to about 99%, should be a focus for clean coal.
Figure 2: Roadmap to net zero by 2050.
But what happens to the coal mining companies?
- Lost expertise and employment will be huge among mining companies if they do not adapt.
- By 2040, the IEA projects that the global market for raw materials used for clean energy technologies will be the same as the size of the coal market today.
- These materials include copper, lithium, and nickel, which will be mainly used in batteries (lithium), EV motors, and wind turbines (rare earths).
- This new, large global market presents a huge opportunity for mining companies whose experience and skills are vital to balance the supply and demand of these raw materials.
- Clean coal has a place in the decarbonization debate.
- Coal use in the energy mix will diminish by 2050 and only clean coal is permitted to be in use by that period.
- Clean coal technologies like CCS should be a focus to achieve a net zero scenario.
- Coal mining companies have an opportunity to refocus their mining activities on raw materials for clean energy technologies.
Groppo, J., 2017. An introduction to the nature of coal. Coal Combustion Products (CCP’s), pp.3-20. https://www.sciencedirect.com/science/article/pii/B9780081009451000010
International Energy Agency, 2008. Clean Coal Technologies. Accelerating Commercial and Policy Drivers for Deployment. Coal Industry Advisory Board, pp.1-54. https://iea.blob.core.windows.net/assets/da9d007d-66fa-490c-8ec7-70c01e8fd1cb/Clean_Coal_CIAB_2008.pdf
International Energy Agency, 2021. Net Zero by 2050. A Roadmap for the Global Energy Sector. International Energy Agency, pp.29-147. https://iea.blob.core.windows.net/assets/deebef5d-0c34-4539-9d0c-10b13d840027/NetZeroby2050-ARoadmapfortheGlobalEnergySector_CORR.pdf
Miller, B., 2011. U.S. and International Activities for Near-Zero Emissions during Electricity Generation. Clean Coal Engineering Technology, pp.513-583. https://www.sciencedirect.com/science/article/pii/B978185617710800011X