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Clean Coal Technology explained

Clean Coal Technology is not a single “silver bullet-type” technology that will remove all the “nasties” from coal and produce a clean, non-polluting product.  Rather it is a collection of technologies and techniques that cover the whole coal value chain and provide specific solutions to specific problems of each section of the chain, from exploration and production to utilisation and waste product capture and disposal.  

Coal is a globally abundant energy and chemical resource, and is especially important to South Africa where we don’t have other conventional energy sources such as oil, gas, hydro, etc. However, coal produces waste products and emissions, which are harmful to the environment and health and contribute to greenhouse gas (GHG) accumulations in the atmosphere, which in turn contribute to global climate change.

Coal is too valuable a commodity to simply abandon.  It provides South Africa with some 90% of our electricity, nearly 30% of our petrol and diesel fuels and contributes some R37 billion to foreign exchange revenues from exports.  Scientists have spent decades formulating and developing technologies to clean up coal before utilisation and to capturing and neutralising waste products after the various production and utilisation operations. To learn more about Clean Coal Technology, read on.

How clean coal technology works

In order to clean the coal of the harmful qualities inherent to it, certain mineral content needs to be removed from the coal before it can be burnt. There are various processes in order to achieve this, which will also make the coal burn more efficiently.  This involves washing and grinding of coal into smaller pieces, which allows for the removal of non-coal mineral matter including some of the sulphur, which if releases to the atmosphere by burning gives rise to acid rain.  The sulphur in the waste material can give rise to acid water (known as acid mine drainage or AMD), but technologies have been developed (if not fully employed) to neutralize these.  Mining of sulphide ore bodies have this same problem.

The current major problem with the mining and combustion of coal is its physical disruption of the land, the production of waste products, and the emission of pollutant gases.  Mining has developed and adopted various methods and technologies to mitigate these negative impacts.  These include: underground coal gasification (UCG), which captures the energy content of in-situ coal as a gas and eliminates the actual removal of coal to the surface; capture of emitted particulate matter and gases; rehabilitation of mined areas; and sealing of waste dumps to prevent spontaneous combustion with concomitant huge gas emissions - as is seen on burning old waste dumps. 

The major current problem is coal’s emissions of GHG such as methane and carbon dioxide.  Methane can be collected and used as a fuel.  Developing technologies such as UCG and Carbon Capture and Storage (CCS) are currently being tested globally and soon in South Africa, and if successful would substantially decrease coal’s carbon dioxide emissions and return coal to the “energy source of choice” because of its abundance and affordability relative to other energy sources available at the present time.  The future of coal depends on the development and application of the above and many other more efficient and “clean coal technologies”, including user-efficient utilization of energy.

The Fossil Fuel Foundation

The Fossil Fuel Foundation offers many courses in aspects related to Clean Coal Technology and alternative energy production. It also hosts the annual Southern African Coal Science and Technology Conference, attended by industry experts and professionals. Contact the Fossil Fuel Foundation of Africafor courses, conferences and publications regarding Clean Coal Technology.