Adopting Clean Coal Technologies (CCTs)
The High Cost of ‘Clean‘ Coal Power Plants Despite their envisaged benefits, adopting Clean Coal Technologies (CCTs) in new coal-fired power entails bearing a significant cost burden. Are organisations willing to bite the bullet? By Nick Barnes the need for a maximum amount of energy with minimum waste production while increasing the overall plant efficiency. But the question is: Are industries willing to go the extra mile for the sake of achieving the collective good in the long term? Would economics allow them? First of all, it is important to analyse the options available, and the commitment to adopting them entails. Available CCT options So far, three main CCTs deployed and operational globally are High-Efficiency, LowEmission, or HELE, pollution abatement, and carbon capture utilization and storage (CCUS) technologies. Boundary Dam Power Station Unit 3 in Canada: The world’s first operating coal-fired power plant to implement a full-scale post-combustion carbon capture and storage system.
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To keep global warming to no more than 1.5°C – as called for in the Paris Agreement – emissions need to be reduced by 45% by 2030 and reach net zero by 2050.” This is the pledge by the United Nations’ Net Zero Coalition on Climate Change. It is a clarion call for everyone to play a part in reducing greenhouse emissions from their respective activities. However, there is a huge burden on industries that utilise huge volumes of fossil fuels, as they are classified as the biggest producers of emissions. Coal-fired power plants Coal-fired power plants are one of the biggest producers of greenhouse gases. Greenhouse gases emitted by coal-fired power stations include but may not be limited to SOx, NOx, CO2, and particulate matter (PM). And so, industries that utilise or own coal-fired power plants should adopt measures to reduce emissions. The reality In an ideal world, industries should ditch coal and adopt the cleaner options of renewables and
nuclear. Nonetheless, the reality is that coal is still the main source of the world’s electricity. Based on the state of affairs, coal will remain a significant source of electricity in the foreseeable future. This is not least in South Africa where coal-fired power plants supply baseload electricity. On the role of coal, the World Coal Association could not have put it more perfectly by stating: “It is not the use of coal but the way coal is used that should be the focus of attention.“ In other words, the world has to use coal responsibly with minimal impact on the environment. It is now or never. Currently, in many countries, South Africa being one of them, coal-fired plants are approaching the end of their life about to be decommissioned. As a replacement, new plants will be developed. Thus, there should be more urgency. Clean Coal Technologies (CCTs) Thanks to recent advances, in new coal-fired power plants Clean Coal Technologies (CCTs) can be incorporated, where applicable, to minimise emissions. In the power generation context, CCTs refer to technologies that meet
4 Mining Business Africa | September - October 2023
1. HELE The scope of ‘clean coal’ has been extended to include supercritical and ultra-supercritical coal-fired plants. Also known as High-Efficiency Low-Emission (HELE) plants, characteristically, these are without CCTs and run at 42-48% thermal efficiency. Compared with a subcritical unit, typically, HELE plants typically cost more than a subcritical unit on average. For instance, the capital cost of ultra-supercritical (USC) HELE technology is 20-30% more than a subcritical unit. However, this is offset by higher efficiency which reduces emissions and fuel costs to about 75% of subcritical plants. Usually, a supercritical steam generator operates at very high temperatures and pressures (above 22Mpa). This is a stage where the liquid and gas phases of water are no longer distinct. Countries that demonstrate that supercritical and ultra-supercritical plants are workable are South Korea and Japan. In these countries, about 70% of coal-fired power comes from supercritical and ultra-supercritical plants. 2. Pollution abatement There are several techniques employed in the abatement of coal. These include: • Washing coal Cleaning coal by washing aims at reducing
