![]() The capital cost of ultra-supercritical (USC) HELE technology is 20-30% greater than a subcritical unit, but the higher efficiency reduces emissions and fuel costs to about 75% of subcritical plants. These are also known as high-efficiency low-emission (HELE) plants. In 2020 about 40 million tonnes of CO 2 per year was being captured and sequestered from all sources, with about the same CCS capacity under construction. See also IEA webpage on CCUS.Ĭonsequently the term 'clean coal' is increasingly being used for supercritical and ultra-supercritical coal-fired plants without CCS, running at 42-48% thermal efficiency. However in its Energy Technology Perspectives 2014 the International Energy Agency (IEA) notes: “CCS is advancing slowly, due to high costs and lack of political and financial commitment.” In Energy Technology Perspectives 2020, CCUS is fairly low profile, and in the Sustainable Development Scenario about 2 billion tonnes per year is captured from coal burning by 2070 (of 10 Gt/yr total). It involves the geological storage of CO 2, typically 2-3 km deep, as a permanent solution. Alongside nuclear power and harnessing renewable energy sources, one hope for this is via 'clean coal' technologies, such as carbon capture and sequestration, also called carbon capture and storage (both abbreviated as CCS) or carbon capture, use and storage (CCUS). Much of the challenge is in commercialising the technology so that coal use would remain economically competitive despite the cost of achieving low, and eventually 'near-zero', emissions. The technologies are both costly and energy-intensive.Īs many coal-fired power stations approach retirement, their replacement gives much scope for 'cleaner' electricity. However, each year burning coal produces over 15 billion tonnes of carbon dioxide (CO 2), which is released to the atmosphere, most of this being from power generation.ĭevelopment of new 'clean coal' technologies is attempting to address this problem so that the world's enormous resources of coal can be utilised for future generations without contributing to global warming. Globally about 2000 GWe of coal-fired generation capacity is operating and another 500 GWe is expected online by 2030. Coal is the world's most abundant and widely distributed fossil fuel source. Some 26% of primary energy needs are met by coal and 37% of electricity is generated from coal, compared with 23% for natural gas. The term 'clean coal' is increasingly being used for supercritical coal-fired plants without CCS, on the basis that CO 2 emissions are less than for older plants, but are still much greater than for nuclear or renewables. ![]() World R&D on CCS exceeded $1 billion per year over 2009 to 2013, then fell sharply.There is typically at least a 20% energy penalty involved in 'clean coal' processes.The greatest challenge is bringing the cost of this down sufficiently for 'clean coal' to compete with nuclear power on the basis of near-zero emissions for base-load power.Attempting to use coal without adding to atmospheric carbon dioxide levels is a major technological challenge.Burning coal produces about 15 billion tonnes of carbon dioxide each year.Coal is used extensively as a fuel in most parts of the world.'Clean Coal' Technologies, Carbon Capture & Sequestration
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