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106-547: Lamma Power Station , informally known as Lamma Island Power Station , is a thermal power station and solar farm in Po Lo Tsui, Lamma Island , Hong Kong . With an installed capacity of 3,617 MW, the power station is the second largest coal-fired power station in Hong Kong after Castle Peak Power Station . Completed in 1982 for Hongkong Electric , the station provides power to Hong Kong Island and Lamma Island . It

212-451: A steam drum , and the furnace with its steam generating tubes and superheater coils. Necessary safety valves are located at suitable points to protect against excessive boiler pressure. The air and flue gas path equipment include: forced draft (FD) fan , air preheater (AP), boiler furnace, induced draft (ID) fan, fly ash collectors ( electrostatic precipitator or baghouse ), and the flue-gas stack . The boiler feed water used in

318-435: A vacuum of about −95 kPa (−28 inHg) relative to atmospheric pressure. The large decrease in volume that occurs when water vapor condenses to liquid creates the vacuum that generally increases the efficiency of the turbines. The limiting factor is the temperature of the cooling water and that, in turn, is limited by the prevailing average climatic conditions at the power station's location (it may be possible to lower

424-507: A CO 2 pipeline ruptured following a mudslide near Satartia, Mississippi , causing people nearby to lose consciousness. 200 people were evacuated and 45 were hospitalized, and some experienced longer term effects on their health. High concentrations of CO 2 in the air also caused vehicle engines to stop running, hampering the rescue effort. Retrofitting facilities with CCS can help to preserve jobs and economic prosperity in regions that rely on emissions-intensive industry, while avoiding

530-571: A critical but limited role in reducing emissions. Other ways to reduce emissions such as solar and wind energy, electrification , and public transit are less expensive than CCS and also much more effective at reducing air pollution. Given its cost and limitations, CCS is envisioned to be most useful in specific niches. These niches include heavy industry and plant retrofits. In the context of deep and sustained cuts in natural gas consumption, CCS can reduce emissions from natural gas processing . In electricity generation and hydrogen production , CCS

636-478: A failure rate above 98% in the electricity sector. As of 2024 CCS was in operation at 44 plants worldwide, collectively capturing about one-thousandth of greenhouse gas emissions. 90% of CCS operations involve the oil and gas industry. Plants with CCS require more energy to operate, thus they typically burn additional fossil fuels and increase the pollution caused by extracting and transporting fuel. In strategies to mitigate climate change, CCS could have

742-683: A flue gas mixture, compress and transport the CO 2 , inject it into the subsurface, and monitor the overall process. There are three ways that CO 2 can be separated from a flue gas mixture: post-combustion capture, pre-combustion capture, and oxy-combustion: Absorption, or carbon scrubbing with amines is the dominant capture technology. Other technologies proposed for carbon capture are membrane gas separation , chemical looping combustion , calcium looping , and use of metal-organic frameworks and other solid sorbents . Impurities in CO 2 streams, like sulfur dioxides and water vapor, can have

848-660: A gas turbine, in the form of hot exhaust gas, can be used to raise steam by passing this gas through a heat recovery steam generator (HRSG). The steam is then used to drive a steam turbine in a combined cycle plant that improves overall efficiency. Power stations burning coal, fuel oil , or natural gas are often called fossil fuel power stations . Some biomass -fueled thermal power stations have appeared also. Non-nuclear thermal power stations, particularly fossil-fueled plants, which do not use cogeneration are sometimes referred to as conventional power stations . Commercial electric utility power stations are usually constructed on

954-442: A gas turbine. The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. Geothermal plants do not need boilers because they use naturally occurring steam sources. Heat exchangers may be used where the geothermal steam is very corrosive or contains excessive suspended solids. A fossil fuel steam generator includes an economizer ,

1060-410: A generator on a common shaft. There is usually a high-pressure turbine at one end, followed by an intermediate-pressure turbine, and finally one, two, or three low-pressure turbines, and the shaft that connects to the generator. As steam moves through the system and loses pressure and thermal energy, it expands in volume, requiring increasing diameter and longer blades at each succeeding stage to extract

1166-480: A large scale and designed for continuous operation. Virtually all electric power stations use three-phase electrical generators to produce alternating current (AC) electric power at a frequency of 50 Hz or 60 Hz . Large companies or institutions may have their own power stations to supply heating or electricity to their facilities, especially if steam is created anyway for other purposes. Steam-driven power stations have been used to drive most ships in most of

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1272-405: A limited impact on global CO 2 emissions.” By July 2024, commercial-scale CCS was in operation at 44 plants worldwide. Sixteen of these facilities were devoted to separating naturally-occurring CO 2 from raw natural gas. Seven facilities were for hydrogen , ammonia , or fertilizer production, seven for chemical production, five for electricity and heat, and two for oil refining . CCS

1378-563: A means of reducing anthropogenic CO 2 emissions is more recent. In 1977, the Italian physicist Cesare Marchetti proposed that CCS could be used to reduce emissions from coal power plants and fuel refineries. The first large-scale CO 2 capture and injection project with dedicated CO 2 storage and monitoring was commissioned at the Sleipner gas field in Norway in 1996. In 2005,

1484-691: A mitigation tool would also be costly and technically unfeasible. According to the IEA, attempting to abate oil and gas consumption only through CCS and direct air capture would cost USD 3.5 trillion per year, which is about the same as the annual revenue of the entire oil and gas industry. Emissions are relatively difficult or expensive to abate without CCS in the following niches: The IPCC stated in 2022 that “implementation of CCS currently faces technological, economic, institutional, ecological-environmental and socio-cultural barriers.” Since CCS can only be used with large, stationary emission sources, it cannot reduce

1590-641: A net increase in air pollution from those facilities. This can be mitigated by pollution control equipment, however no equipment can eliminate all pollutants. Since liquid amine solutions are used to capture CO 2 in many CCS systems, these types of chemicals can also be released as air pollutants if not adequately controlled. Among the chemicals of concern are volatile nitrosamines which are carcinogenic when inhaled or drunk in water. Studies that consider both upstream and downstream impacts indicate that adding CCS to power plants increases overall negative impacts on human health. The health impacts of adding CCS in

1696-447: A process in which captured CO 2 is injected into partially-depleted oil reservoirs in order to extract more oil. EOR is both "utilization" and "storage", as the CO 2 left underground is intended to be trapped indefinitely. Prior to 2013, the process was primarily called CCS. In 2013 the term CCUS was introduced to highlight its potential economic benefit, and this term subsequently gained popularity. Around 1% of captured CO 2

1802-465: A relatively pure stream of carbon dioxide (CO 2 ) from industrial and energy-related sources is separated (captured), conditioned, compressed and transported to a storage location for long-term isolation from the atmosphere." The terms carbon capture and storage (CCS) and carbon capture, utilization, and storage (CCUS) are closely related and often used interchangeably. Both terms have been used predominantly to refer to enhanced oil recovery (EOR)

1908-559: A set of tubes in the furnace. Here the steam picks up more energy from hot flue gases outside the tubing, and its temperature is now superheated above the saturation temperature. The superheated steam is then piped through the main steam lines to the valves before the high-pressure turbine. Nuclear-powered steam plants do not have such sections but produce steam at essentially saturated conditions. Experimental nuclear plants were equipped with fossil-fired superheaters in an attempt to improve overall plant operating cost. The condenser condenses

2014-424: A significant effect on their phase behavior and could cause increased pipeline and well corrosion. In instances where CO 2 impurities exist, a scrubbing separation process is needed to initially clean the flue gas. Storing CO 2 involves the injection of captured CO 2 into a deep underground geological reservoir of porous rock overlaid by an impermeable layer of rocks, which seals the reservoir and prevents

2120-512: A smaller fraction will most likely prove to be technically or commercially feasible. Global capacity estimates are uncertain, particularly for saline aquifers where more site characterization and exploration is still needed. In geologic storage, the CO 2 is held within the reservoir through several trapping mechanisms : structural trapping by the caprock seal, solubility trapping in pore space water, residual trapping in individual or groups of pores, and mineral trapping by reacting with

2226-523: A specific type of large heat exchanger used in a pressurized water reactor (PWR) to thermally connect the primary (reactor plant) and secondary (steam plant) systems, which generates steam. In a boiling water reactor (BWR), no separate steam generator is used and water boils in the reactor core. In some industrial settings, there can also be steam-producing heat exchangers called heat recovery steam generators (HRSG) which utilize heat from some industrial process, most commonly utilizing hot exhaust from

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2332-423: A stationary stator and a spinning rotor , each containing miles of heavy copper conductor. There is generally no permanent magnet , thus preventing black starts . In operation it generates up to 21,000 amperes at 24,000 volts AC (504 MWe) as it spins at either 3,000 or 3,600 rpm , synchronized to the power grid . The rotor spins in a sealed chamber cooled with hydrogen gas, selected because it has

2438-406: A trip-out are avoided by flushing out such gases from the combustion zone before igniting the coal. The steam drum (as well as the superheater coils and headers) have air vents and drains needed for initial start up. Fossil fuel power stations often have a superheater section in the steam generating furnace. The steam passes through drying equipment inside the steam drum on to the superheater,

2544-478: A typical late 20th-century power station, superheated steam from the boiler is delivered through 14–16-inch-diameter (360–410 mm) piping at 2,400 psi (17 MPa; 160 atm) and 1,000 °F (540 °C) to the high-pressure turbine, where it falls in pressure to 600 psi (4.1 MPa; 41 atm) and to 600 °F (320 °C) in temperature through the stage. It exits via 24–26-inch-diameter (610–660 mm) cold reheat lines and passes back into

2650-790: Is a colorless and odorless gas that accumulates near the ground because it is heavier than air. In humans, exposure to CO 2 at concentrations greater than 5% (50,000 parts per million) causes the development of hypercapnia and respiratory acidosis . Concentrations of more than 10% may cause convulsions, coma, and death. CO 2 levels of more than 30% act rapidly leading to loss of consciousness in seconds. Pipelines and storage sites can be sources of large accidental releases of CO 2 that can endanger local communities. A 2005 IPCC report stated that "existing CO2 pipelines, mostly in areas of low population density, accident numbers reported per kilometre of pipeline are very low and are comparable to those for hydrocarbon pipelines." The report also stated that

2756-429: Is also dosed with pH control agents such as ammonia or morpholine to keep the residual acidity low and thus non-corrosive. The boiler is a rectangular furnace about 50 feet (15 m) on a side and 130 feet (40 m) tall. Its walls are made of a web of high pressure steel tubes about 2.3 inches (58 mm) in diameter. Fuel such as pulverized coal is air-blown into the furnace through burners located at

2862-449: Is called an "energy penalty". The energy penalty of CCS varies depending on the source of CO 2 . If the flue gas has a very high concentration of CO 2 , additional energy is needed only to dehydrate, compress, and pump the CO 2 . If the flue gas has a lower concentration of CO 2 , as is the case for power plants, energy is also required to separate CO 2 from other flue gas components. Early studies indicated that to produce

2968-421: Is controversy over whether CCS is beneficial for the climate if the CO 2 is used to extract more oil. Fossil fuel companies heavily promote CCS. Many environmental groups regard CCS as an unproven, expensive technology that will perpetuate dependence on fossil fuels . They believe other ways to reduce emissions are more effective and that CCS is a distraction. Some international climate agreements refer to

3074-556: Is envisioned to complement a broader shift to renewable energy. CCS is a component of bioenergy with carbon capture and storage , which can under some conditions remove carbon from the atmosphere. The effectiveness of CCS in reducing carbon emissions depends on the plant's capture efficiency, the additional energy used for CCS itself, leakage, and business and technical issues that can keep facilities from operating as designed. Some large CCS implementations have sequestered far less CO 2 than originally expected. Additionally, there

3180-487: Is essential to make natural gas ready for commercial sale and distribution. Usually after CO 2 is removed, it is vented to the atmosphere. In 1972, American oil companies discovered that large quantities of CO 2 could profitably be used for EOR. Subsequently, natural gas companies in Texas began capturing the CO 2 produced by their processing plants and selling it to local oil producers for EOR. The use of CCS as

3286-517: Is evidence that CCS can help reduce non-CO2 pollutants along with capturing CO2, environmental justice groups are often concerned that CCS will be used as a way to prolong a facility’s lifetime and continue the local harms it causes. Often, community-based organizations would prefer that a facility be shut down and for investment be focused instead on cleaner production processes, such as renewable electricity. Construction of pipelines often involves setting up work camps in remote areas. In Canada and

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3392-408: Is expected to be increased to 1.2 MW by 2023. This article about a power station is a stub . You can help Misplaced Pages by expanding it . This article about a Hong Kong building or structure is a stub . You can help Misplaced Pages by expanding it . Thermal power station The majority of the world's thermal power stations are driven by steam turbines, gas turbines, or a combination of

3498-473: Is expensive and has seldom been implemented. Government regulations and international agreements are being enforced to reduce harmful emissions and promote cleaner power generation. Almost all coal-fired power stations , petroleum, nuclear , geothermal , solar thermal electric , and waste incineration plants , as well as all natural gas power stations are thermal. Natural gas is frequently burned in gas turbines as well as boilers . The waste heat from

3604-694: Is generally less expensive than EOR because it does not require a high level of CO 2 purity and because suitable sites are more numerous, which means pipelines can be shorter. Various other types of reservoirs for storing captured CO 2 were being researched or piloted as of 2021: CO 2 could be injected into coal beds for enhanced coal bed methane recovery . Ex-situ mineral carbonation involves reacting CO 2 with mine tailings or alkaline industrial waste to form stable minerals such as calcium carbonate . In-situ mineral carbonation involves injecting CO 2 and water into underground formations that are rich in highly-reactive rocks such as basalt . There,

3710-462: Is injected into partially depleted oil fields to enhance production. The CO2 binds with oil to make it less dense, allowing oil to rise to the surface faster. The addition of CO 2 also increases the overall reservoir pressure, thereby improving the mobility of the oil, resulting in a higher flow of oil towards the production wells. Depending on the location, EOR results in around two additional barrels of oil for every tonne of CO 2 injected into

3816-549: Is largely left underground. Since EOR utilizes the CO 2 in addition to storing it, CCS is also known as carbon capture, utilization, and storage (CCUS). Oil and gas companies first used the processes involved in CCS in the mid 20th century. Early versions of CCS technologies served to purify natural gas and to enhance oil production. Subsequently, CCS was discussed as a strategy to reduce greenhouse gas emissions . Around 70% of announced CCS projects have not materialized, with

3922-478: Is likely that over 99% of CO 2 will remain in place for more than 1000 years, with "likely" meaning a probability of 66% to 90%. Estimates of long-term leakage rates rely on complex simulations since field data is limited. If very large amounts of CO 2 are sequestered, even a 1% leakage rate over 1000 years could cause significant impact on the climate for future generations. Facilities with CCS use more energy than those without CCS. The energy consumed by CCS

4028-474: Is limited, and governed by the laws of thermodynamics . The Carnot efficiency dictates that higher efficiencies can be attained by increasing the temperature of the steam. Sub-critical pressure fossil fuel power stations can achieve 36–40% efficiency. Supercritical designs have efficiencies in the low to mid 40% range, with new "ultra critical" designs using pressures above 4,400 psi (30 MPa) and multiple stage reheat reaching 45–48% efficiency. Above

4134-476: Is returned to the downcomers and the steam is passed through a series of steam separators and dryers that remove water droplets from the steam. The dry steam then flows into the superheater coils. The boiler furnace auxiliary equipment includes coal feed nozzles and igniter guns, soot blowers , water lancing, and observation ports (in the furnace walls) for observation of the furnace interior. Furnace explosions due to any accumulation of combustible gases after

4240-464: Is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace. Here the steam is superheated to 1,000 °F (540 °C) to prepare it for the turbine. Plants that use gas turbines to heat the water for conversion into steam use boilers known as heat recovery steam generators (HRSG). The exhaust heat from

4346-465: Is the air-cooled condenser . The process is similar to that of a radiator and fan. Exhaust heat from the low-pressure section of a steam turbine runs through the condensing tubes, the tubes are usually finned and ambient air is pushed through the fins with the help of a large fan. The steam condenses to water to be reused in the water-steam cycle. Air-cooled condensers typically operate at a higher temperature than water-cooled versions. While saving water,

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4452-487: Is used as a feedstock for making products such as fertilizer, fuels, and plastics. These uses are forms of carbon capture and utilization . In some cases, the product durably stores the carbon from the CO 2 and thus is also considered to be a form of CCS. To qualify as CCS, carbon storage must be long-term, therefore utilization of CO 2 to produce fertilizer, fuel, or chemicals is not CCS because these products release CO 2 when burned or consumed. Some sources use

4558-472: Is very expensive. For instance, removing CO 2 from the flue gas of fossil fuel power plants increases costs by USD $ 50 - $ 200 per tonne of CO 2 removed. There are many ways to reduce emissions that cost less than USD $ 20 per tonne of avoided CO 2 emissions. Options that have far more potential to reduce emissions at lower cost than CCS include public transit , electric vehicles , and various energy efficiency measures. Wind and solar power are often

4664-797: The Manhattan Elevated Railway . Each of seventeen units weighed about 500 tons and was rated 6000 kilowatts; a contemporary turbine set of similar rating would have weighed about 20% as much. The energy efficiency of a conventional thermal power station is defined as saleable energy produced as a percent of the heating value of the fuel consumed. A simple cycle gas turbine achieves energy conversion efficiencies from 20 to 35%. Typical coal-based power plants operating at steam pressures of 170 bar and 570 °C run at efficiency of 35 to 38%, with state-of-the-art fossil fuel plants at 46% efficiency. Combined-cycle systems can reach higher values. As with all heat engines, their efficiency

4770-403: The critical point for water of 705 °F (374 °C) and 3,212 psi (22.15 MPa), there is no phase transition from water to steam, but only a gradual decrease in density . Currently most nuclear power stations must operate below the temperatures and pressures that coal-fired plants do, in order to provide more conservative safety margins within the systems that remove heat from

4876-552: The steam boiler is a means of transferring heat energy from the burning fuel to the mechanical energy of the spinning steam turbine . The total feed water consists of recirculated condensate water and purified makeup water . Because the metallic materials it contacts are subject to corrosion at high temperatures and pressures, the makeup water is highly purified before use. A system of water softeners and ion exchange demineralizes produces water so pure that it coincidentally becomes an electrical insulator , with conductivity in

4982-409: The vapor pressure of water is much less than atmospheric pressure, the condenser generally works under vacuum . Thus leaks of non-condensible air into the closed loop must be prevented. Typically the cooling water causes the steam to condense at a temperature of about 25 °C (77 °F) and that creates an absolute pressure in the condenser of about 2–7  kPa (0.59–2.07  inHg ), i.e.

5088-540: The 18th century, with notable improvements being made by James Watt . When the first commercially developed central electrical power stations were established in 1882 at Pearl Street Station in New York and Holborn Viaduct power station in London, reciprocating steam engines were used. The development of the steam turbine in 1884 provided larger and more efficient machine designs for central generating stations. By 1892

5194-743: The 20th century . Shipboard power stations usually directly couple the turbine to the ship's propellers through gearboxes. Power stations in such ships also provide steam to smaller turbines driving electric generators to supply electricity. Nuclear marine propulsion is, with few exceptions, used only in naval vessels. There have been many turbo-electric ships in which a steam-driven turbine drives an electric generator which powers an electric motor for propulsion . Cogeneration plants, often called combined heat and power (CHP) facilities, produce both electric power and heat for process heat or space heating, such as steam and hot water. The reciprocating steam engine has been used to produce mechanical power since

5300-446: The CO 2 may react with the rock to form stable carbonate minerals relatively quickly. Once this process is complete, the risk of CO 2 escape from carbonate minerals is estimated to be close to zero. The global capacity for underground CO 2 storage is potentially very large and is unlikely to be a constraint on the development of CCS. Total storage capacity has been estimated at between 8,000 and 55,000 gigatonnes. However,

5406-459: The IPCC released a report highlighting CCS, leading to increased government support for CCS in several countries. Governments spent an estimated USD $ 30 billion on subsidies for CCS and for fossil-fuel-based hydrogen. Globally, 149 projects to store 130 million tonnes of CO 2 annually were proposed to be operational by 2020. Of these, around 70% were not implemented. Limited one-off capital grants,

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5512-474: The Middle East. CCS facilities capture carbon dioxide before it enters the atmosphere. Generally, a chemical solvent or a porous solid material is used to separate the CO 2 from other components of a plant’s exhaust stream. Most commonly, flue gas passes through an amine solvent , which binds the CO 2 molecule. This CO 2 -rich solvent is heated in a regeneration unit to release the CO 2 from

5618-439: The U.S. Environmental Protection Agency, CCS would increase the cost of electricity generation from coal plants by $ 7 to $ 12/ MWh. The cost of CCS varies greatly by CO 2 source. If the concentration of CO 2 in the flue gas is high, as is the case for natural gas processing, it can be captured and compressed for USD 15-25/tonne. Power plants, cement plants, and iron and steel plants produce more dilute gas streams, for which

5724-561: The United States are about 90 percent efficient in converting the energy of falling water into electricity while the efficiency of a wind turbine is limited by Betz's law , to about 59.3%, and actual wind turbines show lower efficiency. The direct cost of electric energy produced by a thermal power station is the result of cost of fuel, capital cost for the plant, operator labour, maintenance, and such factors as ash handling and disposal. Indirect social or environmental costs, such as

5830-473: The United States, oil and gas pipeline construction has historically been associated with a variety of social harms, including sexual violence committed by workers against Indigenous women. Project cost, low technology readiness levels in capture technologies, and a lack of revenue streams are among the main reasons for CCS projects to stop. A commercial-scale project typically requires an upfront capital investment of up to several billion dollars. According to

5936-563: The absence of measures to address long-term liability for stored CO 2 , high operating costs, limited social acceptability and vulnerability of funding programmes to external budget pressures all contributed to project cancellations. In 2020, the International Energy Agency (IEA) stated, “The story of CCUS has largely been one of unmet expectations: its potential to mitigate climate change has been recognised for decades, but deployment has been slow and so has had only

6042-489: The air in the air preheater for better economy. Secondary air is mixed with the coal/primary air flow in the burners. The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining slightly below atmospheric pressure in the furnace to avoid leakage of combustion products from the boiler casing. A steam turbine generator consists of a series of steam turbines interconnected to each other and

6148-400: The atmosphere, or once-through cooling (OTC) water from a river, lake or ocean. In the United States, about two-thirds of power plants use OTC systems, which often have significant adverse environmental impacts. The impacts include thermal pollution and killing large numbers of fish and other aquatic species at cooling water intakes . The heat absorbed by the circulating cooling water in

6254-422: The atmosphere, then transported to a long-term storage location. The CO 2 is captured from a large point source , such as a natural gas processing plant and is typically stored in a deep geological formation . Around 80% of the CO 2 captured annually is used for enhanced oil recovery (EOR), a process by which CO 2 is injected into partially-depleted oil reservoirs in order to extract more oil and then

6360-464: The atmosphere, which would be potentially dangerous to life in the surrounding area. If the injection of CO 2 creates pressures underground that are too high, the formation will fracture, potentially causing an earthquake. While research suggests that earthquakes from injected CO 2 would be too small to endanger property, they could be large enough to cause a leak. The IPCC estimates that at appropriately-selected and well-managed storage sites, it

6466-433: The boiler, where the steam is reheated in special reheat pendant tubes back to 1,000 °F (540 °C). The hot reheat steam is conducted to the intermediate-pressure turbine, where it falls in both temperature and pressure and exits directly to the long-bladed low-pressure turbines and finally exits to the condenser. The generator, typically about 30 feet (9 m) long and 12 feet (3.7 m) in diameter, contains

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6572-403: The cheapest way of transporting CO 2 in large quantities onshore and, depending on the distance and volumes, offshore. Transport via ship has been researched. CO 2 can also be transported by truck or rail, albeit at higher cost per tonne of CO 2 . CCS processes involve several different technologies working together. Technological components are used to separate and treat CO 2 from

6678-525: The concept of fossil fuel abatement , which is not defined in these agreements but is generally understood to mean use of CCS. Almost all CCS projects operating today have benefited from government financial support. Countries with programs to support or mandate CCS technologies include the US, Canada, Denmark, China, and the UK. The Intergovernmental Panel on Climate Change (IPCC) defines CCS as: "A process in which

6784-443: The condenser tubes must also be removed to maintain the ability of the water to cool as it circulates. This is done by pumping the warm water from the condenser through either natural draft, forced draft or induced draft cooling towers (as seen in the adjacent image) that reduce the temperature of the water by evaporation, by about 11 to 17 °C (52 to 63 °F)—expelling waste heat to the atmosphere. The circulation flow rate of

6890-433: The continued operation of existing plants, as well as associated infrastructure and supply chains. In the United States, the types of facilities that could be retrofitted with CCS are often located in communities that have already borne the negative environmental and health impacts of living near power or industrial facilities. These facilities are disproportionately located in poor and/or minority communities. While there

6996-519: The cooling water in a 500 MW unit is about 14.2 m /s (500 ft /s or 225,000 US gal/min) at full load. The condenser tubes are typically made stainless steel or other alloys to resist corrosion from either side. Nevertheless, they may become internally fouled during operation by bacteria or algae in the cooling water or by mineral scaling, all of which inhibit heat transfer and reduce thermodynamic efficiency . Many plants include an automatic cleaning system that circulates sponge rubber balls through

7102-492: The cost of capture and compression is USD 40-120/tonne CO2. In the United States, the cost of onshore pipeline transport is in the range of USD 2-14/t CO 2 , and more than half of onshore storage capacity is estimated to be available below USD 10/t CO 2 . CCS implementations involve multiple technologies that are highly customized to each site, which limits the industry's ability to reduce costs through learning-by-doing . Compared to other options for reducing emissions, CCS

7208-410: The design of large turbines, since they are highly optimized for one particular speed. The electricity flows to a distribution yard where transformers increase the voltage for transmission to its destination. Carbon capture and storage Carbon capture and storage ( CCS ) is a process by which carbon dioxide (CO 2 ) from industrial installations is separated before it is released into

7314-459: The economic and social disruption of early retirements. For instance, Germany’s plans to retire around 40 GW of coal-fired generation capacity before 2038 is accompanied by a EUR 40 billion (USD 45 billion) package to compensate the owners of coal mines and power plants as well as support the communities that will be affected. There is potential for reducing these costs if plants are retrofitted with CCS. Retrofitting CO2 capture equipment can enable

7420-411: The economic value of environmental impacts, or environmental and health effects of the complete fuel cycle and plant decommissioning, are not usually assigned to generation costs for thermal stations in utility practice, but may form part of an environmental impact assessment. Those indirect costs belong to the broader concept of externalities . In the nuclear plant field, steam generator refers to

7526-472: The efficiency of the cycle is reduced (resulting in more carbon dioxide per megawatt-hour of electricity). From the bottom of the condenser, powerful condensate pumps recycle the condensed steam (water) back to the water/steam cycle. Power station furnaces may have a reheater section containing tubes heated by hot flue gases outside the tubes. Exhaust steam from the high-pressure turbine is passed through these heated tubes to collect more energy before driving

7632-473: The emissions from burning fossil fuels in vehicles and homes. The IEA describes "excessive expectations and reliance" on CCS and direct air capture as a common misconception. To reach targets set in the Paris Agreement , CCS must be accompanied by a steep decline in the production and use of fossil fuels. When CCS is used for electricity generation, most studies assume that 85-90% of the CO 2 in

7738-614: The flue gas is captured. However, industry representatives say actual capture rates are closer to 75%, and have lobbied for government programs to accept this lower target. The potential for a CCS project to reduce emissions depends on several factors in addition to the capture rate. These factors include the amount of additional energy needed to power CCS processes, the source of the additional energy used, and post-capture leakage. The energy needed for CCS usually comes from fossil fuels whose mining, processing, and transport produce emissions. Some studies indicate that under certain circumstances

7844-421: The four corners, or along one wall, or two opposite walls, and it is ignited to rapidly burn, forming a large fireball at the center. The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. The water circulation rate in the boiler is three to four times the throughput. As the water in the boiler circulates it absorbs heat and changes into steam. It

7950-403: The gas turbines is used to make superheated steam that is then used in a conventional water-steam generation cycle, as described in the gas turbine combined-cycle plants section. The water enters the boiler through a section in the convection pass called the economizer . From the economizer it passes to the steam drum and from there it goes through downcomers to inlet headers at the bottom of

8056-536: The ground. Oil extracted through EOR is mixed with CO 2 , which can then mostly be recaptured and re-injected multiple times. This CO 2 recycling process can reduce losses to 1%, however doing so is energy-intensive. Around 20% of captured CO 2 is injected into dedicated geological storage, usually deep saline aquifers . These are layers of porous and permeable rocks saturated with salty water. Worldwide, saline formations have higher potential storage capacity than depleted oil wells. Dedicated geologic storage

8162-443: The higher temperatures and tropical climate of Hong Kong. HK Electric expanded the solar farm to a capacity of 1 MW in 2013. The newly installed panels could generate 40% more electricity than the ones used in the original installation. The total solar farm used 8,662 PV modules covering a total area of 13,000 m. In 2021, it was announced the system had been upgraded to 1.1 MW due to replacement of older panels. The solar power system

8268-615: The highest known heat transfer coefficient of any gas and for its low viscosity , which reduces windage losses. This system requires special handling during startup, with air in the chamber first displaced by carbon dioxide before filling with hydrogen. This ensures that a highly explosive hydrogen– oxygen environment is not created. The power grid frequency is 60 Hz across North America and 50 Hz in Europe , Oceania , Asia ( Korea and parts of Japan are notable exceptions), and parts of Africa . The desired frequency affects

8374-487: The industrial sector are less well-understood. Health impacts vary significantly depending on the fuel used and the capture technology. After CO 2 injected into underground geologic formations, there is a risk of nearby shallow groundwater becoming contaminated. Contamination can occur either from movement of the CO 2 into groundwater or from movement of displaced brine. Careful site selection and long-term monitoring are necessary to mitigate this risk. CO 2

8480-428: The intermediate and then low-pressure turbines. External fans are provided to give sufficient air for combustion. The Primary air fan takes air from the atmosphere and, first warms the air in the air preheater for better economy. Primary air then passes through the coal pulverizers, and carries the coal dust to the burners for injection into the furnace. The Secondary air fan takes air from the atmosphere and, first warms

8586-450: The local economy by creating jobs in construction, maintenance, and fuel extraction industries. On the other hand, burning of fossil fuels releases greenhouse gases (contributing to climate change) and air pollutants such as sulfur oxides and nitrogen oxides (leading to acid rain and respiratory diseases). Carbon capture and storage (CCS) technology can reduce the greenhouse gas emissions of fossil-fuel-based thermal power stations, however it

8692-502: The local health and safety risks of geologic CO 2 storage were "comparable" to the risks of underground storage of natural gas if good site selection processes, regulatory oversight, monitoring, and incident remediation plans are in place. As of 2020, the ways that pipelines can fail is less well-understood for CO 2 pipelines than for natural gas or oil pipelines, and few safety standards exist that are specific to CO 2 pipelines. While infrequent, accidents can be serious. In 2020

8798-562: The lowest-cost ways to produce electricity, even when compared to power plants that do not use CCS. The dramatic fall in the costs of renewable power and batteries has made it difficult for fossil fuel plants with CCS to be cost-competitive. In the literature on climate change mitigation , CCS is described as having a small but critical role in reducing greenhouse gas emissions. The IPCC estimated in 2014 that forgoing CCS altogether would make it 138% more expensive to keep global warming within 2 degrees Celsius. Excessive reliance on CCS as

8904-417: The middle of this series of feedwater heaters, and before the second stage of pressurization, the condensate plus the makeup water flows through a deaerator that removes dissolved air from the water, further purifying and reducing its corrosiveness. The water may be dosed following this point with hydrazine , a chemical that removes the remaining oxygen in the water to below 5 parts per billion (ppb). It

9010-444: The nuclear fuel. This, in turn, limits their thermodynamic efficiency to 30–32%. Some advanced reactor designs being studied, such as the very-high-temperature reactor , Advanced Gas-cooled Reactor , and supercritical water reactor , would operate at temperatures and pressures similar to current coal plants, producing comparable thermodynamic efficiency. The energy of a thermal power station not utilized in power production must leave

9116-630: The plant in the form of heat to the environment. This waste heat can go through a condenser and be disposed of with cooling water or in cooling towers . If the waste heat is instead used for district heating , it is called cogeneration . An important class of thermal power station is that associated with desalination facilities; these are typically found in desert countries with large supplies of natural gas , and in these plants freshwater production and electricity are equally important co-products. Other types of power stations are subject to different efficiency limitations. Most hydropower stations in

9222-405: The range of 0.3–1.0 microsiemens per centimeter. The makeup water in a 500 MWe plant amounts to perhaps 120 US gallons per minute (7.6 L/s) to replace water drawn off from the boiler drums for water purity management, and to also offset the small losses from steam leaks in the system. The feed water cycle begins with condensate water being pumped out of the condenser after traveling through

9328-507: The remaining energy. The entire rotating mass may be over 200 metric tons and 100 feet (30 m) long. It is so heavy that it must be kept turning slowly even when shut down (at 3 rpm ) so that the shaft will not bow even slightly and become unbalanced. This is so important that it is one of only six functions of blackout emergency power batteries on site. (The other five being emergency lighting , communication , station alarms, generator hydrogen seal system, and turbogenerator lube oil.) For

9434-408: The reservoir rocks to form carbonate minerals. Mineral trapping progresses over time but is extremely slow. Once injected, the CO 2 plume tends to rise since it is less dense than its surroundings. Once it encounters a caprock, it will spread laterally until it encounters a gap. If there are fault planes near the injection zone, CO 2 could migrate along the fault to the surface, leaking into

9540-430: The same amount of electricity, a coal power plant would need to burn 14 - 40% more coal and a natural gas combined cycle power plant would need to burn 11 - 22% more gas. When CCS is used in coal power plants, it has been estimated that about 60% of the energy penalty originates from the capture process, 30% comes from compression of the extracted CO 2 , and the remaining 10% comes from pumps and fans. Depending on

9646-686: The simultaneous production of electricity and useful heat from the same fuel source, improves the overall efficiency by using waste heat for heating purposes. Older, less efficient thermal power stations are being decommissioned or adapted to use cleaner and renewable energy sources. Thermal power stations produce 70% of the world's electricity. They often provide reliable, stable, and continuous baseload power supply essential for economic growth. They ensure energy security by maintaining grid stability, especially in regions where they complement intermittent renewable energy sources dependent on weather conditions. The operation of thermal power stations contributes to

9752-449: The solvent. The CO 2 stream then undergoes conditioning to remove impurities and bring the gas to an appropriate temperature for compression. The purified CO 2 stream is compressed and transported for storage or end-use and the released solvents are recycled to again capture CO 2 from the flue gas. After the CO 2 has been captured, it is usually compressed into a supercritical fluid and then injected underground. Pipelines are

9858-460: The steam from the exhaust of the turbine into liquid to allow it to be pumped. If the condenser can be made cooler, the pressure of the exhaust steam is reduced and efficiency of the cycle increases. The surface condenser is a shell and tube heat exchanger in which cooling water is circulated through the tubes. The exhaust steam from the low-pressure turbine enters the shell, where it is cooled and converted to condensate (water) by flowing over

9964-420: The steam turbines. The condensate flow rate at full load in a 500 MW plant is about 6,000 US gallons per minute (400 L/s). The water is usually pressurized in two stages, and typically flows through a series of six or seven intermediate feed water heaters, heated up at each point with steam extracted from an appropriate extraction connection on the turbines and gaining temperature at each stage. Typically, in

10070-571: The technology used, CCS can require large amounts of water. For instance, coal- fired power plants with CCS may need to use 50% more water. Since plants with CCS require more fuel to produce the same amount of electricity or heat, the use of CCS increases the "upstream" environmental problems of fossil fuels. Upstream impacts include pollution caused by coal mining, emissions from the fuel used to transport coal and gas, emissions from gas flaring , and fugitive methane emissions. Since CCS facilities require more fossil fuel to be burned, CCS can cause

10176-433: The temperature beyond the turbine limits during winter, causing excessive condensation in the turbine). Plants operating in hot climates may have to reduce output if their source of condenser cooling water becomes warmer; unfortunately this usually coincides with periods of high electrical demand for air conditioning . The condenser generally uses either circulating cooling water from a cooling tower to reject waste heat to

10282-451: The term CCS, CCU, or CCUS more broadly, encompassing methods such as direct air capture or tree-planting which remove CO 2 from the air. In this article, the term CCS is used according to the IPCC's definition, which requires CO 2 to be captured from point-sources such as the flue gas of a power plant. In the natural gas industry, technology to remove CO 2 from raw natural gas has been used since 1930. This processing

10388-455: The tubes as shown in the adjacent diagram. Such condensers use steam ejectors or rotary motor -driven exhausts for continuous removal of air and gases from the steam side to maintain vacuum . For best efficiency, the temperature in the condenser must be kept as low as practical in order to achieve the lowest possible pressure in the condensing steam. Since the condenser temperature can almost always be kept significantly below 100 °C where

10494-452: The tubes to scrub them clean without the need to take the system off-line. The cooling water used to condense the steam in the condenser returns to its source without having been changed other than having been warmed. If the water returns to a local water body (rather than a circulating cooling tower), it is often tempered with cool 'raw' water to prevent thermal shock when discharged into that body of water. Another form of condensing system

10600-812: The turbine enters a steam condenser where it is cooled to produce hot condensate which is recycled to the heating process to generate even more high pressure steam. The design of thermal power stations depends on the intended energy source. In addition to fossil and nuclear fuel , some stations use geothermal power , solar energy , biofuels , and waste incineration . Certain thermal power stations are also designed to produce heat for industrial purposes, provide district heating , or desalinate water , in addition to generating electrical power. Emerging technologies such as supercritical and ultra-supercritical thermal power stations operate at higher temperatures and pressures for increased efficiency and reduced emissions. Cogeneration or CHP (Combined Heat and Power) technology,

10706-432: The turbine was considered a better alternative to reciprocating engines; turbines offered higher speeds, more compact machinery, and stable speed regulation allowing for parallel synchronous operation of generators on a common bus. After about 1905, turbines entirely replaced reciprocating engines in almost all large central power stations. The largest reciprocating engine-generator sets ever built were completed in 1901 for

10812-520: The two. The efficiency of a thermal power station is determined by how effectively it converts heat energy into electrical energy, specifically the ratio of saleable electricity to the heating value of the fuel used. Different thermodynamic cycles have varying efficiencies, with the Rankine cycle generally being more efficient than the Otto or Diesel cycles. In the Rankine cycle, the low-pressure exhaust from

10918-446: The upward migration of CO 2 and escape into the atmosphere. The gas is usually compressed first into a supercritical fluid. When the compressed CO 2 is injected into a reservoir, it flows through it, filling the pore space. The reservoir must be at depths greater than 800 meters to retain the CO 2 in a fluid state. As of 2024, around 80% of the CO 2 captured annually is used for enhanced oil recovery (EOR). In EOR, CO 2

11024-400: The water walls. From these headers the water rises through the water walls of the furnace where some of it is turned into steam and the mixture of water and steam then re-enters the steam drum. This process may be driven purely by natural circulation (because the water is the downcomers is denser than the water/steam mixture in the water walls) or assisted by pumps. In the steam drum, the water

11130-799: Was also used in one iron and steel plant . Additionally, three facilities worldwide were devoted to CO 2 transport/storage. As of 2024, the oil and gas industry is involved in 90% of CCS capacity in operation around the world. Eighteen facilities were in the United States, fourteen in China, five in Canada, and two in Norway. Australia, Brazil, Qatar, Saudi Arabia, and the United Arab Emirates had one project each. As of 2020, North America has more than 8000 km of CO 2 pipelines, and there are two CO 2 pipeline systems in Europe and two in

11236-583: Was later expanded several times. As of 2021, the total installed capacity of the power station was 3,617 MW, made up of 2,000 MW coal-fired units, 555 MW oil-fired gas turbine units, 1,060 MW gas-fired combined cycle units , and one 1.1 MW solar power system. In 2010, HK Electric began installing a solar farm in Lamma Power Station with a capacity of 550 kW, with a cost of HK$ 23 million. The panels chosen uses 5,500 amorphous silicon photovoltaic modules, which HK Electric says performs better in

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