Polaris Atmospheric Network News: On June 2 10, the State Council Press Office held a press conference, saying that by the end of 20 19, China's ultra-low emission coal-fired power units accounted for 86% of the total installed capacity of coal-fired power, and China has built the world's largest ultra-low emission clean coal-fired power supply system. Looking at foreign countries, although coal-fired power has gradually declined after providing the world with electricity for a hundred years, many countries are still investing in technology to control and transform its pollution, so that it can continue to serve mankind.
According to the data of the International Energy Agency, the world's coal-fired power generation reached a historical peak in 20 18, and then began to decline in 20 19.
India: Controlling coal-fired power pollution will cost tens of billions of dollars.
For a long time, coal-fired power generation has been the leader in global power production. According to the World Energy Statistical Yearbook published by BP in 20 18, the proportion of coal-fired power generation in global power production has basically hovered around 40% since this century, which is almost the sum of nuclear power, hydropower and renewable energy. Judging from the proportion of coal-fired power to energy supply, more than two-thirds of electricity in China, Indian, Polish and South Africa comes from coal-fired power.
The long-term emission of coal-fired power plants in India is not up to standard, which has become the pain point of national environmental problems.
Developing countries in Asia such as India lack advanced clean energy, energy storage technology and mature renewable energy policy framework, so the cost of using clean energy is high. For emerging economies like India, cheap coal-fired power is still the best power generation option, which makes South Asia and Southeast Asia one of the few regions in the world where the proportion of coal-fired power is increasing, but it also brings a lot of trouble to the local coal-fired power pollution control.
Figure A subcritical coal-fired power station located in Dutiguring, India, has the lowest thermal efficiency and the most carbon emissions per unit of electricity.
A few years ago, an air pollution study conducted by the Indian Science, Technology and Policy Research Center (CSTEP) showed that by 2030, as many as 300,000 to 320,000 people will die prematurely because they do not meet the emission standards, and 565,438+000 people will be hospitalized for respiratory diseases. It is a good choice to install more advanced equipment to control sulfur oxides, nitrogen oxides and particulate matter, but according to this account, India's coal-fired power plants will lose 9.8 billion US dollars, reaching1/kloc-0.50 billion US dollars, and the cost per kWh will increase by 9%, reaching 2 1%. After weighing, the Indian authorities finally think that controlling coal-fired power pollution is worth investing. 20 15 12, India's Ministry of Environment, Forestry and Climate Change (MOEFCC) issued new standards to limit the concentration of sulfur oxides, nitrogen oxides and particulate matter in coal-fired power plants, and gave them to domestic coal-fired power plants for two years. However, by 20 17 and 12, the authorities found that almost no coal-fired power plants had installed pollution control equipment, so they were forced to extend the deadline to 2022. A source said that the two-year deadline brought great pressure to the coal-fired power industry, which led to the extension. But most experts believe that by 2022, many coal-fired power plants will still not comply with strict standards. The authorities have long been prepared for this, and are strengthening management from the aspects of bidding and construction approval, putting an end to the falsification of monitoring data and supervising the cost of renovation. At present, India is transforming all the old coal-fired power plants in China to reduce their emission levels to national standards, and at the same time, it will close a number of old power plants that have been seriously shut down.
India is a big coal producer in the world. The picture shows an open-pit coal mine in India.
Aside from the specific technology, we can think that the problems encountered by India in coal-fired power pollution control are common to many developing countries. Fortunately, however, with the decline in the cost of renewable energy generation, the "king" position of coal-fired power in India's energy structure may begin to shake.
Japan: phasing out inefficient coal-fired power plants
According to the data released by the International Energy Agency (EIA) on 2019, the power generation of more than 90 coal-fired power plants in Japan in 20 18 is estimated to be 3170 billion kWh, accounting for about13 of Japan's power structure. 99% of Japan's total coal consumption comes from imports. In 20 18, Japan imported more than 265,438+tons of coal. If natural gas is added to generate electricity, 74% of Japan's electricity comes from fossil energy, which is much higher than that of developed countries in Europe and America.
After the Fukushima nuclear accident, Japan's coal-fired power construction has increased for several consecutive years.
The reason for the high proportion of coal and electricity in Japan is historical emergencies. As early as 20 10, the Ministry of Economy, Trade and Industry of Japan planned to reduce coal-fired power generation, and planned to reduce the share of coal-fired power generation by more than half by 2030, and use nuclear power to make up for this vacancy and increase the proportion of nuclear power to 50%. However, the Fukushima nuclear accident of 20 1 1 not only greatly weakened the "cleanliness" of Japanese power, but also detonated the "anti-nuclear" sentiment that the public could not alleviate for many years. In order to make up for the power gap caused by the shutdown of nuclear power, Japan has launched many coal-fired power projects. However, Japan has handled the contradiction between coal-fired power capacity expansion and pollution control well, because Japan has confidence in coal-fired power pollution control technology.
Since 1970s and 1980s, Japan has developed a large number of advanced technologies in many aspects of coal-fired power generation and put them into use, some of which have been exported to foreign countries (including China). In the flue gas pollution prevention and control technology, the synergistic dust removal efficiency of wet desulfurization can reach 70%~90% in the flue gas collaborative treatment technology route with low temperature electrostatic dust removal technology as the core applied in Japan. Another example is the activated coke desulfurization technology in resource desulfurization technology, which uses activated coke to adsorb and desorb sulfur dioxide through a moving bed, and uses sulfuric acid production process to prepare sulfuric acid, which integrates desulfurization and collection of industrial raw materials. This technology has been applied in large power plants in Japan and other countries, and the application performance of 2 600 MW units has been achieved in Xinjizi Power Plant in Japan.
In the aspect of low nitrogen combustion, Mitsubishi and Hitachi of Japan have made outstanding achievements in the development and application of low nitrogen oxide burners. Among the top 10 patent applicants in the world, there are 6 in Japan and 3 in the United States. But the good news is that the number of patents in this field in China is increasing rapidly in recent years.
From June, 2065438 to June, 2005, Japan established the "Association for Promoting the New Generation of Thermal Power Generation Technology" composed of people from all walks of life in government, industry and academia, and began to promote the development of clean and efficient utilization technologies for the next generation of thermal power generation. From July 2065438 to July 2008, Japan's Cabinet approved the Fifth Energy Strategic Plan to promote Japan's transformation to high-efficiency and next-generation coal-fired power generation and gradually phase out inefficient coal. In July this year, Japanese Minister of Economy, Trade and Industry Hiroshi Daiyama said that Japan would phase out inefficient coal-fired power plants by 2030. As part of its strategic energy plan, officials of the Ministry of Economy, Trade and Industry of Japan began to formulate a more effective new framework to ensure the phasing out of inefficient coal-fired power plants.
United States: the developed country with the largest coal-fired power generation.
According to the data released by the global energy monitoring agency, the top ten countries in the world in 20 19 are China, India, the United States, Japan, South Korea, South Africa, Germany, Russia, Indonesia and Australia. In terms of new coal-fired power plants, only three countries in 20 19 10 did not put new coal-fired power plants into operation, and the capacity of coal-fired power plants closed in 20 19 in the United States ranked first among 10 countries. However, the United States is still the developed country with the largest coal-fired power generation, and the impact of coal-fired power plants on air pollution (including PM2.5, ozone and acid rain) in the United States cannot be ignored. In the United States, coal-fired power plants consume more than 90% of the total coal every year, and the sulfur dioxide emitted by coal-fired power plants accounts for about half of the total emissions in the United States, and the nitrogen oxides emitted account for 10%.
Figure After the closure of Widow Creek coal-fired power plant in Alabama, USA, Google started construction on 20 18, transforming it into a data center using renewable energy.
In the United States, most coal-fired power plants use wet flue gas desulfurization system (WFGD) to control sulfur dioxide emission, low-nitrogen burner, waste gas and selective catalytic reduction system (SCR) to control nitrogen oxide emission, and electrostatic precipitator (ESP) to control particulate matter (PM). About half of coal-fired power plants will also use activated carbon injection system (ACI) and bag filter to control mercury emissions. The United States is good at low nitrogen combustion. A company in the United States has developed the technology of Rotary Counter Burnout Air (ROFA), which extracts about 30% of the air volume from the secondary air of the boiler and injects it into the upper part of the furnace through asymmetric nozzles in the form of high-speed jet to form a vortex, thus improving the material mixing and temperature distribution in the furnace and greatly reducing the generation of nitrogen oxides. At present, this technology has been well applied in developed countries in Europe and America.
The total amount of mercury released into the atmosphere in the world every year is about 5000 tons, and the mercury emission during coal burning accounts for a considerable proportion. Since the end of last century, mercury pollution control has been one of the key prevention and control points of coal-fired power plants in the United States. According to the US Environmental Protection Agency (EPA) statistics, in 1990, the total mercury emissions of the following three industrial sectors accounted for about two-thirds of the United States: medical waste incinerators, municipal waste incinerators and coal-fired power plants. The first two industries have been bound by emission standards, but mercury pollution in coal-fired power plants has yet to be treated.
Fig. 2018110/0. In October, Norman Lake in North Carolina, USA was steaming, and the nearby Marshall Power Plant discharged a large amount of high-temperature wastewater into the lake.
Since the beginning of this century, coal-fired power plants in the United States have begun to focus on solving the problem of mercury emission control according to the requirements of the "Clean Sky Plan", and the US Department of Energy has chosen eight new experimental projects for mercury emission control technology to invest. As part of the experimental project, the patented mercury emission control technology of American Electric Power Research Institute was tested in six projects. In addition, the US Department of Energy plans to conduct long-term large-scale experiments on promising mercury emission control technologies, especially in coal-fired power plants that burn lignite and are equipped with small electrostatic precipitators.
EU: Many countries have announced the timetable for phasing out coal-fired power.
Among European countries, Germany took the lead in attacking the pollution caused by coal-fired power generation. In the 1980s, the Law on Large Combustion Devices was promulgated, which required that the concentration of sulfur dioxide in flue gas discharged from large combustion devices should not exceed 400 mg/m3 from165438+ 1 in July 1987, and the sulfur content in flue gas should be lower than 15% of the fuel sulfur content. Therefore, almost all German power plants have set up tall and brand-new flue gas desulfurization and denitrification equipment next to the original boiler house, which has become a major feature of German power plants. The Germans later called the installation of flue gas purification equipment from 1983 to 1988 throughout West Germany "refitting movement". By 1988, 95% of the installed capacity in West Germany had installed flue gas desulfurization devices, and the sulfur dioxide emission of coal-fired power plants decreased from 198215.5 million tons to 19 1 year15.5 million tons.
The picture shows the German coal-fired power plant in Rausitz. Germany has decided to completely stop coal-fired power plants in 2038.
Because the flue gas from coal-fired power plants can remove mercury in coordination with denitrification, dust removal and desulfurization. The best available technology reference document for large-scale combustion devices in the European Union suggests that mercury removal should give priority to the technical route of high-efficiency dust removal, flue gas desulfurization and denitration coordinated control. The average removal efficiency is 75% (50% for electrostatic precipitator and 50% for flue gas desulfurization) by adding flue gas desulfurization device after using electrostatic precipitator or bag filter, and it can reach 90% if adding SCR device.
In the field of clean coal, EU's R&D projects include integrated gasification combined cycle (IGCC) technology, coal, biomass and waste combined gasification technology, circulating fluidized bed combustion (CFB) technology, solid fuel gasification and fuel cell combined cycle technology.
Egborough Coal-fired Power Plant in North Yorkshire, England was closed in 20 18, and became one of the filming locations of The Fast and the Furious in the same year.
In Europe, the present situation and expectation of coal-fired power development vary from country to country. This mainly depends on the policies of national regulators on decarbonization and air quality, and the position of coal-fired power in power production in various countries. In order to implement the energy saving and emission reduction targets in the Paris Agreement, European governments have also announced the timetable for phasing out coal-fired power: Britain decided to close all coal-fired power facilities by 2025; France plans to close all coal-fired power plants before 202 1; Finland considers a total ban on coal in 2030; The Netherlands will ban the use of coal-fired power generation from 2030. A similar situation has happened in other parts of the world. Many countries, including the United States, are moving away from coal because other clean energy sources are becoming cheaper and cheaper, and environmental regulations have cooled the market for this fossil fuel. Since there are alternatives to coal-fired power generation, why use it?
China: The emission standard of coal-fired power generation is stricter than that of developed countries.
Because coal-fired power accounts for more than half of China's power supply structure, fully implementing ultra-low emission and energy-saving transformation will help improve the clean, efficient and high-quality development level of China's coal-fired power industry. Since 20 14, China has vigorously promoted domestic power generation enterprises to implement ultra-low emission and energy-saving transformation projects. On the one hand, stricter standards for energy efficiency and environmental protection of coal-fired power plants are implemented, and it is proposed that the emission concentration of air pollutants of newly-built coal-fired power units with conditions in China basically reaches the emission limit of gas turbine units, and the existing coal-fired power units with conditions implement ultra-low emission transformation. On the other hand, the relevant departments further clarified the ultra-low emission electricity price policy, which effectively reduced the cost of enterprise transformation and operation.
Earth-fired power plants are one of the most important human heritages in the 20th century.
According to the statistics of China Electric Power Enterprise Association, during the five years from 20 12 to 20 17, when the installed capacity of coal-fired power in China increased by 30%, the emissions of sulfur dioxide, nitrogen oxides and soot decreased by 86%, 89% and 85% respectively. The standard coal consumption for power supply of coal-fired generator sets is reduced from 325g/kW to 312g/kWh. Considering that the installed capacity of coal-fired power in China ranks first in the world, the basic capacity of ultra-low emission transformation has now exceeded 700 million kilowatts, which is unique in the world. In the past, the emission standards of flue gas pollutants in China were looser than those in developed countries, but now the emission levels of flue gas, sulfur dioxide and nitrogen oxides in coal-fired power plants in China are close to those in gas-fired power plants, which are more than 50% stricter than those in developed countries.
Children play near a coal-fired power plant in Chepala, Central Java, Indonesia, turning a blind eye to the pollution sources close at hand. This kind of scene is very common in Southeast Asia where coal and electricity are expanding.
The changes of coal-fired power plants in China show that coal-fired power, as a symbol left over from the last century, is not out of date. As long as we make full use of it wisely, it will continue to survive and revive.
Fig. The new Courcel coal-fired power plant built by South African state-owned power company also uses wet desulfurization device.
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