Cartography: Zhang Fangman
Editor's note: China is a big country for energy consumption. General Secretary Xi Jinping pointed out that 'developing clean energy is an important task for improving energy structure, ensuring energy security, and promoting the construction of ecological civilization. 'We must fight pollution prevention and control at the current stage, and we must adhere to the source of prevention and control, such as : Adjust energy structure, reduce coal consumption, increase clean energy use.
China's coal consumption accounts for about half of the world's energy. The energy structure is changing from coal to diversification. This edition introduces the report 'Beautiful China·Care about Clean Energy', focusing on the reduction and clean use of coal, while paying attention to wind power, photovoltaic The problems faced by power generation and other countermeasures were introduced today.
The appearance is dark, and it smells like a snuff that burns. This is the first impression most people have on coal. However, you know, if modern advanced technology is used, coal can burn cleanly.
Compared with the national emission standards, the emissions of sulfur dioxide, nitrogen oxides, and particulate matter were reduced by 83%, 50%, and 67%, respectively - at the National Science and Technology Awards Conference in January this year, the key technologies for ultra-low emission of coal-fired units were developed and applied. Obtained the first prize of the National Technological Invention Award. This is a big step towards the clean use of coal in China.
The coal-based energy structure is difficult to change in the short term, and coal clean and efficient use should be promoted
According to statistics, in 2017, China’s total energy consumption was 4.49 billion tons of standard coal, of which coal consumption accounted for 60.4% of total energy consumption, which was 1.6 percentage points lower than the previous year. 'China's coal consumption accounts for about half of the world's total, plus Extensive use of the way before, a large number of scattered coal combustion has brought high emissions. 'National Development and Reform Commission Energy Research Institute, said Han Wenke.
Zhang Shaoqiang, chairman of the China Coal Processing and Utilization Association, believes that 'clean use and large-scale combustion are currently effective methods to improve atmospheric quality'.
Many experts believe that coal reduction is the predecessor of clean and efficient utilization. Otherwise, the concentration of pollutants will be low and the total amount will still be huge. From the trend, coal reduction and clean energy substitution are steadily advancing. The coal production capacity exceeded 500 million tons. In 2017, non-fossil energy accounted for 17.6% of the country's total energy production, which was 6.4 percentage points higher than that in 2012.
Although the proportion of coal in primary energy shows a decreasing trend, it is difficult to change the status of the main energy in the short-to-medium term. To achieve the transformation and development of coal is the foothold for China's energy transformation and development.
'We have a consensus on vigorously developing clean energy, but it is far from being able to hydrolyze the recent thirst. On the one hand, in China's proved reserves of fossil energy, coal accounts for more than 94%, oil and natural gas account for only about 6%, both of which are more dependent on foreign resources. High, Regardless of the differences in the use of varieties, the cost of consumption is also much higher than that of coal. On the other hand, the stability and controllability of new energy such as wind power and photovoltaics need to be improved. It is still difficult to replace coal at a large proportion in the short term. We can't get an immediate picture. 'Zhang Shaoqiang believes that the proportion of coal consumption should be reduced in an orderly and scientific manner to promote clean and efficient use of coal.
China's coal-fired power plant pollutant emission control indicators are at the leading level in the world
On the production side, the coal is being used in a clean and efficient manner. The coal quality is better. In 2017, the percentage of raw coal selected in China was 70.2%, an increase of 1.3 percentage points year-on-year; the comprehensive utilization of resources pushed forward, and the national coal gangue comprehensive utilization rate reached 2017 67.3%.
At present, China's coal consumption is mainly distributed in coal-fired power generation, metallurgical coking, coal chemical, boiler coal (including building materials furnaces and heating heating), and civilian bulk coal. Coal consumption accounts for approximately the total coal consumption. 50%, 17.5%, 6.8%, 20% and less than 6%.
'While the proportion of coal for power generation is large, but consumption is concentrated, pollutant control and emission reduction efforts are strong.' Zhang Shaoqiang said that China has broken through large-scale coal-fired ultra-low emission power generation technologies, and the emission of air pollutants from coal-fired power plants has reached or even surpassed the national Emission standards for natural gas power generation, that is, smoke dust is not higher than 5 milligrams per cubic meter, sulfur dioxide is not higher than 35 milligrams per cubic meter, and nitrogen oxides are not higher than 50 milligrams per cubic meter. So, the cost will not be very high? , 'The added power generation cost is about 2-3 points per kilowatt-hour, the incremental cost is less than 10%, and it is lower than the cost of gas-fired power generation.'
According to the person in charge of the National Energy Administration, as of the end of the third quarter of 2017, Beijing, Tianjin, Henan and other cities have completed the task of ultra-low emission reform for all conditioned units 1-2 years ahead of schedule. More than 640 million kilowatts, the goal of rebuilding 580 million kilowatts in 2020 was completed ahead of schedule; all newly-built coal-fired power units are ultra-low emissions, and China's coal-fired power plant pollutant emission control index has reached the world's leading level.
In addition to the ultra-low emission project, the energy-saving transformation in the coal-fired power sector has also accelerated the transformation of its flexibility. 'As of the end of the third quarter of 2017, the country has completed a total of 530 million kilowatts of coal-fired energy-saving transformations; in addition, we have also focused on the implementation of thermal-electrolytic demolition and transformation. Pure coal-fired power unit deepening peak-shaping transformation to maximize the peaking capacity of coal-fired power generation units to make room for new energy power generation. For example, after the implementation of the flexible transformation of some coal-fired power units in Liaoning Province, the new energy wind-reduction rate decreased in 20176 Percentage. 'The person in charge of the National Energy Administration gave an example.
In terms of deep processing of coal, the level of localization in China's technology has been improved. Some key technologies have led the international market. Coal-based raw materials can produce ultra-clean diesel, natural gas, etc. According to the vehicle operation and bench experiment completed by the Chinese Research Academy of Environmental Sciences, coal cleaning Compared with the National Five-Standard Diesel, diesel fuel can reduce carbon monoxide, fine particulate matter, nitrogen oxides, and hydrocarbons emitted from the exhaust gas by 24%, 49%, 12%, and 34%, respectively. However, in the opinion of Han Wenke: 'Coal' Chemicals can be developed, but the scale should be moderate and orderly, especially in the ecological environment can be tolerated.
The treatment of bulk coal is a difficult point. It will insist on the replacement of bulk coal replacement and the substitution of cleanliness.
In general, coal-fired power generation, metallurgical coking, and coal chemical three coal consumption areas can be used on a large scale, and pollutant control is gradually improving. Currently, it is really difficult to operate, and it is difficult to monitor a large number of scattered coal, mainly including industrial fields. Small coal boilers in small and medium coal mines and small furnaces, scattered coal, etc. Usually these scattered coals are scattered procurement, and the circulation links are chaotic and difficult to supervise. Coal has high ash content and sulfur content, and it is dispersed and used, and the combustion process is inefficient. Most are direct-fired in-line, desulphurization, denitrification and other facilities are almost blank.
According to incomplete statistics, there are nearly 480,000 coal-fired heating and industrial heating boilers in China, and about 130,000 kiln stoves and about 750 million tons of coal are consumed annually. 'The efficiency of the boiler is low, the control facilities for pollutants are poor, and a large number of boilers are heated. Due to seasonal changes in load, the actual combustion efficiency, boiler thermal efficiency is on average 15%-20% lower than the international advanced level, resulting in smoke and dust emissions exceeding 40% of the national total, and sulfur dioxide emissions accounting for 35% of the national total emissions. Above, it became a serious source of atmospheric pollutants. ' Zhang Shaoqiang introduced.
He believes that small boilers with less than 10 tons of steam per hour are not suitable for reform due to excessive dispersion, older furnaces, and small capacity, and they should speed up the elimination process and support integrated replacement; Similar boilers in the power station can also achieve ultra-low emissions after supporting the flue gas purification measures.
'Now there is a new type of pulverized coal-fired industrial boiler with a combustion efficiency of over 90%. Energy efficiency alone is more than 30 percent higher than that of the old chain furnace. However, there are certain difficulties in the promotion. This is inconsistent with the low cost of infractions and inadequate supervision. Relevant, but also affected by coal removal in some areas, and some places also require large and medium-sized thermal power units must also be replaced by gas-fired power generation. Whether or not to achieve ultra-low emissions, resulting in corporate technology R & D and application of enthusiasm is not high. It is worth talking about. The relevant departments can raise the emission standards to be consistent with the gas-fired generating units. Who is superior or not can be compared, beyond the standard, and there is no problem when shutting down. ' Zhang Shaoqiang suggested.
The total amount of domestic bulk coal consumption is about 200 million tons per year, of which over 90% is used for winter heating in rural areas in the north. Although the proportion of residential coal is small, most of the stoves are original and scattered, and the economic affordability of users is not high. Clean and efficient use of coal as a difficult 'hard bone'. The responsible person of the National Energy Administration stated that it will adhere to the combination of decentralized coal depletion and cleanup instead of decontamination. It will be able to bridge the barriers and combine coal to build a clean coal distribution center through the implementation of high-quality coal sources. Apply clean coal and briquette, advanced civilian stoves, strengthen supervision and other measures to solve the problem of clean coal utilization in civilian use.
Zhou Dadi, executive vice chairman of the China Energy Research Association, believes that while clean and efficient, it should also work towards low carbon. 'The high carbon nature of coal cannot be changed. The current focus is on clean and efficient, but not to say that low carbon is given up.' The National Energy Work Conference convened recently proposed that we must step up research on experimental carbon capture and application technologies and strive to achieve breakthroughs as soon as possible so that the development of coal-fired power will be more in line with the requirements for clean, low-carbon safety and high efficiency.
'To coordinate the promotion of clean and efficient use of coal is one of the key tasks for energy work in 2018. We will strive to increase the proportion of coal in coal consumption on the basis of controlling the total coal consumption, and strive for the end of the 13th Five-Year Plan period. The proportion of coal is increased to about 55%, and all 300,000 kilowatt-class coal-fired units with conditions have achieved ultra-low emissions. 'The person in charge of the National Energy Administration said.