In January 2022, the State Council issued the “14th Five-Year Plan” Comprehensive Work Plan for Energy Conservation and Emission Reduction, proposing the implementation of clean and efficient coal utilization projects. In June, the National Development and Reform Commission and other departments issued a notice on the “Benchmarking and Benchmarking Levels in Key Fields of Clean and Efficient Coal Utilization (2022 Edition)”, pointing out the task of achieving carbon peaking and carbon neutrality by benchmarking, promoting the clean and efficient utilization of coal, and promoting the Transformation and upgrading of coal consumption. In this issue, experts are invited to discuss related issues.
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Xu Xiangmei, Director and Researcher of Economic Daily’s Theory Department
The connotation of clean and efficient utilization of coal continues to deepen
Moderator: How to understand the role of clean and efficient utilization of coal in my country’s energy transformation?
Li Weiming (Director, Resource Policy Research Office, Institute of Resources and Environmental Policy, Development Research Center of the State Council):Coal is my country’s basic energy and an important industrial raw material, and a solid foundation to ensure my country’s energy security. Since the reform and opening up, with the rapid economic development, the environmental problems caused by coal burning have become increasingly prominent. In order to improve the efficiency of coal combustion and control the pollution of coal combustion, since the 1990s, my country has begun to attach importance to the clean and efficient utilization of coal, established the “National Leading Group for the Promotion of Clean Coal Technology“, and issued the “Ninth Five-Year Plan for China’s Clean Coal Technology and the 2010 National Clean Coal Technology Promotion Planning Leading Group”. The Development Outline for 2019, which provided guidance and deployment for the clean and efficient utilization of coal for the first time. Since the 18th National Congress of the Communist Party of China, the Central Committee of the Communist Party of China has attached great importance to the clean and efficient utilization of coal. A series of policy documents such as Opinions on Safe, Green Development and Clean and Efficient Utilization of Coal, Action Plan for Clean and Efficient Utilization of Coal (2015-2020), and Innovation Action Plan for Energy Technology Revolution (2016-2030), the clean utilization of coal has officially risen. for the national energy development strategy. At this time, the clean and efficient utilization of coal refers to the clean and efficient utilization of coal washing, fuel power generation, clean conversion, decentralized combustion and other links, focusing on efficiency improvement and traditional pollutant control.
During the “14th Five-Year Plan” period, my country’s economy has turned to a stage of high-quality development, and the construction of ecological civilization has entered a strategic direction focusing on carbon reduction, promoting the synergy of pollution reduction and carbon reduction, promoting a comprehensive green transformation of economic and social development, and realizing the improvement of ecological environment quality from quantitative changes. to a critical period of qualitative change. The connotation of clean and efficient utilization of coal continues to deepen. In addition to continuing to emphasize more efficient and cleaner utilization in all aspects, and implementing stricter pollution emission standards, it is also necessary to combine large-scale utilization and the requirements of low-carbon and green times to pay more attention to green, low-carbon Carbon and quality empowerment to achieve clean and low-carbon utilization of all elements in the whole process.
Specifically, the characteristics of clean and efficient utilization of coal in the new era can be summarized as “three highs and three lows”. The “three highs” are embodied in: high efficiency, that is, to make full use of advanced technologies in all aspects of coal utilization, so that coal quality can be accurately adapted to different coal-using technologies and equipment, and the utilization or conversion efficiency can be greatly improved; high quality, that is, continuous application New technologies and processes with economic, social and environmental benefits, upgrading, transforming and reshaping the coal utilization industry, creating new formats and developing new products; high recycling, that is, continuously turning the waste generated in the coal utilization process into reusable materials, forming a circular pattern of “resources-products-resources”. The “three lows” are reflected in: low consumption, that is, all aspects of coal utilization must strictly control energy consumption intensity, water resource consumption intensity, etc., to reduce energy and resource consumption per unit product; low pollution, that is, air, water, and solid waste pollutant discharge concentrations must be Low carbon emissions, to achieve clean production and near zero emissions; low carbon emissions, that is, to enhance carbon reduction capabilities and reduce carbon emissions through deep coupling with renewable energy and carbon capture, utilization and storage technologies.
Under the current situation, speeding up the clean and efficient utilization of coal is an inevitable choice and a strong cornerstone to support energy transformation, ensure national energy security and achieve the “dual carbon” goal. The energy resource endowment characteristics of my country’s rich coal, poor oil and little gas determine that coal’s main energy status will not fundamentally change in the short term. In 2021, my country’s coal consumption will exceed 4 billion tons, accounting for 56% of primary energy consumption, and carbon emissions from coal utilization will account for more than 70% of fossil energy consumption carbon emissions. If the adjustment of the current coal utilization and consumption structure is not accelerated, problems such as carbon emissions and environmental pollution will be exacerbated. At the same time, the realization of energy transformation is not a one-day achievement. The development history of developed countries such as the United States, Germany and Japan shows that even if there are energy sources that can replace coal, coal will still be used after the carbon peaks, but the use will change. As far as my country is concerned, it is even more so. To achieve the “dual carbon” goal, a large amount of clean coal is still needed to provide transition and bottom-up guarantees. On the one hand, the installed capacity of renewable energy such as wind and light will increase significantly, while the power of renewable energy is highly volatile, and it is necessary to use the stability of clean coal-fired power generation to provide a basis for new energy to stabilize fluctuations. On the other hand, coal as a raw material still has a certain application space in the production of modern coal chemical industry (coal to olefins, aromatics, etc.) and coal-based high-end materials (carbon fiber, graphene, carbonaceous reducing agent, high-end activated carbon, etc.), and will gradually It has become one of the main utilization methods of coal in the process of carbon neutrality in my country. In this context, the key to solving the dilemma of “reducing” and “guaranteing” coal is to take a resource-saving and eco-friendly development path and promote clean and efficient use of coal. This will not only help to force coal to eliminate backward production capacity and transform and upgrade, reflect the responsibility of “reduction”, and effectively implement the national carbon emission reduction target; Responsibilities to ensure my country’s energy security and achieve the “dual carbon” goal.
Smart green becomes a new trend of coal production
Moderator: What achievements has my country achieved in coal safe, efficient and clean production? What is the future trend of coal mine construction?
Ren Shihua (Director of Science and Technology Support Center, General Research Institute of Coal Science):Safe, green and efficient development is the basis for a stable supply of coal, which has achieved leapfrog development in recent years. my country’s coal technological innovation has been gradually upgraded from tracking and imitation to parallel running and leading. Technologies such as large-scale mine construction, fully-mechanized caving mining of extra-thick coal seams, and intelligent coal mining have reached international advanced or even leading levels, promoting safe, efficient and clean coal mining in my country.
Coal mine safety has fundamentally improved. my country’s coal resources are generally buried deep, and coal mining is dominated by underground coal mines. The underground environment is complex and there are many disaster risk factors, and the safety production of coal mines faces huge challenges. The level of coal safety production is usually expressed in terms of the death rate per million tons of raw coal production, that is, the average number of deaths due to accidents per 1 million tons of raw coal produced. The indicator was as high as 5.77 in 2000 and was still at 0.749 in 2010. With the continuous improvement of the prevention and control systems for coal mine gas, rock burst, water hazards, and fire, major breakthroughs in advanced technology and equipment have been made and large-scale promotion and application. , an average annual decline of more than 22%. The safety production level of some modern large-scale coal mines is basically the same as that of coal mines with the same mining conditions in developed countries.
Production efficiency is greatly improved. Coal production efficiency is also called production ergonomics, that is, the coal output of an average worker working one day. Technological progress has promoted the gradual increase in the level of mechanization of coal mines in my country and the scale of single-well output, which has led to a rapid increase in the efficiency of coal production. In 2021, the degree of mechanization of coal mining in large coal enterprises will increase to 98.95%, the single well output scale of coal mines will increase to about 920,000 tons/year, and the production efficiency of raw coal in large coal enterprises will increase to 8.79 tons/worker, an increase from 6.43 tons/worker in 2012. up 36.7%. Some modern large-scale coal mines, such as the National Energy Group Shendong Coal Bulianta Coal Mine, have achieved coal production efficiency that has reached the leading level of coal mines with similar conditions in the world.
The level of cleaner production has been significantly improved. With the continuous improvement of the level of mechanization, informatization and intelligence of coal mines, the energy consumption of coal mine production has been reduced year by year. In addition, the transformation and upgrading of coal mines such as “replacing coal with electricity” and “replacing coal with gas” has caused great changes in the energy consumption structure. decrease year by year. In 2021, the comprehensive energy consumption and comprehensive power consumption of raw coal production in large coal mines in my country will drop to 10.4 kg standard coal/ton and 20.7 kWh/ton respectively. At the same time, due to the gradual increase in the utilization rate of coal mine gas extraction, the methane emitted into the air during the coal development process has been greatly reduced, and the greenhouse gas emissions during the coal development process have shown a downward trend. According to estimates, from 2010 to 2020, the average greenhouse gas emissions of 1 ton of coal production will drop from 226.7 kg to 151.1 kg, a drop of one third within 10 years.
Factors such as technological progress, reduction of employees, and ecological environmental protection determine that coal development cannot continue the traditional way of high labor intensity and high ecological damage, and it is an inevitable requirement to take the intelligent green road. In recent years, under the high attention and rapid promotion of government departments at all levels and coal enterprises, the intelligent and green mining of coal has achieved preliminary results.
In terms of intelligent coal mining, since the first intelligent mining face was built in 2014, breakthroughs have been made in key core systems in more than 10 links including intelligent geological support system, intelligent excavation system, intelligent coal mining system, and intelligent main transportation system. The intelligent coal mine integration solution explores the coal mine intelligent construction mode suitable for different regions and different coal seam conditions. By the end of 2021, more than 400 coal mines will carry out intelligent construction, and 813 intelligent mining faces will be built. At present, the intelligentization of coal mines has gradually shifted from pilot demonstration to large-scale promotion and application.
In terms of green coal mining, the coal industry continues to promote the construction of green mines. Breakthroughs have been made in the integration of coal mining and ecological environmental protection technologies such as water conservation mining and backfill mining, which have been popularized and applied, effectively reducing the impact of coal mining on groundwater and reducing surface subsidence in coal mining areas. In 2021, the land reclamation rate in the coal mining area will reach 57%, and the ecological environment quality of the mining area will be stable and improving. By the end of 2021, a total of 284 coal enterprises have been included in the national green mine list. Some coal mines have achieved positive benefits for the ecological environment of the mining area, not only did not damage the environment, but also optimized the environment.
In order to adapt to the new requirements of the new era of giving full play to the role of energy protection and the new requirements of carbon neutralization, my country’s coal industry will show the following trends.
On the one hand, intelligent flexible mines will become a new form of coal mine construction. Under the “dual carbon” goal, the proportion of wind, solar and other renewable energy sources connected to the grid will gradually increase, and the demand for power peaking will increase, which will increase the fluctuation of coal demand. At the same time, the external dependence of oil and gas continues to rise and the geopolitics is complex and changeable. my country’s oil and gas supply security is facing severe challenges, which will further increase the fluctuation of coal demand. In the long run, coal production is not the more the better, but the production can be started quickly when needed, the production capacity can be maintained at low cost when not needed, and flexible supply can be realized. Mine has become a new form of coal mine construction in the future.
On the other hand, coal mining areas will develop into carbon sequestration bases. Coal mining areas not only have coal resources, but also have sufficient underground space and land resources, with huge carbon storage capacity. Relevant studies have shown that the underground space of coal mines with a depth of 500 meters has good stability for storing carbon dioxide. At the same time, the residual coal, rock formations and groundwater in the underground space of coal mines have certain adsorption, dissolution and migration effects on carbon dioxide. Using the land in the mining area and planting fast-growing plants with utilization value can form carbon sinks. Coal is mined from coal mines, carbon dioxide generated by coal utilization is stored in underground space, and surface vegetation forms carbon sinks. Coal mining areas have the potential to realize carbon self-circulation.
Technological Innovation Promotes Energy Saving and Emission Reduction of Coal Power
Moderator: What are the achievements of my country’s coal power technology innovation in recent years, and what role has it played in promoting pollution reduction and carbon reduction in the coal power industry?
Gao Hu (Researcher, Energy Research Institute, China Academy of Macroeconomics):my country’s coal-dominated resource endowment has formed a coal-based electricity production and consumption structure. As my country’s basic power source, coal power provides a strong power guarantee for supporting economic and social development, but coal power used to be an important source of frequent air pollution problems. In order to promote the clean and efficient development of coal-fired power, reduce coal consumption and pollutant emissions, and improve air quality, the Action Plan for Energy-Saving, Emission-reduction, Upgrading and Transformation of Coal Power (2014-2020) and the Comprehensive Implementation of Ultra-Low Emission and Energy-Saving Coal-fired Power Plants The Reform Work Plan has been issued and implemented successively. After years of hard work, my country’s coal power energy conservation and emission reduction work has achieved remarkable results.
From the perspective of clean utilization level, by the end of 2021, my country will have about 1.03 billion kilowatts of coal-fired power units that have reached the ultra-low emission limit, accounting for 93% of the country’s total installed coal power capacity. In 2021, the national electricity soot, sulfur dioxide, and nitrogen oxide emissions will be about 123,000 tons, 547,000 tons, and 862,000 tons, respectively, down 69%, 73%, and 52% from 2015.
From the perspective of energy saving and carbon reduction, the coal consumption for power supply of thermal power plants of 6,000 kilowatts and above in 2021 will be 301.5 grams of standard coal/kWh, a decrease of 13.5 grams of standard coal/kWh compared with 2015, which is equivalent to a reduction of 9,500 grams of coal consumption in 2021. 10,000 tons; the carbon dioxide emission per unit of thermal power generation nationwide is about 828 g/kWh, a decrease of 22 g/kWh compared with 2015. According to the statistics of the China Electricity Council, taking 2005 as the base year, from 2006 to 2021, the reduction of coal consumption in power supply will reduce carbon dioxide emissions by about 8.9 billion tons, contributing 41% to carbon emission reduction in the power sector, effectively reducing carbon dioxide emissions in the power industry. Emissions grow.
The achievement of clean and efficient utilization of coal power is inseparable from the innovation and development of coal power technology. At present, my country has achieved independent research and development and manufacturing of high-parameter, large-capacity ultra-supercritical coal-fired units, and the main parameters have reached the world‘s advanced level. Below gram/kWh; technologies such as million-kilowatt air-cooled generator sets, secondary reheat technology, and large-scale circulating fluidized bed power generation are all world-leading. At the end of 2021, my country’s first large-scale carbon dioxide cycle power generation test unit independently developed and built in China will complete a 72-hour trial operation with a rated power of 5,000 kilowatts. It is the world‘s largest capacity supercritical carbon dioxide cycle power generation unit, laying a solid foundation for further improving the efficiency of thermal power units. With the construction and application of advanced coal power technology and the shutdown and elimination of outdated coal power units, my country’s coal power structure has been continuously optimized, and the proportion of high-efficiency coal power units with large capacity, high parameters, and low emissions has continued to increase. At present, there are more than 860 supercritical and ultra-supercritical advanced coal power units in China, accounting for more than half of the country’s total coal power installed capacity.
With the large-scale development of new energy sources such as wind power and photovoltaic power generation with volatility characteristics, the uncertainty of power supply has increased significantly. The configuration of sufficient and flexible power supply is crucial to ensure the balance of power supply and demand and maintain the safe and stable operation of the power system. At present, the installed capacity of pumped storage in my country accounts for only 1.5% of the power system, and new energy storage technologies such as electrochemistry are still in their infancy. Coal-fired power units are required to have flexible up and down adjustment capabilities to ensure the development of new energy and the construction of new power systems. convoy. Since the “Thirteenth Five-Year Plan”, my country has started the transformation of coal power flexibility, and promoted coal power enterprises to explore various technical routes such as in-depth peak shaving and thermal electrolysis coupling. The minimum power generation output of coal power units can be adjusted from 50% to 60% of rated capacity. It can be reduced to 30% to 35%, and some units can even be as low as 20% to 25%, and the adjustable range is greatly increased. By the end of 2021, the scale of my country’s coal-fired power flexibility transformation will exceed 100 million kilowatts, effectively improving the flexible adjustment capacity of the power system and better promoting the development of renewable energy.
The endowment of my country’s energy resources determines that coal power will still play an important role in ensuring the safe supply of electricity for a long time. In 2021, the national installed capacity of coal power will account for 46.7%, the power generation will account for about 60%, and the coal used for power generation will account for more than half of the country’s total coal consumption. Remarkable results have been achieved, but coal-fired power is still the industry with the largest carbon dioxide emissions in the country. There are still more than 400 million kilowatts of subcritical and below units. Some units have problems such as high energy consumption and insufficient flexible adjustment capabilities.
With the continuous progress of carbon neutralization work and the gradual establishment of new power systems, the pace of coal-fired power generation clean, efficient, flexible, and low-carbon transformation needs to be further accelerated. It is necessary to vigorously promote the transformation of coal power energy saving and carbon reduction, flexibility transformation, and heat supply transformation “three transformations and linkages”, and it is clear that coal power should accelerate the transition from the main power source to the basic guarantee and system adjustment of auxiliary services such as reliable capacity, peak and frequency regulation, etc. Sexual power transition. In October 2021, the National Development and Reform Commission and the National Energy Administration jointly issued the “Implementation Plan for the Transformation and Upgrading of National Coal Power Units”, which clearly stated that during the “14th Five-Year Plan” period, the scale of coal power energy saving and carbon reduction transformation should not be less than 350 million kilowatts, supply The scale of thermal transformation will reach 50 million kilowatts, and the flexibility transformation will be completed at 200 million kilowatts. According to this scale, it is expected to save more than 50 million tons of coal consumption, increase the consumption capacity of new energy by more than 50 million kilowatts, and better promote the optimal combination of coal and new energy.
Multi-party efforts to break through restrictions
Moderator: What are the constraints for the clean and efficient utilization of coal, and what should be done in the next step?
Qin Rongjun (Associate Researcher of China Coal Economic Research Association):Although my country has achieved remarkable results in the development of clean and efficient utilization of coal, it still faces some constraints.
my country’s coal washing technology and equipment have reached the international advanced level, but the raw coal selection rate still needs to be improved. Coal washing and processing can improve and stabilize coal quality and improve subsequent coal utilization efficiency, which is the premise and basis for clean and efficient coal utilization. The selection rate of raw coal in my country has increased from 66% in 2015 to 71.7% in 2021, while the selection rate of raw coal in developed countries such as Australia and the United States has reached 85% to 90%. Based on the conditions of my country’s coal resources, to realize the selection of raw coal in my country, the selection rate of raw coal should reach about 90%. In addition, there are still problems such as uneven quality of sorting products, obvious gaps in information application, and insufficient customization level. There is a long way to go in terms of refined and intelligent washing and processing.
my country’s coal-fired power generation technology level is the world‘s leading, but coal-fired power generation efficiency is low and carbon emissions are large. Coal as a fuel for power generation is the main field of clean and efficient use of coal. On the one hand, the coal consumption of coal-fired power plants nationwide has dropped from 315 grams of standard coal/kWh in 2015 to 299.8 grams of standard coal/kWh in the first half of this year. The coal consumption of advanced coal-fired power plants has reached 270 grams of standard coal/kWh, and the benchmarking is advanced. There is still room for improvement in the coal consumption of power supply in my country. On the other hand, the power generation efficiency of thermal power plants in my country is generally lower than 50%, and the low energy conversion efficiency leads to high coal consumption for power supply and also increases pollutant emissions. In addition, high carbon dioxide emissions are also an important problem in current power plants, and the application of carbon capture technology is still in the demonstration stage.
Coal is used as a raw material for clean transformation, and the industrial technology needs to be further improved and optimized. On the one hand, the energy efficiency level of coal chemical industry needs to be lowered. At present, advanced and backward production capacity coexist in the coal chemical industry, and the energy efficiency levels of different enterprises vary significantly, and the potential for energy saving and carbon reduction transformation and upgrading is great. With reference to the “Benchmarking and Benchmarking Levels in Key Areas of Clean and Efficient Coal Utilization (2022 Edition)” and “Energy Efficiency Benchmarking and Benchmarking Levels in Key Areas of High Energy-consuming Industries (2021 Edition)”, by the end of 2020, the energy efficiency of the coal-to-methanol industry will be lower than the benchmark About 25% of the production capacity is at the same level, about 40% of the production capacity in the coal-to-ethylene glycol industry is lower than the benchmark level, about 19% in the synthetic ammonia industry, and about 19% in the coking industry. accounting for 40%; on the other hand, the carbon emission intensity of the coal chemical industry needs to be further reduced. Coal chemical projects such as coal-to-liquids and coal-to-olefins have the characteristics of long process chain, high carbon emission intensity, and high process carbon emission concentration. The carbon emission intensity of coal conversion process is 3 to 8 times that of petrochemical industry.
There are still deficiencies in the quality utilization of low-rank coal and the use of scattered coal. In terms of quality utilization of low-rank coal, the current technology is still immature, including the failure of high-temperature dust-laden pyrolysis gas dedusting technology to cause pipeline blockage, heavy tar and high dust content, large-scale installations and difficulties in comprehensive utilization of powder coke etc.; in terms of decentralized coal consumption, the amount of decentralized coal consumption will be reduced from 600 million tons in 2015 to about 260 million tons in 2021, but there are also unstable civil briquette quality, poor combustion and heating effect, and the quality of civil stove products. And poor performance, fuel and stove mismatch and other issues.
To effectively promote the clean and efficient utilization of coal, it is recommended to make efforts from the following aspects.
The first is to strengthen the role of legal protection.It is suggested to speed up the revision of the Coal Law, further optimize the content of the clean and efficient utilization of coal, focus on clarifying the status, main measures, policy support and other matters of the clean and efficient utilization of coal, and at the same time strengthen procedural regulations to provide sufficient legal guarantees for the development of related work.
The second is to support the research and development and application of emerging technologies for clean and efficient utilization of coal.Strengthen the research and development of key technologies and equipment for the clean and efficient utilization of coal. Strengthen the layout of basic research and cutting-edge technology, and support the development of forward-looking, pioneering, and “neck-stuck” major technical equipment research. Research and formulate special policies to support industrial demonstration operations for clean and efficient coal utilization technologies that meet major national strategic needs. Increase support for the industrial development of coal as a raw material, and promote the high-end, diversified and low-carbon development of the coal chemical industry.
The third is to formulate fiscal and tax incentive policies.Formulate policies such as financial subsidies, taxes, and loan support to promote the clean and efficient utilization of coal. The technical equipment included in the list of technical equipment for clean and efficient utilization of coal can enjoy preferential policies such as tax reduction and exemption, loan support, etc., and simplify the approval procedures for the projects of clean and efficient utilization of coal planned by the region. Guide venture capital, private equity investment and other support, give full play to the advantages of policy finance, development finance and commercial finance, continue to support the research and development and application of clean and efficient coal utilization technologies; support technical reserve and capacity reserve projects that can ensure national energy security .
The fourth is to encourage the coupled development of coal chemical conversion and new energy.Comparing with the industry energy efficiency benchmarks and benchmark levels, systematic transformation of energy conservation and carbon reduction and elimination of outdated production capacity shall be carried out for existing chemical projects. Encourage the integrated carbon-neutral innovation demonstration model of “solar and wind complementary new energy-hydrogen production by electrolysis of water/energy storage/grid-modern coal chemical industry”, and provide certain policy support. Certain policy support should be given to enterprises that actively develop new technologies and new energy sources, their comprehensive energy consumption should be reduced, and enterprises should be encouraged to participate in the development of new energy technologies.
The fifth is to speed up the management of decentralized coal use.Give priority to industrial waste heat, co-generation, geothermal and other methods to replace coal scattered combustion; promote the development of coal-fired industrial boilers to clean and efficient combustion technologies for multiple fuels such as coal, waste, biomass, semi-coke, and natural gas; accelerate the upgrading of energy-saving and environmentally friendly furnaces With the penetration rate, low-efficiency and backward products are eliminated. In areas that cannot be covered by clean heating, clean briquette and special stoves are sold to achieve clean combustion. Biomass heating, “solar +”, water source heat pumps, “civil clean stoves” Light-storage integrated civil heating, such as solar energy storage + solar energy storage tank”, etc.