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(1) Coal washing technology: Developing coal washing and improving the quality of commercial coal are effective measures to reduce pollution at its source. In 1997, the selection rate of raw coal in our country was 25.73%. The focus of coal washing has shifted from coking coal to thermal coal, and from merely focusing on ash reduction to addressing both ash reduction and desulfurization, as well as recovering pyrite from the washed gangue. The separation process and equipment using small-diameter heavy-media cyclones can simultaneously reduce ash and sulfur content in fine coal sludge; when separating coal sludge with particle sizes ranging from 0.5 to 0.04 mm, the rate of inorganic sulfur removal is 67.90% to 70.30%. A coal processing plant with an annual capacity of 1.5 million tons, equipped with a large 12m2 wind-based dry coal sorting machine, has been put into operation. The investment per ton of coal in this plant is 4.25 yuan, while the processing cost per ton of coal is 2.15 yuan. The sorting efficiency is >90%, and the dust emissions (50 mg/m3) meet environmental standards. Some new technologies to address the challenges of deep ash reduction and desulfurization in coal, such as large-diameter three-product pressureless feed heavy-media cyclones and various types of microbubble flotation, have been successfully developed and put into use. However, China’s coal washing technology is generally quite behind international advanced levels. One issue is the low proportion of raw coal used in this process (25.7% in China, compared to over 90% in developed countries) ； Secondly, advanced coal washing processes account for a low proportion (such as heavy media separation; in China this figure is only 23%, while in developed countries it is over 60%), resulting in poor quality of refined coal ； Third, the average plant size is small, the degree of automation is low, equipment reliability is poor, and production efficiency is low. (II) Water-coal slurry technology: After 2000 hours of trial operation at the Baiyanghe Power Plant, the use of water-coal slurry as a substitute for oil yielded a combustion efficiency of >98% under conditions of complete combustion with water-coal slurry, while the boiler efficiency was >89%. The boiler could maintain stable combustion across load levels ranging from 40% to 100%, achieving results comparable to those obtained when burning heavy oil. Progress has been made in the combustion of slurry made from coal slime in mining areas. Pulp is prepared using high-ash (ash content 41–43%) coal slime for use in a 10 t/h chain furnace. After 2,008 hours of operation in total, the thermal efficiency of the boiler increased from 53.99% when only lump coal was used for combustion to 68% after mixing in coal slurry; meanwhile, the combustion efficiency rose from 63.7% to 79.01%. (III) Circulating Fluidized Bed (CFBC): Abroad, CFBC technology is evolving toward larger scale. At present, the CFBC boiler with the highest single-unit capacity (250 MW, evaporation rate of 700 tons per hour) is in operation in France. The boiler efficiency is 90.5%, the desulfurization rate is 93%, and Nox emissions are below 250 mg/Nm3. China now possesses the capability to design and manufacture circulation fluidized bed boilers with a capacity of 75 t/h ； A demonstration project for a self-developed 220t/h CFB boiler and a project for an imported 410t/h circulating bed boiler are underway. Some progress has also been made in the fundamental research on CFB design, with specialized design software for circulating beds having been developed ； Engineering design research on 125MW reheated boiler types, as well as research and design work on new 75 t/h and 130 t/h circulating fluidized bed boilers. (IV) Integrated Gasification Combined Cycle (IGCC): Integrated Gasification Combined Cycle power generation (IGCC) is an efficient, low-pollution clean coal power generation technology that is being actively developed in developed countries around the world. It not only meets the increasingly stringent environmental regulations but also achieves a power generation efficiency of over 45%, making it highly likely to become one of the main methods for clean coal power generation in the 21st century. Significant progress has been made on the US IGCC demonstration project: the retrofitting of the gasification unit at the Wabash River Power Plant. The system’s power generation capacity is 262 MW, with a designed power generation efficiency of 38% and a desulfurization efficiency of >98%. The project completed its commercial demonstration operation in November 1998. The IGCC power plant of Tampa Electric Company has a system capacity of 250 MW, a designed power generation efficiency of 40%, and a desulfurization efficiency of >96%; commercial demonstration operation is expected to be completed in October 2001. The Pinon Pine IGCC power generation project has a system capacity of 99 MW, with a designed power generation efficiency of 40.7%; commercial demonstration operation is expected to be completed in July 2000. Research on the key technologies of IGCC in our country has already begun, including key technologies related to the IGCC process, coal gasification, gas purification, gas turbines, and waste heat recovery systems. A 1GW demonstration power plant is planned to be built at Yantai Power Plant. (5) Coal gasification: Coal gasification technology is an important energy conversion technique, widely used in industries such as chemicals, metallurgy, machinery, building materials, and domestic gas supply. Currently, the amount of coal used for gasification across the country is around 60 million tons per year. Some advanced large-scale coal gasification technologies introduced into our country are currently in operation. In our country, small and medium-sized gasification processes mainly rely on fixed-bed coal gasification technology; this technology is outdated, inefficient, and causes significant pollution, thus there is an urgent need for technological upgrades. Some of the more advanced gasification technologies introduced also present numerous issues in terms of stable operation, localization of technical equipment, economic investment, and operational efficiency; therefore, it is necessary to develop modern gasification technologies that possess Chinese intellectual property rights, suit China’s national conditions, and are efficient and clean. Certain progress has been made in the experiments on applying underground gasification technology to the gasification of residual gas in coal mines. (VI) Coal liquefaction Coal liquefaction is an important coal conversion technology. Feasibility studies for three industrial demonstration projects on direct coal liquefaction, carried out through cooperation between China and Germany, China and Japan, and China and the United States, are currently in progress. In the China-Germany partnership, industrial-scale tests were conducted using Yunnan Pioneer lignite on the process development equipment of DMT Company in Germany, as well as tests to determine the optimal process conditions; the yield of liquefied oil reached 53% ； Condition tests were conducted on Chinese fixed-bed hydrogenation catalysts, and the results showed that this catalyst is suitable for the German IGOR process ； The feasibility study report for the demonstration plant has been completed. Direct liquefaction tests were conducted using a 1 t/d unit in Japan with Chinese Yilan coal, Chinese Xilin pyrite catalyst, and Japanese synthetic iron sulfide catalyst, yielding oil recovery rates of 52%–57%. The first phase of the feasibility study project on direct coal liquefaction using China Shenhua coal, carried out through Sino-US cooperation, has been completed. Six different test conditions were conducted on Shenhua Ningtiaota coal using HTI’s continuous pilot plant; with HTI’s technology and GelCat catalysts, an oil yield of 63%–68% was achieved ； (7) Fuel cells: With the support of UNDP, the Ministry of Science and Technology is promoting a demonstration program for fuel cell buses. (8) Flue gas purification technology: Currently, there are over 500 flue gas desulfurization units in operation around the world. And over 90% of them (based on unit capacity) use the wet flue gas desulfurization process. The semi-dry rotary spray method and in-furnace desulfurizer injection – wetting and activation desulfurization process are widely used in Europe. Fluidized bed combustion technology, which effectively controls the generation of SO2 and NOx during the combustion process, is receiving increasing attention. Japan has carried out experimental studies on using surface-heat-treated activated carbon fibers (ACF) for the desulfurization and denitrification of flue gas, achieving excellent results. . The technology for purifying flue gas using ACF belongs to the semi-dry oxidation type, and its advantages are that the desulfurization and denitrification reactions take place at room temperature, and the by-products such as sulfuric acid, sulfates, nitric acid, and nitrates can be recovered continuously. This flue gas desulfurization and denitration technology for coal-fired boilers not only exhibits high efficiency in desulfurization and denitration but also requires less water and simpler equipment; practical application research is currently underway. As air pollution in our country becomes increasingly severe, flue gas purification technologies are receiving greater attention from all sectors of society. “The \"Sino-Japanese cooperative electron beam flue gas desulfurization demonstration project\" has been in operation for a total of 2,400 hours, and passed the **completion acceptance inspection on May 28, 1998. This demonstration project handles 300,000 m3/h of flue gas from the boilers of Chengdu Power Plant’s 200MW units, and it is currently the largest electron beam desulfurization unit in operation in the world for treating such volumes of flue gas. Its desulfurization and denitrification rates both exceed the design values of 80% and 10%, respectively, while all operational consumption indicators are below the design values. In addition, the introduction of IVO Company’s combined process of in-furnace calcium injection and humidification activation from Finland, as well as Hitachi Company’s high-speed cross-flow wet process from Japan, is underway. Existing mature international technologies with high desulfurization efficiency can be useful for us to build up experience in equipment design, operation, and management once they are introduced. However, foreign technologies and equipment are expensive; therefore, it is necessary to develop and promote technologies and processes suitable for China’s national conditions, taking into account the country’s economic capabilities. Certain progress has also been made in basic research on flue gas purification technologies in China, as well as in flue gas purification technologies for small and medium-sized boilers. To improve the desulfurization efficiency of the desulfurizer, deliquescent salts and bases are added to Ca(OH)2, or combustion fly ash and hydrates of Ca(OH)2 are used as adsorbents ； Using activated coke or activated carbon as adsorbents has also yielded certain results in laboratory studies. Dust and sulfur removal systems such as the mesh tower type suitable for small and medium-sized boilers, as well as the double-click dust and sulfur removal process, have also achieved initial results. (IX) Comprehensive utilization of fly ash: In China, research and application of fly ash focus on large-scale uses, such as its incorporation into concrete for building bridges, dams, the foundations of high-rise buildings, and the containment structures of nuclear power plants. The Three Gorges Project under construction is expected to consume 1.338 million tons of fly ash. A greater extent of application lies in the construction of high-grade highways; this technology is now mature and has been utilized in the construction of highways such as those between Shanghai and Nanjing, Beijing and Shenzhen, as well as Beijing and Hebei. Fly ash is also used for land reclamation in mining areas and to improve soil in agriculture. It is estimated that by the year 2000, China’s ash emissions will reach 160 million tons; therefore, greater efforts must be made to utilize fly ash, expand its areas of use, increase the amount used, and improve the efficiency of its utilization. (10) Development and utilization of coalbed methane: Significant progress has been made in the exploration and development of coalbed methane. In 1998, 11 coalbed methane wells were drilled in the Qinsui Basin in Shanxi and the Hegang area in the northeast; wells Tunliu-003, Tunliu-006, and Tunliu-007 produced industrial-scale coalbed methane at rates of over 7,000 m3, 10,000 m3, and 16,000 m3 per day respectively, with an area containing gas resources being initially controlled at around 550 square kilometers. Exploration results indicate that the region possesses the geological conditions necessary to form large-scale coalbed methane fields. Three wells were completed in southern Shanxi, and Well Shi 1 achieved a daily production of 7,000 m3 per well. “The research work for the \"China Coalbed Methane Resources Assessment Project\" is currently in progress; studies on the six areas of Liupanshui, North China, the Three Rivers region in the Northeast, and Liaozhong have been initially completed. The final report on this project is expected to be ready by 1999. Cooperative projects for the exploration and development of coalbed methane in five areas—Huaibei, Linxing, Sanjiao, Sanjiao North, and Shilou—are being carried out in partnership with three American oil companies: TEXCO, PHILLIPS, and ARCO. The total area of the five cooperation zones is 11,216.8 km2, with a predicted coalbed methane resource volume of 653.5 billion m3. The drilling of 9 coalbed methane wells has been completed, yielding good coalbed methane data.