Introduction to the ash fusion fluidized bed powder coal gasification technology
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The pressurized ash pyrolysis fluidized bed coal gasification technology developed by Shanxi Tianhe Coal Gasification Technology Co., Ltd., has been in use since the construction of an atmospheric-pressure Ф1000mm pilot plant in 1990. Industrial operations at normal pressure were carried out in Shaanxi Chengguo Fertilizer Co., Ltd. in 2001; a pressurized semi-industrial testing platform was established in 2006. In 2007, a 72-hour operation of Jincheng anthracite under 1.0 MPa pressure was completed, and a kiloton-scale industrial demonstration plant was built by Jinmei Group. In 2008, Shijiazhuang Jinsihua Fertilizer Co., Ltd. constructed an industrial plant operating at 0.6 MPa, while a 0.6 MPa industrial plant for Jinmei Group’s 100,000 t/year MTG project is currently under construction. After more than 20 years of research and development, the gray pyrolytic fluidized-bed coal gasification technology has yielded a set of gasification technologies with independent intellectual property rights. It has been put into industrial use, reaching international standards, and has won the First Prize for Scientific and Technological Progress from the Chinese Academy of Sciences, as well as awards for scientific and technological achievements during the “Eighth Five-Year Plan” period. It has also been granted invention patents (ZL 94 1 06781.5) and utility model patents (ZL 94 202278.5). The principle of the ash-melting fluidized bed powder gasification technology is shown in Figure 1, while the process flow is shown in Figure 2. http://www.meijiaohua.com/WebUpLoadFile/ArticlePhoto/2008102837363501.gif Figure 1: Schematic diagram of the working principle of the ash-melting polymerized fluidized bed powder coal gasification technology. Figure 2: Process flow diagram of the ash-melting polymerized fluidized bed powder coal gasification technology. This technology uses crushed coal as raw material, with air, oxygen-enriched air, or oxygen as oxidants, and steam or carbon dioxide as gasifying agents. The materials in the bed are in a state of bubbling fluidization at appropriate particle sizes and gas flow rates, allowing for thorough mixing between the gas and solid phases. At the high temperatures generated by partial combustion, processes such as breaking down viscosity, removing volatiles, gasification, agglomeration and separation of ash, as well as cracking and re-gasification of tar and phenols, take place. A unique gas distributor and ash agglomeration separation device cause the ash to agglomerate into balls; by utilizing differences in weight, it separates this ash from semi-coke, allowing for the continuous and selective removal of low-carbon ash. This increases the carbon content and operating temperature within the bed, thereby expanding the range of coal types that can be used, including low-activity bituminous coals and even anthracite. This gasification technology has the following characteristics: (1) It has a wide range of coal compatibility, enabling local sourcing of raw materials. (2) Dry feeding of pulverized coal and dry slag discharge, resulting in low energy consumption and low oxygen consumption. (3) The ash agglomerates into balls, allowing for selective separation from semi-coke, and the carbon content in the discharged ash is low. (4) No exhaust gas emissions; the gas contains no tar or volatile phenols, and the washing water is easy to purify. (5) It operates at a moderate temperature, has low operational and maintenance costs, and offers high reliability. (6) Independent intellectual property rights, with investment amounting to only 40%–50% of that for imported gasification technologies.
Industrial demonstration unit for pressurized ash fusion fluidized bed pulverized coal gasification: China’s first such industrial demonstration unit was recently able to complete a 76-hour trial operation at Shijiazhuang Jinshi Petrochemical Fertilizer Co., Ltd. The core gasification system operated smoothly, and the high-quality gas produced was fed into the ammonia synthesis process. After further improvements to its supporting facilities, this setup will be put into trial production. This marks the entry of China’s independently developed gray fused-bed gasification technology into the stage of large-scale commercial demonstration. The commercial demonstration of large-scale, pressurized versions of the gray fusion fluidized bed gasification technology, which relies on independent intellectual property, will provide reliable technical support for the rapidly developing coal chemical industry. The inner diameter of the gasification furnace in this core unit is 2.4 meters, with an operating pressure of 0.6 Mpa. Each furnace can process 324 tons of Jincheng anthracite per day, producing 26,000 Nm3/h of dry gas, and it is designed to support an ammonia synthesis capacity of 60,000 tons per year. After a year and a half of intensive design and construction work, the air separation unit was successfully commissioned on June 25, 2008, producing qualified oxygen and nitrogen products ； On July 21, the gasification unit was ignited for furnace heating, marking the basic completion of the construction and installation work for this project ； Hot-state commissioning began on August 12, and feeding trials were completed on September 5. Gasification technology is the core technology for the efficient and clean utilization of coal. Among them, the ash-melting fluidized bed pulverized coal gasification technology is particularly suitable for China’s characteristic of a wide variety of coal types. Since the 1980s, the Shanxi Coal Chemistry Institute of the Chinese Academy of Sciences has been working on the development of ash-polymerized fluidized-bed pulverized coal gasification technology, and in 2001 it completed an industrial demonstration of an atmospheric-pressure system at a fertilizer plant in Chengguo, Shaanxi. In 2005, with strong support from the Shanxi Provincial Development and Reform Commission, the Shanxi Coal Chemistry Institute and Jinmei Group jointly established the Shanxi Pulverized Coal Gasification Engineering Research Center to develop pressurized ash-polymerized fluidized bed pulverized coal gasification technology. In 2007, a 3.0 MPa semi-industrial pressurization technology platform was established, and a 72-hour test under 1.0 MPa pressure was completed. The successful commissioning of the 0.6MPa pressurized industrial demonstration unit represents another significant advancement in the scaling up and industrial application of the ash fusion fluidized bed gasification technology.
Are there any other manufacturers that have industrial demonstration units for pressurized ash fusion fluidized bed powder gasification? I hope friends can let me know. Thank you
What is the particle size of the coal powder used in the gray fusion fluidized bed? Under such a process, could the outlets for semi-coke and other gas products get clogged easily? This is a crucial factor that affects the proper operation of the gasification furnace.
When will the 0.6MPa industrial plant of Jinmei Group’s 100,000 t/a MTG project begin trial operation?