Key Technological Innovations and Applications in Large-Scale and High-Efficiency Water-Coal Slurry Gasification: From Introduction to Export

Thread Content

Key Technological Innovations and Applications in Large-Scale, High-Efficiency Water-Coal Slurry Gasification: From Introduction to Exportation. Author/Source: Sinochem New Network. Date: 2019-07-26. Clicks: 3. The multi-nozzle opposed water-coal slurry gasification technology developed independently in China has become one of the preferred options for gasification technologies in coal chemical plants. The project on key technology innovation and application for large-scale high-efficiency water-coal slurry gasification, carried out in collaboration between East China University of Science and Technology and Yankuang Group, won the **Second Prize for Scientific and Technological Progress in 2016. At present, this autonomous technology has successfully gone global, marking a shift in China’s coal gasification technology from import to export. 　　Gasification technology is an important component of clean coal utilization technologies. Coal conversion technologies based on gasification transform coal into fuels and chemicals, thereby reducing conventional coal emissions as well as dependence on imported oil and natural gas. However, over 20 years ago, large-scale gasification technology was monopolized by foreign companies, and developing such technology with independent intellectual property rights has been the aspiration of several generations in China’s coal chemical industry. 　　In 2005, the Clean Coal Technology Institute of East China University of Science and Technology successfully developed a multi-nozzle opposed water-coal slurry gasification technology with independent intellectual property rights in China, breaking the long-term foreign monopoly. However, the coal-water slurry gasification technology developed at that time faced technical and engineering challenges such as small scale per furnace, short lifespan of key equipment, poor operational stability, and the need to improve gasification efficiency; there was an urgent need for upgrades and innovations in these key technologies. 　　With the support of scientific and technological programs such as \"973\" and \"863\", East China University of Science and Technology, Yankuang Guotai Chemical Co., Ltd., and Yankuang Lunan Fertilizer Plant carried out joint research on multi-nozzle opposed water-coal slurry gasification technology. After more than 10 years of effort, they overcame key technical barriers related to the large-scale implementation, high efficiency, and long-term stable operation of this technology. As a result, a world-leading set of advanced technologies for water-coal slurry gasification was developed, breaking the monopoly of large multinational companies such as GE and Shell in this field. This represents a milestone in the development of coal gasification technology in China. 　　While developing large-scale gasification technologies, the construction of demonstration units is also in full swing. On June 24, 2014, the world’s largest coal gasification plant at that time, capable of processing 3,000 tons of coal per day per furnace, was officially put into operation at Inner Mongolia Rongxin Chemical Co., Ltd. The effective gas components in the syngas produced by this plant exceeded the specified standards by 1.2%; its oxygen consumption and coal consumption were lower than the specified values by 2.9% and 6.8%, respectively, with a carbon conversion rate of over 99%. The successful commissioning of this project marks a new milestone for the multi-nozzle opposed water-coal slurry gasification technology. 　　This demonstration unit passed the evaluation of scientific and technological achievements organized by the China Petroleum and Chemical Industry Federation in December 2016. The appraisal committee, composed of 13 experts including 2 academicians, concluded that the overall technical parameters of this achievement are at the international leading level, maintaining the dominant position of the multi-nozzle opposed water-coal slurry gasification technology among similar gasification technologies worldwide. 　　Compared with the performance results of gasification units with a daily processing capacity of 2,000 tons per furnace, the carbon conversion rate of the 3,000-ton-per-furnace units increased from 99.2% to 99.63%, while the cold gas efficiency improved from 74.5% to 75.2%. Under high-load operating conditions, the gasification process exhibits superior performance compared to similar technologies; the gasification unit is safe and reliable, features a high degree of automation, offers flexible operation control, and its advantages at larger scales are even more pronounced. 　　From the initial development of proprietary technologies to the demonstration operation of large-scale industrial installations, the multi-nozzle opposed water-coal slurry gasification technology has undergone over 20 years of development, refinement, engineering application, and scale-up. Ultimately, its excellent technical performance has attracted widespread attention worldwide, making it one of the preferred gasification technologies for coal chemical plants. Compared with international advanced technologies, this technology increases the effective gas composition by 3 percentage points, raises the carbon conversion rate by about 4 percentage points, reduces oxygen consumption by 10.2%, and reduces coal consumption by 2.1%, achieving internationally leading technical performance. Currently, all coal-water slurry gasification units in China with a single furnace processing capacity of over 2,000 tons per day utilize this technology. 　　At present, a demonstration unit for water-coal slurry gasification technology with a daily coal processing capacity of 4,000 tons is also under construction. On April 24, 2019, the High-Tech Research and Development Center of the Ministry of Science and Technology organized an expert team to conduct a mid-term inspection of the demonstration facility. As the project developer, Rongxin Chemical focused on researching key parameters such as the flame structure, temperature distribution, and particle behavior within the gasifier during the project implementation phase. It completed the installation of the main equipment for the multi-nozzle opposed water-coal slurry gasifier with a daily coal processing capacity of 4,000 tons, along with related systems. 　　Meng Xiangjun, the chief engineer in charge of Yankuang Group, the lead entity of the project, said that the project has already achieved 7 interim results. First, new types of refractory materials for gasifiers were developed; second, research was conducted on the radiation properties of fly ash; third, a testing platform for the viscosity-temperature characteristics of coal ash slags under high-temperature steam conditions was established; fourth, a coupled reaction network model for the gasification process based on coal quality was initially developed; fifth, the process package for an industrial demonstration unit using multi-nozzle opposed-type water-coal slurry gasification technology with a capacity of 4,000 tons of coal per day was prepared; sixth, the process package for an industrial demonstration unit using waste boiler quenching-type water-coal slurry gasification technology with a capacity of 2,000 tons of coal per day was developed; seventh, the installation of the main equipment for the multi-nozzle opposed-type water-coal slurry gasifier and related systems with a capacity of 4,000 tons of coal per day was completed. 　　To date, the multi-nozzle gasification technology jointly developed by Yankuang Group and East China University of Science and Technology has been licensed to 57 users both domestically and internationally, resulting in a total of 158 gasification units. This technology has yielded significant economic, environmental, and social benefits, while also raising the technical level and international competitiveness of China’s modern coal chemical industry.