Coiled flow coal gasification is the core technology for efficient and clean utilization of coal. It is widely used in coal-based bulk chemicals (methanol, ethylene glycol, olefins, etc.), coal-based clean fuels (direct and indirect coal liquefaction, SNG, etc.), synthetic ammonia, Process industries such as hydrogen production, IGCC power generation and direct reduction ironmaking are the core and key technologies of these industries. In recent years, the entrained flow coal gasification process has developed in the direction of ultra-large, efficient and clean, posing new challenges to related basic research and engineering development.
This project received the 973 plan (2004-2014), with the support of the National 863 Plan, the Yangtze River Scholars and Innovation Team Development Plan of the Ministry of Education and the Shanghai City Major Science and Technology Plan, more than 40 scientific researchers from relevant units spent 10 years solving the scientific problem of interaction between multiphase flow and complex gasification reactions in the gasifier under conditions of high temperature, high pressure, and turbulent multiphase flow, established a mathematical model of the entrained flow coal gasification process, and obtained the scale-up basis for entrained flow coal gasification technology. The main technological innovation achievements include:
(1) The mechanism of coal gasification reaction at high temperature and high pressure was revealed, the change behaviors of the composition, fusibility and viscosity of minerals in coal under gasification conditions and their influence on coal char gasification activity were obtained, and the apparent gasification process was constructed to describe the gasification process. The kinetic model laid the foundation for establishing a mathematical model of the gasifier.
(2) The characteristics of the flow field and the deviation laws of the stagnation points of the impinging stream of the multi-nozzle opposed gasifier were revealed; the flow instability of the impinging stream was discovered, and the flow field shapes and impact surface oscillation laws of the axisymmetric impinging stream and the plane impinging stream were obtained; A particle residence time distribution model in an entrained flow gasifier was established. It provides criteria for the large-scale multi-nozzle opposed gasifier, and provides theoretical guidance for operation optimization and stable operation.
(3) A method to quantitatively characterize the height of the jet diffusion flame through the spatial distribution of excited free radical radiation was established, a high-resolution ultraviolet imaging system for the flame was developed, and the three-dimensional temperature field and flame structure in the gasifier were obtained. The macro and microstructure, particle morphology, behavioral characteristics and transformation laws of particulate matter in the furnace were obtained. It provides theoretical support for the structural optimization of the multi-nozzle opposed coal-water slurry gasifier, becomes the main criterion for the large-scale multi-nozzle opposed coal-water slurry gasifier, and significantly improves the life of the gasifier refractory bricks and nozzles.
(4) Based on detailed models of physical properties, atomization and dispersion, reaction kinetics, heat and mass transfer, and particle and slag behavior, a three-dimensional steady-state model of the entrained flow coal gasification process was established, and the multi-nozzle opposed coal-water slurry gasifier was optimized and simulated; Based on the regional model of the entrained flow coal gasification process, a downgraded model of the multi-nozzle opposed gasifier was established, laying a foundation for dynamic simulation of the gasifier. The simulation results optimize the process conditions of the gasifier and provide theoretical guidance for achieving long-term stable operation.
It has authorized 10 invention patents (2 U.S. patents), published 102 SCI papers and 77 EI papers, was cited 1001 times, and published 2 monographs. The scientific and technological novelty search report of authoritative national departments, expert opinions on the acceptance of the National 973 Project, the evaluation certificate of China Petroleum and Chemical Industry Federation, the evaluation certificate of China Chemical Industry Society, and the user application report all pointed out that the research results of this project are internationally leading and innovative in aspects such as coal gasification reaction mechanism, impinging jet in the furnace, impinging flame structure, and multi-nozzle gasifier simulation.
The results of this project have been applied to 18 domestic enterprises, promoting the further large-scale expansion of the entrained flow coal slurry gasification technology with independent intellectual property rights, promoting the widespread promotion and application of the technology, and supporting the long-term stable operation of entrained flow coal gasification., the world's largest coal slurry gasification unit has been built (A single furnace processes 3000 tons of coal per day), which plays an important role in the development of my country's high-efficiency and clean coal conversion industry. In three years, the new output value has exceeded 18 billion yuan, and the new profits and taxes have exceeded 4.1 billion yuan, saving enterprises 430 million yuan., saving patent fees of 155 million yuan, producing good economic and social benefits.