Abstract: The traditional coal utilization way has a series of disadvantages such as high pollution, high emission and high energy consumption. Supercritical water gasification technology, based on the concept of ordered energy conversion, provides a clean, low-carbon and efficient way of coal utilization owing to the unique physical and chemical properties of supercritical water. For technical application, mild gasification temperature can effectively reduce investment and energy consumption, but it also causes lower reaction driving force. Therefore, the method of resistance analogy analyze was used in this paper to find reasonable regulation methods to achieve the optimal matching of heat transfer, mass transfer and chemical reaction, so as to realize comprehensive resistance reduction. The research was carried out from three aspects: the enhancement of main reaction, the inhibition of side reaction and the coordination of multiple reactions. Firstly, the rate-determining step of gasification process was found, and the method of liquid residual recycle was proposed to increase the free radical concentration at the reactor bottom to promote the gasification of polycyclic aromatic hydrocarbons. Then, based on the obtained drag, heat transfer and diffusion equations, the methods of controlling the nozzle heat flow boundary, adjusting the injection angle and designing the swirl distributor were proposed, which effectively restrain the side reaction in the nozzle and the reactor bottom. Finally, the heat match was conducted for the whole reactor based on the accurate kinetic model, which avoided overheating and reduced the heat transfer resistance. Based on the above optimization methods, a demonstration plant was constructed, where more than ten typical coals in China were completely gasified under mild temperature.

Biography: Hui Jin, Born in 1982, Full professor since 2018 in Xi'an Jiaotong University. He focuses on the supercritical water gasification process and its large scale utilization. He has published more than 100 paper with more than 3800 citations, 14 papers were indexed as ESI paper, and 3 papers were indexed as hot papers. He also has public or authorized 27 patents. Serve as editorial board member of Carbon Resources Conversion, Carbon Capture Science & Technology, and Guest editor in ACS Sustainable Chemistry & Engineering, Renewable Energy, Sustainable Energy Technologies and Assessments, International Journal of Hydrogen Energy, Journal of Renewable Materials. He was awarded by the first prize of science and technology of Shaanxi Province, 2014.