| Low rank coal upgrading theory, especially the microscopic description and simulation, play an important role to the low rank coal upgrading teconology development for our country and even the world. Taking Yu Zhou flame coal as the research object, experimental and numerical simulation were conducted in order to inverstigate low temperature pyrolysis mechanism. The main contents are as follows:1) Non-isothermal and isothermal experimental were explored and the results shows that reaction characteristics temperature determined by chemical reaction and the spread of the volatiles; Pyrolysis reaction of coal sample interval is 280 ℃ to 600 ℃; Heating rate, the higher the more concentrated the pyrolysis reaction of coal samples.2) TG/FTIR- GC- MS was applied and element migration map was founded for pyrolysis product orientation optimization. At 550 ℃ oxygen removal rate is 52.4 %, transfer rate to the gas and tar are 46.9 % and 5.5 %, respectively. In semi-coke, gas, tar, element carring ratios of O to C, H(O: C: H) are 1:12.81:0.76, 1:0.62:0, 1:6.81:7.66, respectively. Semi-coke, tar shows are good ingredients.3) A fluidized bed test bench was built up to inverstigate the effects of particle size, temperature and residence time on pyrolysis products’ yield and separation characteristics of semi-coke. The better particle size, residence time and temperature for drying and pyrolysis are 3 ~ 6 mm, 5 min, 240 ℃ and < 6 mm, 10 min, 550 ℃, respectively, Semicoke yield is about 72 % ~ 75 %, of which the ash content is about 17.4 %. The gas yield is 9.2 % and the tar yield is 4.4 %. Semi-coke density appeared polarized phenomen in the process of pyrolysis. The content of separation density ±0.1 is from 38.5% to 5% when the target ash content is 9 %.4) The caculation of chemical structure parameters of coal was modified and verified. Error between the predicted and experimental results was 6.6 % ~ 17.6 %, correction method is feasible, but there still has optimization space. |
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