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It is necessary to research thoroughly on the pyrolysis process of Zhundong lignite coal, in order to simplify the preparation process of activated coke, cut the production cost and improve the utilization of the lignite coal. The pyrolysis characteristics of Zhundong lignite coal were investigated by thermos-gravimetric analysis (TGA) at different heating rates of 10, 20, 30, 40 and 50 °C/min. Meanwhile, two kinds of activated carbons (SC1 and SC2) were respectively prepared at 800 °C by rapid-pyrolysis and temperature-programmed pyrolysis. To obtain the information of char on pore structure parameters, organic functional groups and carbon skeleton structures, the chars were characterized by BET, FT-IR and Raman. Results showed that the variation range of activation energy and pre-exponential factor were 38.89-229.13 kJ/mol and 108.26-1. 18×109 s-1, which were analyzed by TGA data for the pyrolysis of Zhundong lignite coal. The efficiency energy was transmitted to promote the decomposition of organic molecules and produce a large amount of volatile during the pyrolysis process with a heating rate of 30 °C/min. Simultaneously, a reasonable temperature gradient inside the coal char prevented the pore structure blocking caused by thermal condensation reaction. Also, the smooth release of volatiles promoted the formation of pore structure. The char produced by temperature programmed pyrolysis had the specific surface area of 312. 91 m2/g, average pore volume of 0.178 cm3/g and average pore size of 2. 271 nm at a burning-off rate of 46. 5%. The char produced by rapid-pyrolysis had the specific surface area of 424.25 m2/g, average pore volume of 0.189 cm3/g and average pore size of 2. 342 nm at a burning-off rate of 37.3%. A large number of amorphous structures and defect structures were generated in precursor char during the rapid-pyrolysis process, which were conducive to the construction of microporous pore structure at activation stage. [ABSTRACT FROM AUTHOR]

The powder coke was obtained by three methods: carbonization, carbonization followed by activation（ twostep method） and simultaneous carbonization activation（ one-step method）, respectively, under the condition of simulated coal-fired hot gas in a drop-tube reactor. The biggest advantage of using the one-step method was that it can greatly simplify the process, and the investment were significantly reduced comparing with the other two methods. The active cokes obtained by three different methods were used to explore the adsorption property of Hg0, further, the effects of O2, SO2 and SO2+O2 on Hg0 removal efficiency were examined in flue gas. Besides, the desorption of Hg0 was explored and the regeneration experiments conducted under microwave and thermal methods were investigated. The results indicate that the active coke prepared by the one-step method has a large specific surface area, microporous specific surface area and abundant CO functional groups, thus has a better Hg0 removal efficiency than that of the other two methods, and the adsorption capacity was 6. 53, 3. 62 and 5. 41 μg/g in 3 h, respectively. The O2 provided reactive oxygen sites on the surface of the active coke, promoting the adsorption of Hg0 on the surface of the active coke. However, the SO2 exhibited effect on Hg0 removal due to the competitive adsorption between the SO2 and Hg0 on the active coke. Interestingly, the SO42-with strong oxidation ability would be formed when the O2 and SO2 were injected into the reactor simultaneously, which greatly promoted the chemical adsorption of Hg0. Furthermore, the spent active coke was desorption completely within 15 min by microwave, and its desorption rate was higher than that in high temperature condition. Secondary adsorption for the active coke was performed after the high temperature and microwave desorption, and the adsorption capacity after microwave desorption was remarkably improved comparing with thermal methods, where the adsorption amounts of 5. 962 and 7. 280 μg/g in 3 h were achieved. The reason was that microwave could reactivate the active coke and promote the formation of micropores in the microwave desorption process. [ABSTRACT FROM AUTHOR]