Products characteristics and char gasification reactivity of Naomaohu coal hydropyrolysis
The pyrolysis experiments of Naomaohu coal(NMH)at atmospheric pressure and 1.5 MPa H2and N2 were carried out in a pres-surized fixed-bed reactor.The products yield and composition and char structure under H2 and N2 were comparatively investigated by vari-ous characterization methods.The CO2 gasification reactivity of char was studied by a thermogravimetric analyzer.The results indicate that pyrolysis of coal in pressurized H2 can effectively increase the yield of CH4 and C2-C3,from 53.5 and 16.6 mL/g in atmospheric N2 to 345.6 and 20.8 mL/g in pressurized H2,respectively,during the coal pyrolysis at 800 ℃.Tar yield and quality is also effectively im-proved.Compared coal pyrolysis at 600 ℃ under 1.5 MPa H2 with that under atmospheric pressure N2,the tar yield increases from 19.3％to 22.8％,the aliphatic hydrocarbon content decreases from 35.5％to 14.8％,the monocyclic aromatic hydrocarbon content increases from 8.3％to 28.9％,and the light tar content and yield increases to 95％and 21.8％,respectively.The results of N2 adsorption and Raman spectroscopy show that the specific surface area and pore volume of the char in pressurized hydropyrolysis increase from 40 m2/g and 0.05 cm3/g in atmospheric N2to 289 m2/g and 0.16 cm3/g,and the pore structure is significantly developed.This is beneficial to the CO2 gasification reaction of char.The graphitization degree and the proportion of large aromatic ring increase,which is not conducive to the gasification reaction of char.The thermogravimetric analysis results show that the gasification reactivity of char from pressurized hydro-pyrolysis is significantly higher,which indicates that pore structure plays a main role in the influence on the CO2 gasification reactivity of the char.
万方数据
维普
