Pyrolysis Characteristics Of Shendong Coal Of Ethnol-Hexance Swlloen/Extraction

Coal pyrolysis is the initial and necessary stage in coal conversion,the coal pretreatment and coal pyrolysis had an organic combination so as to invesigate the coal pyrolysis process more comprehensive.The Shendong low rank bituminous coal was investigated in this study,hexane and ethnol were pretreat solvents,TG-FTIR and the improved Steel steamer retort were used to investigate the pyrolysis characteristics of the two kinds different pretreatment coals,research the thermal weight loss and the resolved gases of different pretreated coals,separate the coal tar get the light and heavy components with hexane.Used GC-MS,TG-FTIR,FTIR to have a comprehensive test of the coal tar.In addition,pyrolysis kinetics of different pretreated coals were calculated by the method of Coats-Redfern on the basis of TG experiment.And the main conclusions are as follows:1)By the pretreatment of hexane-ethnol solvent swelling and Soxhlot extraction,the wavenumber at 3405cm-1 have the stretching vibration of-OH and the absorption peak intensity is weaker than the SD demineralied coal,in addition,the position move to low wavenumber,indicating that there might be a hydrogen bond rupture.The C-O stretching vibration at 1086 and 1045 cm-1 disappeared after the hexane-ethnol pretreatment,which indicates the C-O...bond might also have a rupture.2)The final weightlessness of ethnol-hexane swollen coals are higher than SD demineralied coal and the final weightlessness of ethnol-hexane Soxhlot extraction coal is lower than SD demineralied coal.Take hexane swollen coal as an example,with the increasing of heating rate,the temperature of the thermal maximum weight loss rate moves to the high temperature side with the increase of temperature,however,the tendency is not obvious than SD demineralied coal;As for the resolved gases,it also moves to the high temperature side.3)Hexane/Ethnol/Hexane-Ethnol Soxhlot extraction mainly are aliphatic and aromatic hydrocarbons and heteroatom compounds.The heteroatom compounds are mainly oxygen containing compounds and nitrogen compounds;The aliphatic hydrocarbons and oxygen containing compounds accounts for majorities in hexane Soxhlot extraction,ethnol and hexane-ethnol Soxhlot extraction,respectively.4)The hexane solubles of coal tar(CTHS)is mainly aliphatic hydrocarbons,the hexane insolubles of coal tar(CTHIS)is similar to coal tar pitch,it weightlessness is caused by the fracture and aggregation of the molecules produced small molecular weight compounds and gases during the pyrolysis.CTHIS begins weightlessness at 97 ? and almost stops weightlessness at 620?,with the increasing of temperature,the CTHIS easily volatiled or broken into small skeleton and gases such as carbon monoxide,carbon dioxide and methane.The CTHIS of ethnol-hexane swollen coals>DC CTHIS>the CTHIS of ethnol-hexane Soxhlot extraction resdiue coal;In addition,the temperature of the highest weighlessness of ethnol-hexane Soxhlot extraction resdiue coals is higher than that of ethnol-hexane swollen coals.5)During the pyrolysis of ethnol-hexane swlloen coals,the polycondensation of crosslinking network with small molecules reduced and small moleculars phase out easily.While ethnol-hexane Soxhlot extraction residue coals dissolved part of low molecular compounds,reduced the number of activity of hydrogen,make it unavailable to stable the coal free radicals fragments,which resulted in the increased polycondensation reaction;What's more,the coal molecular weight will be larger,and the pyrolysis tar will be generated in a larger molecular weight of heavy components because of the extraction of the Soxhlot.6)According to the first reaction kinetic model,used the Coats-Redfern Integration,the ethnol-hexane swollen could decreased the activation energy during 400-450? and 650-750?compared with the Shendong demineralied coal,while the activation energy of ethnol-hexane Soxhlot extraction resdiue coals increased and need more energy,which illustrate the ethnol-hexane Soxhlot extraction have important infulence during the coal pyrolysis.