【作者】 田誉娇；

【导师】 秦志宏；

【作者基本信息】 中国矿业大学 ， 化学工艺， 2013， 博士

【摘要】 以煤全组分族分离所获得的四大族组分为原料ˋ考察了它们经炭化生成中间相的可能性ˋ分析了沥青质组分成为中间相小球体源质的内在原因以该源质为原料ˋ通过常规热缩聚反应制备了碳质中间相小球体及体中间相ˋ考察了炭化温度炭化恒温时间升温速率和N₂流速对中间相形成过程的影响ˋ确定了较佳工艺条件ˋ探讨了中间相小球体的演变规律采用溶剂萃取法从中间相中分离出炭微球τMCMB并进行了粒度分布和微晶结构等表征通过KOH活化法制备了活性中间相炭微球τAMCMBˋ考察了碱炭比活化温度和活化停留时间对AMCMB的孔结构比表面积及收率的影响ˋ并用碘吸附值测定了AMCMB的吸附性能结果表明炭化反应温度450oC恒温时间4h升温速率4oC/min N₂流速为100cm³/min是源质制备中间相的较佳工艺条件ˋ此时可制备出可溶性中间相含量高达41.3%的广域流线型体中间相经分离得到的MCMB球形度普遍较好ˋ球体表面非常光滑ˋ粒度分布多数集中在10²0m CMB含有类似石墨结构的微晶ˋ结晶度较大ˋ晶格排列规整有序ˋ择优取向性好制备AMCMB的较佳工艺条件为碱炭比5:1ˋ活化停留时间1hˋ活化温度900oCˋ此时AMCMB的比表面积可高达2636.5cm²/gˋ碘吸附值达到2616mg/g在较佳工艺条件下ˋ中间相小球体在恒温0.5h¹h时开始出现恒温2h内的各时间点均有小球体存在ˋ但粒径分布不均其中大粒径的小球体随恒温时间延长直径增加至恒温反应4h后形成排列有序的体中间相不同恒温时间的炭化产物中都含有大量的多核稠环芳烃和类似石墨结构的微晶随恒温时间延长ˋ结晶度呈增大趋势ˋd₀₀₂逐渐减小ˋ而L_c与L_a均增加同时族组分HS与HI-TS含量逐渐减少ˋTI-QS与QI含量增加软化点与真密度也逐渐升高提出基于源质的煤基中间相生成新理论基核球包并合理论ˋ认为中间相的形成过程包括5个步骤常温源质颗粒的形成小球体基核的生成基核的转移与聚集形成球包基核球包的融合与长大及球包并合形成小球体ˋ并利用该理论对源质炭化形成中间相小球体及最终形成体中间相的过程进行了合理解释更多还原

【Abstract】 The possibility of mesophase generated by carbonization was investigated based on theraw materials of the four groups by the group separation of coal components, and theunderlying reasons of the asphaltene component which becomes the source material of themesophase spherule were analysed. The carbonaceous mesophase spherule and bulkmesophase were prepared from the raw material of the source material by the common thermalpolycondensation reaction. The effect of the factors that included carbonization temperature,carbonization holding time, heating rate and N₂flow rate on the formation process wereinvestigated. Afterwards, the optimum process conditions were determined and the evolutionlaws of the mesophase spherule were explored. Mesocarbon microbeads （MCMB） wereseparated from mesophase using a solvent extraction method and the particle size distribution,microcrystalline structure, etc. were characterizated. Activated mesocarbon microbeads（AMCMB） were prepared by KOH activation method and the effects of alkali-carbon ratio,activation temperature and activation holding time on holes structure, specific surface areasand yields of AMCMB were investigated, and the adsorption properties of AMCMB weremeasured by iodine adsorption value.The results show that the optimum process conditions of the source material to preparemesophase are the carbonization reaction temperature at450oC, holding time up to4h, theheating rate of4oC/min and100cm³/min of N₂flow rate. At this time, wide area streamlinedmesophase can be prepared with the soluble mesophase contents as high as41.3%. MCMBobtained by separating possess generally preferable sphericity with a very smooth surface andthe particles size distribution mostly are concentrated in the10²0m and MCMB contain agraphite-like structure of the microcrystalline with relatively large degree of crystallinity, thestructure of orderly lattice arrangement and the preferred orientation. At the optimum processconditions which are alkali-carbon ratio at5:1, activation holding time for1h and activationtemperature at900oC, the specific surface area of the prepared AMCMB is up to2636.5cm²/g,and iodine adsorption value reach2616mg/g.Under the optimum process conditions, mesophase spherules begin to appear during theholding time at0.5h¹h and spherules existe at each time point when holding time at2h withuneven distribution of particles size, wherein the diameter of the spherules with large particlesize increase with the holding time prolonged and the orderly arrangement of the bulkmesophase is formed until the holding time for4h. Carbonized products at different holdingtime contain a large number of polynuclear condensed aromatics and microcrystalline graphite-like structure. With the holding time extended, the degree of crystallinity tends toincrease,d₀₀₂gradually decreases, andL_c andL_a both increase. HS and HI-TS contents ofthe group components decrease gradually, TI-QS and QI contents, softening point and the truedensity gradually increase.A new theory called “Based nuclears-spherical inclusions coalescence” is proposed on thebasis of the coal-based mesophase formation from source material. The mesophase formationprocess includes five steps that are formation of the source material particles at roomtemperature, generation of the based nuclears of spherules, transfer and aggregation of thebased nuclears to form spherical inclusions, integration and growth of the spherical inclusionsand coalescence of the spherical inclusions to form spherules. This theory presents a reasonableexplanation to the formation processes of mesophase spherules and ultimate bulk mesophaseby carbonization of source material.更多还原