研究烟煤热解中胶质体孔结构的演化对于调控煤基炭材料的孔结构具有重要意义。选用三种不同变质程度的烟煤富集镜质组热解至流动度特征温度点(软化温度(tp)、最大流动温度(tm)、固化温度(tk)),采用氮气吸附法研究胶质体焦样的气孔结构特征,分析气孔结构的演化行为。结果表明:三种不同变质程度的烟煤镜质组热解特征温度点胶质体焦样的吸附-脱附曲线均为Ⅲ型吸附等温线且有滞后环;镜质组热解中胶质体焦样的比表面积先增大后减小,且生成阶段比表面积的变化速率小于收缩固化阶段的变化速率;随着热解中特征温度升高,低变质程度的唐口气煤(TK)镜质组胶质体中气孔先生长、孔径变大然后气孔融并贯通形成中孔与大孔,中等变质程度的霍州肥煤(HZ)镜质组胶质体中逐渐形成大量微孔,比表面积高达5.97m2/g,然后微孔融并贯通形成中孔或较大孔,高变质程度的斯凯拉斯焦煤(SK)镜质组胶质体中先形成较多的中孔或大孔(平均孔径达到13.93nm)后收缩为小气孔。

It is of great significance for regulating the pore structure of coal-based carbon  materials to investigate the pore structure evolution in metaplast during the pyrolysis of bituminous  coals.  In this study, three kinds of bituminous coals with different metamorphic degrees, enriched in  vitrinite, were pyrolyzed to their characteristic temperatures point (softening temperature,t ; maxi‐ mum fluidity temperature,t , and solidification temperature,t ).  Nitrogen adsorption method was  used to investigate the evolution behaviors of pore structure for the metaplast.  The results show that  the isothermal adsorption-desorption curves of the metaplast derived from vitrinites in three kinds of  bituminous coals with different metamorphic degrees at the characteristic temperature are of  type-III, with a hysteresis loop. During the pyrolysis of vitrinite, the specific surface area of the metaplast ini‐ tially increases and then decreases, with the rate of change in the generation phase being slower than  that in the shrinkage and solidification phase. As the characteristic temperature in the pyrolysis process  increases, the vitrinite in the low-metamorphic-degree Tangkou gas coal (TK) initially exhibites pore  growth and pore enlargement, followed by pore merging and interconnection, forming mesopores and  macropores.  In the medium-metamorphic-degree Huozhou fat coal (HZ), a large number of micro‐ pores gradually formed in the vitrinite, with a specific surface area as high as 5. 97 m /g, followed by  merging and interconnection of the micropores into mesopores or larger pores.  However, In the high- metamorphic-degree Scarlat coking coal (SK), the vitrinites first formed more mesopores or macro‐ pores, with an average pore diameter of 13. 93 nm, and then shrank into smaller pores.