褐煤孔隙结构及比表面积特征

为揭示褐煤孔隙结构及比表面特征，选取全国主要褐煤产地样品，进行煤岩显微组分含量测定和低温氮吸附实验，从吸附曲线形态、比表面积、孔径结构分布刻画煤储层微孔隙特征，探讨孔径结构与比表面积的关系，分析BET比表面积与煤岩显微组分的相关性。结果表明:褐煤低温液氮曲线形态大致可以分为无吸附回线、有拐点的吸附回线和无拐点的吸附回线3类；BET比表面积随BJH总孔体积的增加呈线性增加趋势，在2~10 nm范围内的孔径和比表面积关系可以分为正相关、负相关和复合相关3种；显微组分组和比表面积的相关性较弱，但比表面积与细屑体含量具有较好的线性关系。 

Characteristics of pore structure and specific surface area of lignite

In order to reveal the characters of lignite pore structure and specific surface area, samples were collected from the major lignite-producing areas in China, the measurement of maceral content and the low temperature nitrogen adsorption test were conducted, the micropore characteristics of coal reservoir were described from the form of adsorption curves, specific surface area and distribution of aperture configuration, the relationship between pore structure and specific surface area was discussed, the correlation of BET specific surface area and marcerals was analyzed. The results showed that the tracing patterns of low temperature liquified nitrogen adsorption of lignite samples could be roughly classified into three kinds:loop without adsorption, adsorption loop with turning point and adsorption loop without turning point. BET specific surface area showed the trend of linear increases with total pore volume. In the range of 2 to 10 nm, the relationship of specific surface area and aperture could be positively correlated, negatively correlated and compoundly correlated. The correlation of maceral group and specific surface area was weaker, but specific surface area and attrinite content had good linear correlation.