通过低温干燥法脱除一种褐煤中的水分，并采用低场核磁共振、傅里叶变换红外光谱、物理吸附和扫描电镜等方法对脱水过程中褐煤中水分的赋存状态、褐煤的化学组成、表面孔结构及微观形貌等特征进行了表征，结合脱水前后褐煤在煤/油加氢共炼过程中转化率的变化情况，深入了解褐煤中水分对褐煤理化结构和加氢转化性能的影响。研究结果表明，褐煤中水分的脱除分为2个阶段，第1个阶段为准稳态干燥阶段，水分基本脱除，且脱除速度较快;第2个阶段为降速干燥阶段，水分的脱除量较小。该褐煤中的水分存在不冻水、吸附水、颗粒间水和自由水4种赋存状态，其中吸附水与不冻水占绝大比例，在准稳态干燥阶段较易脱除，剩余水分更多地存在于褐煤的微孔中，且自由度不断降低。通过低温干燥，褐煤中水分质量分数降低，C/H原子增加，煤的高位发热量增加程度较大，表明脱水过程对褐煤具有明显的提质效果。脱水后褐煤的固定碳与挥发分质量比、表面官能团种类基本不变，表明脱水过程对褐煤分子结构影响较小。然而，随着脱水程度的提高，褐煤更易破碎，平均孔径逐渐减小，BET比表面积和孔容逐渐增加，均在低温干燥两个阶段的分界处达到极值。此外，水分的脱除可明显提高褐煤在煤/油加氢共炼反应中的转化率和油收率，与未脱水时的褐煤(水分质量分数为15.65%)相比，水分质量分数降低至0.52%时褐煤的转化率提高了12.82%，油收率提高了11.79%，在此过程中，吸附水与不冻水为主要脱除组分，颗粒间水和自由水质量分数以及褐煤分子结构基本不变，说明褐煤中的吸附水与不冻水是影响褐煤加氢转化的重要组分。

In this study,the moisture in a lignite was removed by low-temperature drying method,and the state of mois- ture in lignite,the chemical composition of lignite,the characteristics of surface pore structure and micro-morphology during dehydration were studied by low field nuclear magnetic resonance, Fourier-transform infrared spectroscopy, physical adsorption and scanning electron microscopy. Combined with the change of conversion rate of lignite in coal /oil hydrogenation and co-refining process before and after dehydration,the effects of moisture in lignite on the physical and chemical structure of lignite and hydro-conversion performance were further understood. The results show that the removal of moisture in lignite is divided into two stages. The first stage is the quasi-steady-state drying stage,the water is basically removed,and the removal speed is faster. The second stage is the slow-down drying stage,the amount of re- moval is small. The water in the lignite has four states:non-freezing water,adsorbed water,inter-particle water and free water. The adsorbed water and the non-freezing water account for a large proportion,and are easily removed during the quasi-steady-state drying stage,and the remaining water more presents in the pores of lignite and the degree of freedom is decreasing. Through low-temperature drying,the moisture content in lignite is reduced,the C / H atom is increased, and the high calorific value of coal is increased to a large extent,indicating that the dehydration process has an obvious improving effect on lignite. After dehydration,the mass ratio of fixed carbon to volatile matter and the type of surface functional group of lignite are basically unchanged,indicating that the dehydration process has little effect on the mo- lecular structure of lignite. However,with the increase of dehydration degree,lignite is more easily broken,the average pore diameter is gradually decreased,the BET specific surface area and pore volume are gradually increased,and the extreme values are reached at the boundary between the two stages of low temperature drying. In addition,the removal of moisture can significantly improve the conversion rate and oil yield of lignite in the coal / oil hydro-treating reaction, compared with the lignite without dehydration (The moisture content is 15. 65% ),the conversion of lignite increases by 12. 82% when the moisture content is reduced to 0. 52% ,the oil yield increases by 11. 79% . In this process,the adsorbed water and the non-freezing water are the main removal components,the inter-particle water and free water content and the molecular structure of lignite are basically unchanged,indicating that lignite adsorbed water and non- frozen water are important components that affect the hydrogenation conversion of lignite.