褐煤热压脱水实验研究

为提高褐煤脱水率,以锡林郭勒褐煤为研究对象,采用高温反应釜进行了褐煤热压脱水实验,考察了温度、压力和保压时间对褐煤脱水率的影响,并利用静态氮吸附仪对热压脱水前后煤样的孔隙结构进行测定。结果表明:温度250℃、压力3 MPa、保压60 min时褐煤脱水率最大可达到93.67%。在热力协同作用下,加压可使褐煤实现"攥拳式"脱水,压缩褐煤碳骨架的同时,挤出内水,改变褐煤孔隙结构及分布。热压脱水后,褐煤比表面积、总孔体积、平均孔径分别降低了0.70192 m2/g、0.00405 cm3/g和1.38593 nm,煤样孔径分布明显改变,微孔比例增加5.57%,中孔比例增加4.97%,大孔比例减小10.54%。实验证明以气体加压方式进行褐煤热压脱水可行。

Experimental study of hot-pressing dehydration of lignite

In order to improve the dehydration rate of lignite,taking Xilingol lignite as research object,lignite hot-pressing dehydration ex-periments were carried out under different conditions using high temperature reactor.The paper studied the effects of temperature,pressure and pressure preservation time on the lignite dehydration rate.Nitrogen adsorption static tester was used to analyze pore structure of coal samples before and after the test.The results indicated that when the temperature was 250 ℃ ,the pressure was 3 MPa and pressure preser-vation time was 60 minutes,the dehydration rate could reach to 93.67%.With the interaction of pressure and thermal,the increasing pres-sure compressed the carbon skeleton of lignite,squeezed the inherent moisture,changed the pore structure and distribution.After dehydra-tion,the specific surface area of lignite,total pore volume and average aperture decreased by 0.70192 m2 / g,0.00405 cm3 / g,1.38593 nm, the distribution of aperture was changed significantly,the addition of micropore and mesoporous were 5.57% and 4.97%,the decrement of macropore was 10.54%.The test showed that the hot-pressing was suitable for lignite dehydration.