溶胀对褐煤吸水性能的影响

Effect of Swelling on Water Sorption of Lignite

为了改善褐煤脱水后的复吸水问题,用四氢呋喃(THF)、吡啶(C5H5N)、甲醇(CH4O)、丙酮(C3H6O)4种溶剂对内蒙古锡林浩特白音华褐煤(XL)、神东褐煤(SD)进行溶胀处理。利用比表面积分析仪对处理前后的煤样进行表征,比较溶胀处理前后煤样的复吸水含量及不同相对蒸汽压下的平衡含水量。实验表明:煤样溶胀24 h后可达到溶胀平衡;溶剂的供电子数量与得电子数量之差越大,煤的溶胀率越大;溶胀使褐煤脱出更多的极性小分子;吡啶溶胀XL、SD煤样的比表面积降幅最大,分别为52.5%和51.5%;溶胀后的煤样50 h后复吸水含量基本不变,其中吡啶溶胀后的XL、SD煤样复吸水能力减弱了,其值分别为11.23%和18.62%。吡啶溶胀使褐煤在不同相对蒸汽压(RVP)下的平衡含水量(EMC)相比原煤的都减少了。溶胀处理可以减弱褐煤脱水后的复吸水性能。

Fundamental research can assist in the development of lignite-water interactions. The Baiyinhua lignite （XL） and the Shendong lignite （SD） in Xilinhot, Inner Mongolia were treated with tetrahydrofuran （THF）, pyridine （C5H5N）, methanol （CH40）, acetone （C3H60） in this study and the coal samples were characterized by specific surface area analyzerl The re-sorption water contents and equilibrium water contents across a range of relative vapour pressure of treated and untreated samples were determined. The results show that the swelling of the coal reaches equilibrium in 24 h; base value increases with the increase in the swelling ratio; the specific surface area of pyridine swelling lignites are reduced maximally 52.5% and 51.5% , respectively; in 50 h, the re-absorption moisture content tends to balance. Re-absorption capacities of XL and SD swelled by pyridine are weaker relative to the raw lignites, whose values are 11.23% and 18.62% , respectively. The equilibrium moisture contents for the swelling products are all lower than those for the original lignite at each relative vapor pressure. The swelling treatment is an efficient way to reduce the ability of water re-sorption in lignite.