离子液体/NMP对双马萃余煤的结构和萃取性能影响

Influence of ionic liquids /NMP on the structure and extraction performance of Shuangma’s extraction residue

为研究离子液体/NMP对双马萃余煤的结构和萃取性能影响,首先分别用乙醇和丙酮对宁东双马煤样(SM)进行分步萃取,得到萃余煤(SMEC),然后将不同种类的离子液体(ILs)分别与N-甲基吡咯烷酮(NMP)混合后对SMEC进行萃取。用TG研究ILs/NMP萃取前后煤样热分解特性的变化,用FT-IR研究ILs/NMP萃取前后煤样官能团的变化,用GC/MS分析萃取物的种类。结果表明,ILs/NMP萃取后煤样的热失重增大,萃余煤中含氧官能团含量下降。另外,疏水型离子液体/NMP对SMEC煤的累积萃取率大于亲水型离子液体/NMP的累积萃取率。亲水型离子液体[Bmim]Cl/NMP和[Bmim]BF4/NMP分别萃取出51种和44种有机物质;疏水型离子液体[Bmim]NTf2/NMP和[Bmim]PF6/NMP分别萃取出28种和29种有机物质。疏水型离子液体/NMP对SMEC煤中含氧官能团化合物的萃取能力强于亲水型离子液体/NMP;疏水型离子液体/NMP对SMEC煤中含杂原子化合物的萃取能力小于亲水型离子液体/NMP。

In order to study the Influence of ionic liquids/NMP on the structure and extraction performance of Shuangma’s extraction residue, the Ningdong Shuangma coal(SM)was fractional extracted with ethanol and acetone to obtain residue coal(SMEC),and then the SMEC was extracted by mixed solvent of different types of ionic liquids(ILs)and N-methylpyrrolidone(NMP).The changes of thermal decomposition characteristics of coal samples before and after extraction by ILs/NMP were studied through TG,the changes of functional groups of coal samples before and after extraction by ILs/NMP were studied through FT-IR,and the types of extract were analyzed by GC/MS.The results showed that the thermal weight loss of the coal samples increased and the content of oxygen-containing functional groups in the residues decreased after ILs/NMP extraction.In addition, the extraction rate of hydrophobic ionic liquids/NMP to SMEC coal was greater than that of hydrophilic ionic liquids/NMP.The hydrophilic ionic liquid[Bmim]Cl/NMP and[Bmim]BF4/NMP extracted 51 kinds and 44 kinds of organic substances, respectively.Hydrophobic Ionic liquids[Bmim]NTf2/NMP and[Bmim]PF6/NMP extracted 28 and 29 organic substances, respectively.Hydrophobic ionic liquids/NMP had stronger extraction ability for oxygen-containing functional compounds in SMEC coal than hydrophilic ionic liquids/NMP;Hydrophobic ionic liquids/NMP had lower extraction ability for heteroatom-containing compounds in SMEC coal than hydrophilic ionic liquids/NMP.