TEG-NCS/NBS复合溶剂的络合萃取脱氮性能研究

Denitrification Performance of Triethylene Glycol-Succinimide Compound Complex Solvent

采用三乙二醇(TEG)-氯代琥珀酰亚胺(NCS)和溴代琥珀酰亚胺(NBS)复合溶剂作为萃取剂,研究其分别对模型油中喹啉、吖啶、吡啶、吲哚、吡咯以及催化裂化柴油中氮化物的脱除性能。结果表明:复合溶剂可将模型油中碱性氮和非碱性氮完全脱除。对于碱性氮,纯TEG对模型油中喹啉等的脱除率只有85%左右,而TEG-NCS、TEG-NBS复合溶剂对模型油中碱性氮的脱除率却能达99.9%以上,超高的脱氮性能来自于NCS、NBS与碱性氮之间发生的强络合作用。对于非碱性氮,TEG对吲哚、吡咯的脱除率均能达到99%以上,说明TEG与非碱性氮之间存在较强的氢键作用,研究还发现TEG-NBS与吲哚能发生强烈的络合作用,通过红外、紫外和^(1)H-核磁共振等表征方法也进一步证实了上述这些相互作用。此外,复合溶剂对催化裂化柴油也表现出良好的脱氮性能。可见,对于萃取脱氮而言,TEG-NCS和TEG-NBS具有良好的应用前景。

Two composite solvents,i.e.,triethylene glycol(TEG)with N-chlorosuccinimide(NCS)and with N-bromosuccinimide(NBS),were used as extractants to study their N-removal performance of quinoline,acridine,pyridine,indole,and pyrrole in model oil and N-compounds in fluid catalytic cracking(FCC)diesel.The results showed that both basic nitrogen and non-basic nitrogen in the model oil can be completely removed by the composite solvents used here.For basic nitrogen,the N removal of quinoline etc.by pure TEG is only about 85%,but TEG-NCS and TEG-NBS can remove more than 99.9%of basic nitrogen in the model oil.The ultra-high denitrification performance is due to the strong complexation between NCS/NBS and basic nitrogen.For non-basic nitrogen,the N-removal of indole and pyrrole by TEG can be beyond 99%,indicating that there is a strong H-bond between TEG and non-basic nitrogen.The study also found that TEG-NBS and indole have a strong complexation,and the above mentioned interactions were further confirmed by characterization methods such as Fourier transform infrared spectroscopy,ultraviolet visible spectroscopy,and 1H-nuclear magnetic resonance.In addition,the composite solvent also shows great denitrification performance for FCC diesel.Apparently,TEG-NCS and TEG-NBS are the promising solvents for extractive denitrification.