NF3与CF4分离纯化技术路线研究进展

Progress on technology route for separation and purification of NF3 and CF4

在NF_(3)的工业化生产中,会与原料氟气(F_(2))一起引入不纯物质四氟甲烷(CF_(4)),严重影响了NF_(3)的品质。需要开发出具有经济效益成本的NF_(3)和CF_(4)分离纯化技术方法。CF_(4)和NF_(3)这两种气体具有非常相似的物理特性,很难通过传统的技术进行分离。因此,总结了NF_(3)中CF_(4)杂质的分离纯化技术研究进展,从纯度、效率、成本和安全等角度对比分析了包括低温精馏、吸附、膜分离、萃取精馏和吸收在内的5种纯化技术路线的优势和不足。低温精馏通常需要在-100~-192℃的低温下操作,而膜技术和使用沸石和分子筛的吸附技术过程在能耗、维护成本、连续化和处理能力等方面受到分离材料性能的显著限制。在此基础上,提出了克服当前工业挑战的潜在的分离纯化方法。指出基于吸收和萃取精馏的方法适用于从NF_(3)中纯化CF_(4)杂质的最佳的工艺技术路线。

In the industrial production of NF_(3),the impure substance tetrafluoromethane(CF_(4)) will be introduced together with the raw material fluorine gas(F_(2)),which seriously affects the quality of NF_(3).It is necessary to develop a cost-effective separation and purification technology method for NF_(3)and CF_(4).The two gases between CF_(4)and NF_(3)have very similar physical properties, so it is difficult to separate them by traditional techniques.The research progress of the separation and purification technology for CF_(4)impurities in NF_(3)is summarized, and the advantages and disadvantages of five purification technologies including cryogenic distillation, adsorption, membrane separation, extractive distillation and absorption are compared and analyzed from the perspectives of purity, efficiency, cost and safety.Cryogenic rectification usually needs to be operated at a very low temperature of-100~-192 ℃,while membrane technology and adsorption technology using zeolite and molecular sieves are significantly affected by the performance of the separation material in terms of energy consumption, maintenance costs, continuity and processing capacity limit.On this basis, a potential separation and purification method that overcomes the current industrial challenges is proposed.It is pointed out that the methods based on absorption and extractive distillation are the suitable candidates of the technological route for purifying CF_(4)impurities from NF_(3).