Research And Development Of Solvent N-methyl Pyrrolidone Recycling In Production Of Aramid Fiber

In this paper, the recycle process of cosolvent N-methyl pyrrolidone (NMP) andaqueous solution of calcium chloride during the production of Aramid Fiber (poly-p-phenylene terephthamide) polymerization process have been researched. Low waste,environmental protection, high efficient and reliable production process have beendeveloped by experimental and calculation methods.This process has been verificatedby actual production. Satisfactory results have been achieved.In this paper, the liquid-liquid separation methods used in the NMP solvent recoveryprosess have been studied.Chloroform was chosed as the extraction agent according tothe material properties and the experimental data, The experimental results have shownthat liquid-liquid extraction separation method is better than that of ordinarydistillation method.In this paper, simulation software PRO/II simulation project produced by theAmerican company Simsci was used to do the calculation work. it is concluded that inthe industrial production processing raw materials (NMP and calcium chloride aqueoussolution)2000tons/year, operating at300days per year, under the condition ofindustrial equipment specific to choose size, best theoretical plate number andoptimum reflux ratio and so on all kinds of process and equipment conditions.Calculation data obtained by using this software is more accurate than that of manualcalculation ever before and the is more close to the actual engineering conditions.A variety of extraction equipment was studied in this paper. Efficient packed towerwas chosen as the core of the process equipment. After comparing the variety of fillers,structured packing tower was chosed as the tower internals. Experiments show thatthis equipment is more suitable for the process conditions, to improve the separationefficiency, reduces the equipment investment, it is less than the other devices do. DCSautomatic control was used in the engineering process design in this article. Operatingpersonnel number was reduced greatly in the the industrial production safely on thebasis of continuous production line. Different material pipes in pipeline was chosedaccording to paragraphs material properties. These have saved project investment andensured to produced safely.