Method for preparing lyocell fibers from sugarcane bagasse as raw material

Abstract

A method for preparing Lyocell fibers from sugarcane bagasse is provided, which includes: crushing sugarcane bagasse to 40-80 mesh to obtain sugarcane bagasse powder; putting the sugarcane bagasse powder into a first solution and obtaining pretreated sugarcane bagasse powder; adding the pretreated sugarcane bagasse powder into a second solution and obtaining sugarcane bagasse cellulose; the second solution includes 15-17.5 mol/L glacial acetic acid, 10-15 g/L sodium hypochlorite, and remaining water; adding the sugarcane bagasse cellulose into an NMMO aqueous solution with a mass fraction of 85-88%, stirring and dissolving in a reaction kettle under a vacuum condition at 90-110° C. for 3-5 hours to obtain a transparent spinning solution, where the sugarcane bagasse cellulose has a mass ration of 6-10%; sending the spinning solution into a spinning system for spinning. The process of the present disclosure is simpler, more environmentally friendly, and can reduce costs.

What is claimed is: 
     
         1 . A method for preparing Lyocell fibers from sugarcane bagasse, comprises following steps:
 step A, crushing sugarcane bagasse to 80 mesh to obtain sugarcane bagasse powder;   step B, putting the sugarcane bagasse powder obtained in step A into a first solution, stirring at 70° C. for 3 hours, filtering and washing after reaction is complete, drying filter residue, and then grinding it to 60 mesh to obtain a pre-treated sugarcane bagasse powder; the first solution comprises hydrogen peroxide with a mass fraction of 1%, sodium hydroxide with a mass fraction of 5%, and remaining water; a mass ratio of the first solution to the sugarcane bagasse powder is 20:1;   step C, putting the pre-treated sugarcane bagasse powder obtained in step B into a second solution, immersing it in 90° C. for 3 hours, filtering and washing until neutral after reaction is complete, and drying a filter residue in an oven at 60° C. to obtain sugarcane bagasse cellulose; wherein the second solution comprises 17.5 mol/L glacial acetic acid, 10 g/L sodium hypochlorite, and remaining water; a mass ratio of the second solution to the pre-treated sugarcane bagasse powder is 25:1;   step D, adding the sugarcane bagasse cellulose obtained in step C into an NMMO aqueous solution with a mass fraction of 85%, stirring and dissolving in a reaction kettle under a vacuum condition at 100° C. for 3 hours to obtain a transparent spinning solution, where a mass fraction of the sugarcane bagasse cellulose in solution is 4/46;   step E, sending the spinning solution obtained in step D into a spinning system for spinning;   in step A, the sugarcane bagasse is crushed and treated in a water bath at 70° C. for 3 hours, filtered and washed, and dried at 60° C. for 10 hours to obtain the sugarcane bagasse powder;   wherein in step D, the NMMO aqueous solution with a mass fraction of 85% is obtained by vacuum distillation of an NMMO aqueous solution with a mass fraction of 50%.   
     
     
         2 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 1 , wherein in step B, drying is carried out under a vacuum condition at a drying temperature of 60° C. 
     
     
         3 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 2 , wherein in step E, before entering the spinning system, the spinning solution is added to a screw extruder and dissolved at 110° C. for 20 minutes, followed by filtration. 
     
     
         4 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 3 , wherein in step E, entering a spinning system, and the sprayed silk thread is vertically stretched in air, entering a coagulation bath, solidifying and forming, and a coagulation bath temperature is 30° C.; wherein the coagulation bath is an NMMO aqueous solution with a mass fraction of 20%, and then undergoes fiber alcohol washing, bleaching, water washing, oiling, and drying. 
     
     
         5 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 4 , wherein a mass concentration of ethanol in the alcohol washing is 75%, and an alcohol washing time is 3 hours. 
     
     
         6 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 5 , wherein the bleaching uses a strong chlorine solution of 0.1 g/L, a bleaching temperature of 30° C., and a bleaching time of 60 minutes. 
     
     
         7 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 6 , wherein in step E, a water washing temperature is 80° C. and a water washing time is 2 hours. 
     
     
         8 . The method for preparing Lyocell fibers from sugarcane bagasse according to  claim 7 , wherein in step E, a drying temperature is 60° C. and a drying time is 24 hours.