乙醇沉淀法处理利用粘胶纤维生产废弃的压榨碱液

Treatment and reuse of the press lye from viscose production with ethanol precipitation

针对粘胶纤维生产过程中排放的含有半纤维素的NaOH水溶液,研究了乙醇沉淀、然后精馏分离的方法实现NaOH的全循环利用,在乙醇与碱液体积比达到3∶1左右,碱液中半纤维素沉淀率可以到达75%~80%以上,随着乙醇用量增加,半纤维素沉淀率会有增加,但不明显、不经济。采用精馏方法可以实现乙醇和碱液的分离,碱液中残留乙醇浓度可低至0.01%以下,碱液可以循环使用。模拟计算表明,该方法用于处理压榨碱液经济上也是可行的。

Separation of the hemicelluloses from the press lye discharged from viscose production and insurance of sodium hydroxide reuse after the hemicelluloses removal was studied in this article. Over 75%~80% of the hemi-celluloses in the lye precipitates when ethanol was mixed with the press lye in 3∶1(v/v). After the solid-liquid separation, the solution can be separated by rectification. The ethanol content remained in the treated lye was lower than 100×10^-6. Therefore, the lye can be reused. The method is economically viable with optimal design.