Preparation of N-butyl acetate from Dilute Acetic Acid Wastewater by Phase Transfer Catalyst CTMAB

摘要

The experiment disposing waste water with dilute acetic acid aimed to recycle acetic acid and synthesize high value added n-butyl acetate with cetyl trimethyl ammonium bromide (CTMAB) as the phrase transfer catalyst. Over-dose n-butanol was added and n-butyl acetate was extracted with the mixed solution of trioctylamine (TOA) (20%,w) and tributylphosphate (TBP) (80%,w) as the extractant. After the still standing and liquid separation, the organic phase was depressurized and distilled under the pressure 25kPa.The n-butanol and a part of acetic acid were recycled, and n-butyl acetate was collected between temperature 70°C-75°C. The synthetic process parameters were optimized, that was: CTMAB 0.35g /0.127mol acetic acid, TOA/TBP 30ml, the ratio of alcohol and acid 1.3:1.0, reaction time 2.5h, reaction temperature 30°C.The extraction rate of acetic acid was 88.2%.The yield of n-butyl acetate was 81.3% and phrase transfer catalyst with extractant was recycled for 6 times whose effect was reduced a little but good enough. This experiment, which included esterification reaction with phase transfer catalyst and extractive distillation process, has received a satisfactory effect and can be used in similar system.