Recovery And Application Of Mixed Solvent In Alkali Metal Alkoxide Production

The alkali metal alkoxides are widely applied in the areas of pharmaceutical chem-istry and biochemistry as important fine chemicals, such as potassium tert-buto xide, sodium tert-butoxide, potassium tert-pentyloxide and sodium tert-pentyloxide, etc. A large number of the mixed waste solvent with useful constituent is inevitably produced during the manufacturing process of alkali metal alkoxides. The ternary mixture mainly included tert butanol alcohol, tert amyl alcohol and water. Some effective measures should be used to enhance the recovery rate of tert butyl alcohol and tert amyl alcohol, which could make the water phase meet the discharge standard.The research of the separation of tert butyl alcohol-tertiary amyl alcohol-water was summarized in this paper. The advantages and disadvantaged of different process routes were considered based on the purity, yield, energy dissipation and apparatus cost of the products. The process route of three-tower continuous separation was put forward com-bining extractive distillation with azeotropic distillation. The two projects were ana-lyzed by the chemical engineering software Aspen Plus and the final scheme was con-firmed after considering all kinds of conditions.The project of extractive distillation was analyzed by the chemical engineering software Aspen Plus. The process parameters, which lead to the separating effects, such as theoretical plate number, raw material feed stage, extraction agent feed stage and reflux ratio, were simulated via the orthogonal experiment combing the single-factor-alternate method.On the foundation of previous results, the extractive distillation and continuous rectification apparatus was designed to verify the simulation process. In the best oper-ating condition, the experimental were as follows:purity of tert butyl alcohol ω= 99.7%, yield of ert butyl alcohol η= 99.7%, purity of tertiary amyl alcohol ω=98.3%, yield of tertiary amyl alcohol η= 98.2%. The purity of the products were matched with the stand-ard of circulation.The recycled tert butyl alcohol and tertiary amyl alcohol was used for the synthesis of alkali metal alkoxides such as potassium tert-butoxide, sodium tert-butoxide, potas-sium tert-pentyloxide and sodium tert-pentyloxide. As a result, the content of free alkali is important along with the content of the water during the recovery of tert butyl alcohol and tertiary amyl alcohol. Various process and apparatus was summarized in this paper to measure free alkali online, manufacture prototype and recycle tert butyl alcohol and tertiary amyl alcohol. This simulation provides a theoretical basis for the recovery of tert butyl alcohol and tertiary amyl alcohol.This work in this paper provides a new method for the regeneration of the waste solvent during the manufacture of the alkali metal alkoxides.