非均相批次反應蒸餾於乙酸酯化反應程序之應用

Abstract

批次蒸餾操作於特殊化學用品、食品、色料和製藥等產量較少之特定工業中為主要製程操作模式。批次反應蒸餾則結合了批次操作之彈性以及反應蒸餾系統的優勢，非均相批次反應蒸餾系統為其中一種操作型式。本研究針對最輕共沸物落在兩相區中之系統，以塔頂加裝分相槽的非均相批次反應蒸餾塔為設計架構，並利用有機相全回流及水相累積之操作策略，以乙酸丁酯、乙酸異丙酯及乙酸乙酯三種酯化反應系統為例進行可行性分析。 乙酸丁酯系統其最輕共沸物落在兩相區中，且乙酸丁酯為最重成份，經由有機相全回流及水相累積之操作，最終可在塔底獲得乙酸丁酯，而塔頂分相槽為高純度水相；同為最輕共沸物落在兩相區中之乙酸異丙酯系統，其乙酸異丙酯雖非最重成份，但假設其最重成份乙酸可完全反應完，並且將水完全自塔頂水相移除，最終仍可在塔底獲得乙酸異丙酯產物，而塔頂分相槽為高純度水相。本研究亦探討在相同架構下利用水相部分回流操作、以及分相槽進料之操作對分相槽水相組成的影響；乙酸乙酯系統的兩相區較小，其最輕成份的共沸物亦非落在兩相區內，本研究在相同設計架構下利用分相槽持續進料使其塔頂組成落入兩相區內分相，討論於塔底獲得乙酸乙酯產物之可行性。

Batch distillation process has been widely used for small scale productions in pharmaceuticals, fine chemicals, and specialty chemicals. The latest batch reactive distillation (abbreviated as BReaD) combines the flexibility of batch distillation and the advantages of reactive distillation. This research studies policies for operating a heterogeneous BReaD process which has a lightest azeotrope in a two phase region. The policies include total organic reflux and zero aqueous discharge in the productions of butyl, isopropyl and ethyl acetates. From the proposed BReaD, the objective is aimed to obtain the esters from the bottom and high purity water from the top decanter. This study also discusses the effects of partial aqueous reflux and decanter charging strategies on the product compositions；This latter study is motivated by a small two-phase region in the ethyl acetate that does not include the azetrope. The decanter charging strategy has an opportunity to push the top vapor composition into the two phase region, which will then enhance the production of qualified product from a heterogeneous BReaD.