進料中雜質對非均相共沸蒸餾之影響

Influences of Feed Impurity for Heterogeneous Azeotropic Distillation

王俊惠(Chun-Hui Wang)

指導教授 ： 黃孝平

共同指導教授 ： 錢義隆(I-Lung Chien)

國立臺灣大學/工學院/化學工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00985

摘要

本研究主要針對醋酸去水製程中進料之雜質對非均相共沸蒸餾程序之影響進行探討，採實際工廠的操作數據利用電腦穩態與動態模擬，以探討醋酸異丁酯為共沸劑的醋酸去水製程在進料中同時含有間位二甲苯和醋酸甲酯時對整體蒸餾分離系統所造成的影響。發現蒸餾過程中間位二甲苯會在蒸餾塔中會慢慢累積，最後將導致無法控制系統以符合產品規格。改善的方法是在蒸餾塔上加一側分流(sidedraw)來解決，並由年總成本(TAC)的計算分析尋找最經濟的設計架構，包括側分流的出料板數、流量與共沸劑的最適補充流量等影響因素。但因側流量太小不易操作，本文亦模擬採用溫度測量，定時由側分流排出的操作方式，並在模擬中決定側分流排出之時間及流量。吾人進一步發現在不須醋酸異丁酯為共沸劑的情況下，原本存在於進料中所含的間位二甲苯在電腦模擬中顯示其亦可以做為絕佳的共沸劑，如此可以省去醋酸異丁酯的添加，對此工業醋酸去水製程的改善可能會有極佳的助益。

關鍵字

非均相共沸蒸餾

並列摘要

In this research, we discuss the influence of feed impurities m-xylene and methyl acetate on the operation for dehydration of acetic acid by heterogeneous azeotropic distillation. A concept is presented for the design of side-draw to prevent the accumulation of m-xylene composition in distillation column from long-term operation. The theoretical research illustrates steady-state and dynamic simulations of an industrial column. Optimal TAC estimation decides the best side-draw stage, flow rate and feasible make-up flowrate of entrainer, iso-butyl acetate, into the column. As the flowrate of side-draw is too low it will be not easy to operate smoothly in experiential application. We purge higher side-draw flowrate to make the process more practicable in dynamic simulation. According to the result of simulation we can decide the better purge time and flowrate of side-draw stream. In particular, we find the m-xylene from feed line could be a better entrainer for the industrial separation of acetic acid-water system. It can improve the process to have more economic benefits.

並列關鍵字

Heterogeneous Azeotropic Distillation

參考文獻

[35] 錢義隆教授, "共沸蒸餾系統之設計與控制",化工月刊, 第49卷第4期 程序系統工程專刊 (2002)

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