混合正丁戊醇及正戊己醇之酯化 反應性分隔內壁蒸餾塔之程序設計與控制

Design and Control of Reactive Divided Wall Column for Esterification with Mixed Butanol and Pentanol or Mixed Pentanol and Hexanol Feed

李宗翰(Chung-Han Lee)

指導教授 ： 錢義隆

國立臺灣大學/工學院/化學工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.03241

摘要

反應性分隔內壁蒸餾塔(RDWC)之研究文獻到目前為止所見不多，
但以現有已發表的文獻來看， 在設計反應性分隔內壁蒸餾塔前， 須先針對原有的反應蒸餾系統(RD system)架構設計去做研究後， 再進一步去進行熱整合， 才能有效地利用反應性分隔內壁蒸餾塔之設計來達到節能之目的。
本研究主要參考Lee 等人[16]針對混合丁、戊醇酯化反應製程以
「先酯化反應， 後分離產物」之概念做設計所提出之兩種架構直接序列設計和間接序列設計- 「水相回流」，作反應性分隔內壁蒸餾塔之設計，藉由程序最小年總成本(TAC)的計算以獲得最適設計的架構，並比較此兩種架構對於混合正丁、戊醇酯化系統及混合戊、己醇酯化系統之優劣， 其結果顯示在混合正丁、戊醇酯化系統中， 直接序列設計由於乙酸與乙酸丁酯難以分離之緣故， 因此為了顧及塔底乙酸之規格而耗費大量之精餾板數，使得間接序列設計-「水相回流」之架構較具競爭性；但在混合戊、己醇酯化系統中， 排除了乙酸與乙酸丁酯難以分離之限制， 所以塔底不需耗費大量之精餾板數使乙酸達至規格， 雖然直接序列設計於反應蒸餾塔塔底因產生兩個酯類而有再混合效應產生， 但可藉由反應性分隔內壁蒸餾塔之設計， 而更具競爭性。
　　接著在動態模擬方面， 針對混合正戊、己醇酯化系統直接序列設計整合後之架構作動態模擬之分析， 由於在選取控制點上， 受到了開環路靈敏度之限制， 使得擾動結果在產品規格上有些許偏差。另外，在增加進料流量之擾動下， 有轉化率不足之現象， 導致產品規格受到影響， 但在最後擾動測試之結果， 僅有少部分擾動產品規格偏差較大外， 其餘擾動測試結果皆僅有0.1mol%左右的偏差。

關鍵字

酯化反應 ； 混合醇 ； 反應性分隔內壁蒸餾塔

並列摘要

There are little amounts of literatures related to reactive dividing wall column(RDWC) to date. But from the already published literatures, before designing a reactive
dividing wall column, a configuration with reactive distillation system(RD system) needs to be studied, then thermally integrating the system. It will help in　efficiently using the reactive dividing wall column to bring about a saving in energy.This research is based on the work of Lee et al.[16] which focuses on the
esterification of alcohol mixtures of butanol and pentanol, using the concept of reaction
first then separation. There are two types of configurations in which are direct sequence
and indirect sequence–aqueous reflux in their work. We not only use the above as the
foundation of the reactive dividing wall column design, but also minimize the total
annual cost (TAC) to find the optimum design. Comparison of the pros and cons
between the two configuration of esterification of butanol and pentanol system and
esterification of pentanol and hexanol system has been conducted. The results show that
in the esterification of pentanol and hexanol system that the separation of acetic acid
and butyl acetate is hard to separate in the direct system, in order to maintain the
product specification of acetic acid in the bottoms requires a lot of trays. Therefore the
indirect sequence-aqua phase reflux is more competitive. But in the esterification of
pentanol and hexanol system, ignoring the problem relating to the limit in separation of
acetic acid and butyl acetate, so the column doesn’t need that much amount of trays to
maintain the product specifications. Even though the direct sequence has a remixing
effect of the two esters in the bottom of the reactive distillation column, using a reactive
dividing wall column design is more competitive.
In the dynamic simulation, the pentanol and hexanol system in the direct sequence
6
after integration is studied, due to the limit of the open loop sensitivity analysis, the
choice of control points are affected, causing the product specification to have small
deviations under disturbances. Also, under throughput disturbances, the conversion also
dropped, affecting the product specifications. But in the end of the disturbances test,
only some of the disturbances causes a large deviation to the product specification, the
rest of the disturbances shows only a 0.1mol% deviation.

並列關鍵字

esterification ； alcohol ； reactive divided wall column

參考文獻

(1) 何瑞鴻，[理想系統之反應性分隔內壁蒸餾塔設計與節能研究]，

(2) 許智鈞，[乙酸甲酯水解反應之反應性分隔內壁蒸餾塔架構設計與

structures for an ideal two-product reactive distillation column.

Ind. Eng. Chem. Res. 2000, 39, (9), 3298-3307.

ether reactive distillation. Ind. Eng. Chem. Res. 2002, 41, (16),