Dynamic control for Agrawal divided-wall column

doi:10.16085/j.issn.1000-6613.2025-0672

Abstract

Abstract:

The Agrawal divided-wall column (ADWC) is a modified configuration of the divided-wall column (DWC) that offers economic benefits in terms of capital and operational costs for multi-component separation. This study aims to investigate the dynamic control structure of the ADWC for MEPB systems (methanol, ethanol, n-propanol, and n-butanol) separation. Initially, the steady-state configuration of the ADWC is optimized and analyzed. Composition control structure (CC) can handle feed disturbances of ±20%, while it may not be practical for industrial applications. Temperature control structure (TC) is more commonly used in industry but has a weaker control efficiency of ±10%. Composition-temperature control structure (CTC) is the most promising control structure due to its lower capital cost and adjustment time than CC, as well as its superior control efficiency compared to TC.

Key words: distillation, dynamic simulation, control, four-component separation, Agrawal divided-wall column, composition-temperature control

摘要：

Agrawal分壁精馏塔（Agrawal divided-wall column，ADWC）作为分隔壁精馏塔的一种改进构型，能够显著降低四组分分离的设备投资和操作投资，展现出良好的经济效益。本研究旨在针对ADWC在甲醇/乙醇/正丙醇/正丁醇（MEPB）四元醇体系分离中的动态控制问题展开研究。首先，分析ADWC的稳态构型特点。在此基础上，构建了三种控制结构，包括组成控制结构（CC）、温度控制结构（TC）以及组分-温度控制结构（CTC）。结果表明，CC结构能够有效处理±20%的进料扰动；TC结构因仅需温度检测器在工业中易于实施，但其仅能有效处理约±10%的扰动。CTC结构相较于CC结构具有更低的控制设备投资和更短的调节时间；相较TC结构具有优的控制性能和鲁棒性，是最具应用前景的控制方案。

关键词: 精馏, 动态仿真, 控制, 四组分分离, Agrawal 分壁精馏塔, 组成-温度控制

CLC Number:

TQ028.4

GAO Yan, LI Yongshuai, LI Gaoyang, PAN Hui, LING Hao. Dynamic control for Agrawal divided-wall column[J]. Chemical Industry and Engineering Progress, 2025, 44(8): 4594-4605.

高岩, 李永帅, 李高洋, 潘慧, 凌昊. Agrawal分壁精馏塔的动态控制[J]. 化工进展, 2025, 44(8): 4594-4605.

Figures/Tables 17

References 38

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参数	数值
进料速率/kmol·s^-1	1
进料成分	全部为25%
进料塔板数	59
产品纯度/%	99
塔顶压力/atm	1
单板压力降/atm	0.0068
模拟软件	Aspen Plus
总理论塔板数（包括冷凝器和再沸器）	101
柱直径/m	5.979
内部类型	筛板
冷凝器热负荷/MW	57.506
再沸器热负荷/MW	56.158
年总成本/10⁶USD·a^-1	11.287

参数	数值
进料速率/kmol·s^-1	1
进料成分	全部为25%
进料塔板数	59
产品纯度/%	99
塔顶压力/atm	1
单板压力降/atm	0.0068
模拟软件	Aspen Plus
总理论塔板数（包括冷凝器和再沸器）	101
柱直径/m	5.979
内部类型	筛板
冷凝器热负荷/MW	57.506
再沸器热负荷/MW	56.158
年总成本/10⁶USD·a^-1	11.287

控制回路	被控变量	操作变量	K_c	τ_I/ min	被控变量设定值
CC1	预分馏段底部乙醇摩尔分数	Q_R	0.106	77.88	0.0139
CC2	塔顶产品中乙醇摩尔分数	R	0.086	130.68	0.0100
CC3	上侧线流股中正丙醇摩尔分数	F_S1	0.119	52.80	0.0056
CC4	塔釜产品中正丙醇摩尔分数	F_S2	0.202	100.32	0.0100
CC5	中间塔5号塔板中正丙醇摩尔分数	β_LM	0.128	48.84	0.1946

控制回路	被控变量	操作变量	K_c	τ_I/ min	被控变量设定值
CC1	预分馏段底部乙醇摩尔分数	Q_R	0.106	77.88	0.0139
CC2	塔顶产品中乙醇摩尔分数	R	0.086	130.68	0.0100
CC3	上侧线流股中正丙醇摩尔分数	F_S1	0.119	52.80	0.0056
CC4	塔釜产品中正丙醇摩尔分数	F_S2	0.202	100.32	0.0100
CC5	中间塔5号塔板中正丙醇摩尔分数	β_LM	0.128	48.84	0.1946

控制回路	被控变量	操作变量	K_c	τ_I/ min	被控变量设定值/℃
TC1	预分馏段33号塔板温度	Q_R	2.904	21.12	101.89
TC2	主塔13号塔板温度	R	2.427	40.92	72.74
TC3	主塔53号塔板温度	F_S1	2.947	40.92	93.50
TC4	主塔94号塔板温度	F_S2	10.218	73.92	118.58
TC5	中间塔29号塔板温度	β_LM	3.357	71.28	87.17