Simulation and economic evaluation of separating dimethyl carbonate-methanol by extractive distillation with propylene carbonate as solvent

doi:10.16085/j.issn.1000-6613.2023-1956

Abstract

Abstract:

Aiming at the separation of DMC-MeOH azeotrope at the top of the tower for dimethyl carbonate (DMC) production by reactive distillation with propylene carbonate (PC) and methanol (MeOH) as raw materials, a extractive distillation process with PC as solvent was presented. The simulation and economic evaluation were carried out on the Aspen Plus software platform. The feasibility and selectivity of the solvent were investigated, the process flow scheme was determined, and the process parameters of the extractive distillation process were optimized. The energy consumption and economy of PC extractive distillation and heat integrated pressure swing distillation for separating DMC-MeOH azeotrope were compared. The results show that the total energy consumption and total annual cost (TAC) of the extractive distillation process are reduced by 53.9% and 49.5%, respectively, compared with the pressure swing distillation process, showing the feasibility and technical and economic advantages of the extractive distillation process.

Key words: propylene carbonate, extractive distillation, dimethyl carbonate, optimal design, economic evaluation

摘要：

针对以碳酸丙烯酯（PC）和甲醇（MeOH）为原料反应精馏合成碳酸二甲酯（DMC）塔顶DMC-MeOH共沸物分离问题，提出以PC为萃取剂、萃取精馏分离共沸物的工艺。在Aspen Plus软件平台上开展模拟与经济性评价研究，考察了萃取剂的可行性和选择性，确定了工艺流程方案，对萃取精馏流程的工艺参数进行了优化；比较了PC萃取精馏与热集成变压精馏分离DMC-MeOH共沸物的能耗与经济性。结果表明，萃取精馏工艺的总能耗和年总费用（TAC）较变压精馏工艺分别降低了53.9%和49.5%，体现了萃取精馏工艺的可行性和技术经济优势。

关键词: 碳酸丙烯酯, 萃取精馏, 碳酸二甲酯, 优化设计, 经济评价

CLC Number:

TQ028.3

MA Changjin, LI Teng, AN Weizhong, LIN Zixin, BIE Haiyan. Simulation and economic evaluation of separating dimethyl carbonate-methanol by extractive distillation with propylene carbonate as solvent[J]. Chemical Industry and Engineering Progress, 2024, 43(12): 6608-6614.

马长金, 李腾, 安维中, 林子昕, 别海燕. 碳酸丙烯酯为萃取剂萃取精馏分离碳酸二甲酯-甲醇流程模拟与经济性评价[J]. 化工进展, 2024, 43(12): 6608-6614.

Figures/Tables 11

References 14

15	FENG Zemin, SHEN Weifeng, RANGAIAH G P, et al. Design and control of vapor recompression assisted extractive distillation for separating n-hexane and ethyl acetate[J]. Separation and Purification Technology, 2020, 240: 116655.
16	LI Yudong, YE Qing, WANG Naigen, et al. Energy-efficient extractive distillation combined with heat-integrated and intermediate reboilers for separating acetonitrile/isopropanol/water mixture[J]. Separation and Purification Technology, 2021, 262: 118343.
17	卫红梅, 马秀峰, 王栋. 热集成变压分离碳酸二甲酯-甲醇过程模拟[J]. 化学工程, 2023, 51(2): 78-82.
	WEI Hongmei, MA Xiufeng, WANG Dong. Process simulation of dimethyl carbonate-methanol separation via heat-integrated pressure swing distillation[J]. Chemical Engineering, 2023, 51(2): 78-82.
1	YIN Kexin, SHEN Yuanyuan, JIAO Yuyang, et al. Mechanism analysis of liquid-liquid extraction separation for dimethyl carbonate and methanol by choline-based DESs as extractants[J]. Fluid Phase Equilibria, 2023, 566: 113701.
2	卫敏, 李忠, 谢克昌. DMC-CH₃OH二元共沸物的分离进展[J]. 化工进展, 2005, 24(11): 1234-1238.
	WEI Min, LI Zhong, XIE Kechang. Separation of dimethyl carbonate from methanol-dimethyl carbonate azeotrope[J]. Chemical Industry and Engineering Progress, 2005, 24(11): 1234-1238.
3	CHEN Jianhua, DONG Xinfei, HE Yashan. Investigation into glutaraldehyde crosslinked chitosan/cardo-poly-etherketone composite membrane for pervaporation separation of methanol and dimethyl carbonate mixtures[J]. RSC Advances, 2016, 6(65): 60765-60772.
4	GUO Chao, WANG Fuqiang, XING Jiafu, et al. Thermodynamic and economic comparison of extractive distillation sequences for separating methanol/dimethyl carbonate/water azeotropic mixtures[J]. Separation and Purification Technology, 2022, 282: 120150.
5	郭建军, 王家, 李新, 等. 碳酸丙烯酯萃取精馏分离甲醇-碳酸二甲酯恒沸物模拟[J]. 辽宁化工, 2020, 49(12): 1497-1501.
	GUO Jianjun, WANG Jia, LI Xin, et al. Simulation on continous extractive distillation process of methanol and dimethyl carbonate azeotropic system[J]. Liaoning Chemical Industry, 2020, 49(12): 1497-1501.
6	李群生, 朱炜, 付永泉, 等. 常压下甲醇-碳酸二甲酯汽液平衡测定及其萃取剂选择[J]. 化学工程, 2011, 39(8): 44-47.
	LI Qunsheng, ZHU Wei, FU Yongquan, et al. Vapor-liquid equilibrium of methanol-dimethyl carbonate at normal pressure and selection of extractant[J]. Chemical Engineering, 2011, 39(8): 44-47.
7	SHEN Yuanyuan, SU Zihao, ZHAO Qing, et al. Molecular simulation and optimization of extractive distillation for separation of dimethyl carbonate and methanol[J]. Process Safety and Environmental Protection, 2022, 158: 181-188.
8	HU Chi-Chih, CHENG Shueh-Hen. Development of alternative methanol/dimethyl carbonate separation systems by extractive distillation—A holistic approach[J]. Chemical Engineering Research and Design, 2017, 127: 189-214.
9	李群生, 付永泉, 朱炜, 等. UNIFAC关联甲醇-碳酸二甲酯汽液平衡[J]. 化工进展, 2011, 30(S1): 622-625.
	LI Qunsheng, FU Yongquan, ZHU Wei, et al. Correlation of vapor-liquid equilibrium for methanol-diethylcarbonate by UNIFAC model[J]. Chemical Industry and Engineering Progress, 2011, 30(S1): 622-625.
10	HUANG Zhixian, LIN Yixiong, WANG Xiaoda, et al. Optimization and control of a reactive distillation process for the synthesis of dimethyl carbonate[J]. Chinese Journal of Chemical Engineering, 2017, 25(8): 1079-1090.
11	HOLTBRUEGGE Johannes, LEIMBRINK Mathias, LUTZE Philip, et al. Synthesis of dimethyl carbonate and propylene glycol by transesterification of propylene carbonate with methanol: Catalyst screening, chemical equilibrium and reaction kinetics[J]. Chemical Engineering Science, 2013, 104: 347-360.
12	AN Ran, CHEN Shengxin, LI Hao, et al. Energy-saving reactive pressure-swing distillation process for separation of methanol-dimethyl carbonate azeotrope via reacting with propylene oxide[J]. Separation and Purification Technology. 2022, 292: 120889.
13	张少钢, 骆有寿. 碳酸二甲酯合成反应的工艺条件及动力学研究[J]. 化学反应工程与工艺, 1991, 7(1): 10-19.
	ZHANG Shaogang, LUO Youshou. Studies on the kinetics and technological conditions of the synthesis of dimethyl carbonate[J]. Chemical Reaction Engineering and Technology, 1991, 7(1): 10-19.
14	LUYBEN William L. Comparison of extractive distillation and pressure-swing distillation for acetone/chloroform separation[J]. Computers & Chemical Engineering, 2013, 50: 1-7.

β/mol	x_PC	γ_MeOH	γ_DMC	α_MeOH/DMC	S_MeOH/DMC
0	0	1.041	2.438	1.041	1.000
0.111	0.1	1.095	1.932	1.387	1.332
0.250	0.2	1.165	1.632	1.753	1.684
0.429	0.3	1.252	1.438	2.145	2.061
0.667	0.4	1.356	1.305	2.570	2.468
1.000	0.5	1.478	1.211	3.031	2.912
1.500	0.6	1.618	1.145	3.531	3.392
2.333	0.7	1.772	1.100	4.063	3.903
4.000	0.8	1.921	1.072	4.588	4.407
9.000	0.9	1.986	1.060	4.960	4.764

β/mol	x_PC	γ_MeOH	γ_DMC	α_MeOH/DMC	S_MeOH/DMC
0	0	1.041	2.438	1.041	1.000
0.111	0.1	1.095	1.932	1.387	1.332
0.250	0.2	1.165	1.632	1.753	1.684
0.429	0.3	1.252	1.438	2.145	2.061
0.667	0.4	1.356	1.305	2.570	2.468
1.000	0.5	1.478	1.211	3.031	2.912
1.500	0.6	1.618	1.145	3.531	3.392
2.333	0.7	1.772	1.100	4.063	3.903
4.000	0.8	1.921	1.072	4.588	4.407
9.000	0.9	1.986	1.060	4.960	4.764

参数	基础参数	参数范围
萃取剂进料量S/kmol·h^-1	100	60～260
萃取精馏塔理论级数N_T2	80	50～90
萃取剂进料位置N_FE	10	5～25
共沸物进料位置N_F2	60	30～70
萃取剂回收塔理论级数N_T3	30	10～40
萃取剂回收塔进料位置N_F3	15	5～25

参数	基础参数	参数范围
萃取剂进料量S/kmol·h^-1	100	60～260
萃取精馏塔理论级数N_T2	80	50～90
萃取剂进料位置N_FE	10	5～25
共沸物进料位置N_F2	60	30～70
萃取剂回收塔理论级数N_T3	30	10～40
萃取剂回收塔进料位置N_F3	15	5～25

项目	萃取精馏		变压精馏
项目	T2	T3	T4	T5
操作压力/MPa	0.1	0.02	0.76	0.1
塔顶温度/℃	64.5	46.4	126.0	63.4
塔底温度/℃	164.7	194.2	169.3	65.4
冷凝器负荷/MW	-3.48	-0.55	9.62	9.85
再沸器负荷/MW	3.88	0.66	9.60	9.09
LP消耗量//t·h^-1	—	—	1.52	—
MP消耗量/t·h^-1	7.15	—	17.2	0
HP消耗量/t·h^-1	—	1.39	—	—
塔板数	60	10	60	60
塔高/m	43.9	7.3	43.9	43.9
塔径/m	2.4	1.1	2.1	2.4
塔费用/10⁶USD	1.03		1.74
换热器费用/10⁶USD	0.84		1.33
设备总费用/10⁶USD	1.87		3.07
冷却水费用/10⁶USD·a^-1	0.04		0.09
蒸汽费用/10⁶USD·a^-1	1.02		2.21
总操作费用/10⁶USD·a^-1	1.06		2.30
年均总费用/10⁶USD·a^-1	1.68		3.32