Simulation and optimization of MTO product separation process based on front-end depropanization and pre-segmentation

doi:10.16085/j.issn.1000-6613.2015.07.047

Abstract

Abstract: In this work the "front-end depropanization" process to separate methanol to olefins crude products was studied. First the high and low pressure depropanizer distillation tower was utilized, then through demethanizer, deethanizer, ethylene fractionator and propylene fractionator, the paradigmatic level olefin product was obtained, in which the "pre-cutting-oil absorption demethanation" process was applied in the demethanizing section. Smaller energy was consumed through intercooling method and propane produced from the process itself was selected as absorbent. The propylene distillation section used pre-fractionator process to reduce the height of tower. Aspen Plus was utilized to simulate and optimize the demethanizer section, Radfrac distillation model and RKS-BM thermodynamic model were applied to calculate, and based on the sensitivity analysis, the section's feed entrance point, stage number and reflux ratio were optimized. In addition, the dosage and temperature of dimethyl methane absorbent were confirmed. Finally, ethylene at a purity degree of 99.98% and propylene at a purity degree of 99.90% were obtained.

Key words: Aspen Plus simulation, methanol to olefin, demethanizer, oil absorption

摘要： 选择"前脱丙烷"流程对甲醇制烯烃粗产物进行分离。先利用高低塔脱丙烷工艺, 然后经过脱甲烷塔、脱乙烷塔、乙烯精馏塔、丙烯精馏塔, 最终得到聚合级的烯烃产品, 其中脱甲烷工段采用"预切割-油吸收"脱甲烷工艺, 使用耗能较小的中冷分离, 吸收剂选择产自工艺自身的丙烷产品。丙烯精馏工段采用双塔预分流程, 降低塔高。采用Aspen Plus流程模拟软件对脱甲烷工段进行模拟和优化, 选用Radfrac精馏模型和RKS-BM热力学模型进行计算, 对脱甲烷工艺段进料位置、塔板数、回流比进行灵敏度分析, 并确定出丙烷吸收剂的用量和温度, 最终得到纯度为99.98%的乙烯和99.90%的丙烯。

关键词: Aspen Plus模拟, 甲醇制烯烃, 脱甲烷塔, 油吸收

CLC Number:

TQ211

ZHAN Baorui, LI Tao, MA Hongfang, YING Weiyong, FANG Dingye. Simulation and optimization of MTO product separation process based on front-end depropanization and pre-segmentation[J]. Chemical Industry and Engineering Progree, 2015, 34(07): 2086-2091.

展宝瑞, 李涛, 马宏方, 应卫勇, 房鼎业. 前脱丙烷预切割分离MTO粗产品工艺的模拟与优化[J]. 化工进展, 2015, 34(07): 2086-2091.

References

[1] 赵良, 程广伟, 高文刚, 等. 甲醇制烯烃下游烯烃分离技术的简介、对比及发展方向[J]. 河南科技, 2013(16):25-26.
[2] Senetar J, Miller J, Lawrence W. Process for producing ethylene:WO, 01/25174A1[P]. 2001.
[3] Kimberly Russell. 2004 world light olefins analysis[R]. Houston, TX:Chemical Market Associates, Inc (CMAI), 2003.
[4] 刘剑峰, 王健红, 张树增, 等. 脂肪醇装置酯分馏过程模拟[J]. 北京化工大学学报:自然科学版, 2003, 30(6):27-30.
[5] 堵祖荫. 用Aspen Plus模拟汽油分馏塔系统[J]. 乙烯工业, 2002, 04:13-17+5.
[6] 王政, 吕向红, 陆恩锡, 等. 气体分馏过程工艺条件的优化[J]. 青岛科技大学学报:自然科学版, 2004, 25(4):311-313.
[7] 张少石, 陈晓蓉, 梅华, 等. MTO脱甲烷塔分离过程模拟及优化[J]. 化工进展, 2014, 33(5):1093-1100.
[8] 李立新, 刘长旭, 徐国辉, 等. 烯烃催化裂解制丙烯分离技术进展[J]. 化工进展, 2009, 28(7):1159-1164.
[9] 李立新, 倪进方, 李延生, 等. 甲醇制烯烃分离技术进展及评述[J]. 化工进展, 2008, 27(9):1332-1335.
[10] 唐锦文. 甲醇精馏工艺模拟计算及分析[J]. 化工设计, 2006(2):13-17.
[11] Chen J Q, Vora B V, Pujado P R, et al. Most recent developments in ethylene and propylene production from natural gas using the UOP/Hydro MTO process[J]. Studies in Surface Science and Catalysis, 2004, 147:1-6.
[12] Liu Fuyu, Li Chunyi, Ding Xue. Studies on catalytic conversion of ethylene[J]. Journal of Nature Gas, 2007, 16(3):301-307.
[13] UOP LLC. Fast-fluidized bed reactor for MTO process:US, 006166282A[P]. 2000.
[14] UOP LLC. Process for producing polymer grade olefins:US, 005914433A[P]. 1999.
[15] UOP LLC. Conversion of oxygenate to propylene using moving bed technology:WO, 2006/012150 A2[P]. 2006.
[16] UOP LLC. Conversion of oxygenate to propylene with selective hydrogen treatment of heavy olefin recycle stream:US, 2006/0063956 A1[P]. 2006.
[17] 卢光明, 李进良, 陈俊豪, 等. 乙烯装置前脱乙烷工艺节能及长周期运行研究[J]. 化学工程, 2011, 39(12):95-99.
[18] 刘静霄. 煤基乙烯工艺的流程模拟与分析[D]. 北京:北京化工大学, 2013.
[19] 王振维, 盛在行. 乙烯装置分离顺序选择及前脱丙烷技术[J]. 乙烯工业, 2008, 20(4):52-58.
[20] 李建隆, 娄晓燕, 刘颖, 等. MTO产品分离工艺的模拟与优化[J]. 计算机与应用化学, 2013(5):527-530.
[21] Godingz C, Cabanes A L, Villora G, et al. Experimental study of the selective hydrogenation of steam cracking C2 cut. front end and talt end variants[J]. Chemical Engineering Communications, 1998, 164(1):225-247.
[22] 李立新, 杨林林, 李鑫钢等. 乙烯装置前脱丙烷前加氢流程设计要点的分析[J]. 石油化工, 2009, 38(2):174-178.
[23] 张东明. 甲醇制烯烃装置分离流程述评[J]. 化学工业, 2012(6):12-17.
[24] 张臻, 李涛, 应卫勇, 等. 煤间接液化系统中用PSA法回收氢气的模拟[J]. 华东理工大学学报:自然科学版, 2009, 35(4):525-529.
[25] 李沺, 王雷. 甲醇制低碳烯烃反应气体分离的吸收剂分析[J]. 炼油技术与工程, 2011, 41(8):18-21.
[26] Lam W K, Mehra Y R, Mullins D W. Front-end hydrogenation and absorption process for ethylene recovery:US, 5220097[P]. 1993-6-15.
[27] 王学明. 双塔脱丙烷工艺技术[J]. 乙烯工业, 2002, 14(2):53-58.
[28] Godínez C L, Cabanes G, Víllora A. Experimental study of the selective hydrogenation of steam cracking C₂ cut. Front end and tail end variants[J]. Chemical Engineering Communications, 2007, 164(1):225-247.
[29] 李沺, 马婧舒, 刘茜, 等. La-SAPO-34上甲醇制烯烃反应性能及反应气分离的吸收剂分析[J]. 稀土, 2011, 32(4):46-49.