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均三甲苯生产与分离技术新进展 总被引:8,自引:0,他引:8
本文评述了均三甲苯生产技术的新进展,重点介绍了作者最近开发的通过偏三甲苯异构化和烷基化反应生产高纯均三甲苯联产均四甲苯的新工艺。该工艺已实现年产600吨均三甲苯工业化生产,产品纯度达98.5%。它是目前国内较先进的均三甲苯、均四甲苯生产技术,具有以下优点:采用异构化和烷基化相结合的方法既可消除甲乙苯的累积,又可保证均三甲苯和均四甲苯的产量和质量;采用变压强-塔顶累积联合操作法进行精馏分离可显著提高分离效率、缩短操作周期、 降低能耗与生产成本,是对传统分批精馏操作的有效改进。 相似文献
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匡华 《化学反应工程与工艺》2004,20(2):184-187
介绍了均三甲苯分离技术的新发展,研究开发了一种新工艺,以叔丁醇为烷基化剂,无水三氯化铝为催化剂,通过傅-克烷基化反应将邻甲乙苯转化成沸点较均三甲苯高的重组分,使二者能通过常规精馏的方法得以有效地分离。研究了反应温度、原料配比、催化剂用量等反应条件对烷基化反应的影响,烷基化反应的最佳工艺条件为室温、反应时问2~4h、C9芳烃与烷基化剂(叔丁醇)及催化剂的摩尔配比为1:1:0.4,可使邻甲乙苯100%转化,而均三甲苯损失率小于2%。 相似文献
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均三甲苯是一种重要的化工原料,通常存在于重整重芳烃中,其中均三甲苯与偏三甲苯、邻甲乙苯的分离较为困难。测定了2 kPa下均三甲苯(1)-偏三甲苯(2)、均三甲苯(1)-邻甲乙苯(3)两个体系的汽液相平衡数据,并分别采用NRTL和UNIQUAC活度系数模型对相平衡数据进行关联,回归获得二元交互参数,并进行了热力学一致性检验。结果表明,在2 kPa下,均三甲苯与邻甲乙苯无法通过普通精馏实现分离。通过对均三甲苯-偏三甲苯-邻甲乙苯体系进行烷基化反应,而后分别采用单塔减压精馏和双塔减压精馏对反应产物的分离进行精馏模拟,得出较优工艺为双塔连续减压精馏,两塔塔板数分别为50,回流比分别为7和8,此时均三甲苯纯度可达98%(质量)。该研究不仅补充了汽液相平衡数据库,也为低压下C9体系的分离工艺设计提供参考。 相似文献
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均三甲苯合成新工艺研究 总被引:4,自引:0,他引:4
研究了以廉价的混合二甲苯和一氯甲烷为原料、液相法合成均三甲苯的新工艺 ,讨论了各种工艺条件对反应的影响 ,并找到了最佳工艺条件 ,即混合二甲苯 10 0 0mL ,反应温度 12 0— 130℃ ,催化剂用量5 % ,烷基化剂流量 0 .0 6m3 /h ,搅拌速度 40 0r/min ,反应时间 5h ,通入氯甲烷 3h。在此条件下反应液中均三甲苯的含量达到 14%左右。该工艺具有原料价廉易得、产品含量较高的特点 ,满足工业化的要求 ,具有广阔的发展前景 相似文献
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异丁烯烷基化使C9芳烃中的邻甲乙苯生成重组分而采用精馏方法除去,同时异丁烯难以与1,3,5-三甲苯(均三甲苯)反应而有效降低消耗。异丁烯催化烷基化方法得到工业要求含量为98.5%的高纯度均三甲苯合格产品。 相似文献
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The catalytic properties of zeolite NU-87 were investigated in the conversion of 1,2,4-trimethylbenzene in view of the product selectivity. To examine the catalysis by external acid sites, experiments were conducted over NU-87 with external surface poisoned by 1,1,1,3,3,3-hexamethyldisilazane. For comparison, the results obtained over MCM-22, which has a similar pore structure, are also included. Both disproportionation (to xylene and tetramethylbenzene) and isomerization (to 1,2,3- and 1,3,5-isomers) take place over NU-87. Under the present conditions, it is found that the disproportionation proceeds largely within the micropores of NU-87, while the isomerization reaction occurs mainly on the external surface. The distribution of xylene isomers is thermodynamically controlled inside the pores, whereas amongst tetramethylbenzene isomers, the 1,2,4,5-isomer is selectively produced through the channel system. The bulky product, 1,2,3,5-tetramethylbenzene (or 1,3,5-trimethylbenzene), is severely hindered from diffusing through the channel system of NU-87. However, 1,2,3,4-tetramethylbenzene and 1,2,3-trimethylbenzene diffuse out of the micropores to a certain extent. In the case of MCM-22, the conversion of 1,2,4-trimethylbenzene hardly proceeds within the micropores. It is evident that NU-87 has larger pores and thus higher accessibility to 12-MR cavities than MCM-22. 相似文献
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Ferri- and gallo-silicate analogues of NCL-1, a high silica large pore zeolite, have been synthesized and characterized through spectroscopic methods (XRD, IR, ESR and solid state MAS NMR), ion exchange capacity, adsorption (n-hexane, 1,3,5-trimethylbenzene and water), BET surface area and catalytic activity and selectivity in Brønsted acid catalyzed conversion of 1,3,5trimethylbenzene measurements. These data were compared with those exhibited by Al-NCL-1 analogue. During 1,3,5-trimethylbenzene (mesitylene) isomerization into 1,2,4-trimethylbenzene (pseudocumene), the conversion decreased in the order: Al> Ga-> Fe-NCL-1 (at the same reaction temperature, WHSV and time on stream). However, the selectivity for pseudocumene and isomerization selectivity (vis-á-vis disproportionation) followed the reverse order at comparable conversion level. 相似文献
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在加压固定床反应器上,研究了Ni-Mo/HM催化剂的偏三甲苯异构化性能。重点考察了反应温度、反应压力、质量空速和氢油比[n(氢气)/n(偏三甲苯),下同]等因素对反应的影响,得到了较适宜的反应工艺条件:反应温度260~270 ℃,反应压力1.2 ~1.4 MPa,质量空速0.9~1.1 h-1,氢油比为5~6。在反应温度260 ℃,压力1.2 MPa,质量空速1.0 h-1,氢油比为5的条件下,偏三甲苯的质量转化率为49.17%,均三甲苯的质量收率为23.10%,均三甲苯的选择性为46.98%。实验结果表明在该反应条件下,该催化剂具有良好的催化活性。 相似文献
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James D. Burrington John R. Johnson Paul A. Lewis 《Applied Catalysis A: General》2001,210(1-2):193-206
A heterogeneous gas/solid catalytic process for the simultaneous isomerization and dechlorination of nonenes has been identified. Several catalyst systems, including a variety of solid acids, are effective for these reactions. The catalytic isomerization reaction increases the relative level of isomers with higher reactivity towards aromatic alkylation. The dechlorination reaction involves elimination of HCl. The process has been applied to the reactivation and recycle of recovered nonenes from the AlCl3-catalyzed alkylation of diphenylamine. The relative reactivites of the various proposed isomers towards alkylation of diphenylamine catalyzed by AlCl3, and a mechanism for their redistribution in the recovered alkylate after catalytic re-isomerization are proposed. 相似文献