催化干气制乙苯装置工业操作条件优化

催化干气制乙苯气相烷基化和液相烷基转移组合技术及催化剂,可利用干气中乙烯与苯反应生产我国紧缺的乙苯产品,具有良好的适应性。受干气原料限制在相对较低的生产负荷条件运行时,可通过优化脱丙烯系统、提高C3+脱除率、适当提高苯烯比、稳定反应压力、调整干气进料分布、实际生产中充分保护催化剂,减少MDEA、水、液相苯等对催化剂的影响等措施,有效保护催化剂反应性能充分发挥,延长催化剂使用寿命,提高乙苯产量,降低加工成本。     

变床层高度固定床反应器的分析

在分子筛催化剂苯气相乙基化制乙苯过程开发中,根据该反应过程的特点,提出了变床层高度固定床反应器的构想。利用催化剂失活动力学模型,通过模拟计算,对常规固定床反应器和变床层高度固定床反应器的性能进行比较,结果表明后者对延长反应器操作周期和改善反应选择性均有显著作用。上述分析已在300吨乙苯/年中试反应器的运转中得到证实。     

乙苯装置催化干气进料系统改造

乙苯装置烃化反应器催化剂床层反应温升低于设计值,导致乙苯的收率下降,另外,随环境温度的变化参数波动较大;改用SEB-08型烃化催化剂后,要求烃化反应器入口温度提高20℃,现循环苯加热炉热负荷已无法满足生产需要。为此,利用脱氢单元工艺凝液余热将催化干气进行提温,使烃化反应床层温升达到设计要求。改造后,乙苯收率提高0.6%,二乙苯收率下降3.8%,增效约480万元/a;循环苯加热炉的负荷得到下降,减少燃料气费用约250万元/a。     

USY分子筛上苯与多仲丁苯烷基转移反应

在微型固定床反应器上研究USY分子筛对苯与多仲丁苯烷基转移反应的催化性能,考察反应温度、原料配比和空速等工艺条件对反应的影响。采用NH₃-TPD、吡啶IR吸附和N2吸附-脱附等手段对USY分子筛酸性质和孔结构进行表征。结果表明,USY分子筛在烷基转移反应中具有较好的催化性能,二仲丁苯转化率为87.7%,三仲丁苯转化率为19.3%,仲丁苯选择性为91.38%,与USY分子筛的多级孔道和较多B酸位有关。多仲丁苯转化率和仲丁苯选择性随反应温度的提高而增大,原料中苯的增加可提高仲丁苯选择性,空速对二仲丁苯转化率影响较小,但对仲丁苯选择性和三仲丁苯转化率影响显著。USY分子筛上反应较适宜的工艺条件为：反应温度240 ℃,反应压力3 MPa,苯与二仲丁苯物质的量比16,二仲丁苯空速1.4 h^-1。     

SEB-08催化剂在300 kt·a-1稀乙烯制乙苯装置上的工业应用

中海石油宁波大榭石化有限公司300 kt·a^-1稀乙烯制乙苯装置为国内最大的稀乙烯制乙苯装置,上游采用增强型催化裂解(DCC-plus)技术,原料稀乙烯中乙烯浓度较大。介绍SEB-08稀乙烯制乙苯催化剂在该装置的工业应用情况,结果表明,乙烯转化率和乙基选择性均>99.50%,乙苯纯度>99.85%,SEB-08催化剂具有活性高、选择性好和单程使用寿命长等优点,适用于以催化裂解尾气为原料的大规模装置。     

沸石液相烃化合成异丙苯中烷基转移技术进展

多异丙苯烷基转移是苯与丙烯烃化合成异丙苯工艺的重要组成部分。本文介绍了工业化沸石液相烃化中烷基转移技术的特点, 综述了多异丙苯烷基转移催化剂的研究进展, 总结了多异丙苯烷基转移反应的基础研究, 以期对研制高活性催化剂、提高选择性、抑制正丙苯生成、延长催化剂使用寿命等有所裨益, 使沸石液相烃化技术更具竞争力。     

Transalkylation of diisopropylbenzene with benzene over SAPO‐5 catalyst: a kinetic study

BACKGROUND: The objective of this work was to improve the selective yield of cumene by transalkylating the (diisopropylbenzene) DIPB formed in benzene alkylation with propene and select the optimum process conditions for this transalkylation over SAPO‐5 catalyst. RESULTS: Higher benzene/DIPB mole ratios and higher space velocities were found to give better cumene selectivity. An apparent activation energy value of 130.2 kJ mol^?1 was obtained for the reaction with SAPO‐5 as the catalyst. CONCLUSION: SAPO‐5 shows promise when loaded with a small quantity of platinum (0.005% w/w) in the transalkylation of commercial DIPB (cumene column bottoms) with benzene. The kinetic investigations help in selecting optimum process operating conditions for maximizing the cumene yields in transalkylation of commercial DIPB over SAPO‐5. Copyright © 2008 Society of Chemical Industry     

SEB-08催化剂在干气制乙苯装置的工业应用

中国石油化工股份有限公司广州分公司采用新一代SGEB气相法干气（稀乙烯）制乙苯技术,建成一套年产85 kt干气制乙苯装置。烷基化催化剂使用中国石油化工股份有限公司上海石油化工研究院研制的SEB-08稀乙烯制乙苯催化剂。运行结果表明,SEB-08催化剂可适用不同浓度的稀乙烯原料,具有较强的抗工艺波动能力,原料循环苯中甲苯含量对二甲苯的产生有较大影响,必须严格控制循环苯中甲苯含量;标定结果表明,在反应器入口温度344 ℃、入口压力0.86 MPa、苯与乙烯物质的量比6.71、乙烯质量空速0.297 h^-1和装置反应负荷109%条件下,乙烯转化率为99.73%,乙基选择性为99.65%,二甲苯含量为848×10^-6。SEB-08催化剂具有处理量大、活性高、选择性和稳定性好等优点,有利于提供现有干气制乙苯装置的生产能力。     

YSBH-3分子筛催化剂上苯与丙烯泡点烷基化工艺条件

采用等温固定床积分反应器,对YSBH-3分子筛催化剂上苯与丙烯烷基化合成异丙苯进行了实验研究,系统考察了反应体系相态变化(液相反应泡点反应气相反应)对YSBH-3分子筛催化剂性能的影响,并与工业YSBH-3分子筛催化剂的液相烷基化(操作压力3 MPa)结果进行了对比分析。结果表明(1)YSBH-3分子筛催化剂在2 MPa操作压力下的性能明显优于3 MPa操作压力下的性能,具有更高的异丙苯选择性和更低的二异丙苯和三异丙苯选择性;(2)与2 MPa下气相和液相烷基化结果相比,2 MPa泡点温度下进行苯与丙烯烷基化具有最高的异丙苯选择性,更低的二异丙苯、三异丙苯和正丙苯选择性。这一结论对提高工业装置的异丙苯产品质量、降低后续分离工段负荷和减少烷基转移反应器处理量非常有利。以单因素实验法系统考察了液相空速(5~35 h-1)和苯与丙烯的物质的量之比(5~12)对2 MPa压力下、苯与丙烯泡点烷基化的影响,最终确定的相对适宜泡点烷基化工艺条件范围为:压力2 MPa,苯与丙烯的物质的量之比8:1~10:1(对应的泡点温度为176~184℃),液相空速8~11 h-1。在此条件下,丙烯转化率保持在99%以上,异丙苯和二异丙苯选择性分别保持在86%和13%左右。     

带侧反应器反应精馏塔的苯氯化与氯苯精馏过程模拟研究

引入独立反应量概念建立了多侧线进料的带侧反应器的反应精馏塔平衡级模型,并运用Newton-Raphson法解该模型的MESH方程. 将该方法应用于苯氯化反应精馏过程模拟,模型具有很好的收敛效果. 在给定的模拟条件下,Cl2进料量为8 kmol/h时,产品氯化苯纯度达96.8%,最佳苯进料量为7.77 kmol/h. 模拟结果可用于指导苯氯化生产.     

苯与乙烯在ZSM－5上的烷基化反应（Ⅲ）固定床反应器行为的化较

给出了低浓度乙烯和苯在ＺＳＭ－５型分子筛催化剂上的宏观动力学方程。建立了中试固定床反应器模型。模型值与中试结果相一致。化较了单段绝热床、等温床和多段绝热床反应器行为。结果表明：在达到乙烯９５％转化率时，苯生成乙苯和乙烯生成乙苯的选择性为等温床要化单段绝热床好；四段绝热床可达到与等温床相当的指标。考虑到绝热床投资少，操作简单，可变性强，四段绝热床反应器应该是首选的反应装置。     

300kt/a干气制乙苯装置运行分析及优化

介绍了300kt/a催化干气制乙苯装置运行情况。装置从2016年6月首次投料一次开车成功,装置运行平稳,乙苯产品达99.836%,达到国家优级品指标。乙苯装置苯单耗0.747,乙烯单耗0.272,乙苯装置的综合能耗117.7kg,物耗和能耗均优于国内其他同类装置。通过设计上进一步优化,乙苯装置增加循环苯汽化器,提高装置的稳定性,降低操作难度。     

Comparative Study Between Ethylbenzene Disproportionation Reaction and its Ethylation Reaction with Ethanol over ZSM-5

Ethylation of ethylbenzene with ethanol has been studied over ZSM-5 catalyst in a riser simulator that mimics the operation of a fluidized-bed reactor. The feed molar ratio of ethylbenzene:ethanol is 1:1. The study was carried out at 350, 400, 450, and 500 °C for reaction times of 3, 5, 7, 10, 13, and 15 s. Comparisons are made between the results of the ethylbenzene ethylation reaction with that of ethylbenzene disproportionation reaction earlier reported. The effect of reaction conditions on ethylbenzene reactivity, p-diethylbenzene selectivity, total diethylbenzene (DEB) isomers selectivity, p-DEB-to-m-DEB ratio, benzene-to-DEB molar ratio, and benzene selectivity, are reported. Benzene selectivity is about 10 times more in the EB disproportion reaction as compared to its ethylation reaction with ethanol at 350 °C. In addition, the results showed a p-DEB/m-DEB ratio for the EB ethylation reaction varying between 1.2–1.7, which is greater than the equilibrium values. Increase in temperature shifts the alkylation/dealkylation equilibrium towards dealkylation, thereby decreasing conversion and selectivity to DEB.     

Y沸石催化剂催化蒸馏干气与苯制乙苯

采用耐水、耐硫的改性Y沸石催化剂,对催化蒸馏干气与苯制乙苯工艺进行了研究,得到了较佳的催化蒸馏反应工艺条件。乙烯重量空速、反应温度和压力、回流比是影响乙烯转化率的主要因素,而乙苯选择性随反应条件的变化较小,一般在90%~95%。反应段温度分布均匀,乙苯等反应产物的含量很低,一般不超过2%(mol)。     

Alkylation of Benzene with Isopropyl Alcohol over SAPO-5 Catalyst in an Integral Pressure Reactor

The alkylation of benzene with isopropyl alcohol was studied in an integral pressure reactor over silicon substituted aluminophosphate molecular sieves, SAPO-5. The influence of various process parameters such as temperature, pressure, time on stream, weight hourly space velocity, and mole ratio of reactants on cumene yield and selectivity were investigated. The activity of SAPO-5 was compared with that of Hbeta for this reaction under similar conditions and in the same reactor. At pressures higher than atmospheric, almost the theoretical maximum yields of cumene were achieved on this SAPO-5. Among the diisopropyl benzenes formed by the alkylation of cumene, the meta-isomer was found to form in a significant amount followed by the para-isomer. The ortho-isomer with relatively high strain energy of 4.26 kcal/mol was almost negligible. The cumene yield goes through a maximum in the temperature range 498-543 K studied. Cumene selectivity was found to decrease at higher temperatures, higher pressures and lower benzene to isopropanol mole ratios.     

气相法乙苯清洁生产工艺技术进展

随着乙苯需求不断增加,乙苯工艺的开发和应用也不断进步。20多年来,我国气相法乙苯清洁生产工艺技术经历了由国外引进到催化剂国产、再到成套技术自主创新的发展历程。中国科学院大连化学物理研究所开发了用于气相法干气制乙苯的ZSM-5/ZSM-11分子筛催化剂,中国石化上海石油化工研究院开发了一系列以ZSM-5分子筛为活性组分的气相法制乙苯催化剂,我国乙苯总产能已跃居世界首位,其中,采用气相法催化剂及工艺技术的装置规模达2 410 kt·a-1,催化剂性能和工艺技术指标达到世界先进水平,所用原料也由纯乙烯拓展到稀乙烯和乙醇。在气相法工艺大规模推广的同时,对现有技术的改进、新催化剂和新工艺技术的开发工作也在进行中,未来气相法乙苯生产工艺的能耗将进一步降低,原料普适性也更好。     

Alkylierung und Umalkylierung von Aromaten an Alumosilicaten

Alkylation and Transalkylation of Aromatics on Alumosilicates The alkylation of toluene (benzene) with methanol and the isomerization of metaxylene on alumina-silica and modified zeolites (HNaY, HM, HZSM-5) are acid-catalyzed proceed via a same intermediate. Except for the samples HZSM-5, the alkylation of toluene (benzene) can be explained by activity — selectivity — correlations. The referential diffusion of para-xylene in the channels of zeolithe ZSM-5 leads to a high product selectivity in alkylation and transalkylation reactions. Suggesting the supposition of a triangular reaction scheme.     

催化裂化干气烃化制二乙苯

在装有100 mL LaZSM5-Al-Mg催化剂的固定床反应器内进行了质量分数为68.5％的苯和质量分数为18.9％的乙苯混合原料与催化裂化干气制二乙苯反应，在反应温度340 ℃、反应压力0.7 MPa、乙苯空速7 h^-1和n(乙苯)∶n(乙烯)=4.5∶1的反应条件下，乙苯不转化，只消耗苯，乙烯转化率在90%左右，对二乙苯选择性和收率分别为85％和75％左右，无邻位二乙苯生成。同时考察了催化剂的运行寿命。     

微通道反应器内乙苯连续氧化反应工艺研究

研究了在"心型"结构微通道反应器内乙苯与过氧化氢反应连续合成苯乙酮的氧化工艺过程,考察了乙苯与催化剂醋酸钴的摩尔比、停留时间、溶剂量、反应温度等对单程转化率及选择性的影响。在典型的工艺条件下,n(醋酸钴)∶n(乙苯)=13%,停留时间70 s,促进剂Br/Co=1.75,V(冰乙酸)/V(乙苯)=10∶1,温度为100℃,乙苯的转化率达到30.7%,苯乙酮的选择性达到100%。     

Synthesis of ethylbenzene by alkylation of benzene with diethyl oxalate over HZSM-5

Catalytic synthesis of ethylbenzene by alkylation of benzene with diethyl oxalate was carried out over HZSM-5 with Si/Al ratios from 50 to 250. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature-programmed desorption (NH₃-TPD) and pyridine IR techniques. As revealed by the results of NH₃-TPD and pyridine IR spectra, a significant decrease in acidic strength and the number of acidic sites is observed with increasing Si/Al ratio from 50 to 250. The benzene conversion and ethylbenzene selectivity increases obviously with increasing Si/Al ratio from 50 to 200. With a further increase in Si/Al ratios, a slight decrease in the conversion of benzene and selectivity for ethylbenzene is detected, indicating that a proper acidic strength was required in this reaction. In addition, the effects of temperature and feed ratio on the catalytic activity and product distributions are also investigated in this study.