Sorption effect on kinetics of etherification of tert-amyl alcohol and ethanol

The kinetics of the etherification of tert-amyl alcohol with ethanol, catalysed by a strong ion-exchange resin, Amberlyst 15, has been studied in a batch reactor at temperatures between 323 and and at a pressure of . The kinetics was described by a coupled sorption-reaction model. Flory-Huggins (F-H) model was used to predict the solubility of reaction components in the resin phase at (non-reactive conditions). Both sorption interaction parameters of F-H model and kinetic constants were determined by non-linear least-squares method. Langmuir-Hinshelwood (L-H) and power law (PL) kinetic models were compared with the experimental data. Although both the models were found to be equally successful, L-H model has shown a slightly better representation than PL model.     

乙基叔丁基醚合成研究进展

乙基叔丁基醚具有较高的辛烷值,是一种环境友好的汽油添加剂。介绍乙基叔丁基醚在不同催化剂上合成的反应机理,综述国内外合成乙基叔丁基醚的催化剂研究现状及国外几种典型的乙基叔丁基醚生产工艺流程。比较不同催化剂的催化活性、稳定性和选择性。指出通过改性提高树脂催化剂的热稳定性是该领域重要的研究方向。国外已拥有成熟的乙基叔丁基醚合成技术,国内大部分还处于研究阶段,应尽快加强技术开发,早日实现产业化。     

醚化反应法合成乙二醇醚催化剂研究进展

介绍了醚化反应法合成乙二醇醚催化剂的研究进展,并对催化剂的开发提出了建议。在进行环氧乙烷与醇的醚化反应时,使用传统的碱性催化剂,反应容易形成多醚;使用传统的酸性催化剂,反应容易形成有毒物质二烷。已开发的新型催化剂如固体酸、可溶性磺酸盐、高氯酸盐可代替传统催化剂,提高反应产物的选择性和收率。磺酸盐类催化剂和高氯酸盐类催化剂具有较高的工业应用价值,值得进一步研究;研究重点应为镁盐、铝盐和锌盐。     

碳五叔碳烯烃乙醇醚化研究进展

FCC轻汽油中的叔碳烯烃和乙醇醚化,不仅可以降低油品中的烯烃含量,而且可获得优良的汽油增辛剂乙基叔烷基醚。本文全面回顾了碳五（C₅）叔碳烯烃与乙醇醚化合成乙基叔戊基醚（TAEE）的研究进展,分析了所涉及的醚化、异构化、烯烃聚合以及水合等各类反应,并通过对反应体系的热力学分析,考察了各反应进行的难易程度。同时对醚化催化剂、反应机理及动力学等方面的研究成果进行了综合分析,并对今后该领域的发展方向进行了展望。     

Liquid–liquid–solid mass transfer and phase behavior of heterogeneous etherification of glycerol with isobutene

Previous experiments observed auto‐acceleration in the etherification of glycerol with isobutene. This article engaged to uncover the reason for this phenomenon via investigating the heterogenicity, including liquid–liquid phase equilibrium and liquid–liquid–solid mass transfer, of the reaction system. Phase behavior analysis showed that the reaction mixture separates into two liquid phases during the whole course of the reaction. The produced mono ethers of glycerol thermodynamically promote the homogenization of the two liquid phases. The modeling results of liquid–liquid–solid mass transfer indicated that the resistance of mass transfer is insignificant during the reaction. The bulk compositions of the two liquid phases are very close to their corresponding equilibrium compositions. An increase of isobutene concentration in the reaction phase is believed to lead all reactions speeding up. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2526–2535, 2018     

硅酸钠为硅源的介孔分子筛SBA-15-SO3H的研究

在强酸性和水热条件下以硅酸钠（Na₂SiO₃·9H₂O）为硅源合成表面含磺酸基的介孔分子筛催化剂SBA-15-SO₃H。XRD结果表明，该分子筛具有规则的六方立柱形介孔结构。SBA-15-SO3H用于叔丁醇和乙醇合成乙基叔丁基醚（ETBE）的醚化反应研究，分别考察了反应温度、原料配比和反应时间等因素对醚化反应的影响。最佳操作条件为：温度120 ℃，n(乙醇)∶n(叔丁醇)=2∶1，反应时间5 h，m(催化剂) ∶m(原料)=1∶10。在此条件下，叔丁醇的转化率为62.83%。     

Functionalized Multi-Walled Carbon Nanotubes as Heterogeneous Lewis Acid Catalysts in the Etherification Reaction of tert-Butyl Alcohol and Ethanol

Most of the conventional catalysts exhibited limitations in catalyzing etherification reactions. In this study, functionalized multi-walled carbon nanotube (F-CNT) catalyst containing Lewis acid sites were prepared via functionalization with sulfuric acid and the catalytic performances in the etherification of tert-butyl alcohol (TBA) with ethanol were investigated. Characterization of F-CNTs with thermogravimetric analysis, Raman spectroscopy, Fourier transform-infrared spectroscopy, pyridine adsorption, temperature-programmed desorption of ammonia and nitrogen adsorption were performed to correlate the characteristics with the catalytic performances. The catalyst showed a high catalytic performance and high selectivity in the etherification reaction. The best reaction conditions obtained consist of 4 h of reaction time at 140°C, an ethanol:TBA molar ratio of 2:1 and a catalyst loading of 3 wt%. The best conversion of TBA and TBA selectivity toward ethyl tert-butyl ether (ETBE) were 64% and 68%, respectively. No significant degradation of the catalytic performance was observed after four consecutive reactions and the catalyst was easily regained after regeneration. A mechanism for the etherification reaction was also proposed.     

Linear and networked polymers formed by the near simultaneous occurrence of etherification and esterification under mild reaction conditions

Despite the large difference in their nucleophilicity, phenoxide and carboxylate anions take part nearly simultaneously in the aliphatic nucleophilic substitution reaction with 1,4‐dibromo‐2‐butene. This leads to the formation of ether (? O? ) and ester (? COO? ) linkages simultaneously under mild reaction conditions when hydroxyl benzoic acids are employed as nucleophiles. The process yields a new class of polymer broadly classified as unsaturated poly(ether ester) which are potentially functionalizable. This methodology has also been extended for preparing networked polymers by making use of 3,5‐dihydroxybenzoic acid as A₃ type monomer. Copyright © 2011 Society of Chemical Industry     

醚-醇-水体系等压汽液平衡数据的测定

用改进的Rose平衡釜测定了等压 (0 .10 13MPa)下五个二元体系 (乙醇 水、叔丁醇 水、乙醇 叔丁醇、乙基叔丁基醚 乙醇、叔丁醇 乙基叔丁基醚 )和一个四元体系 (水 乙醇 叔丁醇 乙基叔丁基醚 )的汽液相平衡数据。用UNIFAC基团贡献法预测了上述五个二元体系及一个四元体系的汽液相平衡 ,预测结果与实验数据吻合较好。     

乙基叔丁基醚合成技术进展

乙基叔丁基醚(ETBE)是一种性能优良的高辛烷值汽油调和组分.综述了国外几种典型的ETBE生产工艺流程以及国内ETBE合成技术的研究现状.目前国外ETBE生产技术已经成熟,建议国内应加快研究开发并实现产业化.指出采用催化蒸馏技术和渗透蒸发膜分离回收乙醇技术将成为今后的发展方向.     

水＋醋酸＋甲基叔丁醚三元体系汽液平衡数据的实验测定及数学模拟

用改进的Rose釜测定了常压下H2O＋HAc＋甲基叔丁醚三元体系部分汽液平衡数据,借助实验数据,利用AspenPlus软件对该三元体系NRTL和UNIQUAC方程的模型参数进行了回归。回归结果反过来用于汽液平衡的数学模拟,结果表明实验数据与模拟结果很吻合,该结果可以为相关研究及工业设计提供帮助。     

离子液体的固载化及其在甘油醚化中的性能

将实验室自制的离子液体[BMIM]BF_4固载在活性炭上作为催化剂,研究其在甘油与叔丁醇醚化反应中的催化性能,并利用单因素实验考察反应温度、反应时间、n(叔丁醇)∶n(甘油)和催化剂离子液体负载量对甘油转化率以及醚化产物选择性的影响。结果表明,在无需额外添加溶剂、n(叔丁醇)∶n(甘油)=4∶1和离子液体负载量为甘油质量的9%条件下,在85℃,以150 r·min~(-1)速率反应10 h,甘油羟基转化率最高可达73%,甘油二醚和甘油三醚选择性分别为32.67%和16.81%。     

用新离子交换树脂催化剂优化连续催化精馏塔中乙基叔丁基醚的合成(英文)

Liquid phase synthesis of one of the important fuel oxygenate, ethyl tert-butyl ether （ETBE）, from etha-nol and tert-butyl alcohol （TBA） has been studied in catalytic distillation column （CDC） using ion exchange resin catalyst CT-145H. A packed CDC of 1.2 m height and 50 mm diameter with indigenously developed reactive sec-tion packing was used to generate experimental data. Effect of different key variables on product purity in distillate, was investigated to find the optimum operating conditions for ETBE synthesis. The optimum conditions for 0.2 kg·s-1 of ethanol feed were found：reboiler duty of 375 W, molar feed ratio of 1︰1.3 of reactants, and reflux ratio of 7. Concentration profiles for each component along each column section at optimum conditions were also drawn. Neither output nor input multiplicity was observed at experimental conditions.     

关于压力、惰性组分对平衡移动影响的讨论

本文由化学反应等温方程出发,利用微分法导出了压力变化后平衡移动之前,摩尔反应吉布斯函数随压力的变化规律（恒温）,惰性组分物质的量变化后平衡移动之前,摩尔反应吉布斯函数随惰性组分物质的量的变化规律（恒温、恒压）,并对压力、惰性组分对化学平衡移动的影响进行了讨论。     

水-异丙醚-对苯二酚液-液-固等温平衡数据的实验测定

用气相色谱仪测定了常压下水-二异丙基醚-对苯二酚在50℃和46℃的两个等温平衡数据.这两个等温截面的特点是:存在单相液体与对苯二酚固体的平衡区域,同时存在液相分层的广阔的两相共存区域.实验表明,等温截面上没有液-液-固三相共存点.实验数据包括对苯二酚的饱和溶解度数据和两液相共存数据.二异丙基醚萃取水中对苯二酚的饱和分配系数仅为0.7～1.3,远小于二异丙基醚萃取水中苯酚的分配系数.结论是:等温下用二异丙基醚萃取水中对苯二酚并不很有效.     

水-醋酸-二异丙醚三元体系液液相平衡数据的测定

实验测定了水-醋酸-二异丙醚三元体系在293.15 K、303.15 K的液液相平衡数据.分别采用Othmer-Tobias和Bachman方程对实验数据进行了可靠性检验,相关性系数均大于0.983.绘制了三元液液平衡相图.     

Thermodynamic Equilibrium Analysis of Propane Dehydrogenation with Carbon Dioxide and Side Reactions

A thermodynamic analysis of propane dehydrogenation with carbon dioxide was performed using constrained Gibbs free energy minimization method. Different reaction networks corresponding to different catalytic systems, including non-redox and redox oxide catalysts, were simulated. The influences of CO₂/C₃H₈ molar ratio (1–10), temperature (700–1000 K), and pressure (0.5–5 bar) on equilibrium conversion and product composition were studied. In the presence of CO₂ with a molar ratio of CO₂/C₃H₈ = 1, the temperature of dehydrogenation can be 30 K lower than that of dehydrogenation in the presence of steam (H₂O/C₃H₈ = 1) and about 50 K lower than that of simple dehydrogenation without dilution to achieve 60% propane conversion. It was found that the occurrence of dry reforming of propane and coke-forming side reactions could strongly impact the equilibrium product composition of the multireaction system and, therefore, these reactions should be kinetically controlled. Comparison of the simulated reactant conversions with those reported in the literatures revealed that the experimental conversion levels of propane are far below the corresponding equilibrium values due to rapid catalyst deactivation by coke, implying that research efforts should be directed toward formulation of more active and selective catalysts.     

基于EXCEL分析减压精馏对乙苯-苯乙烯相平衡的影响

用EXCEL定量分析了减压对乙苯—苯乙烯相平衡的影响。结果表明,减压确实大大降低了乙苯—苯乙烯的泡、露点,但并末提高相对挥发度α．且α几乎不随塔内液相组成变化。这两个结论与现有化工原理教科书对气—液相平衡的有关阐述不相吻合。     

苯酚羟化液萃取脱水的液液相平衡数据的测定

本文研究了异丙醚和甲基异丁基甲酮作为苯酚羟化液萃取脱水剂在20℃时的液-液相平衡关系。采用浊度法和色谱法相结合的策略测定了体系的相平衡曲线,并绘制了三元相图：从三元相图的平衡曲线看,所用萃取剂具有较好的萃取性能。     

在改性HY分子筛催化剂上甲基叔丁基醚与苯酚合成步丁基苯酚的研究

甲基叔丁基醚(MTBE)作为烷基化剂,以改性HY分子筛为催化剂,在常压连续流动固定床反应器上,对苯酚烷基化合成对叔丁基和2,4-二叔丁基苯酚(2,4-DTBP)的反应规律进行了较为系统的研究.以不同改性物及其含量改性HY分子筛可调变其表面酸量、酸分布及孔道尺寸,从而改变催化剂的反应活性及产物选择性.苯酚与MTBE烷基化反应主要在中等强度和弱的B酸中心上进行.催化剂表面的酸量和酸分布不但影响活性,同时影响2,4-DTBP的选择性.对10种单组分氧化物改性的HY分子筛催化剂研究表明,每种改性物均存在一个最佳含量,P2O5改性后HY催化剂的性能最优越.苯酚的转化率达99.60%,2,4-DTBP选择性达63.90%.这一结果是目前分子筛用催化剂合成2,4-DTBP的最好结果,具有潜在的应用前景.