甲基叔丁基醚(MTBE)的合成

介绍了甲醇、异丁烯合成甲基叔丁基醚的催化剂、热力学、动力学。综述了合成ＭＴＢＥ的主要原料异丁烯的生产过程，并总结了甲醇、异丁醇和甲醇、叔丁醇合成ＭＴＢＥ的研究开发进展。参考文献１６篇。     

Pyrolysis of methyl tert-butyl ether (MTBE). 2. Theoretical study of decomposition pathways

The thermal decomposition pathways of MTBE have been investigated using the G3B3 method. On the basis of the experimental observation and theoretical calculation, the pyrolysis channels are provided, especially for primary pyrolysis reactions. The primary decomposition pathways include formation of methanol and isobutene, CH4 elimination, H2 elimination and C-H, C-C, C-O bond cleavage reactions. Among them, the formation channel of methanol and isobutene is the lowest energy pathway, which is in accordance with experimental observation. Furthermore, the secondary pyrolysis pathways have been calculated as well, including decomposition of tert-butyl radical, isobutene, methanol and acetone. The radicals play an important role in the formation of pyrolysis products, for example, tert-butyl radical and allyl radical are major precursors for the formation of allene and propyne. Although some isomers (isobutene and 1-butene, allene and propyne, acetone and propanal) are identified in our experiment, these isomerization reaction pathways occur merely at the high temperature due to their high activation energies. The theoretical calculation can explain the experimental results reported in part 1 and shed further light on the thermal decomposition pathways.     

Layered Group(IV) Metal Phosphates as Catalysts for MTBE Synthesis

Layered group(IV) metal phosphates and their phenylsulfonic acid derivatives were used as catalysts for the synthesis of methyl tert-butyl ether (MTBE) from methanol and isobutene. Because zirconium and titanium phosphates have only moderate acidic strength, relatively high temperatures are required to activate their Brønsted acidic sites. The optimal activity was obtained at ca. 443 K. Their phenylsulfonic acid derivatives, however, demonstrated higher acidic strength by giving much higher activity toward MTBE formation at relatively low temperaures. The catalysts were characterized in terms of their structure, thermal stability, surface area and acidic strength.     

High-temperature ignition of propane with MTBE as an additive: Shock tube experiments and modeling

Ignition of propane has been studied in a shock tube and by computational modeling to determine the effect of methyl tert-butyl ether (MTBE) as a fuel additive. MTBE and isobutene were added in amounts up to 25% of the fuel to propane-oxygen-argon mixtures in shock tube experiments covering a range of temperatures between 1450 and 1800 K. Ignition delays were measured from chemiluminescence at 432 nm due to excited CH radicals. The temperature dependence of the ignition rates was analyzed to yield Arrhenius parameters of E_a ca. 40 kcal/mol and A ca. 10⁹ s^?1 for the overall propane reaction and E_a ca. 34 kcal/mol and A ca. 10^8.3 s^?1 for the overall propane/MTBE reaction. Reactions involving MTBE and its decomposition products were combined with an established propane mechanism in a numerical model to describe the kinetic interaction of this additive with a typical hydrocarbon fuel. The experiments and the kinetic model both show that MTBE and isobutene retard propane ignition with nearly equal efficiency. The kinetic model demonstrates that isobutene kinetics are responsible for inhibition by both MTBE and isobutene, and the specific elementary reactions that produce this behavior are identified. © 1994 John Wiley & Sons, Inc.     

Multiple steady states in a CSTR with total condenser: Comparison of equilibrium and nonequilibrium models

Comparison of equilibrium and nonequilibrium models of a CSTR with total condenser focused on the multiple steady states and dynamic behaviour was carried out. The steady-state behaviour of the model system, MTBE synthesis from methanol and isobutene in a reactive distillation column, was studied in terms of the input parameters, i. e. feed flow rate of methanol or butenes, reflux ratio, and mass of catalyst. The dynamic behaviour of the system during the start-up was investigated and perturbations of manipulated variables were found to cause transitions between the parallel steady states. Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May 2006.     

甲基叔丁基醚裂解制备高纯度异丁烯

制备了一系列用于甲基叔丁基醚（MTBE）裂解制异丁烯反应的硅酸铝催化剂，评价了其反应活性和选择性，用X光衍射（XRD）、物理吸附、傅立叶变换红外（FT-IR）等技术对催化剂结构性质进行表征。结果表明，添加合适的助剂、适宜的温度下焙烧有助于MTBE裂解制异丁烯硅酸铝催化剂的性能改善和活性提高。在催化剂的物化性质中，与活性关系较密切的是催化剂的比表面积、总酸量和B酸与L酸的比值。同时发现，一种添加助剂并经过特殊处理的催化剂WVI，在常压、WHSV为2 h－1条件下，反应温度从220 ℃提高到360 ℃，累计时间达3 840 h时，MTBE转化率可达99.9%，异丁烯选择性可维持在99%。     

异丁烯二聚反应

由于甲基叔丁基醚(MTBE)对水源的污染,它作为汽油添加剂的应用受到环保限制,并对其生产和应用前景带来消极影响。MTBE经裂解、二聚和加氢生产异辛烷成为国外现有MTBE装置转产的主要途径。本文对异丁烯二聚催化剂、反应活性位、机理及动力学研究成果进行了综述,试图解释在异丁烯二聚时,加入的叔丁醇对二聚反应选择性提高的作用机理,为今后二聚反应的研究提供参考。     

β分子筛的物化性质对其催化活性的影响

研究了β分子筛的物化性质对其催化活性的影响。实验发现,β分子筛对甲基叔丁基醚(MTBE)反应的催化活性是各类酸中心共同作用的结果,但强Lewis酸密度对其活性的影响较大;比表面积、二次孔体积及微孔比表面积等因素与异丁烯转化率无明显的相关性;C4原料中的惰性组分对MTBE反应的影响较小,但以混合C4为原料时MTBE反应的初始反应速率较低。     

Excess enthalpies of mixtures containing n-heptane,methanol and methyl tert-butyl ether (MTBE)

Molar excess enthalpies H ^E have been measured for the binary mixtures MTBE+methanol, MTBE+n-heptane and methanol+n-heptane using a quasi-isothermal flow calorimeter. The measurements have been performed at atmospheric pressure and at 25 and 40°C for all the mixtures and for MTBE+methanol also at 50°C. The experimental results for MTBE methanol and MTBE+n-heptane are compared with those calculated using the NRTL equation.Communicated at the Festsymposium celebrating Dr. Henry V. Kehiaian's 60^th birthday, Clermont-Ferrand, France, 17–18 May 1990     

Vapor–liquid equilibria and excess properties for methyl tert-butyl ether (MTBE) containing binary systems

Methyl tert-butyl ether (MTBE) is recently widely used in the chemical and petrochemical industry as a non-polluting octane booster for gasoline and as an organic solvent. The isobaric or isothermal vapor–liquid equilibria (VLE) were determined directly for MTBE+C₁–C₄ alcohols. The excess enthalpy (H^E) for butane+MTBE or isobutene+MTBE and excess volume (V^E) for MTBE+C₃–C₄ alcohols were also determined. Besides, the infinite dilute activity coefficient, partial molar excess enthalpies and volumes at infinite dilution (γ^∞, H^E,∞, V^E,∞) were calculated from measured data. Each experimental data were correlated with various g^E models or empirical polynomial.     

Sorption of methanol/MTBE and diffusion of methanol in 6FDA–ODA polyimide

This article discusses the diffusion and solubility behavior of methanol/methyl tert‐butyl ether (MTBE) in glassy 6FDA–ODA polyimide prepared from hexafluoroisopropylidene 2,2‐bis(phthalic anhydride) (6FDA) and oxydianiline (ODA). The diffusion coefficients and sorption isotherm of methanol vapor in 6FDA–ODA polyimide at various pressures and film thicknesses were obtained with a McBain‐type vapor sorption apparatus. Methanol/MTBE mixed‐liquid sorption isotherms were obtained by head‐space chromatography and compared with a pure methanol sorption isotherm obtained with a quartz spring balance. Methanol sorption isotherms obtained with the two methods were almost identical. Both methanol sorption isotherms obeyed the dual‐mode model at a lower activity, which is typical for glassy polymer behavior. The MTBE was readily sorbed into the polymer in the presence of methanol, but the MTBE sorption isotherm exhibited a highly nonideal behavior. The MTBE sorption levels were a strong function of the methanol sorption level. Methanol diffusion in the polymer was analyzed in terms of the partial immobilization model with model parameters obtained from average diffusion coefficients and the dual‐mode sorption parameters. Simple average diffusion coefficients were obtained from sorption kinetics experiments, whereas the dual‐mode sorption parameters were obtained from equilibrium methanol sorption experiments. An analysis of the mobility and solubility data for methanol indicated that methanol tends to form clusters at higher sorption levels. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2254–2267, 2000     

12-钨磷酸催化合成甲基叔丁基醚

甲基叔丁基醚(MTBE)作为汽油抗暴剂已经在全世界范围内普遍使用,它不仅能提高汽油辛烷值,而且还能改善汽车性能,降低排气中CO和有机物含量,同时降低汽油生产成本.     

聚酰亚胺、聚砜、聚醚砜及其共混改性中空纤维膜用于醇/醚气相分离的研究

甲醇／ 甲基叔丁基醚的分离是目前具有实用意义的重要研究课题之一,采用气流吹扫式操作,研究了聚酰亚胺、不同结构的聚砜中空纤维膜在不同操作条件下,对甲醇／ 甲基叔丁基醚气相混合体系的分离性能,也研究共混改性对分离膜性能的影响。结果表明,各种材料的膜具有相近的分离行为,即随着气相中甲醇含量的增加,透过通量逐渐增大而分离系数逐渐减小,聚酰亚胺膜具有适中的透过通量,但具有很高的分离系数,在甲醇浓度低于２０ ％ 时,分离系数可达数千。采用聚醚砜共混改性的聚酰亚胺膜在未明显降低透过通量的条件下,使醇／ 醚分离系数大幅度提高,有很好的应用前景。     

聚酰亚胺中空纤维膜用于甲醇/甲基叔丁基醚的分离

甲醇／甲基叔丁基醚混合物的膜法分离，大多采用渗透汽化方法，少有采用蒸汽渗透法。用聚酰亚胺中空纤维膜，对以蒸汽渗透和渗透汽化两种方式分离甲醇／甲基叔丁基醚混合物（甲醇质量分数为0．01－0．30）的效果进行了对比。结果显示，在甲醇质量分数低于0．05时，蒸汽渗透较渗透汽化法的分离性能优越。     

Pyrolysis of methyl tert-butyl ether (MTBE). 1. Experimental study with molecular-beam mass spectrometry and tunable synchrotron VUV photoionization

An experimental study of methyl tert-butyl ether (MTBE) pyrolysis (3.72% MTBE in argon) has been performed at low pressure (267 Pa) within the temperature range from 700 to 1420 K. The pyrolysis process was detected with the tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry (MBMS). About thirty intermediates are identified from near-threshold measurements of photoionization mass spectrum and photoionization efficiency spectrum. Among them, H2, CO, CH4, CH3OH and C4H8 are the major pyrolysis products. The radicals such as methyl, methoxy, propargyl, allyl, C4H5 and C4H7 are detected. The isomers of pyrolysis products are identified as well, i.e., propyne and allene, 1,2,3-butatriene and vinylacetylene, isobutene and 1-butene, propanal and acetone. Furthermore, the mole fractions of the pyrolysis products have been evaluated under various temperatures. Meanwhile, the initial formation temperatures of different pyrolysis products can be obtained. This work is anticipated to present a new experimental method for pyrolysis study and help understand the pyrolysis and combustion chemistry of MTBE and other oxygenated fuels.     

Study on the Nondestructive Analysis of Methanol,Ethanol and Methyl tert-butyl ether in Gasoline by Principal Component Analysis Near Infrared Spectroscopy

Methanol, ethanol, methyl tert-butyl ether (MTBE) and other oxygenates can be added to gasoline to increase octane number and to reduce emission. Concentration of these oxygenates are specified and regulated to ensure acceptable commercial gasoline quality. Thus,the determination of these oxygenates in gasoline are of interest. The amounts of methanol, ethanol and MTBE have been determined by a gas chromatography.     

甲醇与异丁烯在改性β分子筛上的吸附行为研究

采用过渡应答技术对甲醇和异丁烯在改性β分子筛上的吸附行为进行了研究,研究结果表明,异丁烯和甲醇在改性β分子筛上符合先快吸附后慢吸附的Elovich吸附规律。甲醇的吸附量大,但速率慢;异丁烯吸附量小,速率快。由于甲醇的饱和吸附量大于异丁烯的饱和吸附量,对合成MTBE反应的选择性具有重要意义,对它们的吸附行为进行动力学研究,得到了不同温度下吸附活化能随吸附量变化的关系。不同温度下相对饱和吸附量预测表明：当温度从288K升高到383K时,qMeOH/q1BWW 6．1降低到4．6,甲醇的相对饱和吸附量随温度升高而减小,但仍保持较高值,证明了甲醇在分子筛上是强吸附的观点,为解释选择性高和动力学方程的建立提供依据,对反应机理的研究有指导作用。     

甲醇与异丁烯在改性β分子筛上的吸附行为研究

采用过渡应答技术对甲醇和异丁烯在改性β分子筛上的吸附行为进行了研究,研究结果表明：异丁烯和甲醇有改性β分子筛上符合先快吸附后慢吸附的Elovich吸附规律。甲醇的吸附量大,但速率慢,异丁烯吸附量小,速率快;由于甲醇的饱和吸附量大于异下烯的饱和吸附量,对合成MTBE反应的选择性具有重要意义。对它们的吸附行为进行动力学研究,得到不同温度下吸附活化能随吸附量变化的关系。不同温度下相对饱和吸附量预测表明：当温度从288K升高到383K时,qMeOH/qIB从6．1降低到4．6,甲醇的相对饱和吸附量随温度升高而减小,但仍保持较高值,证明了甲醇在分子筛上是强吸附的观点,为解释选择性和高和动力学方程的建立提供依据,对反应机理的研究有指导作用。     

基于纳米SnO2材料的二维纳米催化发光传感器研制及其测定甲基叔丁基醚的应用

以碳纳米管(CNT)为模板,采用液相沉积法可控合成了SnO2-CNT复合纳米材料、SnO2纳米棒两种形貌的SnO2纳米材料,研究了它们对甲醇、MTBE催化发光的影响.通过考察两种不同形貌SnO2纳米材料的结构、比表面积与其催化发光的关系,建立了一种二维纳米催化发光传感器,并测定了MTBE产品的纯度和其中的甲醇含量,甲醇...     

Synthesis of Methyl tert-Butyl Ether from tert-Butyl Alcohol and Methanol Using Beta Zeolite Catalysts

MTBE synthesis from tert-butyl alcohol (t-BA) and methanol has been studied using beta zeolites. Increasing the reaction temperature results in an increase of t-BA conversion with concomittant decrease of MTBE selectivity. The t-BA conversion decreases with increasing calcination temperature and alkali metal ion exchange of H zeolite. The catalytic results are correlated with the surface area and the acidity of catalysts.