混合C4齐聚制高辛烷值汽油调和组合

Methyl-tert-butyl-ether (MTBE) and aro-matics have been used as standard high-octane gasoline additives for many years, but for environmental reason, they will be phased out in the US from the beginning of 2003[1].     

Synthesis and Crystal Structure of 1,2,4,6-Tetraphenyl-2-hydroxy-8-azabicycle[3,2,1]octane

1 INTRODUCTIONAtrope alkaloids, which exist in eggplant plants, such as atrope and scopolamine, are used as a series of important drugs in medical science [1,2]. The typical character of atrope alkaloid is that these compounds contain the main skeleton of 8-azabicycle[3,2,1]octane , which results in the very complicated synthetic routine[3]. During our research for the reaction of 1,3,5,7-tetraphenyl-4- nitro-1,7-heptadione with low-valent titanium reagent, we easily synthesized the title …     

液相氧化羰基化合成碳酸二乙酯的新型催化体系CuCl/1,10-菲罗啉/N-甲咪唑

Diethyl carbonate (DEC) is one of the important green chemicals widely used for organic synthesis because of its various functional groups. DEC is a better octane blending fuel, and has more oxygen in the molecule than methyl tert-butyl ether (MTBE), 40.6% versus 18.2%, which reduces emissions from gasoline and diesel engine. For these reasons many studies on the production of DEC have been extensively carried out.     

Enhancing the Deactivation Durability of Nano-sized HZSM-5 for Aromatization by Adjusting its Ratio of Lewis/Brφnsted Acid Sites

Nano-sized zeolites have special physicochemical properties compared to micron-sized ones1,2. Recently, we have demonstrated the effectiveness and the remarkable deactivation durability of nano-sized HZSM-5 in converting the olefins of FCC gasoline to high octane number alkylbenzenes3. The role of zeolitic acidity is an intensively studied topic in the aromatizations of light hydrocarbons over micron-sized HZSM-5. But it is seldom reported for the aromatization of gasoline olefins over …     

碘甲烷在碳酸二甲酯直接合成中的作用

Dimethyl carbonate (DMC) is an environmentally friendly compound and a substitutive intermediate for highly toxic phosgene or dimethyl sulfate in carbonylation and methylation reactions as well as a promising octane booster. The common methods for its preparation are the oxidative carbonylation of methanol catalyzed by a variety of transition metal ions and the transesterification of ethylene carbonate or propene carbonate with methanol[1]. The direct synthesis of DMC from carbon dioxide and methanol is a challenging route in which the most abundant carbon resources and a main greenhouse gas is used as feedstock. A new method for the direct synthesis of DMC catalyzed by the methoxide of main group metal has attracted more and more attention since it was reported[2～6] . However the lower conversion of the reaction has become the main obstacle for its application. In this letter, an efficient promoter for the direct synthesis of DMC is reported.     

A Novel Way to Prepareγ-A1_2O_3 Supported SO_4~(2-)/ZrO_2 Solid Superacid Catalysts for n-Butane Isomerization

The isomerization of n-butane to isobutane, which is a valuable precursor for theproduction of MTBE and alkylated gasoline, on strong acid catalysts is an importantprocess in refining industry. Solid superacid, especially sulfated zirconia, has highcatalytic activity in n-butane isomerization at comparatively low temperatures andtherefore has attracted more attention of researchers in the past twenty years.' However,from the view point of practice, the activity of SZ needs to be improved fur…     

DABCO-based ionic liquids:Green and efficient catalysts with a dual catalytic role for aza-Michael addition

Four recoverable and reusable ionic liquids based on 1,4-diazobicyclo[2.2.2]octane(DABCO) have been synthesized to catalyze the aza-Michael addition of secondary amines to a,b-unsaturated compounds.Among the catalysts tested,[DABCO-PDO][OAc] was found to be most suitable for the reaction of a wide range of cyclic substrates without any solvent at room temperature,and afford the products in good to excellent yields within an appropriate amount of time.The proposed mechanism for the dual activation of the catalyst was supported by experimental results as well as the DFT calculation.In addition,the ionic liquids used can be regenerated and recycled several times without any loss of activity.     

Mono-lacunary PrIII-Polyoxotungstate： Epoxidation of Alkenes with Unusual Selectivity

The utilization of polyoxometalates (POMs) or their derivatives as homogeneous or heterogeneous catalysts in alkene epoxidation is a subject of considerable research activity[1]. The limitation to the use of POMs in these catalytic reactions is either their relatively low selectivity in epoxide formation or applicability for a rather limited type of alkenes. Therefore, it would be beneficial if the catalysts bear high selectivity for epoxidation and are applicable for a rather wide variety of alkenes, which is desirable in industrial processes and also vital for the selection of an ideal catalyst[2]. In search for an efficient and practical epoxidation method to utilize aqueous H2O2 as terminal oxidant, we focus on the rare-earth complexes with lacunary POM ligands.     

An improved and scalable process for 3,8-diazabicyclo[3.2.1]-octane analogues

An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylated to afford N-Boc-2,5- dihydroxymethylpyrrolidine 10.After mesylation of the diol 10 and cyclization with benzylamine,a diversity of scaffold,3,8- diazabicyclo[3.2.1]octane analogue 12 was obtained in a total yield of 42%in five steps.     

Synthesis and Supramolecular Structure of Chloro（1,10-phenanthroline ）copper（I） Hexahydrate

1INTRODUCTION Atom transfer radical addition is an efficient me-thod for carbon-carbon bond formation in organic synthesis[1,2].In some of these reactions,a transi-tion-metal catalyst acts as a carrier of the halogen atom in a reversible redox process.The transition-metal-catalyzed has been successfully used to con-trol radical polymerization[3].In the process,the transition-metal species initially abstracts halogen atom X from organic halide to form oxidized species and carbon-centered r…     

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.     

A simple gas chromatographic method for the analysis of oxygenates in gasoline

Chromatographia - A number of oxygenated compounds such as C1?C4 alcohols, methyl tert-butyl ether (MTBE), and tertamyl methyl ether (TAME) are increasingly being used in gasoline as octane...     

Fast detection of methyl tert-butyl ether from water using solid phase microextraction and ion mobility spectrometry

Methyl tert-butyl ether (MTBE) is commonly used as chemical additive to increase oxygen content and octane rating of reformulated gasoline. Despite its impact on enhancing cleaner combustion of gasoline, MTBE poses a threat to surface and ground water when gasoline is released into the environment. Methods for onsite analysis of MTBE in water samples are also needed. A less common technique for MTBE detection from water is ion mobility spectrometry (IMS). We describe a method for fast sampling and screening of MTBE from water by solid phase microextraction (SPME) and IMS. MTBE is adsorbed from the head space of a sample to the coating of SPME fiber. The interface containing a heated sample chamber, which couples SPME and IMS, was constructed and the SPME fiber was introduced into the sample chamber for thermal desorption and IMS detection of MTBE vapors. The demonstrated SPME-IMS method proved to be a straightforward method for the detection of trace quantities of MTBE from waters including surface and ground water. We determined the relative standard deviation of 8.3% and detection limit of 5 mg L⁻¹ for MTBE. Because of short sampling, desorption, and detection times, the described configuration of combined SPME and IMS is a feasible method for the detection of hazardous substances from environmental matrices.     

甲基叔丁基醚光催化降解的反应历程

以自制的TiO2为催化剂,在间歇式光催化反应装置中考察了水中甲基叔丁基醚的光催化降解反应.结果表明,水中MTBE在TiO2催化剂、氧气和紫外光照射的条件下能被光催化转化成无毒产物并最终被矿化.MTBE光催化降解过程中产生的主要中间产物有甲酸叔丁酯、叔丁醇和丙酮,尽管降解速率不同,它们也都能被光催化降解.通过对反应物、中间物及产物的追踪分析,认为MTBE的光催化降解首先是通过羟基化过程来进行,进而提出MTBE光催化降解的可能反应历程.     

The Efficient Photocatalytic Degradation of Methyl Tert‐butyl Ether Under Pd/ZnO and Visible Light Irradiation

Methyl tert‐butyl ether is a commonly used fuel oxygenate that is present in gasoline. It was introduced to eliminate the use of leaded gasoline and to improve the octane quality because it aids in the complete combustion of fuel by supplying oxygen during the combustion process. Over the past decade, the use of MTBE has increased tremendously worldwide. For obvious reasons relating to accidental spillage, MTBE started to appear as an environmental and human health threat because of its nonbiodegradable nature and carcinogenic potential, respectively. In this work, MTBE was degraded with the help of an advanced oxidation process through the use of zinc oxide as a photocatalyst in the presence of visible light. A mixture of 200 mg of zinc oxide in 350 mL of 50 ppm MTBE aqueous solution was irradiated with visible light for a given time. The complete degradation of MTBE was recorded, and approximately 99% photocatalytic degradation of 100 ppm MTBE solution was observed. Additionally, the photoactivity of 1% Pd‐doped ZnO was tested under similar conditions to understand the effect of Pd doping on ZnO. Our results obtained under visible light irradiation are very promising, and they could be further explored for the degradation of several nondegradable environmental pollutants.     

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.     

Experimental and Theoretical Study of MTBE Adsorption from Polluted Water on GAC and PAC in Continuous Process

Methyl tertiary butyl ether (MTBE) is an organic compound thatis used to increase the gasoline octane number. At the beginning of 1980s, by discovering the undesirable effects of tetra ethyl lead usage in fuel, MTBE began to be used worldwide. But gradually the undesirable effects of MTBE on environment had been revealed. Adsorption is the most conventional and economical technology for MTBE removal from polluted water. In this research, some experiments have been done for studying the adsorption of MTBE on different solid adsorbent in continuous processes. In continuous experiments, the water polluted with known initial MTBE concentration passes through an adsorption column containing two kinds of adsorbent including granular activated carbon (GAC), powdered activated carbon (PAC). By measuring MTBE concentration in exit flow at different times the effect of different operating parameters such as temperature, pH, and flow rate have been studied and the optimum condition have been determined. The batch experimental results have been used to calculate the constant parameters of Langmuir adsorption isotherm equations. A dynamic simulation of MTBE adsorption on activated carbon in an adsorption column has been proposed. The comparison of the experimental data with the values given by the proposed model for similar operating conditions, verifies the accuracy of the proposed mathematical model.      

Method for determination of methyl tert-butyl ether in gasoline by gas chromatography

A simple method for the determination of methyl tert-butyl ether (MTBE) in gasoline has been developed. The separation of MTBE from other analytes was controlled by the use of gas chromatography–mass spectrometry in the full scan mode using the characteristic primary, secondary and tertiary ions m/z 73, 57 and 43. The sample mass spectrum did not show any superimposition of other analytes. The separation from the common gasoline component 2-methylpentane was sufficient for reliable quantitation. An application of the developed conditions using gas chromatography with flame ionization detection was performed by the analysis of regular, euro super, super premium unleaded and ‘Optimax’ gasoline from petrol stations in the area of Frankfurt/Main, Germany. Regular unleaded gasoline shows an average MTBE content of 0.4% (w/w), whereas the MTBE content in euro super gasoline varies between 0.4 and 4.2% (w/w). The blending of MTBE to super premium has increased from 8.2% (w/w) in 1998 to 9.8% (w/w) on average in 1999. The recently introduced gasoline ‘Optimax’ shows an average MTBE content of 11.9% (w/w). The presented method might also be used for the analysis of other ethers, such as ethyl tert-butyl ether, which requires the use of another internal standard.