Ethanol-tert-butyl-ether

Typical normal-phase operations involved combinations of alcohols and hexane or heptane. In many cases, the addition of small amounts (< 0.1 %) of acid and/or base is necessary to improve peak efficiency and selectivity. Usually, the concentration of polar solvents such as alcohol determines the retention and selectivity (Fig. 2-18). Since flow rate has no impact on selectivity (see Fig. 2-11), the most productive flow rate was determined to be 2 mL miiT. Ethanol normally gives the best efficiency and resolution with reasonable back-pressures. It has been reported that halogenated solvents have also been used successfully on these stationary phases as well as acetonitrile, dioxane and methyl tert-butyl ether, or combinations of the these. The optimization parameters under three different mobile phase modes on glycopeptide CSPs are summarized in Table 2-7. 

Oxygen was added as oxygenated hydrocarbon components methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE), ethanol, methanol, and tertiary butyl alcohol (TBA). The properties of oxygenates, as they relate to gasoline blending, are shown in Table 10-1. 

Ethyl tert-butyl ether (ETBE) Ethanol + /.sobutylene... 

The United States Environmental Protection Agency (U.S. EPA) has identified several hundred MTBE-contaminated sites that have performed treatment of soil and groundwater to remove or destroy MTBE.1 Many of these sites have also treated other fuel components, primarily benzene, toluene, ethylbenzene, and xylene (BTEX), and some have treated fuel oxygenates other than MTBE. Although others have reported about treatment technologies for MTBE cleanup,2 only limited information has been published about cleanup of other oxygenates. These oxygenates include ether compounds, such as ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), diisopropyl ether (DIPE), and tert-amyl ethyl ether (TAEE), as well as alcohol compounds, such as tert-butyl alcohol (TBA), tert-amyl alcohol (TAA), ethanol, and methanol. 

Fig. 5.2 The main crop-to-energy chains. BtL Biomass-to-Liquid, GtL Gas-to-Liquid, ETBE Ethyl tert-butyl ether, MTBE Methyl tert-butyl ether, MeOH Methanol, DME Dimethyl ether. Pyrolysis oil, HTU-Diesel (Hydro Thermal Upgrading), ethanol and hydrogen from ligno-cellulosic species are not considered here because of their minor practical relevance in the near future...

This strategy appears to be very attractive because of the possibility of completely solubilizing the support in most of the common solvents. From a chemical perspective, that property allows one to benefit from all the solvent conditions used in classical solution chemistry. This could prove to be very advantageous, especially to obtain stereoselective glycosylation without neighboring-group assistance. Moreover, isolation and purification of the polymer is easily achieved by precipitation usually in diethyl ether or methyl-tert-butyl ether (MTBE) and recrystallisation from ethanol. One major drawback of this type of support is its tendency to solidify at low temperature, thus limiting the variety of temperature conditions. 

The other large-scale ethanol user is the USA, where ethanol has been used to increase the octane rating of gasoline, to decrease carbon monoxide emissions, and, more recently, to replace MTBE (methyl tert-butyl ether) in reformulated gasoline. Ethanol production in the USA grew from about 0.6 billion liters in 1980 to... 

In the European Union, ethanol is consumed in Spain, France, Sweden and Germany, especially after conversion into ETBE (ethyl tert-butyl ether), except in Sweden, but its use is increasing in all the other countries. New uses of bioethanol, e.g., in ethanol-direct fuel cells or as raw material for other chemicals, will further expand bioethanol use and production. Table 9.1 summarizes bioethanol production in different countries by 2004 [1], Owing to political decisions (EU directive setting at 5.75% the proportion of biofuels in fuels) and incentive taxation... 

Grosjean, E D. Grosjean, R. Gunawardena, and R. A. Rasmussen, Ambient Concentrations of Ethanol and Methyl tert-Butyl Ether in Porto Alegre, Brazil, March 1996-April 1997, Environ. Sci. Technol., 32, 736-742 (1998a). 

Arce, A., Rodriguez, H., Soto, A., Purification of ethyl tert-butyl ether from its mixtures with ethanol by using an ionic liquid, Chem. Eng.., 115, 219-223, 2006. 

Ethers, such as MTBE and methyl / -amyl ether (TAME) are made by a catalytic process from methanol (qv) and the corresponding isomeric olefin. These ethers have excellent octane values and compete on an economic basis with alkylation for inclusion in gasoline. Another ether, ethyl tert-butyl ether (ETBE) is made from ethanol (qv) and isobutylene (see Butylenes). The cost and economic driving forces to use ETBE vs MTBE or TAME are a function of the raw material costs and any tax incentives that may be provided because of the ethanol that is used to produce it. 

BHT, butylated hydroxytoluene BHA, butylated hydroxyanisole EDTA, ethylenediaminetetraacetic acid MeOH, methanol EtOH, ethanol 2-PrOH, 2-propanol BuOH, butanol MeCN, acetonitrile CHC13, chloroform CH2C12, dichloromethane (methylene chloride) THF, tetrahydrofuran DMF, dimethylformamide DMSO, dimethylsulfoxide MTBE, methyl tert-butyl ether. 

Ethyl tert-Butyl Ether. Ethanol can react with isobutylene to form ETBE much the same way as methanol is now processed into MTBE, methyl tert-butyl ether (see Ethers). 

Notes LOD, limit of detection MeOH, methanol EtOH, ethanol ACN, acetonitrile MTBE, methyl tert-butyl ether DCM, dichloromethane THF, tetrahy-drofuran KOH, potassium hydroxide SFE, supercritical fluid extraction MS, mass spectrometry HPLC, high-performance liquid chromatography DAD, diode array detector PDA, photodiode array detector FD, fluorescence detector ECD, electrochemical detector ESI, electrospray ionization APCI, atmosphere pressure chemical ionization TLC, thin layer chromatography FAB, fast atom bombardment NMR, nuclear magnetic resonance BHT, butylated hydroxytoluene SPE, solid phase extraction. 

From a functional point of view, Nguyen et al. examined the pervapora-tion characteristics of CA/P(VP-co-VAc) blends for application as alcohol-selective membrane materials [107]. The blend membranes were shown to be very efficient in the removal of ethanol from its mixture with ethyl tert-butyl ether (ETBE). ferf-butyl ethers are octane-value enhancers for gasoline, and the synthesis requires an excess of alcohol in the reaction to reach high... 

Prior to the winter of 2003, the primary oxygenate added to gasoline sold in California was methyl tert-butyl ether (MTBE). Since that time, refiners in California have been discontinuing the use of MTBE, while increasing their use of ethanol as an oxygenate. As MTBE use is discontinued, most of the ethanol that will be used in its place likely will be imported from other states. An economic analysis of the potential for producing... 

To the stirred mixture of mibefradil and ethanol was added at 20°C a solution of 4.4 g of hydrogen chloride in 44.6 mL (35.0 g) ethanol. The mixture was heated to 50°C and 1.0 mL water was added, followed by a solution of 3.4 mL water in 332 mL methyl tert-butyl ether over one hour. The mixture was... 

Ethanol Acetaldehyde, butadiene, diethyl succinate, ETBE (ethyl tert-butyl ether), ethyl acetate, ethylene Fuel, monomers Gucbilmez etal., 2006 Patel etal., 2006 Rass-Hansen etal., 2007... 

The octane number (.R + M/2) of such reformates is typically in the range of 88.9—94.5, depending on severity of the reforming operation. Toluene itself has a blending octane number of 103—106, which, as shown in Table 19, is exceeded only by oxygenated compounds such as methyl tert-butyl ether, ethanol, and methanol. 

Here, Ca is the concentration of pollutant, f is the time, is the reaction rate constant, Ka is the adsorption coefficient of A, and 6a is the surface coverage of this specie. Gas-phase examples include the degradation of toluene (Bouzaza and Laplanche, 2002), methyl tert-butyl-ether (Boulamanti and Philippopoulos, 2008), dimethylamine (Kachina et al., 2007), ethanol (Vorontsov and Dubovitskaya, 2004), and other VOCs (Mills and Le Hunte, 1997). When KaCa is small, this equation is degenerated into a typical first-order expression, where fcapp the apparent first-order constant is approximately fcrA A- Since the apparent rate constant depends on both fcr A and Ka, a lower adsorption constant does not always result in a lower degradation rate, as demonstrated by Bouzaza et al. (2006). 

Some diverse VOCs (halocarbons, isoprene (CH2C(CH3) CH2CH2), monoterpenes, ethanol, and methyl tert-butyl ether, (CHslsCOCHs)) were found to be photooxidized efficiently on solid aerosols. Solid photocatalyst particles, such as Ti02, ZnO, and Fe20s, were here of special importance, but the VOC oxidation was photoassisted also by dessert sand, volcanic ash, or even by chalk particles (23-25). Similarly, sulfur dioxide was found to... 

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