Equilibria in the hydration of ethylene at elevated pressures and temperatures

Cope, C. S.; Dodge, Barnett F.

doi:10.1002/aic.690050104

“…The results of his study are limited in significance since he, like many other investigators of esterification and other reactions of ethanol, failed to recognize the importance of the side reaction of ethanol to ethyl ether. Detailed discussions of such instances are found elsewhere (11,4 ) . Nevertheless Herrman's work demonstrated the excellent characteristics of hydrogen ion exchange resin as a vapor-phase catalyst.…”

Section: Reaction Rate Studiesmentioning

confidence: 99%

Reaction kinetics and adsorption equilibria in the vapor‐phase dehydration of ethanol

Kabel

¹

,

Johanson

²

1962

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This work is an experimental assessment of the Langmuir-Hinshelwood model of heterogeneous catalysis. The vopor-phase dehydration of ethanol to diethyl ether, as catalyzed by cation exchange resin in the acid form, was the reaction chosen for study.Initial reaction rate data, determined from the integral kinetic data obtained experimentally, allowed selection of the most suitable rate equation from among several plausible equations derived in accordance with the above model. The Langmuir equilibrium adsorption constants in the rate equation were compared with the corresponding constants determined directly from pure component studies in a static adsorption system. The adsorption constants determined for the three reacting components by these independent methods showed definite order-of-magnitude agreement. The adsorption studies also provided significant information about the nature of the catalytic site.The extent of agreement in the constants determined by these two independent approaches is considered to be evidence of the theoreticol validity of this model. Additional interpretation of the adsorption and kinetic data via this model suggests that the ethanol dehydration reaction proceeds through the reaction of adjacently adsorbed ethanol molecules.The Langmuir-Hinshelwood model of heterogeneous catalysis has been widely used by chemical engineers in the correlation of experimental reaction rate data. The model stems directly from the Langmuir theory of activated adsorption (14) and the application by Hinshelwood (8) of that theory to a large number of reactions. Hougen and Watson (10) extended and popularized this theory for chemical engineering use. Rate equations, derived for many situations, were systematized and put into a generalized form by Yang and Hougen ( 2 3 ) . Although the model has been used quite successfully in the correlation of kinetic data, its theoretical significance has been questioned. This argument has been put into focus in back-to-back articles by Weller ( 2 2 ) and Boudart (1).Weller suggests that the LangmuirHinshelwood approach does not have the theoretical validity commonly attributed to it and that, lacking theoretical validity, it is unnecessarily complex for use as an empirical equation when compared for simplicity to the common power function type of equation. Boudart has supported the rational use of the Langmuir-Hinshelwood approach with his discussion of the limitations and strengths of that theory. Because this model of heterogeneous catalysis has not been adequately tested the direct experimental evaluation presented in this paper has been carried out.The general approach utilized in this work was to correlate reaction rate data with an equation of the Langmuir-Hinshelwood model, obtaining values of the Langmuir equilibrium Robert L. Kabel is with the United States Air

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“…5 Alcohol dehydration is endothermic and reversible, with the equilibrium favouring dehydration over hydration. 41,42 The water that is produced during the dehydration reaction has a small impact on the conversion and water is often co-fed with the alcohols to reduce the adiabatic temperature decrease during dehydration. Co-feeding water with the alcohols has the additional benefit of diluting the surface concentration of the alcohols and the alkenes formed during the conversion, thereby reducing side-reactions.…”

Section: Alcohol Dehydration To Alkenesmentioning

confidence: 99%

Catalysis in the Refining of Fischer–Tropsch Syncrude

2010

Catalysis in the Refining of Fischer-Tropsch Syncrude

2

0

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There are meaningful differences in composition between Fischer–Tropsch syncrude and conventional crude oil. These differences influence the catalysis, catalyst selection and refining technologies that can be used. Some catalysts are particularly well suited for the conversion of Fischer–Tropsch syncrude, wereas some catalysts and conversion processes that are ubiquitous in crude oil refining are not. Conversion technologies relevant to Fischer–Tropsch fuel refineries, but that have not yet been covered in detail, are discussed: catalytic reforming, aromatic alkylation, alcohol dehydration and etherification. A short discussion is included on Fischer–Tropsch related oxygenate conversions that resolve specific FT refining challenges, but have not yet found their way into conceptual refinery designs.

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“…The amount of ether thus obtained exceeds the demand. Therefore, the ether yield is matched to the demand by recycling it into the process (for reaction equilibrium, see [28]) or by appropriate adjustment of the reaction conditions. The indirect hydration process technology of ethylene has not been used commercially in Europe since end 2007.…”

Section: Individual Aliphatic Ethersmentioning

confidence: 99%

“…Bis(chloromethyl) ether is produced by reacting paraformaldehyde and chlorosulfonic acid in sulfuric acid (65 %) under permanent cooling at temperatures between [26][27][28] C; the reaction is controlled to prevent any hydrochloric acid formation.…”

Section: Bis(chloromethyl) Ethermentioning

confidence: 99%

Ethers, Aliphatic

Sakuth¹,

Mensing²,

Schuler³

et al. 2010

Ullmann's Encyclopedia of Industrial Chemistry

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The article contains sections titled: 1. Introduction 2. Properties 2.1. Physical Properties 2.2. Chemical Properties 2.2.1 General Aspects 2.2.2 Peroxide Formation Tendency of Ethers 3. Synthesis 4. Individual Aliphatic Ethers 4.1. Diethyl Ether 4.2. Diisopropyl Ether 4.3. Other Aliphatic Ethers 4.3.1. Di‐ n ‐propyl Ether 4.3.2. Di‐ n ‐butyl Ether 4.3.3. Diamyl Ether 4.4. Chloroalkyl Ethers 4.4.1. Bis(chloromethyl) Ether 4.4.2. Bis(2‐chloroethyl) Ether 4.4.3. Bis(2‐chloroisopropyl) Ether 5. Toxicology

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Equilibria in the hydration of ethylene at elevated pressures and temperatures

Cited by 19 publications

References 41 publications

Reaction kinetics and adsorption equilibria in the vapor‐phase dehydration of ethanol

Reaction kinetics and adsorption equilibria in the vapor‐phase dehydration of ethanol

Catalysis in the Refining of Fischer–Tropsch Syncrude

Ethers, Aliphatic

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