- Alkali Metal, Chlorine and other Promoters in the Silver-catalysed Selective Oxidation of Ethylene
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Ethylene oxidation over well characterised Ag(111) surfaces has been investigated by temperature-programmed reaction measurements and by differential batch reactor studies at pressures up to 50 Torr.The influence of chlorine predosing on catalytic activity indicates that a chemisorbed atomic oxygen species is responsible for both partial oxidation and complete oxidation to CO2 + H2O.This tends to be confirmed by experiments using N2O as the oxidant, both with the single crystal specimen and with a practical Ag-αAl2O3 catalyst in a flow microreactor.Dissolved oxygen, like adsorbed chlorine, is found to be a selectivity promoter.Adsorbed Cs also increases the rate of ethylene oxide production but can also positively influence the overall activity of the system.The results suggest that chlorine and dissloved oxygen promoters principally affect the primary chemistry, whereas the main effect of Cs is on the secondary chemistry (further oxidation of ethylene oxide).This view tends to be confirmed by temperature-programmed reaction measurements and by direct experiments on the influence of Cl and Cs on the isomerisation and combustion of ethylene oxide itself.It is suggested that these effects are primarily electronic in origin and a mechanism based on this view is presented.In the presence of Cs, both CO2 and NOx can act as selectivity promoters for the formation of ethylene oxide.
- Grant, Robert B.,Harbach, Christopher A. J.,Lambert, Richard M.,Tan, S. Aun
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- In situ controlled promotion of catalyst surfaces via solid electrolytes: the NEMCA effect
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The catalytic activity and selectivity of metal films interfaced with solid electrolytes can be varied in situ in a dramatic and reversible manner by applying currents or voltages (typically ± 1-2 V) between the catalyst film and a counter electrode also
- Vayenas,Yentekakis,Bebelis,Neophytides
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Read Online
- A Nanoarchitecture Based on Silver and Copper Oxide with an Exceptional Response in the Chlorine-Promoted Epoxidation of Ethylene
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The selective oxidation of ethylene to ethylene epoxide is highly challenging as a result of competing reaction pathways leading to the deep oxidation of both ethylene and ethylene oxide. Herein we present a novel catalyst based on silver and copper oxide
- Ramirez, Adrian,Hueso, Jose L.,Suarez, Hugo,Mallada, Reyes,Ibarra, Alfonso,Irusta, Silvia,Santamaria, Jesus
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- Epoxidation of Ethylene over Silver Catalysts modified by Sodium Chloride
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The selectivity of epoxide synthesis in the direct oxidation of ethylene is increased to 85-87percent by addition of sodium chloride to the silver catalyst; this selectivity corresponds to the maximum expected by mechanistic studies.
- Ayame, Akimi,Takeno, Noboru,Kanoh, Hisao
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Read Online
- Study of the Real Structure of Silver Supported Catalysts of Different Dispersity
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The real structure of silver supported catalysts for ethylene epoxidation (Ag/α-Al2O3) was investigated using precision X-ray diffraction on synchrotron radiation, in situ high-temperature X-ray diffraction, and transmission electron microscopy.Stacking f
- Tsybulya, S. V.,Kryukova, G. N.,Goncharova, S. N.,Shmakov, A. N.,Bal'zhinimaev, B. S.
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- XPS study of the size effect in ethene epoxidation on supported silver catalysts
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Supported silver catalysts (Ag/α-Al2O3) with different particle sizes (100-1000 A?) have been prepared and studied by XPS. It has been shown that the increase in the ethene epoxidation rate with silver particle size (size effect) is
- Bukhtiyarov, Valery I.,Prosvirin, Igor P.,Kvon, Ren I.,Goncharova, Svetlana N.,Bal'zhinimaev, Bair S.
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- Direct conversion of ethane to ethylene oxide over Ni-Ag-O catalyst
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Ethylene oxide was directly synthesized by oxidation of ethane over Ni-Ag-O catalyst with ethane conversion of 10% and ethylene oxide yield of 1.2% at 310°C. NiOx and Ag in the catalyst favor ethane activation and the formation of ethylene oxid
- Wu, Ying,Wu, Binfu,He, Yiming,Wu, Tinghua
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- Cs-Promoted Ag(111): Model Studies of Selective Ethylene Oxidation Catalysts
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The role of cesium promoters in silver catalysts for the selective epoxidation of ethylene (C2H4 + 1/2O2 -> C2H4O) has been studied by using adsorbed cesium on the surface of clean Ag(111) as a model catalysts.The experiments are performed in an apparatus
- Campbell, Charles T.
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Read Online
- Thio Diels-Alder reactions of α,β-unsaturated 1,3-oxathiolanes with aliphatic olefins and 1,3-dienes
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A series of α,β-unsaturated 1,3-oxathiolanes reacted with aliphatic olefins such as norbornene and with various 1,3-dienes in the presence of TiCl4 leading to dihydrothiapyrans, via a cycloaddition-type reaction. The unsaturated oxathiolanes acted as masked heterodienes in this thio Diels-Alder reaction.
- Kerverdo, Sébastien,Lizzani-Cuvelier, Louisette,Du?ach, Elisabet
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- PRODUCTION PROCESS OF ALKYLENE OXIDES FROM ALKYLENE CARBONATES
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Catalytic process for producing alkylene epoxide, selected between ethylene oxide or propylene oxide, from the corresponding alkylene carbonate, selected between ethylene carbonate or propylene carbonate, comprising the decomposition reaction of alkylene carbonate, in the presence of sodium bromide as catalyst, in which: the reaction temperature is between 207 and 245°C, and the catalyst is in amounts comprised between 5x10-4 and 8x10-3 moles per mole of alkylene carbonate. This process can be carried out continuously. A further object of the invention is the modular plant which allows carrying out such a process.
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(2022/04/03)
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- PROCESS FOR PRODUCING ETHYLENE OXIDE FROM ETHANE BY OXIDATIVE DEHYDROGENATION AND EPOXIDATION WITH SPLIT RECYCLE
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An ethylene oxide (EO) production process comprising (a) introducing a first reactant mixture (C2H6, O2) to a first reactor to produce a first effluent stream (C2H4,C2H6,O2); (b) introducing a second reactant mixture to a second reactor to produce a second effluent stream (EO, C2H4,C2H6,O2); wherein the second reactant mixture comprises at least a portion of first effluent stream; (c) separating the second effluent stream into an EO product stream (EO) and recycle stream (C2H4,C2H6,O2); wherein ethylene is not separated from recycle stream and/or first effluent stream; and (d) recycling a first portion of recycle stream to the first reactor, and a second portion of recycle stream to the second reactor; wherein recycle split ratio 0.6; and wherein recycle split ratio is defined as ratio of volumetric flowrate of first portion of recycle stream divided by the sum of volumetric flowrates of first portion and second portion of recycle stream.
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Paragraph 0079; 0083
(2021/09/17)
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- Epoxidation of Ethylene with Products of Thermal Gas-Phase Oxidation of n-Butane
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Abstract: Epoxidation of ethylene with the reactive products formed during thermal gas-phase oxidation of n-butane has been carried out under flow conditions with the separation of the zones of generation of radicals and their interaction with ethylene. Butane is oxidized in the first section of a two-section reactor, and ethylene is fed to the second section. It has been found that increasing the residence time of a butane–oxygen mixture in the first section of the reactor from 7 to 13 s increases the ethylene oxide accumulation rate. A further increase in the contact time leads to a decrease in the rate. Similarly, increasing the C4H10/O2 ratio in the range of 0.05–0.25 leads to an increase in the rate of accumulation of ethylene oxide. A further increase in this ratio decreases the rate of epoxidation. It has also been found that the temperature dependences of the ethylene oxide accumulation rate in both sections of the reactor pass through a maximum. The obtained data give evidence for the occurrence of the ethylene epoxidation reaction initiated by the n-butane oxidation products under the conditions when ethylene itself is slightly oxidized.
- Arsentev, S. D.,Grigoryan, R. R.
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p. 187 - 193
(2020/03/30)
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- Chemical Behaviour of CaAg2 under Ethylene Epoxidation Conditions
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The binary compound CaAg2 is examined as a catalyst for the ethylene epoxidation reaction. During the induction phase, conversion and selectivity increase and then remain stable for several hundred hours. The presence of ethyl chloride as a promoter is crucial. The pristine CaAg2 reacts with the gaseous reactants and forms a porous microstructure of calcium-containing oxidation products on the surface, in which particles of elemental silver are embedded. The microstructure is remarkably stable, and in particular, prevents further sintering of the silver particles.
- Antonyshyn, Iryna,Sichevych, Olga,Rasim, Karsten,Ormeci, Alim,Burkhardt, Ulrich,Titlbach, Sven,Schunk, Stephan Andreas,Armbrüster, Marc,Grin, Yuri
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p. 3933 - 3941
(2018/09/10)
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- CATALYST FOR THE OXIDATION OF ETHYLENE TO ETHYLENE OXIDE
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The present invention is directed to a shaped catalyst body for preparing ethylene oxide, which comprises at least silver, cesium and rhenium applied to an alumina support, wherein the alumina support comprises Si, Ca, and Mg in a defined amount. Furthermore, the present invention is directed to a process for preparing the catalyst according to the present invention and process for preparing ethylene oxide by gas-phase oxidation of ethylene by means of oxygen in the presence of a shaped catalyst body according to the present invention.
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(2018/03/06)
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- Kinetics of Ethylene Epoxidation on a Promoted Ag/α-Al2O3 Catalyst—The Effects of Product and Chloride Co-Feeds on Rates and Selectivity
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The overall chloriding effectiveness factor (Z*), defined as the ratio of ethyl chloride concentration in parts per million to the sum of ethylene and ethane concentration in mole percent multiplied by a weighting factor to account for their efficacy in removing chlorine-adatoms from the surface, was used as a parameter to account for the effects of chlorine on the kinetics of ethylene epoxidation on a highly promoted 35 wt % Ag/α-Al2O3 catalyst. An increase in O2 order (≈0.7 to 1) and a decrease in C2H4 order (≈0.5 to 2 activation on chloride-promoted silver catalysts. Carbon dioxide co-feed (1–5 mol %) was found to promote ethylene oxide selectivity as CO2 co-feed reversibly inhibits CO2 synthesis rates (?0.6 order) more than ethylene oxide synthesis rates (?0.49 order) at all Z* values. Ethylene oxide and CO2 rates were found to be invariant with ethylene oxide (0–0.5 mol %) and acetaldehyde (0–1.7 ppm) co-feeds, suggesting that there is minimal product inhibition under reaction conditions. A model involving a common reaction intermediate for ethylene oxide and carbon dioxide synthesis and two types of atomically adsorbed oxygen species—nucleophilic and electrophilic oxygen—is proposed to plausibly describe the observed reaction rate dependencies and selectivity trends as a function of the chloriding effectiveness.
- Chen, Cha-Jung,Harris, James W.,Bhan, Aditya
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p. 12405 - 12415
(2018/08/28)
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- METHODS FOR CONDITIONING AN ETHYLENE EPOXIDATION CATALYST AND ASSOCIATED METHODS FOR THE PRODUCTION OF ETHYLENE OXIDE
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Methods for conditioning an ethylene epoxidation catalyst are provided. The conditioning methods comprise contacting an ethylene epoxidation catalyst comprising a carrier, having silver and a rhenium promoter deposited thereon, with a conditioning feed gas comprising oxygen for a period of time of at least 2 hours at a temperature that is above 180℃ and at most 250℃, wherein the contacting of the ethylene epoxidation catalyst with the conditioning feed gas occurs in an epoxidation reactor and in the absence of ethylene. Associated methods for the epoxidation of ethylene are also provided.
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(2018/06/22)
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- Chemical looping epoxidation
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Chemical looping epoxidation of ethylene was demonstrated, whereby the sole oxidant was a solid oxygen carrier, 15 wt% Ag supported on SrFeO3. Ethylene reacted with a bed of carrier particles, without any O2(g) in the feed, to produc
- Chan, Martin S.C.,Marek, Ewa,Scott, Stuart A.,Dennis
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- Method for preparing halogen ethyl alcohol and ethylene oxide
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The invention provides a method for preparing halogen ethyl alcohol. The method comprises the following step: (1) halogen alcoholization: adding halogen hydride, H2O2, ethylene and a Ti heteroatom-containing molecular sieve into a reaction device, and carrying out halogen alcoholization reaction to obtain the halogen ethyl alcohol. The invention also provides a method for preparing ethylene oxide with a halogenohydrin method. The method comprises the following steps: (1) halogen alcoholization: adding halogen hydride, H2O2, ethylene and a Ti heteroatom-containing molecular sieve into the reaction device, and carrying out the halogen alcoholization reaction to obtain the halogen ethyl alcohol; (2) saponification: carrying out saponification reaction on the halogen ethyl alcohol in the step (1) and a hydroxide of alkali metal, and separating to obtain the ethylene oxide and alkali halide metal salt; optionally (3) electroosmosis: carrying out bipolar membrane electroosmosis on alkali halide metal salt obtained in step (2) to obtain the hydroxide of alkali metal and the halogen hydride. According to the methods, the halogen ethyl alcohol or the ethylene oxide can be prepared at extremely high selectivity and yield, and the discharging of waste water and waste residues can be drastically lowered.
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Paragraph 0099; 0100-0102; 0105-0108; 0119-0120; 0130; 0131
(2017/05/19)
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- Ethylene Epoxidation at the Phase Transition of Copper Oxides
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Catalytic materials tend to be metastable. When a material becomes metastable close to a thermodynamic phase transition it can exhibit unique catalytic behavior. Using in situ photoemission spectroscopy and online product analysis, we have found that close to the Cu2O-CuO phase transition there is a boost in activity for a kinetically driven reaction, ethylene epoxidation, giving rise to a 20-fold selectivity enhancement relative to the selectivity observed far from the phase transition. By tuning conditions toward low oxygen chemical potential, this metastable state and the resulting enhanced selectivity can be sustained. Using density functional theory, we find that metastable O precursors to the CuO phase can account for the selectivity enhancements near the phase transition.
- Greiner, Mark T.,Jones, Travis E.,Klyushin, Alexander,Knop-Gericke, Axel,Schl?gl, Robert
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p. 11825 - 11832
(2017/09/07)
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- Method for producing epoxides
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PROBLEM TO BE SOLVED: To provide a method for producing epoxides capable of enhancing the selectivity of epoxides, in reactions for forming epoxides from glycols.SOLUTION: The method for producing epoxides is a method for producing epoxides by the vapor-phase dehydration reaction of glycols in the presence of a catalyst. The catalyst is a catalyst including an alkali metal (A)-containing salt or a catalyst composed of a carrier on which the alkali metal (A)-containing salt is carried. In the method, each glycol and a carrier gas containing carbon dioxide are introduced into a reactor filled with the catalyst, and the glycol is reacted at a reaction temperature of the cloud point or higher of the glycol and 500°C or less.
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Paragraph 0050; 0052
(2018/09/30)
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- Studies of styrene oxidation by catalyst based on zeolite-Y nanohybrid materials
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Metal complexes of VO(IV), Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and HNIMMPP (4-(((2-hydroxy-5-nitrophenyl)imino)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol) schiff base ligand have been synthesized within zeolite-Y along with neat one. Synthesized compounds were characterized by physico-chemical techniques such as elemental analysis of catalysts, BET, XRD, SEM, FT-IR, UV–vis, ICP-OES and TGA. Synthesized zeolite-Y based nanohybrid materials and their uncovered complexes were used in styrene oxidation with TBHP as an oxidizing agent. Oxidation reaction of styrene furnished benzaldehyde as the major product and styrene glycol, chalcone and 2-phenyloxirane as minor products. Amongst all catalysts, [VO(HNIMMPP)(H2O)]-Y produced the highest conversion at 93.35% and selectivity of benzaldehyde (45.70%) was the greatest. These nanohybrid materials can be easily reprocessed and recovered within these reaction parameters. The reaction mechanism for catalytically oxidized styrene is discussed in the present paper.
- Desai, Nisheeth C.,Chudasama, Jiten A.,Karkar, Tushar J.,Patel, Bonny Y.,Jadeja, Krunalsinh A.,Godhani, Dinesh R.,Mehta, Jignasu P.
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p. 203 - 219
(2016/09/09)
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- PROCESS FOR MANUFACTURING AN EPOXIDE
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Process for manufacturing an epoxide by reacting at least one chlorohydrin with at least one dehydrochlorinating agent in order to give the epoxide and at least one chlorinated co-product, said process comprising regenerating the dehydrochlorinating agent from the chlorinated co-product by a treatment which does not comprise an electrolysis operation.
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(2015/07/07)
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- 4,5-Dihydro-1,2,3-oxadiazole: A Very Elusive Key Intermediate in Various Important Chemical Transformations
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4,5-Dihydro-1,2,3-oxadiazoles are postulated to be key intermediates in the industrial synthesis of ketones from alkenes, in the alkylation of DNA in vivo, and in the decomposition of N-nitrosoureas; they are also a subject of great interest for theoretical chemists. In the presented report, the formation of 4,5-dihydro-1,2,3-oxadiazole and the subsequent decay into secondary products have been studied by NMR monitoring analysis. The elusive properties evading characterization have now been confirmed by 1H, 13C, and 15N NMR spectroscopy, and relevant 2D experiments at very low temperatures. Our experiments with suitably substituted N-nitrosoureas using thallium(I) alkoxides as bases under apolar conditions answer important questions on the existence and the secondary products of 4,5-dihydro-1,2,3-oxadiazole. Short-lived! 4,5-Dihydro-1,2,3-oxadiazole is generated by treatment of N-(2-chloroethyl)-N-nitrosourea with thallium alkoxides at low temperatures, but it is not formed by nucleophilic dealkylation of the corresponding N-methyloxadiazolinium salt. Even at -90 °C, 4,5-dihydro-1,2,3-oxadiazole cannot be detected directly. However, it was identified by analysis of its decay products, acetaldehyde, ethylene oxide, and diazomethane (see scheme).
- Banert, Klaus,Singh, Neeraj,Fiedler, Benjamin,Friedrich, Joachim,Korb, Marcus,Lang, Heinrich
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supporting information
p. 15092 - 15099
(2015/11/02)
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- Gas-phase dehydration of vicinal diols to epoxides: Dehydrative epoxidation over a Cs/SiO2 catalyst
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A novel type of dehydration reaction that produces epoxides from vicinal diols (dehydrative epoxidation) using a basic catalyst is reported. Epoxyethane, 1,2-epoxypropane, and 2,3-epoxybutane were produced from the dehydrative epoxidation of ethylene glycol, 1,2-propanediol, and 2,3-butanediol, respectively. Among a number of tested basic catalysts, the Cs/SiO2 catalyst showed outstanding performance for the dehydrative epoxidation of 2,3-butanediol and is considered to be the most promising catalyst for this type of reaction. In order to identify the superiority of the Cs/SiO2 catalyst and a mechanism of the reaction, structure-activity relationships were studied along with density functional theory (DFT) calculations. The following features are found to be responsible for the excellent activity of the Cs/SiO2 catalyst: i) strong basic sites formed by Cs+, ii) low penetration of Cs+ into SiO2 which permits basic sites to be accessible to the reactant, iii) stable basic sites due to the strong interactions between Cs+ and SiO2 surface, and iv) mildly acidic surface of SiO2 which is advantageous for the elimination to H2O. In addition, the dehydrative epoxidation involves an inversion of chirality (e.g. meso-2,3-butanediol (R,S) to trans-2,3-epoxybutane (R,R or S,S)), which is in agreement with DFT results that the reaction follows a stereospecific SN2-like mechanism.
- Kim, Tae Yong,Baek, Jayeon,Song, Chyan Kyung,Yun, Yang Sik,Park, Dae Sung,Kim, Wooyoung,Han, Jeong Woo,Yi, Jongheop
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- Synthesis and characterization of different types of epoxide-based Mannich polyols from low-cost cashew nut shell liquid
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Cashew nut shell liquid (CNSL) is a natural aromatic organic oil consisting of phenolic compounds with interesting structures. Extraction of CNSL was performed in a Soxhlet apparatus. The major (90 %) component of CNSL is anacardic acid, which is easily decarboxylated to cardanol (10 %) by use of conventional methods. In this paper we describe a three-step synthesis of Mannich polyols for rigid foams. The first step is synthesis of N-(2-hydroxyethyl)-1,3-oxazolidine (the Mannich precursor) by condensation of paraformaldehyde and diethanolamine. The second step involves synthesis of the Mannich base phenolic ring of cardanol by reaction with N-(2-hydroxyethyl)-1,3- oxazolidine. The third step is alkoxylation. The synthesized polyols were characterized by FTIR and 1H NMR spectroscopy and thin-layer chromatography. Springer Science+Business Media Dordrecht 2013.
- Gandhi, Tejas S.,Patel, Mayank R.,Dholakiya, Bharatkumar Z.
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p. 1223 - 1232
(2014/05/06)
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- Synthesis of ethyl (R)-4-cyano-3-hydroxybutyrate in high concentration using a novel halohydrin dehalogenase HHDH-PL from Parvibaculum lavamentivorans DS-1
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We identified and characterized a novel halohydrin dehalogenase HHDH-PL from Parvibaculum lavamentivorans DS-1. Study of substrate specificity indicated that HHDH-PL possessed a high activity toward ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE). After optimizations of the pH and temperature, whole cell catalysis of HHDH-PL was applied to the synthesis of ethyl (R)-4-cyano-3-hydroxybutyrate (HN) at 200 g L-1 of (S)-CHBE, which gave 95% conversion and 85% yield in 14 h.
- Wan, Nan-Wei,Liu, Zhi-Qiang,Huang, Kai,Shen, Zhen-Yang,Xue, Feng,Zheng, Yu-Guo,Shen, Yin-Chu
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p. 64027 - 64031
(2015/02/19)
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- PROCESS FOR THE PRODUCTION OF ETHYLENE OXIDE
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The invention relates to a process for the production of ethylene oxide, comprising the steps of producing ethylene resulting in a stream comprising ethylene and ethane; producing ethylene oxide by subjecting ethylene and ethane from the stream comprising
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Paragraph 0062-0065
(2014/02/16)
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- Experimental investigation of the low temperature oxidation of the five isomers of hexane
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The low-temperature oxidation of the five hexane isomers (n-hexane, 2-methyl-pentane, 3-methyl-pentane, 2,2-dimethylbutane, and 2,3-dimethylbutane) was studied in a jet-stirred reactor (JSR) at atmospheric pressure under stoichiometric conditions between 550 and 1000 K. The evolution of reactant and product mole fraction profiles were recorded as a function of the temperature using two analytical methods: gas chromatography and synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Experimental data obtained with both methods were in good agreement for the five fuels. These data were used to compare the reactivity and the nature of the reaction products and their distribution. At low temperature (below 800 K), n-hexane was the most reactive isomer. The two methyl-pentane isomers have about the same reactivity, which was lower than that of n-hexane. 2,2-Dimethylbutane was less reactive than the two methyl-pentane isomers, and 2,3-dimethylbutane was the least reactive isomer. These observations are in good agreement with research octane numbers given in the literature. Cyclic ethers with rings including 3, 4, 5, and 6 atoms have been identified and quantified for the five fuels. While the cyclic ether distribution was notably more detailed than in other literature of JSR studies of branched alkane oxidation, some oxiranes were missing among the cyclic ethers expected from methyl-pentanes. Using SVUV-PIMS, the formation of C 2-C3 monocarboxylic acids, ketohydroperoxides, and species with two carbonyl groups have also been observed, supporting their possible formation from branched reactants. This is in line with what was previously experimentally demonstrated from linear fuels. Possible structures and ways of decomposition of the most probable ketohydroperoxides were discussed. Above 800 K, all five isomers have about the same reactivity, with a larger formation from branched alkanes of some unsaturated species, such as allene and propyne, which are known to be soot precursors.
- Wang, Zhandong,Herbinet, Olivier,Cheng, Zhanjun,Husson, Benoit,Fournet, Rene,Qi, Fei,Battin-Leclerc, Frederique
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p. 5573 - 5594
(2014/08/18)
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- Dehydrochlorination of 2-chloroethanol, 2-chloro-1-propanol, 1-chloro-2-propanol, 2-chloro-2-methyl-1-propanol and 1-chloro-2-methyl-2- propanol
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The reactions between a few 1,2-chlorohydrins and sodium hydroxide have been studied and shown to involve a two-step nucleophilic elimination of hydrogen chloride. The data are given for the slow rate-determining step of 2-chloroethanol 1, 2-chloro-1-propanol 2, 1-chloro-2- propanol 3, 2-chloro-2-methyl-1-propanol 4 and 1-chloro-2-methyl-2-propanol 5. Compounds 4 and 5 gave 2-methyl-1,2-propanediol as the final product instead of oxiranes given by compounds 13. In contrast to some earlier reports the mere water reaction was shown to be almost negligible. In constant ionic strength the base concentration had no effect on the rates whereas at different base concentrations (0.0500.250 mol dm-3) alone the rate of alkaline dehydrochlorination of 1 clearly decreased (103k2, dm 3 mol-1 s-1: 10.0-8.7, respectively). The rate of 2 at constant base concentration (0.010 mol dm-3) and at different ionic strengths (dm3 mol-1: 0.010-0.500) decreased also (103k2, dm3 mol-1 s-1: 76-65, respectively) indicating that the decrease is mainly due to the change in the ionic strength also in the former case. ARKAT-USA, Inc.
- Pihlaja, Kalevi,Kiuru, Marja-Leena,Sippola, Anne
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p. 120 - 133
(2013/09/24)
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- Routes for reactions of alkylene oxides with R-β-hydroxyalkyl sulfides: Unusual exchange of functional groups
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Possible routes of the previously unknown exchange reaction of alkylene oxides with R-β-hydroxyalkyl sulfides have been considered. Each route has intermediates and transition states of its own, but all the directions in the final stage lead to the formation of a single intermediate cyclic bipolar ion with intramolecular hydrogen bonding, which determines the common nature and composition of end products for all routes. The features of the reaction have been analyzed. The quantitative description of each route has been given. Pleiades Publishing, Ltd., 2012.
- Malievskii
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experimental part
p. 194 - 203
(2012/10/18)
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- PROCESS FOR MAKING ETHYLENE OXIDE USING MICROCHANNEL PROCESS TECHNOLOGY
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This invention relates to a process comprising reacting ethylene and oxygen or a source of oxygen in a process microchannel in the presence of a catalyst to form a product comprising ethylene oxide.
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Page/Page column 26-27
(2011/02/15)
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- Ethylene epoxidation under the effect of gas phase thermal oxidation of methane
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The process of ethylene epoxidation under the effect of gas phase thermal oxidation of methane has been studied. It was shown that if methane oxidation is carried out in the first section of two-sectional reactor and ethylene is injected into the second section then epoxidation occurs as a result of interaction of ethylene and peroxy radicals generated by methane oxidation reaction. The dependence of ethylene oxide accumulation rate on methane/oxygen ratio in the first section of reactor as well as flow velocity and temperatures in the first and second sections has been studied. The results show that in the second section of the reactor the ethylene epoxidation takes place trough C 2H4 + RO?2 → C 2H4O + RO reaction. Pleiades Publishing, Ltd., 2011.
- Grigoryan,Arsentev,Mantashyan
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experimental part
p. 448 - 453
(2012/04/23)
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- PROCESS FOR HYDROCHLORINATION OF MULTIHYDROXYLATED ALIPHATIC HYDROCARBONS
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A process for producing a chlorohydrin, an ester of a chlorohydrin, or a mixture thereof including the steps of contacting, in a hydrochlorination reactor, a multihydroxylated aliphatic hydrocarbon, an ester of a multihydroxylated aliphatic hydrocarbon, or a mixture thereof with a source of a hydrogen chloride, in the presence of a hydrophobic or extractable carboxylic acid catalyst is provided.
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Page/Page column 21-23
(2011/12/14)
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- Switching on the electrocatalytic ethene epoxidation on nanocrystalline RuO2
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Ruthenium-based oxides with rutile structure were examined regarding their properties in electrocatalytic ethene oxidation in acid media. A possible promoting effect of chloride ions toward oxirane formation was explored. Online differential electrochemical mass spectrometry combined with electrochemical polarization techniques were used to monitor the potential dependence of organic products resulting from ethene oxidation as well as the reaction solution decomposition products. Quantum chemical modeling by means of density functional theory was employed to study key reaction steps. The ethene oxidation in acid media led to CO2, whereas oxirane was formed in the presence of 0.3 M Cl-. In the Cl- promoted oxidation on RuO2, oxirane and a small amount of CO2 were the only detected electro-oxidation products at potentials below the onset of Cl2 and O2 evolution, resulting from Cl- and water oxidation. It is demonstrated here that the epoxidation is a surface-related electrocatalytic process that depends on the surface properties. Cl acts as the epoxidation promoter that switches off the combustion pathway toward CO2 and enables the epoxidation reaction channel by surface reactive sites blocking. The proposed epoxidation mechanism implies binuclear (recombination) mechanism for O2 evolution reaction on considered surfaces.
- Jirkovsky, Jakub S.,Busch, Michael,Ahlberg, Elisabet,Panas, Itai,Krtil, Petr
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experimental part
p. 5882 - 5892
(2011/06/19)
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- ALKYL ALKOXYLATES CONTAINING UNIQUE END GROUPS
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Described is a process for the alkoxylation of alcohols with I, Cl, or CH3CO2 endgroups, using alkylene epoxides in the presence of boron based catalysts.
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Page/Page column 3; 4
(2010/12/29)
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- Direct conversion of ethanol into ethylene oxide on copper and silver nanoparticles: Effect of addition of CeOx and Li2O
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The behavior of nanoparticles of copper and silver on an alumina support in the oxidation and dehydrogenation of ethanol is investigated. Pure alumina mainly acts as an acidic catalyst and produces diethyl ether and ethylene. Addition of copper and silver nanoparticles results in a direct conversion of ethanol into ethylene oxide. Addition of Li2O influences the selectivity by suppressing the formation of diethyl ether and ethylene. Using Ag/Li2O/Al2O3 and Cu/Li2O/Al 2O3 catalysts it is possible to obtain high selectivity towards ethylene oxide at a temperature of 200 °C. It is suggested that at low concentrations the main role of oxygen is to prevent coke formation on the catalytic surface. Addition of CeOx results in higher selectivities towards CO.
- Lippits,Nieuwenhuys
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experimental part
p. 127 - 132
(2010/12/18)
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- Direct conversion of ethanol into ethylene oxide on gold-based catalysts: Effect of CeOx and Li2O addition on the selectivity
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Results are presented concerning the behavior of alumina-supported gold catalysts and the effects of addition of Li2O and CeOx on the oxidation, dehydrogenation and dehydration reactions of ethanol. Pure alumina mainly acts as an acidic catalyst and produces diethyl ether and ethylene. Gold particles play an important role in converting ethanol into ethylene oxide and acetaldehyde. Addition of Li2O influences the selectivity by suppressing the formation of diethyl ether and ethylene. With the Au/Li2O/Al2O3 catalysts, a high selectivity toward ethylene oxide can be obtained. The influence of the oxygen concentration on the gas flow is investigated. It is suggested that at low concentrations, the role of oxygen is mainly to prevent coke formation on the catalytic surface.
- Lippits,Nieuwenhuys
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experimental part
p. 142 - 149
(2011/01/08)
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- Formation of epoxides from pentacoordinated organoarsenic compounds with a β-hydroxyethyl group
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A series of pentacoordinated organoarsenic compounds (arsoranes) bearing a β-hydroxyethyl group (4a, 6a and 6b) was synthesized. The crystal structures were determined by single crystal X-ray analysis. Treatment of these arsoranes with KH almost quantitatively gave the corresponding epoxide. The reaction of 4a having an unsubstituted β-hydroxyethyl group with KH was monitored by 1H and 19F NMR in CD3CN, suggesting that a hexacoordinate arsenic anion was formed as the intermediate. However, a further stereochemical study of the epoxide formation suggested that the reaction proceeded in the SN2 manner and not in the ligand coupling reaction (LCR) of the intermediate hexacoordinate arsenic anion.
- Jiang, Xin-Dong,Matsukawa, Shiro,Fukuzaki, Yuta,Yamamoto, Yohsuke
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experimental part
p. 1623 - 1629
(2010/10/04)
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- METHOD OF ACHIEVING AND MAINTAINING A SPECIFIED ALKYLENE OXIDE PRODUCTION PARAMETER WITH A HIGH EFFICIENCY CATALYST
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An improved method of operating an alkylene oxide production process to achieve and maintain a desired alkylene oxide production parameter is shown and described. The method comprises adjusting one of an overall catalyst chloriding effectiveness parameter or reaction temperature to obtain the desired alkylene oxide production parameter.
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Page/Page column 14
(2010/11/03)
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- A Simple, effective boron-halide ethoxylation catalyst
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Boron esters B(OR)3, readily derived from boric acid and alcohols, combine with iodide or bromide to catalyze the ethoxylation of alcohols and phenols, giving good rates and narrow product distributions. The combined action of a weak electrophile [B(OR)3] and a weak nucleophile (halide) allows for the ethoxylation of base-sensitive alcohols. Experiment suggests a new mechanism for this commercially important reaction proceeding through key β-haloalkoxy intermediates.
- Moloy, Kenneth G.
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body text
p. 821 - 826
(2010/07/05)
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- Kinetic studies of hydrazine and 2-hydroxyethylhydrazine alkylation by 2-chloroethanol: influence of a strong base in the medium
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To optimize yields, the study of reaction kinetics related to the synthesis of 2-hydroxyethylhydrazine (HEH) obtained from the alkylation of N 2H4 by 2-chloroethanol (CletOH) was carried out with and without sodium hydroxide. In both cases, the main reaction of HEH formation was followed by a consecutive, parallel reaction of HEH alkylation (or dialkylation of N2H4), leading to the formation of two isomers: 1,1-di(hydroxyethyl)hydrazine and 1,2-di(hydroxyethyl)hydrazine. In this study, hydrazine and hydroxyalkylhydrazine alkylations followed SN2 reactions triggered directly by CletOH or indirectly in the presence of a strong base by ethylene oxide, an intermediate compound. The kinetics was studied in diluted mediums by quantifying HEH and CletOH by gas chromatography and gas chromatography coupled with mass spectrometry (GC-MS). The activation parameters of each reaction and the influence of a strong base present in the medium on the reaction mechanisms were established. A global mathematical treatment was applied for each alternative. It allowed modeling the reactions as a function of reagent concentrations and temperature. In the case of direct alkylation by CletOH, simulation was established for semi-batch and batch syntheses and was confirmed in experiments for concentrated mediums (1.0 M≤[CletOH]0 ≤3.2 M and 15.7 M≤[N2H4]0 ≤18.8 M). Simulation therefore permits the prediction of the instantaneous concentration of reagents and products, in particular ethylene oxide concentration in the case of indirect alkylation, which must be as weak as possible.
- Goutelle,Pasquet,Stephan,Bougrine,Delalu
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experimental part
p. 382 - 393
(2009/11/30)
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- PROCESS FOR PREPARING FLUORINE-CONTAINING ALKOXYALKANE
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A process for preparing a fluorine-containing alkoxyalkane represented by the general formula (1) R1—O—R2—O—R3 where at least one of R1, R2 and R3 contains one or more fluorine atoms. An alcohol with the highest acidity selected from the group consisting of the compounds represented by the general formula (2) R1—OH, the general formula (3) R3—O—R2—OH, the general formula (4) R1—O—R2—OH, and the general formula (5) R3—OH is reacted with at least one selected from the group consisting of the compounds represented by the general formula (6) Lg-R2—O—R3, the general formula (7) Lg-R1, the general formula (8) Lg-R3, and the general formula (9) Lg-R2—O—R1 where Lg represents an anionic leaving group in the presence of a basic compound.
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Page/Page column 8-9
(2009/01/20)
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- Catalyst system and process for the production of epoxides
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The present invention relates to a catalyst system which is a mixture of at least two catalytic species, the first catalytic species providing dehydrogenation activity and the second catalytic species providing epoxidation activity and comprising silver. The present invention also relates to a process for the production of epoxides, in particular a process for the production of an epoxide from a mixture comprising an alkane and an alkene, which process comprises contacting said mixture comprising said alkane and said alkene and a source of oxygen with such a catalyst system comprising a mixture of at least two catalytic species, the first catalytic species providing dehydrogenation activity and the second catalytic species providing epoxidation activity and comprising silver.
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Page/Page column 5
(2008/12/06)
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- Carbocyclization reaction of malonate derivatives with allylsilane moiety mediated by AICI3-n-BU3N
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Allylsilane bearing malonate moiety underwent intramolecular carbocyclization reaction by means of AlCl3-n-BU3N to give silyl-substituted cyclopentanes in good yields.
- Imazeki, Shigeaki,Kinoshita, Ryohiko,Akiyama, Takahiko
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experimental part
p. 972 - 978
(2009/06/05)
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- Catalyst for epoxidation of an alkene to an alkene oxide, method of making and method of using thereof
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The present invention if for a catalyst for epoxidation of an alkene, such as ethylene, to an alkene oxide, such as ethylene oxide, on which silver has been deposited on alumina as a support which has been modified with certain weak base compounds, such as oxides of a Group 1A, Group 2A, Group 3A or the first transition series of the Periodic Table of Elements, and with a high temperature heat treatment. Optional promoters selected from the group consisting of compounds of Group 1A, Group 2A, Group 7A and Group 8 may be contacted with the alpha-alumina support in solution with a silver compound, with the catalyst precursor before calcination or with the catalyst after calcination. The catalyst is brought into contact with alkene and oxygen under reaction conditions to selectively convert the alkene to an alkene oxide.
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Page/Page column 3
(2008/06/13)
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- PROCESS FOR PREPARING A REJUVENATED EPOXIDATION CATALYST
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A process for preparing a rejuvenated epoxidation catalyst, for the epoxidation of one or more olefins using the rejuvenated epoxidation catalyst to produce olefin oxide, and for the production of a 1,2-diol, a 1,2-diol ether, or an alkanol amine from the olefin oxide, the process comprising: providing a quantity of spent epoxidation catalyst having a cumulative alkylene oxide production of 0.16 kT/m3 of the spent epoxidation catalyst or more; and, depositing additional silver on the spent epoxidation catalyst in an amount of 0.2% w or more, based on the weight of the spent epoxidation catalyst.
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Page/Page column 13
(2008/06/13)
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- PROCESS FOR TREATING A CATALYST, THE CATALYST, AND USE OF THE CATALYST
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A process for treating a supported epoxidation catalyst comprising silver in a quantity of at most 0.15 g per m2 surface area of the support, which process comprises: contacting the catalyst, or a precursor of the catalyst comprising silver in cationic form, with a treatment feed comprising oxygen at a catalyst temperature of at least 350° C. for a duration of at least 5 minutes; the catalyst; a process for the epoxidation of an olefin; and a process for producing a 1,2-diol, 1,2-diol ether, or an alkanolamine.
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Page/Page column 7
(2008/06/13)
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- Process for selective oxidation of olefins to epoxides
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A process for the selective oxidation of olefins to epoxides comprising the step of contacting the olefin (propylene) with an oxidant (hydrogen peroxide) in the presence of a Lewis acid oxidation catalyst (MTO), organic base (pyridine or its N-oxide), in a solvent system comprising an organic water-miscible solvent (methanol); and adding a pressurizing gas (nitrogen) to increase the pressure, whereby olefin is further dissolved in organic solvent system to increase the selectivity and yield of the desired epoxide (propylene oxide).
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Page/Page column 6
(2008/06/13)
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- Activation of high selectivity ethylene Oxide catalyst
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The invention describes a process for producing a catalyst useful for the epoxidation of an olefin. More particularly, the invention pertains to a catalyst useful for the oxidation of ethylene to ethylene oxide. The catalyst comprises a solid support such as alpha-alumina, which has a catalytically effective amount of silver or a silver-containing compound, and a promoting amount of rhenium or a rhenium-containing compound, and a promoting amount of one or more alkali metals or alkali metal-containing compounds on the surface of the support. To produce a catalyst precursor. The catalyst precursor is contacted with an atmosphere comprising oxygen and steam, which atmosphere is substantially absent of an olefin, to hasten the attainment of peak selectivity in the process of oxidation of ethylene to ethylene oxide.
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Page/Page column 5-6
(2008/06/13)
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- A novel biosurfactant, 2-acyloxyethylphosphonate, isolated from waterblooms of Aphanizomenon flos-aquae
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A novel biosurfactant, 2-acyloxyethylphosphonate, was isolated from waterblooms of Aphanizomenon flos-aquae. Its structure was elucidated by chemical degradation and HRFABMS, GC/EI-MS and 1D- and 2D-NMR spectral analyses. The surfactant contained one mole of 2-hydroxyethylphosphonate and one mole of fatty acid, with hexadecanoic acid accounting for 84.1% of the total fatty acid content. The structure was confirmed by synthesis of 2-oleoyloxyethylphosphonate from ethylene oxide, phosphorus acid and oleic acid chloride. Considering the isolated surfactant molecule as hexadecanoyloxyethylphosphonic acid (mw. 364), the critical micelle concentration (CMC) was about 22 mM.
- Kaya, Kunimitsu,Morrison, Louise F.,Codd, Geoffrey A.,Metcalf, James S.,Sano, Tomoharu,Takagi, Hiroo,Kubo, Takuya
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p. 539 - 548
(2007/10/03)
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- Process for the production of an olefin oxide, a 1, 2-diol, a 1,2-diol ether, or an alkanolamine
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A process is provided for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a high-selectivity dopant deposited on a fluoride-mineralized carrier; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the feed is less than about 2 mole-%, relative to the total feed.
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Page/Page column 7
(2008/06/13)
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- Method of preparing a shaped catalyst, the catalyst, and use of the catalyst
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A method of preparing a shaped catalyst, which method comprises moulding a dough into shaped particles and drying at least a portion of the shaped particles at a temperature below 1000° C., wherein the dough comprises a support material, or a precursor-thereof, and a silver component; the shaped catalyst, and a use of the shaped catalyst.
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Page/Page column 7
(2008/06/13)
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- Mechanistic studies of an unusual epoxide-forming elimination of a β-hydroxyalkyl rhodium porphyrin
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A new and remarkably facile sp3-C-O bond forming reaction of β-hydroxyalkyl Rh porphyrins to form epoxides has been discovered and its mechanism investigated. The Royal Society of Chemistry 2006.
- Han, Yuan-Zhang,Sanford, Melanie S.,England, Michael D.,Groves, John T.
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p. 549 - 551
(2008/02/08)
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- PROCESS FOR THE MANUFACTURE OF ETHYLENE OXIDE
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A process for the manufacture of ethylene oxide successively comprising: (a) a stage of synthesis of the ethylene oxide carried out by bringing ethylene into contact with oxygen in the presence of a catalyst, so as to form a gaseous reaction mixture comprising ethylene oxide and impurities, in particular aldehyde impurities, (b) a stage of absorption carried out by bringing the gaseous reaction mixture into contact with water, so as to form a dilute aqueous ethylene oxide solution, (c) a stage of desorption carried out by entrainment with steam of the dilute aqueous ethylene oxide solution, so as to form a mixture of water enriched in ethylene oxide and to separate, from the said mixture, an aqueous solution depleted in ethylene oxide which is preferably returned to the stage (b) of absorption, and (d) a stage of purification of the ethylene oxide by distillation of the mixture of water enriched in ethylene oxide, so as to isolate and recover a purified ethylene oxide, which process is characterized in that an alkali metal borohydride is employed after the stage (a) of synthesis but before or during the stage (d) of purification is disclosed.
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Page/Page column 9-10
(2008/06/13)
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- A PROCESS FOR THE PRODUCTION OF ALKYLENE OXIDE USING A GAS-PHASE PROMOTER SYSTEM
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An improved process for the manufacture of ethylene oxide through the epoxidation of ethylene using a catalyst comprising silver and at least one efficiency-enhancing salt of a member of a redox-half reaction pair. Added to the epoxidation reaction is a two-component gas-phase promoter system comprising a chlorine-containing component (for example ethyl chloride, methyl chloride, vinyl chloride and ethylene dichloride), and a nitrogen-containing component of nitric oxide and other compounds capable of generating under reaction conditions at least one gaseous efficiency-enhancing member of a redox-half reaction pair comprising NO, NO2, N2O3 or N2O4. The amount of each component of said gaseous promoter is adjusted to maintain the ration of N* to Z* less than or equal to 1 wherein, N* is the nitric oxide equivalent in ppmv, ranging from 1 to 20 ppmv and Z* =ethyl chloride equivalent (ppmv) * 100 percent / ethane equivalent (mol percent) * 100 ranging from 5 to 40 ppmv.
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Page/Page column 23-28
(2008/06/13)
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- Oxidation process and catalyst
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Ethylene is oxidized by contact at oxidizing conditions with an admixture of a solid particulate catalyst and a solid particulate alkali metal treated inert.
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Page/Page column 2
(2008/06/13)
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- Process for preparing a catalyst, the catalyst, and a use of the catalyst
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A process for preparing an epoxidation catalyst comprising silver and a high-selectivity dopant on a support, which process comprises depositing a base having a pKb of at most 3.5 when measured in water at 25° C., on the support prior to depositing silver on the support, and depositing silver and a high-selectivity dopant on the support; the epoxidation catalyst; and a process for preparing an olefin oxide by reacting an olefin with oxygen in the presence of the epoxidation catalyst.
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Page/Page column 6
(2008/06/13)
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