Vapour-phase synthesis of thiophene from crotonaldehyde and carbon disulfide over promoted chromia on γ-alumina catalysts

Tomov, Atanas K.; Fajula, François; Moreau, Claude

doi:10.1016/s0926-860x(99)00336-1

Cited by 6 publications

(5 citation statements)

References 6 publications

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“…3 illustrates products' distribution resulting from the reaction. As shown, a selectivity to thiophene of 70.5% was achieved at 500 o C. Also, the alkylthiophenes were detected above 300 o C. Temperature enhancement favors thiophene formation but inhibits butanethiol formation from 300 to 500 o C. These results are consistent with those of Atanas Tomov and Claude Moreau [15], who have claimed that both lower and higher temperatures tend to reduce both selectivity and yield in primary butanethiol. Fig.…”

Section: Study Of the Reactivity Of The Individual Initial Compoundssupporting

confidence: 89%

“…The first involves the reaction of C 4 + alcohols or carbonyls with CS 2 over alkali-promoted alumina [2,[9][10][11][12][13][14]. The second is based upon the reaction of an α,β-unsaturated aldehyde with H 2 S over an alkali-promoted alumina [15]. The third is through the reaction of C 4 + alkyl hydrocarbon or olefins with CS 2 , S, and H 2 S over alkali-promoted alumina [16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

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Catalytic synthesis of thiophene from the reaction of n-butanol and carbon disulfide over K2CO3-promoted Cr2O3/γ-alumina catalyst

Liu

Kim

2009

Korean J. Chem. Eng.

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The synthesis of thiophene from the reaction of n-Butanol and carbon disulfide was performed in a fixedbed reactor in the presence of promoted chromia on γ-alumina. A high selectivity to thiophene (87%) and a long lifetime of the catalyst (55 hour) was obtained at 450 o C with a 1 : 6 n-Butanol to carbon disulfide molar ratio and LHSV 1 h −1 over γ-Al 2 O 3 promoted by 7% K 2 CO 3 with 15% Cr 2 O 3 loaded. The catalytic behavior of these catalysts can be attributed to their dual-functional acidity and dehydrogenating and cyclized properties.

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Section: Study Of the Reactivity Of The Individual Initial Compoundssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Catalytic synthesis of thiophene from the reaction of n-butanol and carbon disulfide over K2CO3-promoted Cr2O3/γ-alumina catalyst

Liu

Kim

2009

Korean J. Chem. Eng.

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“…In volcanic gases, production of CS 2 may occur through sulfonation processes involving compounds typical of magmatic degassing (SO 2 and CO 2 ), as well as gases from secondary gas‐water‐rock interactions (H 2 S and CH 4 ) [ Petherbridge et al , 2002]. Among the various catalytic processes able to synthesize thiophenes [ Southward et al , 1998; Tomov et al , 2000; Li et al , 2008], ring closure of dienes, known as Paal–Knorr synthesis, through addition of H 2 S in presence of H + and metals [ Campaigne and Foye , 1952], is to be considered the most reliable genetic mechanism in active volcanoes that are rich in these catalysts [ Tassi et al , 2010a]. Similarly, ring closure of oxygenated alkenes may represent the main genetic mechanism for furans, which are the most abundant fraction of oxygenated species (Table 2).…”

Section: Discussionmentioning

confidence: 99%

Geogenic and atmospheric sources for volatile organic compounds in fumarolic emissions from Mt. Etna and Vulcano Island (Sicily, Italy)

et al. 2012

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In this paper, fluid source(s) and processes controlling the chemical composition of volatile organic compounds (VOCs) in gas discharges from Mt. Etna and Vulcano Island (Sicily, Italy) were investigated. The main composition of the Etnean and Volcano gas emissions is produced by mixing, to various degrees, of magmatic and hydrothermal components. VOCs are dominated by alkanes, alkenes and aromatics, with minor, though significant, concentrations of O‐, S‐ and Cl(F)‐substituted compounds. The main mechanism for the production of alkanes is likely related to pyrolysis of organic‐matter‐bearing sediments that interact with the ascending magmatic fluids. Alkanes are then converted to alkene and aromatic compounds via catalytic reactions (dehydrogenation and dehydroaromatization, respectively). Nevertheless, an abiogenic origin for the light hydrocarbons cannot be ruled out. Oxidative processes of hydrocarbons at relatively high temperatures and oxidizing conditions, typical of these volcanic‐hydrothermal fluids, may explain the production of alcohols, esters, aldehydes, as well as O‐ and S‐bearing heterocycles. By comparing the concentrations of hydrochlorofluorocarbons (HCFCs) in the fumarolic discharges with respect to those of background air, it is possible to highlight that they have a geogenic origin likely due to halogenation of both methane and alkenes. Finally, chlorofluorocarbon (CFC) abundances appear to be consistent with background air, although the strong air contamination that affects the Mt. Etna fumaroles may mask a possible geogenic contribution for these compounds. On the other hand, no CFCs were detected in the Vulcano gases, which are characterized by low air contribution. Nevertheless, a geogenic source for these compounds cannot be excluded on the basis of the present data.

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“…On an industrial scale thiophene is synthesized through the following catalytic processes: 1) reaction of C 4 + alcohols or carbonyls with CS 2 over alkali-promoted alumina; 2) reaction of unsaturated aldehydes with H 2 S over an alkali-promoted alumina; 3) reaction of C 4 + alkyl hydrocarbons or olefins with CS 2 , S, and H 2 S over alkali-promoted alumina; 4) catalytic dehydrogenation of tetrahydrothiophene; 5) synthesis from furan and H 2 S over alumina [ 53 – 56 ]. The thiophene Paal-Knorr synthesis involves the reaction of 1,4-diketones with H 2 S as sulphurising agent [ 57 ].…”

Section: Resultsmentioning

confidence: 99%

Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems

Tassi

Montegrossi

Capecchiacci

et al. 2010

IJMS

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The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C2–C20 species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C4H8O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.

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Vapour-phase synthesis of thiophene from crotonaldehyde and carbon disulfide over promoted chromia on γ-alumina catalysts

Cited by 6 publications

References 6 publications

Catalytic synthesis of thiophene from the reaction of n-butanol and carbon disulfide over K2CO3-promoted Cr2O3/γ-alumina catalyst

Catalytic synthesis of thiophene from the reaction of n-butanol and carbon disulfide over K2CO3-promoted Cr2O3/γ-alumina catalyst

Geogenic and atmospheric sources for volatile organic compounds in fumarolic emissions from Mt. Etna and Vulcano Island (Sicily, Italy)

Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems

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