Metathesis of n-alkenes over a CsNO3-Re2O7-Al2O3 catalyst

Kawai, Tadashi; Gotō, Hitoshi; Yamazaki, Yasuo; Ishikawa, Tomomichi

doi:10.1016/0304-5102(88)85091-0

Cited by 28 publications

(4 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, van Roosmalen and Mol [13] reported that isomerization occurs on the Brönsted acid sites of the WO3/SiO2 catalysts. This led to several recent studies that focused on poisoning the acid sites with small amounts of an alkali metal such as Na, K, Rb, and Cs [19,20]. Spamer et al [20] found that branched metathesis products were decreased by the addition of small amounts of an alkali metal ion, that is, isomerization was reduced.…”

Section: Introductionmentioning

confidence: 99%

NaOH modified WO3/SiO2 catalysts for propylene production from 2-butene and ethylene metathesis

Maksasithorn

Debecker

Praserthdam

et al. 2014

Chinese Journal of Catalysis

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

NaOH modified WO3/SiO2 catalysts for propylene production from 2-butene and ethylene metathesis

Maksasithorn

Debecker

Praserthdam

et al. 2014

Chinese Journal of Catalysis

View full text Add to dashboard Cite

“…It is considered that acid sites influence the asphaltenes conversion [100]. Isomerization reactions occur on the Brønsted acid sites of the WO 3 /SiO 2 catalysts, and studies have concluded that by poisoning the surface acid sites with small amounts of alkali elements, such as Na, K, Rb, and Cs, branched metathesis products were decreased, that is, isomerization was reduced, obtaining a greater degree of asphaltenes consumption [101][102][103].…”

Section: Mass Loss Analysismentioning

confidence: 99%

Catalytic Decomposition of n-C7 Asphaltenes Using Tungsten Oxides–Functionalized SiO2 Nanoparticles in Steam/Air Atmospheres

et al. 2022

View full text Add to dashboard Cite

A wide range of technologies are being developed to increase oil recovery, reserves, and perform in situ upgrading of heavy crude oils. In this study, supported tungsten oxide nanoparticles were synthesized, characterized, and evaluated for adsorption and catalytic performance during wet in situ combustion (6% of steam in the air, in volumetric fraction) of n-C7 asphaltenes. Silica nanoparticles of 30 nm in diameter were synthesized using a sol–gel methodology and functionalized with tungsten oxides, using three different concentrations and calcination temperatures: 1%, 3%, 5% (mass fraction), and 350 °C, 450 °C, and 650 °C, respectively. Equilibrium batch adsorption experiments were carried out at 25 ℃ with model solutions of n-C7 asphaltenes diluted in toluene at concentrations from 100 mg·L−1 to 2000 mg·L−1, and catalytic wet in situ combustion of adsorbed heavy fractions was carried out by thermogravimetric analysis coupled to FT-IR. The results showed improvements of asphaltenes decomposition by the action of the tungsten oxide nanoparticles due to the reduction in the decomposition temperature of the asphaltenes up to 120 °C in comparison with the system in the absence of WOX nanoparticles. Those synthesis parameters, such as temperature and impregnation dosage, play an important role in the adsorptive and catalytic activity of the materials, due to the different WOX–support interactions as were found through XPS. The mixture released during the catalyzed asphaltene decomposition in the wet air atmosphere reveals an increase in light hydrocarbons, methane, and hydrogen content. Hydrogen production was prioritized between 300 and 400 °C where, similarly, the reduction of CO, CH4, and the increase in CO2 content, associated with water–gas shift, and methane reforming reactions occur, respectively. The results show that these catalysts can be used either for in situ upgrading of crude oil, or any application where heavy fractions must be transformed.

show abstract

“…This would have created a diolefin, and there would then be two double bond locations for metathesis to occur. Past studies have suggested that internal olefins were more reactive than terminal olefins . Diolefins are not the same as internal olefins; however, it was possible that the more internal double bond of a diolefin was more reactive for metathesis than the more terminal double bond.…”

Section: Bench Reactor Experimentation: Overall Data Comparisonmentioning

confidence: 99%

“…Past studies have suggested that internal olefins were more reactive than terminal olefins. 3 Diolefins are not the same as internal olefins; however, it was possible that the more internal double bond of a diolefin was more reactive for metathesis than the more terminal double bond. A good test to determine whether dehydrogenation was occurring would be to take a gas sample on the vapor outlet and measure for hydrogen.…”

Section: Data Comparisonmentioning

confidence: 99%

Rhenium Oxide based Olefin Metathesis

Morrison

Lipscomb

Eldridge

et al. 2014

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

In support of a reactive distillation experimental program, bench scale experiments were conducted for the production of high molecular weight olefins via metathesis. A fixed bed rhenium oxide (Re2O7) catalyst on a γ-alumina support was utilized to study the reaction of C6, C8, and C10 olefins to form light and heavy olefin products. Initial experiments determined the impact temperature and weight hourly space velocity (WHSV) had on the reactivity of three different α- olefins. The investigated temperatures and WHSV were conditions that encompassed the anticipated reactive distillation column reactor zones temperatures and WHSV. All of these runs displayed high conversions, low selectivities, and significant secondary isomerization coupled with subsequent metathesis. This isomerization compromised the ability to make any quantitative assessments on the reactivity of olefins with respect to temperature, flow rate, and carbon number in the feed. However, it was concluded that there was a possible optimal condition of a low flow and low temperature. Additional experiments revealed the impact temperature had on conversion and selectivity of C8 and C10 α-olefins. These experiments concluded that between an ambient temperature condition and 60 °C, there was a moderate conversion of the feed and a relatively high selectivity to the primary liquid product. However, above 60 °C, there was a step change in the amount of isomerization, which resulted in significantly higher conversions and significantly lower selectivities. An experiment with a temperature ramp over time located this step change in isomerization by suggesting that this temperature occurred between 60 and 70 °C.

show abstract

Metathesis of n-alkenes over a CsNO3-Re2O7-Al2O3 catalyst

Cited by 28 publications

References 17 publications

NaOH modified WO3/SiO2 catalysts for propylene production from 2-butene and ethylene metathesis

NaOH modified WO3/SiO2 catalysts for propylene production from 2-butene and ethylene metathesis

Catalytic Decomposition of n-C7 Asphaltenes Using Tungsten Oxides–Functionalized SiO2 Nanoparticles in Steam/Air Atmospheres

Rhenium Oxide based Olefin Metathesis

Contact Info

Product

Resources

About