Dimerization of α-methylstyrene in the presence of mordenite, aimed at preparation of transformer oils

Rustamov, M. I.; Seidov, N. M.; Ibragimov, Kh. D.; Mamedbeili, E. G.

doi:10.1134/s1070427209020281

Cited by 2 publications

(6 citation statements)

References 3 publications

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“…Another common example of the reaction conditions influencing AMS dimerization was the increase in the yield of saturated AMS dimer during cationic polymerization at higher temperatures (>100 °C). 28,46 Despite the similarities between free radical and cationic dimerization of AMS, it was found in the current study that the overall abundance of the AMS dimers (indicated by the cumulative peak areas) decreased upon addition of pyridine for both types of minerals used, as shown in Table 8. The addition of pyridine would inhibit the cationic addition of AMS by deactivating the acid sites on the mineral surface.…”

Section: Energy and Fuelsmentioning

confidence: 54%

“…According to the literature, the solvent system, the type of initiator and the reaction conditions such as temperature used in the reactions would influence the product selectivity and conversion of AMS dimerization. ,,,,, For example, cationic polymerization reactions performed in non-polar solvents, similar to toluene in the current study, mostly favored the formation of AMS dimers as opposed to polar solvents. It was said that the polar solvents could reduce the contact between the active sites in clays and the monomer due to the preferential adsorption of the polar molecules from the solvent onto the mineral surface, thereby affecting reaction rate and conversion. , In this study, toluene is not expected to contribute to such a situation.…”

Section: Discussionmentioning

confidence: 87%

“…It was said that the polar solvents could reduce the contact between the active sites in clays and the monomer due to the preferential adsorption of the polar molecules from the solvent onto the mineral surface, thereby affecting reaction rate and conversion. , In this study, toluene is not expected to contribute to such a situation. Another common example of the reaction conditions influencing AMS dimerization was the increase in the yield of saturated AMS dimer during cationic polymerization at higher temperatures (>100 °C). , …”

Section: Discussionmentioning

confidence: 99%

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Free Radical and Cationic Addition due to Clay Minerals Found in Bitumen Froth at 250 °C Probed with Use of α-Methylstyrene and 1-Octene

Turuga

Klerk

2022

Energy Fuels

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Following previous evidence that hydrothermal treatment of bitumen froth does not lead to bitumen upgrading at 250 °C and promotes viscosity increase, the current study explores the free radical and cationic reactivity of clay minerals found in bitumen froth in promoting heavier material formation through addition reactions. The current investigation employed α-methylstyrene (AMS) and 1-octene as probe molecules instead of bitumen froth, and their conversion at 250 °C in the presence of clay minerals kaolinite and illite was studied in batch reactors. Thermal conversion of AMS and 1-octene at 250 °C in the absence of minerals was observed to be low. In the presence of clay minerals, not only the conversion of AMS and 1-octene was increased but also reactions such as dimerization of AMS and alkylation of 1-octene and toluene (used as solvents) were mainly promoted, leading to heavier product formation. Double-bond isomerization of 1-octene and cumene formation from AMS was side reactions that were also promoted by the clay minerals. Suppression of mineral-related conversion by pyridine and selectivity to different reaction products that enabled differentiation between free radical and cationic reaction pathways indicated that the mineral-related conversion was predominantly cationic in nature. Using the reactions in the presence of minerals and pyridine as surrogates for alkaline bitumen froth, it was concluded that even under alkaline conditions, minerals could promote heavier material formation through cationic addition.

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Section: Energy and Fuelsmentioning

confidence: 54%

Section: Discussionmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Free Radical and Cationic Addition due to Clay Minerals Found in Bitumen Froth at 250 °C Probed with Use of α-Methylstyrene and 1-Octene

Turuga

Klerk

2022

Energy Fuels

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“…The acid catalyzed formation of E1 from AMS was also reported for acidic resin catalysts and mordenite. 79,80 This outcome contrasts with the findings of a study where AMS was thermally treated at 250 °C in the presence and absence of kaolinite, and the tricyclic dimer was only detected when AMS was treated in the absence of kaolinite. 51 In that study, kaolinite favored the formation of the dimer E5 (with two potential dimerization pathways illustrated in Figure 12) but hindered the formation of E1.…”

Section: Effect Of Kaolinite On Ams Conversionmentioning

confidence: 84%

“…79 Nevertheless, the formation of E1 was reported at temperatures as low as 60 °C. 80 The formation of dimer E4 is likely to proceed through the hydrogen disproportionation of two AMS molecules. A potential concerted bimolecular mechanism for the formation of E4, involving a 1,4-diradical intermediate, has been reported before.…”

Section: Effect Of Kaolinite On Ams Conversionmentioning

confidence: 99%

Role of Water and Kaolinite on the Conversion Rate and Reaction Pathways during Thermal Conversion of α-Methylstyrene at 400 °C

P Bassane,

de Klerk

2024

Energy Fuels

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Research examining the impact of water and mineral matter on the thermal conversion of crude oil has indicated that retaining these components during treatment affects cracking, hydrogen transfer, and addition reactions. However, the complex nature of a reaction medium containing crude oil poses a challenge in relating the influence of water and minerals to particular reaction pathways. To enhance understanding of the specific contributions of water and minerals to reaction chemistry during thermal conversion, a practical approach is to make use of simpler model systems to capture relevant information for petroleum processing. The current study explored the impact of water and kaolinite on the reaction rates and pathways during the thermal conversion of a model system comprising αmethylstyrene (AMS), tetralin, and n-pentadecane at 400 °C for 1, 5, 10, and 30 min. The effect of kaolinite at different concentrations was also compared to that of rutile and quartz during the conversion of AMS alone. Water and kaolinite, individually and collectively, affected the reaction rates. Water suppressed the AMS conversion rates, but no evidence was found that water affected reaction pathways. Kaolinite increased the conversion rates of both AMS and tetralin, while also enhancing the formation rates of cumene and naphthalene. This suggested that kaolinite somehow favored hydrogen transfer during the treatment. The presence of kaolinite also increased the formation rates of benzene by dealkylation and the tricyclic AMS dimer 1,1,3-trimethyl-3-phenyl indane, indicating that kaolinite was catalytically active, influencing reaction pathways by promoting cationic conversion. The adsorption of water on the surface of kaolinite appeared to contribute to reduced reaction rates when reacting AMS in the presence of both water and kaolinite. The deposition of carbonaceous material on kaolinite suggested that the mineral is rapidly fouled during the conversion.

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Dimerization of α-methylstyrene in the presence of mordenite, aimed at preparation of transformer oils

Cited by 2 publications

References 3 publications

Free Radical and Cationic Addition due to Clay Minerals Found in Bitumen Froth at 250 °C Probed with Use of α-Methylstyrene and 1-Octene

Free Radical and Cationic Addition due to Clay Minerals Found in Bitumen Froth at 250 °C Probed with Use of α-Methylstyrene and 1-Octene

Role of Water and Kaolinite on the Conversion Rate and Reaction Pathways during Thermal Conversion of α-Methylstyrene at 400 °C

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