Adsorption desulfurization and weak competitive behavior from 1-hexene over cesium-exchanged Y zeolites (CsY)

“…Some literatures − have reported that the modified NaY zeolite shown a very high adsorption desulfurization activity for thiophene due to its high ion-exchange ability and size-selective capacities as well as thermal and mechanical stabilities. Many scholars − insisted that surface acidity of zeolites is an important factor that influences the desulfurization performance of sorbents, and aromatics could cause the competitive effect on thiophene adsorption. ,− However, the interaction mechanisms for two kinds of acidic sites on the surface of NaY zeolite, the Brønsted acidic site and Lewis acidic site, have not been distinctively discussed and the different strength of them are also not distinguished. The questions needed to be made clear are mainly: (1) how are the thiophene and benzene adsorbed on the acidic sites with different forms and different strength?…”

Section: Introductionmentioning

confidence: 99%

Insight into the Acid Sites over Modified NaY Zeolite and Their Adsorption Mechanisms for Thiophene and Benzene

Liao

Zhang²,

Fan

et al. 2019

Ind. Eng. Chem. Res.

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Series of HY sorbents with different amounts and strength of Brønsted and Lewis acidic sites were prepared. Their adsorption performance in thiophene–benzene solution, pure benzene, and pure thiophene were evaluated, and the desulfurization mechanisms were studied. The results show that both thiophene and benzene could be effectively adsorbed through the interaction between Lewis acid sites and the conjugated π bond in these two molecules, and thus thiophene adsorption could be obviously competed by benzene on Lewis acidic sites. By contrast, on Brønsted acidic sites, thiophene can be efficiently adsorbed via H–S bond, which is stronger than the former interaction. Moreover, the middle strong Brønsted acid could cause thiophene oligomerization. Hence, for the desulfurization purpose by NaY zeolite in aromatic free system, its weak and middle strong Lewis acid should be increased, and for that in aromatic existing system, the Brønsted acid site with relative low strength should be promoted.

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“…In order to obtain the sulfur adsorption capacity of each adsorbent, the static adsorption tests were conducted. The static adsorption tests were carried out by adding 0.2 g adsorbent into a 20 mL MTBE solvent with DMDS as the solute (sulfur content: 748.52 mg/L) in an 30 mL airtight container standing at room temperature for 24 h. After a full adsorption, a TS-3000 fluorescence sulfur tester was used to analyze the concentration of sulfur before and after the static tests. ,, The sulfur adsorption capacity of the adsorbent was calculated as follows: sulfur adsorption capacity (mg s /g adsorbent ) = (748.52 – C t ) × 20/0.2; where C t (mg/L) was the sulfur concentration of MTBE solution after static tests.…”

Section: Methodsmentioning

confidence: 99%

Alkali-Treatment of Silicalite-1/CuY Core–Shell Structure for the Adsorption Desulfurization of Dimethyl Disulfide from Methyl tert-Butyl Ether

Yang

Meng

et al. 2019

Ind. Eng. Chem. Res.

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NaOH treated silicalite-1/CuY OH core−shell composites were synthesized at the mass ratio of tetraethyl orthosilicate (TEOS)/ tetrapropylammonium hydroxide (TPAOH)/ethanol/H 2 O/CuY = 20 g (0.096 molar):19 g (0.0234 molar):17 g (0.369 molar):87 g (4.8293 molar):5 g to achieve the selective adsorption desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE). As the core zeolite, CuY was obtained by Cu 2+ ion-exchange on NaY. After alkali treatment, NaY zeolite was provided with more loading positions for silicalite-1 crystals owing to the desilication effect of NaOH. Results showed that the core−shell Y OH -CuCl 2 displayed the best performance in desulfurizing DMDS from MTBE with a sulfur adsorption capacity of 37.073 mg s /g adsorbent for the sake of its significant mass gain and compact silicalite-1 coatings. The preparation of silicalite-1/CuY OH core−shell composites and the shape selective adsorption mechanism of desulfurizing DMDS on these core−shell composites were expounded.

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Adsorption desulfurization and weak competitive behavior from 1-hexene over cesium-exchanged Y zeolites (CsY)

Cited by 31 publications

References 28 publications

Highly active Pd containing EMT zeolite catalyst for indirect oxidative carbonylation of methanol to dimethyl carbonate

Highly active Pd containing EMT zeolite catalyst for indirect oxidative carbonylation of methanol to dimethyl carbonate

Insight into the Acid Sites over Modified NaY Zeolite and Their Adsorption Mechanisms for Thiophene and Benzene

Alkali-Treatment of Silicalite-1/CuY Core–Shell Structure for the Adsorption Desulfurization of Dimethyl Disulfide from Methyl tert-Butyl Ether

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