Dehydration of methanol over Nordstrandite based catalysts for dimethyl ether synthesis

Seo, Chang Won; Jung, Kwang Deok; Lee, Kwan Young; Yoo, Kye Sang

doi:10.1016/j.jiec.2009.09.037

Cited by 21 publications

(3 citation statements)

References 20 publications

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“…Moreover, this compound is used as a building block for many value-added chemicals, such as lower olefins, methyl acetate, and dimethyl sulphate [3,4]. Two alternatives can be used for DME production: (i) a two-step process (the so-called indirect process), which consists of one stage of methanol production from syngas while using a Cu/ZnO based catalyst [5,6,7], followed by a second stage of methanol dehydration over a solid acid catalyst [2,8,9,10]; (ii) a direct process, in which syngas is fed to a reactor that contains a bifunctional catalyst where the two aforementioned reactions take place [11,12,13,14]. The synthesis gas can be produced by partial oxidation or reforming of natural gas or by gasification of coal or biomass.…”

Section: Introductionmentioning

confidence: 99%

Methanol Dehydration to Dimethyl Ether on Zr-Loaded P-Containing Mesoporous Activated Carbon Catalysts

2019

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Activated carbons have been prepared by the chemical activation of olive stones with phosphoric acid and loaded with Zr. The addition of Zr to the phosphorus-containing activated carbons resulted in the formation of zirconium phosphate surface groups. Gas phase methanol dehydration has been studied while using the prepared Zr-loaded P-containing activated carbons as catalysts. Carbon catalysts showed high steady-state methanol conversion values, which increased with Zr loading up to a limit that was related to P content. The selectivity towards dimethyl ether was higher than 95% for all Zr loadings. Zirconium phosphate species that were present on catalysts surface were responsible for the catalytic activity.

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Section: Introductionmentioning

confidence: 99%

Methanol Dehydration to Dimethyl Ether on Zr-Loaded P-Containing Mesoporous Activated Carbon Catalysts

2019

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“…The formation of DME is favorable at relatively low temperatures, whereas the MTG and MTO occur at higher temperatures. In addition to γ-alumina, acidic zeolites, especially MFI (HZSM-5), and heteropoly acids (HPAs) are among the most studied catalysts in methanol dehydration − (and references therein). These show significantly higher catalytic activities but as yet are less resistant to deactivation than γ-alumina. …”

Section: Introductionmentioning

confidence: 99%

Dehydration of Methanol to Dimethyl Ether over Heteropoly Acid Catalysts: The Relationship between Reaction Rate and Catalyst Acid Strength

2015

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Dehydration of methanol to dimethyl ether (DME) was studied at a gas/solid interface over a wide range of bulk and supported Brønsted acid catalysts based on tungsten Keggin heteropoly acids (HPA) and compared with the reaction over HZSM-5 zeolites (Si/Al = 10−120). Turnover rates for these catalysts were measured under zero-order reaction conditions. The HPA catalysts were demonstrated to have much higher catalytic activities than the HZSM-5 zeolites. A good correlation between the turnover rates and catalyst acid strengths, represented by the initial enthalpies of ammonia adsorption, was established. This correlation holds for the HPA and HZSM-5 catalysts studied, which indicates that the methanol-to-DME dehydration with both HPA and HZSM-5 catalysts occurs via the same (or similar) mechanism and the turnover rate of methanol dehydration for both catalysts is primarily determined by the strength of catalyst acid sites, regardless of the catalyst pore geometry.

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“…Recently, some researchers began to focus on the catalytic performance of heteropolyacids (HPAs) in methanol conversion to DME reaction and obtained excellent performance, they exhibit high reaction rates at much lower reaction temperatures [30,[33][34][35][36][37][38][39][40]. The main drawbacks of HPAs are the low surface area and high acid strength, which cause strong interactions between H 2 O molecules and the acid sites of the HPAs [33].…”

Section: Introductionmentioning

confidence: 99%

Heteropolyacid Salt Catalysts for Methanol Conversion to Hydrocarbons and Dimethyl Ether: Effect of Reaction Temperature

Sun

Wang

et al. 2019

Catalysts

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Phosphotungstic and silicotungstic acid salt catalysts (CuPW, CuSiW, FePW, FeSiW) were synthesized by substitution of protons with ferric and copper ions through a simple replacement reaction. The structure and thermal stability were characterized by IR, XRD and TG, and the salts showed a keggin structure and a thermal tolerance near 450 °C. Temperature programmed reactions indicated that the four catalysts showed similar trends in the change of methanol conversion, DME selectivity, and light olefins selectivity at 100–400 °C. Copper salt catalysts showed a 100% DME selectivity at temperatures ranging from 100–250 °C, while FeSiW and FePW catalysts had a 100% DME selectivity near 250 °C. Moreover, the heteropolyacid salt catalysts also produced a certain number of light olefins at the temperature ranging from 250–350 °C, and the CuSiW catalyst exhibited the highest ethylene and propylene selectivity of 44%. In the stability test evaluated at 200 °C, the catalysts showed different tendencies during the induction period and the same trends during the reduction period for the methanol conversion to DME, due to the differences in the strengths of the strong acid sites. Finally, the silicotungstic acid salt catalysts showed the longest lifetime of 120 h, much longer than the heteropolyacids. This approach provides an effective way to synthesize hydrocarbons through methanol, especially DME, at different temperatures using one catalyst.

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Dehydration of methanol over Nordstrandite based catalysts for dimethyl ether synthesis

Cited by 21 publications

References 20 publications

Methanol Dehydration to Dimethyl Ether on Zr-Loaded P-Containing Mesoporous Activated Carbon Catalysts

Methanol Dehydration to Dimethyl Ether on Zr-Loaded P-Containing Mesoporous Activated Carbon Catalysts

Dehydration of Methanol to Dimethyl Ether over Heteropoly Acid Catalysts: The Relationship between Reaction Rate and Catalyst Acid Strength

Heteropolyacid Salt Catalysts for Methanol Conversion to Hydrocarbons and Dimethyl Ether: Effect of Reaction Temperature

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