Catalytic Ethanol Dehydration to Ethylene over Nanocrystalline χ- and γ-Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Catalysts

Janlamool, Jakrapan; Jongsomjit, Bunjerd

doi:10.5650/jos.ess17026

Cited by 37 publications

(23 citation statements)

References 27 publications

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“…In the rst step, protonation takes place at alcoholic oxygen in the ethanol For the e ect of acid density, it can be seen that the ethanol conversion of the catalysts signi cantly increased with the acid density. is e ect was also observed in our previous study [23], which revealed that high acid density of the alumina catalysts apparently results in high catalytic activity in the ethanol dehydration.…”

Section: International Journal Of Chemical Engineeringsupporting

confidence: 84%

Carbon-Based Catalyst from Pyrolysis of Waste Tire for Catalytic Ethanol Dehydration to Ethylene and Diethyl Ether

Chaichana

Wiwatthanodom

Jongsomjit

2019

International Journal of Chemical Engineering

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This work investigated the use of waste tire as a source of carbon in preparation of carbon-based catalysts for applying in ethanol dehydration. The pyrolysis of waste tire was performed to obtain the solid carbon, and then it was treated with two different acids including HCl and HNO3 prior to the activation process with different temperatures to gain suitable carbon catalysts. All carbon catalysts were characterized using nitrogen physisorption, XRD, FTIR, and acid-base titration. The catalysts were tested for catalytic ethanol dehydration in a micropacked-bed reactor under the temperature range from 200°C to 400°C. It revealed that the ethanol conversion increased with increasing the reaction temperature for all catalysts. The carbon catalyst treated with HCl and calcined at 420°C (AC_H420) exhibited the highest ethanol conversion of 36.2% at 400°C having ethylene and diethyl ether selectivity of 65.9 and 33.5%, respectively. The high activity of this catalyst can be attributed to the high acid density at the surface (18.5 μmol/m2), which was significantly higher than those of most other catalysts (less than 8.0 μmol/m2).

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Section: International Journal Of Chemical Engineeringsupporting

confidence: 84%

Carbon-Based Catalyst from Pyrolysis of Waste Tire for Catalytic Ethanol Dehydration to Ethylene and Diethyl Ether

Chaichana

Wiwatthanodom

Jongsomjit

2019

International Journal of Chemical Engineering

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“…This result indicated that the presence of Mo and V on the surface of Mg-Al catalyst enhanced the rate of dehydrogenation of ethanol in the absence of oxygen. It was probably due to the enhancement of surface base density of modified catalysts 32 . The proposed mechanism of nonoxidative dehydrogenation of ethanol over V/Mg-Al catalyst is described as followed.…”

Section: Non-oxidative Dehydrogenation Of Ethanolmentioning

confidence: 99%

Oxidative Dehydrogenation of Ethanol over Vanadium- and Molybdenum-modified Mg-Al Mixed Oxide Derived from Hydrotalcite

2019

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Hydrotalcite or Mg-Al LDHs were synthesized by co-precipitation method. The Mg-Al mixed oxide was then derived by calcination of hydrotalcite at 450℃. The metal modified catalysts (Mo/Mg-Al and V/Mg-Al) were prepared by incipient wetness impregnation method. The obtained catalysts were characterized by several useful techniques and tested the reactivity for dehydrogenation and oxidative dehydrogenation of ethanol (gas-phase) to produce acetaldehyde. The catalytic reactions were performed at temperature range from 200 to 400℃ for both non-oxidative and oxidative atmospheres. The results showed that the vanadium-modified hydrotalcite (V/Mg-Al) exhibited the highest ethanol conversion (34.3%) and acetaldehyde yield (15.5%) at 400℃ in the non-oxidative atmosphere. For the oxidative dehydrogenation of ethanol, the V/Mg-Al catalyst showed the highest activity at 400℃ giving the ethanol conversion and acetaldehyde yield of 73.7% and 29.5%, respectively. This result probably related to the highest base density of V/Mg-Al catalyst (6.13 µmol CO 2 /m 2) measured by CO 2-TPD. The catalytic activity of Mg-Al catalyst and metal modified catalyst slightly decreased upon time-on-stream test for 10 h on oxidative dehydrogenation of ethanol due to carbon deposition.

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“…C 2 H 5 OC 2 H 5 was formed through the dehydration between two C 2 H 5 OH molecules (Equation (2)) [39]. At high reaction temperatures, the by-product C 2 H 5 OC 2 H 5 decomposed to C 2 H 5 OH and C 2 H 4 (Equation (3)) [8]. CH 3 CHO was formed at high temperatures through the dehydrogenation of ethanol (Equation 4 Figure 7 shows the influence of water amount in feed for the dehydration of ethanol over H-ZSM-5.…”

Section: Catalytic Ethanol Dehydration Over H-zsm-5mentioning

confidence: 99%

“…Ethylene is a platform in conversion of bio-ethanol to higher olefins [6][7][8]. At first, ethylene is obtained through the hydration of bio-ethanol.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Ethylene Oligomerization over Ni/Al-HMS: A Key Step in Conversion of Bio-Ethanol to Higher Olefins

Liu¹

2018

Catalysts

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Al-modified hexagonal mesoporous silica (HMS) materials were synthesized using dodecylamine as a template according to the methods reported in the literature. FT-IR spectra proved that Al3+ ions entered in the HMS framework in Al-HMS (prepared by sol-gel reaction) but Al3+ ions existed in the extra-framework in Al/HMS (prepared by post-modification). NH3-TPD indicated that either Al-HMS or Al/HMS had solid acid sites on the surface, and the acidic strength of Al/HMS was stronger than that of Al-HMS. For ethylene oligomerization at 200 °C under 1 MPa, Ni/Al-HMS showed an ethylene conversion of 96.3%, which was much higher than that over Ni/Al/HMS (45.6%). The selectivity for C4H8, C6H12, C8H16, and C8+ was 37.7%, 24.5%, 24.0%, and 9.1% for ethylene oligomerization over Ni/Al-HMS, respectively. Ni/Al-MCM-41, which has been reported as an effective catalyst for ethylene oligomerization in the literature, showed a high ethylene conversion (95.2%) similar to that of Ni/Al-HMS in this study. However, the selectivity for C8H16 over Ni/Al-MCM-41 (16.3%) was lower than that over Ni/Al-HMS (24.0%) in the ethylene oligomerization. For ethanol dehydration at 300 °C under 1 MPa, a commercial H-ZSM-5 catalyst showed a high ethylene yield (91.2%) after reaction for 24 h using a feed containing 90 wt.% ethanol and 10 wt.% water. In this study, a two-step process containing two fixed-bed reactors and one cold trap was designed to achieve the direct synthesis of higher olefins from bio-ethanol. The cold trap was used to collect the water formed from ethanol dehydration. By using H-ZSM-5 as a catalyst for ethanol dehydration in the first reactor and using Ni/Al-HMS as a catalyst for ethylene oligomerization in the second reactor, higher olefins were continuously formed by feeding a mixture containing 90 wt.% ethanol and 10 wt.% water. The yields of higher olefins did not decrease after reaction for 8 h in the two-step reaction system.

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Catalytic Ethanol Dehydration to Ethylene over Nanocrystalline χ- and γ-Al<sub>2</sub>O<sub>3</sub> Catalysts

Cited by 37 publications

References 27 publications

Carbon-Based Catalyst from Pyrolysis of Waste Tire for Catalytic Ethanol Dehydration to Ethylene and Diethyl Ether

Carbon-Based Catalyst from Pyrolysis of Waste Tire for Catalytic Ethanol Dehydration to Ethylene and Diethyl Ether

Oxidative Dehydrogenation of Ethanol over Vanadium- and Molybdenum-modified Mg-Al Mixed Oxide Derived from Hydrotalcite

Catalytic Ethylene Oligomerization over Ni/Al-HMS: A Key Step in Conversion of Bio-Ethanol to Higher Olefins

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