Optimization of CO2/CO Ratio and Temperature for Dimethyl Ether Synthesis from Syngas over a New Bifunctional Catalyst Pair Containing Heteropolyacid Impregnated Mesoporous Alumina

Date

2016-11-09

Author

Bayat, Aysegul
Doğu, Timur

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

170
views

0
downloads

Dimethyl ether (DME) is a promising nonpetroleum diesel fuel alternate. Synthesis of DME was achieved directly from synthesis gas having different compositions, over bifunctional hybrid catalysts. Silicotungstic acid impregnated mesoporous alumina (STA@MA) was shown to be an excellent catalyst to be used as the dehydration component of the hybrid catalyst combination. Results proved that feed composition, as well as reaction temperature had important influence on product distributions, as well as on DME yield. Results obtained with different CO/CO2 ratios in the feed stream proved the positive effect of CO2 on both overall conversion of CO + CO2 and DME yield. Overall fractional conversion of CO + CO2 and DME yield values were shown to increase with an increase in CO2/CO ratio and also with an increase in reaction temperature, reaching to the values of 0.70 and 0.55, respectively, at 275 degrees C, with the feed stream composition of H-2/CO/CO2 = 50/10/40. However, from the DME selectivity point of view, a DME selectivity value of about 0.9 was obtained with a feed stream composition of H-2/CO/CO2 = 50/40/10, at 275 degrees C. Further increase of CO2/CO ratio in the feed stream caused some decrease in DME selectivity, due to increased contribution of reverse water gas shift reaction, which caused formation of higher amounts of water. Increase of water concentration in the product stream has a negative effect on the dehydration reaction of methanol.

Subject Keywords

Performance, Alcohols, Ethylene, Acid, Single-step synthesis, Direct dme synthesis, Hybrid catalysts, Carbon-monoxide, Diethyl-ether, Dehydration

URI

https://hdl.handle.net/11511/29951

Journal

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

DOI

https://doi.org/10.1021/acs.iecr.6b03001

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Synthesis of Tungstophosphoric Acid Incorporated Mesoporous Alumina Catalysts for Methanol Dehydration in DME Synthesis Şener, M İlker; Sezgi, Naime Aslı; Doğu, Timur; Doğu, Güşen; Oktar, Nuray (null; 2016-04-27) Dimethyl ether (DME) is considered as a highly promising environmentally clean diesel fuel alternate, which can be produced from synthesis gas. It has high cetane number (55-60) and clean burning properties [1]. Possibility of using CO2 as the carbon source in DME production makes this process even more attractive as a carbon neutral technology. Production of DME from synthesis gas requires a bifunctional catalyst combination, for methanol synthesis and dehydration functions. As for the methanol synthesis ...
Development of anodes for direct oxidation of methane fuel in solid oxide fuel cells Akdeniz, Yelda; Timurkutluk, Bora; Timurkutluk, Cigdem (2016-06-22) In addition to pure hydrogen, solid oxide fuel cells (SOFCs) can utilize hydrocarbons as a fuel. However, conventional Ni-based anodes exhibit an excellent catalytic activity towards the hydrocarbon cracking reaction and thus the carbon deposition occurs in the anode. The deposited carbons quickly deactivate the anode irreversibly by covering the active surface of the anode catalyst. As a result, a significant degradation in the cell performance can be seen. In this study, the anode structure is modified by...
Performance of silicotungstic acid incorporated mesoporous catalyst in direct synthesis of dimethyl ether from syngas in the presence and absence of CO2 Çelik, Gökhan; Bayat, Aysegul; Ozbelge, H. Onder; Doğu, Timur (2013-12-01) Dimethyl ether (DME), which is an excellent green diesel fuel alternate, is synthesized following a direct synthesis route from synthesis gas, by using a bi-functional catalyst mixture, which was composed of a silicotungstic acid incorporated mesoporous catalyst [TRC-75(L)] and a commercial Cu-Zn based catalyst. Higher DME selectivity values were obtained by using TRC-75(L), than commercial gamma-alumina at 50 bars. Presence of CO2 in the feed stream caused significant enhancement in DME selectivity. Result...
Selective methane bromination over sulfated zirconia in SBA-15 catalysts Yılmaz, Ayşen; Üner, Deniz (2009-04-15) Methane activation via bromination can be a feasible route with selective synthesis of mono-bromomethane. It is known that the condensation of brominated products into higher hydrocarbons can result in coking and deactivation in the presence of di-bromomethane. In this study, selective production of methyl bromide was investigated over sulfated ZrO2 included SBA-15 structures. It was observed that the higher the ZrO2 amounts the higher the conversion, while the catalyst remained >99% selective for the monob...
Dimethyl ether synthesis over alumina based catalysts Tokay, Kenan Cem; Doğu, Timur; DOĞU, GÜLŞEN (2012-03-01) Dimethyl ether is an excellent clean burning transportation fuel alternate for compression ignition engines and also an excellent fuel for household use. In the present study, catalytic performances of different alumina based catalysts, namely alumina impregnated SBA-15, a mesoporous aluminosilicate, which was synthesized following a one-pot hydrothermal procedure, and a commercial alumina catalyst, were tested in dehydration of methanol to produce dimethyl ether. Alumina impregnated SBA-15 had high Bronste...

Citation Formats

A. Bayat and T. Doğu, “Optimization of CO2/CO Ratio and Temperature for Dimethyl Ether Synthesis from Syngas over a New Bifunctional Catalyst Pair Containing Heteropolyacid Impregnated Mesoporous Alumina,” INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, pp. 11431–11439, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/29951.