Effects of Feed Composition and Space Velocity on Direct Synthesis of Dimethyl Ether from Syngas

Moradi, Gholamreza; Ahmadpour, Javad; Nazari, Mohadese; Yaripour, Fereydoon

doi:10.1021/ie800888z

Cited by 36 publications

(21 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the case of zeolite-based hybrid catalysts for the direct DME synthesis, however, no systematic studies aimed at addressing the influence of the zeolite structure on the final catalytic performance have been so far reported. Indeed, in most of the previous works, ZSM-5 (MFI, 10-ring pore system) has been the zeolite of choice as the methanol dehydration component of the bifunctional catalysts [8,9,13,16,24,25,26,27,28,29,30,31,32,33]. Besides MFI, other 10-ring pore structures such as FER (ferrierite) [10,14,34] and MWW (MCM-22, MCM-49) [15,35,36] as well as 12-ring pore systems such as FAU (Y) [13,14,37,38,39,40] and MOR (mordenite) [37,41] have also been studied.…”

Section: Introductionmentioning

confidence: 99%

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

García‐Trenco

Valencia

Martı́nez

2013

Applied Catalysis A: General

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

García‐Trenco

Valencia

Martı́nez

2013

Applied Catalysis A: General

View full text Add to dashboard Cite

“…A H 2 :CO ratio near 1 can be used to produce dimethyl ether (DME), a possible diesel replacement. 15 Increasing the ratio to 2 or higher enables the generation of a host of hydrocarbons including methanol. 7 The E C (Figs.…”

Section: Resultsmentioning

confidence: 99%

Influence of Electrolytes and Membranes on Cell Operation for Syn-Gas Production

Dufek

Lister

McIlwain

2012

Electrochem. Solid-State Lett.

View full text Add to dashboard Cite

The impact of membrane type and electrolyte composition for the electrochemical generation of synthesis gas (CO + H 2 ) using an electrolysis cell containing a Ag gas diffusion cathode is presented. Changing from a cation exchange membrane to an anion exchange membrane extended the cell operational time at low cell voltages (E cell ) without impacting product composition. The use of KOH as the catholyte decreased the E cell and resulted in a minimum electrolyte cost reduction of 34%. The prime factor in determining operational time at low E cell was the ability to maintain a sufficiently high anolyte pH.The co-reduction of CO 2 and water for the production of CO and H 2 (syn-gas) has seen renewed interest. 1-9 The optimism for this process is the possibility of generating syn-gas without fossil energy (Equations 12, E 0 vs. NHE). If performed using sustainable energy, carbon neutral liquid fuels or chemicals products (such as plastics) which sequester carbon can be produced from the syn-gas. In performing CO 2 reduction Ag and Au have almost exclusive selectivity for CO. 1-4, 10, 11 While a variety of cell configurations have been proposed for the reduction of CO 2 , 1, 3, 6, 9, 12-14 filter press cells which incorporate Ag gas diffusion electrodes (GDE) have shown promising early results. 1, 6 GDEs allow generation of CO to occur at levels above what would be possible at planar electrodes due to the lack of reliance on CO 2 solubility which is low in aqueous systems. GDEs enable the cell temperature to be elevated above ambient decreasing overpotentials and electrolyte impedance and increasing cell efficiency without significantly impacting syn-gas production. 1T otal r xn :Transitioning CO 2 reduction from the research arena to an industrial electrolysis process will require complete system optimization in terms of electrical input, syn-gas composition, and the rate of electrolyte consumption. Studies to date have utilized OH − oxidation to O 2 as the anode reaction as shown in Equation 3. 1, 6 At a 1:1 balance of CO and H 2 production, a complete reaction can be written as shown in Equation 4. Such a process consumes only CO 2 and H 2 O while generating syn-gas and O 2 .The acid/base chemistry of CO 2 (Equations 5-7) can dramatically alter solution chemistry during extended cell operation and leads to eventual precipitation of carbonates in the catholyte. 1 The consumption of OH − in the anolyte (Eqn. 3) also limits electrolyte lifetime. One means to address the issues of carbonate formation and OH − consumption is to use an anion exchange membrane (AEM). This letter provides results from initial investigations which show the impact CO 2 acid/base chemistry has on cell operation and how electrolyte and membrane type can be used to mitigate the impact.

show abstract

“…The objective of RSM is to optimize the response based on the factors investigated [27][28][29][30][31]. In this work, the developed response surface design was based on central composite design (CCD) and accordingly, a quadratic regression model was considered for developing the response surface models of second order as indicated in Eq.…”

Section: -1 Optimization Methodsmentioning

confidence: 99%

“…The degree of freedom (DF) for the regression and residual error sources directs one to determine the related F tab using the F-distribution table. In this manner, the lack-of-fit related F tab is determined using degree of freedom (DF) for the lack-of-fit and pure error sources [27][28][29][30][31]. Note that the residuals will be distributed normally if the model provides an adequate goodness-of-fit.…”

Section: -1 Optimization Methodsmentioning

confidence: 99%

Copper-based nanocatalysts for 2-butanol dehydrogenation: Screening and optimization of preparation parameters by response surface methodology

Geravand

Shariatinia‬

Yaripour

et al. 2015

Korean J. Chem. Eng.

View full text Add to dashboard Cite

Two types of copper-based dehydrogenation nanocatalysts (Cu/ZnO/Al 2 O 3 and Cu/SiO 2 ) were prepared from various precursors by impregnation (IM), sol-gel (SG) and co precipitation (COPRE) methods. The structures of samples were characterized by N 2 adsorption-desorption, XRD, XRF, TPR, N 2 O-Titration, FT-IR, FE-SEM and TEM techniques. The catalytic performance tests in vapor-phase dehydrogenation of 2-butanol to methyl ethyl ketone (MEK) were carried out in a fixed-bed reactor at a temperature of 260 o C under atmospheric pressure and LHSV of 4 mL/(h·g cat). The experimental results indicated that (i) the copper oxide over the COPRE nanocatalyst was reduced at a lower temperature (222 o C) in comparison with the CuO reduced on the SG and IM samples (243 and 327 o C, respectively). Also, the percentage of reduction of CuO species on COPRE catalyst was the highest (98.8%) in comparison with the two other samples, (ii) the COPRE nanocatalyst exhibited the highest activity for the dehydrogenation of 2-butanol to MEK, and (iii) co-precipitation method was selected as an optimum method for preparation of nanocatalyst. The central composite experimental design method was applied for investigation of the effects of four critical preparation factors on the MEK selectivity of Cu/ZnO/Al 2 O 3 nanocatalyst. The results showed that Cu/Zn molar ratio and precipitation pH are the most effective factors on the response and the optimum conditions for synthesis of Cu/ZnO/Al 2 O 3 nanocatalyst with maximum selectivity of MEK were T (pre) =67.5 o C, T (aging) =68.8 o C, pH (pre) =7.27 and Cu/Zn molar ratio=1.38. The performance of the prepared nanocatalyst at the optimum conditions was comparable to the commercially available nanocatalyst.

show abstract

Effects of Feed Composition and Space Velocity on Direct Synthesis of Dimethyl Ether from Syngas

Cited by 36 publications

References 20 publications

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

Influence of Electrolytes and Membranes on Cell Operation for Syn-Gas Production

Copper-based nanocatalysts for 2-butanol dehydrogenation: Screening and optimization of preparation parameters by response surface methodology

Contact Info

Product

Resources

About