Dimethyl reforming catalyst

Table VI shows results obtained with a mixture of dimethyl- and ethylcyclohexanes reformed with catalysts of different acidity. The two functions of a reforming catalyst—the acidity and the hydrogenation-dehydrogenation function of the platinum—are balanced carefully for...

Steam reforming of dimethyl ether can be performed over methanol steam reforming catalysts mixed with an acidic catalyst [277]. In fact dimethyl ether is frequently a by-product of methanol steam reforming (see Section 3.1). However, the reforming of dimethyl ether is obviously more difficult than methanol reforming, as discussed... 

Preheated natural gas is fed at about 600°C to the reformer and exits at about 880°C and 2.1 MPa. Methanol synthesis is then performed over copper-based catalysts at about 240-270°C and 10.3 MPa. The product gas contains about 5% methanol. By-products are 1-2% dimethyl ether and 0.3-0.5% higher alcohols. Because of equilibrium limitations, conversion of synthesis gas is only a few percent per pass in the catalytic reactor, and the product gas stream after... 

Men and coworkers investigated methanol steam reforming over Cu/Ce02/Al203 catalysts [12-14] in a 10-fold screening reactor developed by Kolb et al. [3]. At a reaction temperature of 250 °C and an S/C ratio of 0.9, the atomic ratio of copper to ceria was varied from 0 to 0.9, revealing the lowest conversion for pure ceria and a sharp maximum for a ratio of 0.1. The carbon monoxide selectivity was lower than 2% for all samples. As byproduct, substantial amounts of dimethyl ether were observed for all samples the highest selectivity of 23% was detected for pure ceria. The dimethyl ether formation was attributed to separate dehydration of methanol on the alumina surface. 

Dimethyl ether formation was also observed by Men et al. for Cu/ZnO/Al203 catalysts [15]. Lowering the WHSV to 10 Lh g J was required at an S/C ratio of 2 to achieve full conversion of the methanol without byproduct formation. Under these conditions, around 1 vol.% of carbon monoxide was detected in the reformate. 

The dimethyl ether conversion into methanol could be performed over an acid catalyst such as alumina, while the second step is then methanol steam reforming... 

AlSahhaf, T. A. Kapetanovic, E. (1996). Liquid-liquid equilibria for the system naphtha reformate-dimethyl sulphoxide. Fluid Phase Equilib. 118, 271-285, ISSN 0378-3812. Al-Shahrani, F. Xiao, T. C. Llewellyn, S. A. Barri, S. Jiang, Z. Shi, H. H. Martinie, G. Green, M. L. H. (2007). Desulfurization of diesel via the H2O2 oxidation of aromatic sulfides to sulfones using a tungstate catalyst. Appl. Catal. B., 73, 311-316, ISSN 0926-3373. 

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