Ethylene and acetaldehyde production by selective oxidation of ethanol using mesoporous V-MCM-41 catalysts

2006-05-10
Gucbilmez, Yesim
Doğu, Timur
Balci, Suna
Vanadium-incorporated MCM-41 type catalytic materials, which were synthesized by a direct hydrothermal synthesis procedure, showed very high activity and high selectivity in the production of ethylene from ethanol in an oxidative process. Ethylene selectivity showed a significant increase with an increase in temperature over 300 degrees C, while relatively high acetaldehyde selectivities were observed at lower temperatures. An ethylene yield value of 0.66 obtained at 400 degrees C with an O-2/ethanol feed ratio of 0.5 was beneficial from the point of view that these results might open a new pathway for the production of ethylene from a nonpetroleum environmentally friendly feedstock, namely, bioethanol. The optimum V/Si ratio of the catalyst, which gave the maximum ethylene yield, was found to be around 0.04. Experimental results showing the formation of acetaldehyde and not showing the formation of ethylene in the absence of gas-phase oxygen and the catalyst deactivation observed in such conditions suggested a redox mechanism involving the surface lattice oxygen of the catalyst in acetaldehyde production, while the involvement of adsorbed oxygen was concluded to take place in the formation of ethylene.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

Suggestions

Direct hydrothermal synthesis of palladium-incorporated silicate-structured mesoporous catalysts
Sener, Canan; Doğu, Timur; Dogu, Guelsen (2007-01-01)
Pd-Si-structured novel mesoporous nanocomposite catalytic materials, having quite high Pd/Si ratios, were synthesized by an acidic direct hydrothermal synthesis route. The nanocomposite catalytic materials were then characterized by XRD, XPS, EDS, nitrogen adsorption, and SEM techniques. Unlike MCM-41, the XRD patterns indicated a rather wide d((100)) band at a 2 theta value of about 1.9. The materials, with very high Pd/Si wt ratios between 1.43 and 2.66, were synthesized and had BJH surface area values be...
Enantioselective direct aldol reactions promoted by phosphine oxide aziridinyl phosphonate organocatalysts
Doğan, Özdemir (2015-12-15)
A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphonate POAP-A Lewis bases formed the aldol products in up to 75% yield and with 65% ee.
Dynamic and steady state analysis of low temperature ethane oxidative dehydrogenation over chromia and chromia-vanadia catalysts
Karamullaoglu, Gulsun; Doğu, Timur (2007-11-02)
Oxidative dehydrogenation of ethane to ethylene was investigated over Chromia and Cr-V mixed oxide catalysts synthesized following a complexation procedure. With an O-2/C2H6 feed ratio of 0.17, Chromia exhibited a total conversion value of about 0.20 at 447 degrees C (at a space time of 0.24 s.g/mL) with an ethylene selectivity of 0.82. Chromia catalyst was more active than Cr-V mixed oxide at temperatures as low as 200 degrees C. Pulse-response experiments carried out with ethane pulses injected into O-2-H...
Petrochemicals from ethanol over a W-Si-based nanocomposite bidisperse solid acid catalyst
Varisli, Dilek; Doğu, Timur; DOĞU, GÜLŞEN (2010-01-01)
Very high ethylene selectivity values approaching 100% and very high ethanol conversion values approaching 85% were obtained in dehydration of ethanol over a new W-silicate-based nanocomposite catalyst having both meso and macropores and containing a W/Si atomic ratio of 0.85. Silicotungsticacid was successfully incorporated into the catalyst structure following a one-pot hydrothermal synthesis procedure. This catalyst is highly stable and does not loose activity in polar solvents and it has a sufficiently ...
Ethylene and diethyl-ether production by dehydration reaction of ethanol over different heteropolyacid catalysts
Varisli, Dilek; Doğu, Timur; Dogu, Gulsen (2007-09-01)
Dehydration reaction of ethanol was investigated in a temperature range of 140-250 degrees C with three different heteropolyacid catalysts, namely tungstophosphoricacid (TPA), silicotungsticacid (STA) and molybdophosphoricacid (NIPA). Very high ethylene yields over 0.75 obtained at 250 degrees C with TPA was highly promising. At temperatures lower than 180 degrees C the main product was diethyl-ether. Presence of water vapor was shown to cause some decrease of catalyst activity. Results showing that product...
Citation Formats
Y. Gucbilmez, T. Doğu, and S. Balci, “Ethylene and acetaldehyde production by selective oxidation of ethanol using mesoporous V-MCM-41 catalysts,” INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, pp. 3496–3502, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31481.