Butanol dehydrogenation

Domestic capacity declined correspondingly duriug the 1980s as ARGO closed its 33, 000 t/yr 2-butanol dehydrogenation plant iu 1991 (50), Exxon closed a 136, 000 t/yr plant at Bayway, New Jersey iu 1988, and Union Carbide closed its Brownsville, Texas plant. Consumption was further squee2ed iu... 

Tessag Edeleanu GmbH Methyl ethyl ketone (MEK) Secondary butanol Dehydrogenation reaction with copper-containing catalyst 7 1995... 

Ag/Si02 and Cu/SiOa cogelled xerogel catalysts for benzene combustion and 2-butanol dehydrogenation... 

For 2-butanol dehydrogenation, catalytic reactions were carried out at atmospheric pressure in a fixed bed flow-microreactor. The feed was 4.2 Nl/h of helium with a partial pressure of 8.5 kPa of 2-butanol. Reaction temperatures were from 373 K to 573 K. Concentrations of reactants and products were measured at the reactor outlet by on-line gas chromatography. 

In order to explain the results in Figs. 2 and 3, it is necessary to obtain intrinsic kinetic rates for benzene oxidation and 2-butanol dehydrogenation. With the experimental conditions used, the reactor is not a differential reactor because conversion is too high. The kinetic rates are obtained by considering the reactor as an integral reactor with the following assumptions ... 

Fig. 4 presents the specific kinetic rates at 533 K and 553 K for benzene oxidation on Ag/Si02 and Cu/Si02 catalysts as a function of metal loading and Fig. 5 presents the specific kinetic rates at 513 K and 533 K for 2-butanol dehydrogenation on Cu/Si02 catalysts as a function of copper loading. 

Fig. 4 shows, for benzene oxidation, that nen increases when the silver or copper loading decreases. In fact, visual observations by TEM show that in samples AgO.25, Ag0.40, Agl.OO and Cul.OO, it seems that there are no larger silver or copper particles located on silica particles external surface. Thus the metal dispersion values are greater in these samples. So this could be the proof that Ag and Cu particles located inside the silica particles are accessible for benzene in this catalytic system. Fig. 5 shows, for 2-butanol dehydrogenation, that rbui increases when the copper loading increases or when the metal... 

Fig. 5. Kinetic rates at T = 513 K (A) and T = 553 K (A and 6) as a function of copper loading for Cu/Si02 catalysts for 2-butanol dehydrogenation...

C4H8O, CH3COCH2CH3. Colourless liquid with a pleasant odour, b.p. 80°C. It occurs with propanone in the products of the destructive distillation of wood. Manufactured by the liquid or vapour phase dehydrogenation of 2-butanol over a catalyst. Used as a solvent, particularly for vinyl and acrylic resins, and for nitrocellulose and cellulose acetate, also for the dewaxing of lubricating oils. U.S. production 1978 300 000 tonnes. 

Direct oxidation yields biacetyl (2,3-butanedione), a flavorant, or methyl ethyl ketone peroxide, an initiator used in polyester production. Ma.nufa.cture. MEK is predominandy produced by the dehydrogenation of 2-butanol. The reaction mechanism (11—13) and reaction equihbtium (14) have been reported, and the process is in many ways analogous to the production of acetone (qv) from isopropyl alcohol. 

The dehydrogenation of 2-butanol is conducted in a multitube vapor-phase reactor over a zinc oxide (20—23), copper (24—27), or brass (28) catalyst, at temperatures of 250—400°C, and pressures slightly above atmospheric. The reaction is endothermic and heat is suppHed from a heat-transfer fluid on the shell side of the reactor. A typical process flow sheet is shown in Figure 1 (29). Catalyst life is three to five years operating in three to six month cycles between oxidative reactivations (30). Catalyst life is impaired by exposure to water, butene oligomers, and di-j -butyl ether (27). 

Ref. 47. Process is dehydrogenation of 2-butanol unless otherwise noted. 

In a process which is now largely of historical interest, 1-butanol has been produced from ethanol [64-17-5] via successive dehydrogenation (to acetaldehyde [75-07-0]) condensation (to crotonaldehyde [4170-30-3]) and hydrogenation. 

The chloranil dehydrogenation of A -3-ketones offers a convenient direct conversion to A -ketones. t-Butanol and xylene are the most suitable solvents. Slightly higher yields have been claimed with mixed organic acid-inert solvent systems, although somewhat lower yields (50-60%) are... 

The major use of sec-butanol is to produce MEK by dehydrogenation, as mentioned earlier. 2-Butanol is also used as a solvent, a paint remover, and an intermediate in organic synthesis. 

The Raney nickel is a very efficient catalyst for the dehydrogenation of 2-butanol into butanone (Scheme 45) with a good selectivity (90%). But, for industrial applications selectivities as high as 99% are required. This can be achieved by poisoning some sites by reaction with Bu4Sn (the best results are obtained with a Sn/Ni ratio of 0.02), which probably occurs first on the sites responsible for the side reactions. The consequence is a slight decrease of the catalytic activity and an increase of the selectivity in 2-butanone which can reach 99%. This catalyst, developed by IFF, has been used commercially in Japan for several years [180]. 

Methyl ethyl ketone (MEK) is manufactured by the dehydrogenation of 2-butanol. A simplified description of the processes listing the various units used is given below ... 

Such a possibility has been recognized by early workers,9 but in spite of this intriguing possibility, only recently has such a metal surface been created. Chiral kink sites were created on Ag single crystal surfaces to produce the enantiomeric surfaces Ag(643)s and Ag(643)R however, no differences between (R)- and (S)-2-butanol were observed for either the temperature-programmed desorption from the clean surfaces or the dehydrogenation (to 2-butanone) from preoxidized surfaces.10 Unfortunately, Ag exhibits few catalytic properties, so only a limited array of test reactions is available to probe enantioselectivity over this metal. It would be good if this technique were applied to a more catalytically active metal such as Pt. 

In the isomerization of (+)-3-carene into (+)-2-carene or the dehydrogenation of 2-butanol into 2-butanone, the selectivity into the desired product is also increased by the introduction of small amounts of Sn, which will form adatoms poisoning unselective sites.324... 

Dehydration was common for copper ions particularly Cu+, but only observed in the reaction of Ag+ with terf-butanol, where the [Ag(alkene)]+ was formed. Dehydrogenation... 

Butanol, reaction over reduced nickel oxide catalysts, 35 357-359 effect of ammonia, 35 343 effect of hydrogen, 35 345 effect of pyridine, 35 344 effect of sodium, 35 342, 351 effect of temperature, 35 339 over nickel-Kieselguhr, 35 348 over supported nickel catalysts, 35 350 Butanone, hydrogenation of, 25 103 Butene, 33 22, 104-128, 131, 135 adsorption on zinc oxide, 22 42-45 by butyl alcohol dehydration, 41 348 chemisorption, 27 285 dehydrogenation, 27 191 isomerization, 27 124, 31 122-123, 32 305-308, 311-313, 41 187, 188 isomerization of, 22 45, 46 isomers... 

Microporous, amorphous Mg-Si-O metallosilicates with a very narrow pore size distribution around 6 A diameter and a typical surface area of ca 350 m /g were obtained from the controlled calcination of compound 22. The resulting Mg-Si-O material was found to be very active in 1-butanol conversion even at 200 °C giving both dehydrogenation and dehydration. 

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