2-propanol conversion

Fig. 4. Catalytic performance of H3PW12O40 and H3PW12O40/T-AI2O3 catalysts at 330°C (a) 2-propanol conversions and (b) product yields.

Fig. 31. Catalytic activities of acidic Na or Cs salts of HjPW 204o as a function of Na or Cs content, (a) M = Na (O) dehydration of 2-propanol, (A) decomposition of formic acid, ( ) conversion of methanol, ( ) conversion of dimethyl ether, (b) M = Cs (O) dehydration of 2-propanol, ( ) conversion of dimethyl ether, (A) alkylation of 1,3,5-trimethylbenzene with cyclohexene. (From Refs. 46 and 128.)...

As shown in Fig. 44a, the catalytic activity of NaxH3- PW,2O40 for dehydration of 2-propanol, conversion of methanol, and decomposition of formic acid decreased monotonically with the Na content in the salts. The activities for these... 

It has previously been reported that hydrotalcite catalyzes the aldol condensation of acetone (25). Polyoxometalates are known to dehydrate alcohols due to their acidic nature (IS ). In order to compare the relative basicity of polyoxometalate-pillared hydrotalcites to that of hydrotalcite itself, a variety of hydrotalcites were screened for 2-propanol conversion (Table II). This reaction is known to give propylene when the catalyst contains acidic sites (such as alumina) and acetone when the catalyst contains basic sites (such as magnesium oxide). 

Table II. 2-Propanol Conversion Over Various Catalysts (a)...

Microcalorimetry of ammonia and sulfur dioxide adsorption and the catalytic reachon of 2-propanol conversion have been used to study the effects on the acid-base properhes of adding small amounts of various ions (Ca, Li, Nd, Ni, Zn, SO ) to y-alumina, silica or magnesia surfaces [51]. 

The E2 mechanism for the acid catalyzed dehydration of 1-propanol is kinetically consistent with a wide range of experimental measurements of 1-propanol disappearance in supercritical water at 375 C and 34.5 MPa. The agreement of the calculated values of 1-propanol conversion with the experimental data is excellent (Xv 0.25). 

The results of 2-propanol conversion at 175"C on different catalyst samples are given in Table-2. The chlorided aluminas provide only acid function responsible for dehydration reaction, where propylene was selectively formed. The conversion to propylene increases with increasing chlorine in the support from 1.63% on y-Al203-A to 12.75% on AI2O3-E. The reaction rate also indicate similar trend. 

Fig. 4 Correlation plot between surface acidity and 2-propanol conversion at 225°C.

Table 13.16 Catalyst properties and selectivity to MIBK from 2-propanol. Reaction conditions temperature 200 °C H2 atmospheric pressure 2-propanol partial pressure 7.8 kPa 2-propanol conversion 40%.

The FTIR lattice spectra reveal the formation of defect sites in the titania matrix after Fe doping at veiy low Fe content. Even these samples are photocalalytically active in the oxidation of /-propanol to acetone prior to all other catalysts. This finding tends to show that the improvement of photocatalytic activity might be related to the appearance of defect sites. After lOh of reaction, /-propanol conversion reached the value of 70%. 

Fig. 8.8 Dependence of selectivity to acetone on 2-propanol conversion for all the titania-based systems used in the present study. Highlighted values conespraid to platinnni-eontaining titania (Reprinted with permission [61]. Copyright 2012 Elsevier)...

However, this advance has an important shortcoming the lack of context. More than one idea is expressed in a document a patent on oxidation catalysts, for example, could include examples of the oxidation of methanol to formaldehyde and of 2-propanol to acetone. A simple coordinate search for conversion of methanol to acetone would retrieve such a document from a file that provides no context. 

Kinetics are slow and many hours are requited for a 95% conversion of the reactants. In the case of the subject compound, there is evidence that the reaction is autocatalytic but only when approximately 30% conversion to the product has occurred (19). Reaction kinetics are heavily dependent on the species of halogen ia the alkyl haHde and decrease ia the order I >Br >C1. Tetrabutylphosphonium chloride exhibits a high solubiHty ia a variety of solvents, for example, >80% ia water, >70% ia 2-propanol, and >50% ia toluene at 25°C. Its analogues show similar properties. One of the latest appHcations for this phosphonium salt is the manufacture of readily dyeable polyester yams (20,21). 

In this process, the fine powder of lithium phosphate used as catalyst is dispersed, and propylene oxide is fed at 300°C to the reactor, and the product, ahyl alcohol, together with unreacted propylene oxide is removed by distihation (25). By-products such as acetone and propionaldehyde, which are isomers of propylene oxide, are formed, but the conversion of propylene oxide is 40% and the selectivity to ahyl alcohol reaches more than 90% (25). However, ahyl alcohol obtained by this process contains approximately 0.6% of propanol. Until 1984, ah ahyl alcohol manufacturers were using this process. Since 1985 Showa Denko K.K. has produced ahyl alcohol industriahy by a new process which they developed (6,7). This process, which was developed partiy for the purpose of producing epichlorohydrin via ahyl alcohol as the intermediate, has the potential to be the main process for production of ahyl alcohol. The reaction scheme is as fohows ... 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

Propylene is hydrated at ca 540 K under pressure. Conversions are 60—70% and selectivity to 2-propanol is 99%. 

Introduction of the cobalt atom into the corrin ring is preceeded by conversion of hydrogenobyrinic acid to the diamide (34). The resultant cobalt(II) complex (35) is reduced to the cobalt(I) complex (36) prior to adenosylation to adenosylcobyrinic acid i7,i -diamide (37). Four of the six remaining carboxyhc acids are converted to primary amides (adenosylcobyric acid) (38) and the other amidated with (R)-l-amino-2-propanol to provide adenosylcobinamide (39). Completion of the nucleotide loop involves conversion to the monophosphate followed by reaction with guanosyl triphosphate to give diphosphate (40). Reaction with a-ribazole 5 -phosphate, derived biosyntheticaHy in several steps from riboflavin, and dephosphorylation completes the synthesis. 

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