Isopropanol propene

Figure 1. Results of PFG NMR measurements of the self-diffusivities of acetone, isopropanol, propene, and water in NaX...

Table 2 Results from the decomposition reaction of isopropanol on (MPMol2)b and (MPMol2)b series at 150°C conversion, rate for propene formation (rp) and rate for acetone formation (ra).

Isopropylatlon by isopropanol occurred by using high silica mordenlte with more than 20 S1/A12- Similar activity and selectivity were observed as in the case of propene. Although acid catalyzed reactions are usually inhibited by water, high silica mordenltes produce hydrophobic circumstances at acidic sites to enhance the acid catalysis. 

Isopropanol [67-63-0] M 60.1, b 82.5°, d 0.783, n25-8 1.3739. Isopropyl alcohol is prepared commercially by dissolution of propene in H2SO4, followed by hydrolysis of the sulphate ester. Major impurities are water, lower alcohols and oxidation products such as aldehydes and ketones. Purification of isopropanol follows substantially the same procedure as for n-propyl alcohol. 

Cyclization with aminoacrolein (xvii), which is prepared by treatment of with 2-chloro-3-hydroxy-propenal (xv) with isopropanol, yielding the ether derivative and followed by reaction with ammonium hydroxide... 

Similarly, benzo[6]thiophene also yields mixtures of 2- and 3-alkyl derivatives on alkylation with alkenes or alkanols in the presence of acids <70AHC(11)177). Thus with isopropyl chloride, isopropanol or propene, mixtures of 2- and 3-isopropyl derivatives are formed. Alkylation by 2-methylpropene in the presence of PPA gives 2-7-butyl- (22%) and 3-7-butyl-(71%) benzo[6]thiophenes with 7-butanol and cone. H2S04, the yields are 2-7-butyl (6%) and 3-7-butyl (89%) (72JCS(Pl)414). 

Friedel-Crafts alkylation of benzo[6]thiophene has received little attention. The published results, which deserve reexamination, indicate that exclusive 3-substitution occurs in some cases, whereas in others, 2-substitution predominates. Benzo[6]thiophene is alkylated with isopropyl chloride, isopropanol, or propene in the presence of various acid catalysts under a variety of reaction conditions to give a mixture of 2- and 3-isopropylbenzo[6]thiophene in which the 2-isomer predominates (78-92%).358 410 In contrast, alkylation with isobutene in the presence of either 80% sulfuric acid415 or 100% phosphoric acid416 is said to afford exclusively 3-/er<-butylbenzo[6]thiophene in yields of 100 and 75%, respectively. In neither case was the structure of the product rigorously confirmed. Likewise, 3-Jeri-amylbenzo [63-thiophene is the exclusive product of alkylation with tert-amyl alcohol in the presence of stannic chloride414 alkylation with pent-l-ene, hex-l-ene, and a Ci8 propylene polymer is also claimed to give... 

The decomposition of isopropanol proceeds either via (A) dehydration to propene or (B) dehydrogenation to acetone. Both continuous- and pulse-flow measurements have shown that the reactions have similar rates on VI and V8, but (A) is faster than (B) on V8. Reaction (A) requires acid centers these are entirely removed when the soluble vanadium species are removed by isobutanol or NH4OH [28q],... 

This ester oxidizes very easily [95], reaction being perceptible even below 140 °C. Above about 300 °C, pyrolysis to propene and acetic acid also takes place. It too, gives cool flames [47]. Fish and Waris [95] detected only acetone, organic peroxides and peroxyacids in the products. Between 280 and 360 °C, Hoare and Kamil [97] found a wider range of products including hydrogen peroxide, formaldehyde, methanol, isopropanol, acetic acid and at 320 °C and below, acetaldehyde. Propene and acetone were found at 360 °C but organic peroxides and peroxyacids were always absent. 

Using nearly straight-pore alumina membrane plates as both a separator and a catalyst, Fumeaux et al. [1987] demonstrated the dehydration of isopropanol to form propene and hydrogenolysis of ethane to make methane. No quantitative information, however, was provided for the conversion or yield of the associated reactions. 

Qualitatively similar results were obtained for reaction and desorption of normal and iso-propanol on the 011 [-faceted TiO2(001) surface. In the case of normal propanol, almost half of the molecules initially adsorbed desorbed as the parent molecule at 370 K, while half of the remaining surface species reacted to form propanol at 580 K. The ratio of propene to propionaldehyde generated at 580 K was 10 1. Desorption of isopropanol quantitatively mirrored the desorption of normal propanol in two desorption states at 365 and 512 K. Isopropanol did not generate any dehydrogenation products (e.g., acetone), and the surface did not generate any bimolecular coupling products for any of the probe alcohol molecules. The absence of ether formation on the (Oil [-faceted surface is consistent with the need for double-coordination vacancies to facilitate that reaction, and the absence of such sites on this surface of titanium dioxide [80]. 

The decomposition of isopropanol can lead to the formation of propene and/or isopropyl ether (depending on the reaction temperature) if the catalyst possesses acidic sites [8], The dehydrogenation process towards acetone requires the catalyst to possess redox properties [15]. 

Methanol conversion to hydrocarbons has been studied In a flow micro reactor using a mixture of C-methanol and ordinary C-ethene (from ethanol) or propene (from Isopropanol) over SAPO-34, H-ZSM-5 and dealumlnated mordenlte catalysts In a temperature range extending from 300 to 450 °C. Space velocities (WHSV) ranged from 1 to 30 h. The products were analyzed with a GC-MS Instrument allowing the determination of the Isotopic composition of the reaction products. The Isotope distribution pattern appear to be consistent with a previously proposed carbon pool mechanism, but not with consecutive-type mechanisms. 

As a means of obtaining additional information on the methanol to hydrocarbons reaction over zeohtes we have investigated the reaction between C labeled methanol and ( C) ethene or propene (made in situ from ethanol or isopropanol) over SAPO-34, H-ZSM-5, and dealumlnated mordenlte. The isotopic composition of the reaction products was measured by GC-MS. 

It has earUer been reported that ethene in a mixed feed of ethene and ( methanol over SAPO-34 emerged virtually un-reacted [5,6]. The experiments have now been extended to Include also reaction mixtures of propene and methanol (obtained in situ from Isopropanol). 

Will other zeotype catalyst give similar restilts In order to get some tnformatlon about this issue co-reaction experiments of methanol and propene (from Isopropanol) have been carried out over H-ZSM-5 and dealumlnated mordenlte. Details will be published later. 

Figures 1 and 2 show the self-diffusivities of the various adsorbates in NaX and CsNaX, respectively. Acetone and isopropanol are the largest of the molecules studied and have the lowest mobilities. Specific interactions of the adsorbate oxygen atoms with the cations of the zeolite may also reduce the mobility. The smaller molecules, propene and water, are considerably more mobile. Water is seen to have the highest activation energy for diffusion of the adsorbates investigated.

The results in Figures 1 and 2 could have important bearing on the observed catalytic behavior of this system. The diffusivity of propene, the product of the acid-catalyzed dehydration of isopropanol, is seen to be more than one order of magnitude larger than that of acetone, the product of the base-catalyzed reaction. If both reactions occur in parallel, the difference in product diffusivities could lead to a transport-promoted output of the acid-catalyzed product if the process is diffusion limited. 

NMR. was also used to investigate the catalytic activity of the CsNaX and CsNaX-CsOH zeolites [16]. The samples were loaded with 3 molecules per supercage of isopropanol-2-and heated in an oven for a. specified time. CP MAS NMR investigations were then performed at room temperature. Contrary to expectations, CsNaX did not display any basic activity, i.e. no acetone was produced. Rather, propene was formed, which at 723 K reacted further to various coking products. The CsNaX-CsOH sample, on the other hand, showed neither propene activity nor a clear signal for the presence of acetone. We are currently investigating this further. 

Propene is used as a chemical intermediate in the production of polypropylene, acrylonitrile, propylene oxide, isopropanol, and cumene. Refineries use much of their production of propene internally as a refinery heating gas, to produce alkylates in gasoline, and to produce liquefied petroleum gas. 

Propylene, or propene by lUPAC (International Union of Pure and Applied Chemistry) nomenclature, is probably the oldest petrochemical feedstock, employed as it was in the early processes to isopropanol. It is produced by the cracking of propane or higher hydrocarbons in the presence of steam... 

Hydrolytic and non-hydrolytic sol-gel routes are implemented to prepare various pure and silica-dispersed vanadium- or niobium-based oxide catalysts corresponding to the compositions Nb-V, Sb-V and Nb-V-M (M = Sb, Mo, Si). Starting reagents in the hydrolytic procedure are isopropanol solutions of the metal alkoxides. The non-hydrolytic route is based on reactions between metal and Si alkoxides and hexane suspensions of niobium(V) chloride. The catalysts are tested in propane oxidative dehydrogenation. NbVOs, SbV04 and Nb2Mo30n are the major crystalline phases detected in the fresh catalysts, but structural modifications are in some cases observed after the use in the catalytic tests. At 500 C, propane conversions of 30 % and selectivities to propene between 20 and 40 % are attained. When the space velocity is decreased, acrolein is in some cases found as by-product. 

Catalytic properties were studied for two reactions namely isopropanol conversion and propene partial oxidation. The first reaction is a test reaction which allows to characterize acidic, basic or redox properties of a catalyst. One gets dehydration to propene or di-isopropylether for acid catalyst, acetone for basic catalyst in absence of air and acetone and water for redox type catalyst in presence of air. The experimental results at 100°C clearly show that at low Mo loadings acidic features are favored while redox features are favored at higher loadings. This indicates that monomeric MoOj" species are acidic (presumably as in silicomolybdic acid) while polymeric species exhibit redox properties. 

The acid-base features of the catalysts were studied by the reaction of isopropanol conversion to propene (acidic feature) and acetone (basic feature) under N2 in the feed and the redox features by the reaction under air in the feed. It was observed at 230°C (table 4 from ref 40) that the pyrovanadate sample was much more basic than the other two pure phases and that excess MgO with respect to crystallized phase stoichiometry induced even more basic character (table 4). 

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