2-propanol Dehydration Research Articles

Selectivities of rare earth oxide catalysts for dehydration of butanols

The catalytic dehydration of 2-propanol, 1-butanol, and 2-butanol over La 2O 3, CeO 2, Pr 6O 11, Sm 2O 3, Eu 2O 3, Dy 2O 3, Ho 2O 3, and Yb 2O 3 is studied. Because of the gradual variation of the general properties of 4 f oxides, the former group has been considered a likely series to analyze the existence of definite correlations between alkene distribution and catalyst properties, often reported in the literature. According to our study, the effect of temperature on product distribution may strongly restrict the validity of such correlations. This point is discussed on the basis of the linear relationships found here between E a and log A.

Acidity and Catalytic Activity of Iron(II) Sulfate Heat-treated at High Temperature

Abstract Acidity and catalytic activity of FeSO4 calcined at 500–900 °C were studied. The product obtained by calcination at 700 °C showed maximum acidity at H0≤1.5 and activity for isomerization of d-limonene oxide, polymerization of isobutyl vinyl ether and dehydration of 2-propanol. When calcined at 750 °C the product showed no acidity or activity.

Combined differential and integral kinetic modeling in an infrared cell-recycle reactor

The dehydration of 2-propanol over γ-alumina was studied at 246 °C by combined in situ ir measurements of adsorbed species and steady-state reaction kinetics. The resulting kinetic model accounted for catalyst deactivation, product inhibition, and autoinhibition by 2-propanol. The model also predicted the integral kinetic behavior during transient (batch) operation of the reactor.

ChemInform Abstract: PROMOTING ACTION OF INORGANIC GASES ON THE RATE OF DEHYDRATION OF 2‐PROPANOL OVER CA‐Y ZEOLITE

Chemischer InformationsdienstVolume 10, Issue 27 Preparative Organic Chemistry ChemInform Abstract: PROMOTING ACTION OF INORGANIC GASES ON THE RATE OF DEHYDRATION OF 2-PROPANOL OVER CA-Y ZEOLITE Y. ISHINAGA, Y. ISHINAGASearch for more papers by this authorK. OTSUKA, K. OTSUKASearch for more papers by this authorA. MORIKAWA, A. MORIKAWASearch for more papers by this author Y. ISHINAGA, Y. ISHINAGASearch for more papers by this authorK. OTSUKA, K. OTSUKASearch for more papers by this authorA. MORIKAWA, A. MORIKAWASearch for more papers by this author First published: July 3, 1979 https://doi.org/10.1002/chin.197927177AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue27July 3, 1979 RelatedInformation

Promoting Action of Inorganic Gases on the Rate of Dehydration of 2-Propanol over Ca-Y Zeolite

Abstract The dehydration of 2-propanol over Ca-Y zeolite has been enhanced in the presence of NO2, SO2, and Cl2 at 100 °C. This promoting action has been ascribed to the formation of acidic hydroxyl groups resulting from the reaction of the inorganic gases with zeolitic water or basic hydroxyl groups attached to the metal cations.

Use of natural zeolite treated with a mixed solution NaOH and NaCl as a solid acid catalyst.

It was found that faujasite could be formed by a simple treatment of the zeolite(clinoptilolite) with a mixed solution of NaOH and NaCl under special conditions. The X-ray diffraction pattern was the same as that of commercially available synthetic X or Y zeolite. Further, the faujasite was exchangeable with various ions to almost the same extent as commercial zeolite. The solid acidity or the catalytic activities of the ion exchanged faujasite used for the cumene cracking and for the dehydration of 2-propanol was dependent primarily on the electronegativity of the metal ion. This dependence had already been known in the case of ion exchanged commercial zeolite. The catalytic activity of the La form used for the cumene cracking was somewhat less than that of La-Y. However, the treated natural zeolite, as a whole, has similar properties and activities as the synthetic zeolite.

The effect of cross-linking on catalytic properties of macroporous styrene-divinylbenzene ion exchangers

Gas-phase dehydration of 1-propanol at 130 °C has been studied on a series of differently cross-linked sulfonated macroporous styrene-divinylbenzene copolymers. The degree of cross-linking of the catalysts influences the values of the constants of the Langmuir-Hinshelwood kinetic equation and brings about changes in total dehydration rate as well as in the ratio of the products formed by parallel reactions, propene and dipropyl ether. These phenomena are probably due to the extensive and fast permeation of 1-propanol into the polymer mass of the ion exchangers and the slow permeation of both reaction products from the polymer mass; during permeation the ether is transformed to a different extent into propene, which results in changes in selectivity. These conclusions were supported by measurements of 1-propanol dehydration on an ion exchanger containing functional groups only on the polymer surface, by the study of partial poisoning of the ion exchangers with nitrogen-containing bases, and by measurements of the relative sorption ability of the reaction components.

Quantum chemical calculations on the catalytic dehydration of 2-propanol

The charge on atoms and the bond strengths in CH3CHOHCH3, CH3 $$CH\mathop O\limits^ + H_2 $$ CH3, CH3CHOHCH 2 − , CH3 $$CH\mathop O\limits^ + H_2 $$ CH 2 − and CH3 $$CH\mathop O\limits^ + H_2 $$ CH3...O(H)CH(CH3)2 have been calculated by the CNDO/2 method. The results are in agreement with published experimental observations on catalytic dehydration. A modified mechanism of anti-elimination on solid catalysts is proposed.

Kinetics of parallel dehydrogenation and dehydration of 2-propanol on oxide catalysts

Kinetics of parallel dehydrogenation and dehydration of 2-propanol on oxide catalysts

Decomposition of 2-propanol over alkali cation exchanged zeolites

The decomposition of 2-propanol over alkali cation exchanged X and Y type zeolites was studied. Over Li and Na zeolites, most of the 2-propanol was converted to propylene and water. Over K, Rb, and Cs zeolites both dehydration and dehydrogenation of 2-propanol occurred. The dehydration and the dehydrogenation were selectively depressed by the addition of a basic reagent (pyridine) and an acidic reagent (phenol), respectively. These results showed that the K, Rb, and Cs zeolites had both acidic sites and basic sites. When the ion exchange procedure was carried out in a low pH solution, protons were introduced into the zeolite by cation exchange and these sites acted as acidic sites. The ratio of the dehydration to the dehydrogenation depended on the kind of exchanged alkali cations and the type of zeolites. It is concluded that the acidic sites of the alkali exchanged zeolites are the decationated sites, the electrostatic field, and possibly the alkali cations, and their basic sites are the lattice (AlO4− paired with the alkali cations.

The Catalytic Decomposition of 2-Propanol over the Silica-Manganese(II), -Zinc(II) and -Magnesium(II) Prepared by the Homogeneous Method

The catalytic dehydration and dehydrogenation of 2-propanol over thesilica-manganeset (II), -zinc(II)and-magnesium(II), which were prepared by the method of precipitation from homogeneous solution were compared with those over usual coprecipitated metals.Dehydration took place to a large extent over the catalysts prepared by the homogeneous method, while dehydrogenate did only toa small extent at 300Cover the catalysts prepared by the both methods. The catalytic dehydration activities on the homogeneous catalysts were much higher than those on the coprecipitated catalysts, and the order of activity was Mg(II) Zn(II) Mn(II).Kinetics studies using a fiow reactor indicated that the dehydration and the dehydrogenation were of both first-order irreversible reactions. From theArrhepius plots the activation energies for the dehydration Over the homogeneoussilica-manganese(E), -zinc(II) and -magnesium(E), were found to be 16.0, 17.9 and20.6kcal/mol.m2, respectively.From the consideration, of the changes of relative activities by adding various amounts of KOH and of the differences of thepH titration curves for the catalysts and silica gel, it was concludedthat the active sites of the dehydration were. Lewis acid site, vi2., the metals with the vacant orbitals which combined with the silica gel and those of the dehydrogenation were the electron pair donor or the oxygen atom of the metallic oxide bended to the silica gel.

ChemInform Abstract: THE DEHYDROGENATION AND DEHYDRATION OF 2‐PROPANOL VAPOR ON MANGANESE FERRITE

The dehydrogenation and dehydration of 2-propanol on manganese ferrite has been studied between 306 and 362 °C. The selectivity for dehydrogenation was constant throughout the temperature range. At...

The Dehydrogenation and Dehydration of 2-Propanol Vapor on Manganese Ferrite

The dehydrogenation and dehydration of 2-propanol on manganese ferrite has been studied between 306 and 362 °C. The selectivity for dehydrogenation was constant throughout the temperature range. At 362 °C a trace of condensation of the alcohol to mesityl oxide was detected, < 0.1% v/v of the reaction products.

Catalytic Activity of Zirconium Phosphate for Dehydration of 2-Propanol

Catalytic activity tests were carried out by a flow system-over thgzirco-nu.m phospl ate catThstl which wa's prepared from ZrO(NO3)2 and NaHPO4. Acidity, DTA TGA curve low frequency infrared spectrum and xrray pattern of catalyst samples were measured to characterize the catalyst structure.The conversion data of the reaction were arranged in the integral form of the zero-order kinetics and the apparent activation energy of the reaction was nearly equal to 22kcal/mol at low temperatures ranging from 170 to 230C and 9.1kcal/mol at high temperature above 230C. The catalytic activity and the acidity of catalyst showed a rough linier relationship and both of them exhibited the maximum values at about 400C in the calcination temperature ranging from 200 to 1000C. Lewis-type acid sites, formed by the removal of water from zirconium phosphate having a hydrate sturucture, would be a cause od an acidic property and an origin of catalytic activity.The zirconium phosphate, showed a similar characteristic to alumina in catalysis, was not effective for the reactions such as polymerization of propylene or dealkylation of cumene.

金属リン酸塩の酸性質とイソプロピルアルコール脱水反応活性

金属リン酸塩の酸性質とイソプロピルアルコール脱水反応活性

Vapor-phase reactions catalyzed by ion exchange resins: I. Isopropanol dehydration

The dehydration of 2-propanol has been studied using ion exchange resin as catalyst, in a gas-phase flow reactor. The temperature was 90 °, 100 °, and 110 °C and the pressure, atmospheric. The production of both propylene and diisopropyl ether have been measured. The Langmuir-Hinshelwood model only fits the data in a limited range of partial pressure of water ( p w p w 0 = 0.20 ). The reactions are zero order with respect to alcohol and strongly inhibited by water. The ether did not react in the presence of alcohol and its influence on the velocity of reaction is negligible. No appreciable effect of the partial pressure of propylene has been observed either. A comparative analysis with inorganic catalysts shows that the reaction mechanism should be the same although the ion exchange resin seems to be more active. The controlling step for both reactions is the surface reaction on two adjacent sites.

Kinetics of the catalytic dehydration of 2-propanol

The dehydration of 2-propanol is chosen as an activity test of oxide catalysts. The thermal kinetics of the decomposition are studied. Catalytic kinetics are examined on silica, alumina, thoria, and modified silica-aluminas. In the range T = 100 − 160 °C, p (2-propanol) = 8 − 23 mm Hg, the reaction is zero order with respect to alcohol, inhibited by water and acetone, but not by propene. Silica-alumina catalysts have a higher activity than alumina, silica or sodium silica-alumina.