Showing papers on "Activated alumina published in 1968"

Kinetics of physical adsorption of propane from helium on fixed beds of activated alumina

Abstract: The kinetics of physical adsorption of propane from helium on fixed beds of activated alumina at 30°C. and at atmospheric pressure was studied. Two grades of activated alumina with the same average pore size distribution but different pore size distributions were used. Gas concentration, flow rate, and adsorbent particle size were also varied. The rate of internal diffusion controlled the adsorption process and was best described by Ficks' equation for unsteady state diffusion into a sphere. The internal diffusion appeared to be by a pore diffusion rather than by a surface diffusion mechanism.

Catalytic removal of vanadium and nickel from oils

Abstract: VANANDIUM AND NICKEL ARE REMOVED FROM PETROLEUM OILS BY CONTACT WITH A PREFORMED VANADIUM OXIDE CATALYST ON ACTIVATED ALUMINA IN THE PRESENCE. THE CATALYST IS PREPARED BY CONTACTING ACTIVATED ALUMINA WTIH A NON-OILY MEDIUM CONTAINING A SOLUBLE VANADIUM COMPOUND.

Synthesis of beta-mercaptoethanol

Abstract: ETHYLENE OXIDE AND HYDROGEN SULFIDE ARE REACTED IN LIQUID PHASE TO PRODUCE MONOTHIOGLYCOL HSCH2CH2OH (2-MERCAPTOETHANOL). LIQUID PHASE RETENTION OF PRODUCT CATALYZES THE REACTION. THE LIQUID PHASE WITH A LARGE EXCESS OF H2S PERMITS GOOD TEMPERATURE CONTROL. SUFFICIENT LARGE EXCESS OF THE H2S OVER THE ETHYLENE OXIDE IS USED TO CONTROL THE TEMPERATURE OF THE EXOTHERMIC REACTION BY VAPORIZING THE LIQUID EXCESS H2S. HIGH YIELDS OF HIGH PURITY PRODUCT OF THE ORDER OF SUBSTANTIALLY IN THE RANGE OF 9O PLUS PERCENT, E.G. 95 PLUS PERCENT, IS REALIZED. THE MOLECULAR RATIO OF H2S TO THE OXIDE IS BROADLY 5-1K, AND MORE PREFERABLY IN THE RANGE 7-13. LOW TEMPERATURES OF THE ORDER OF ABOUT 125-3OO*F., PREFERABLY OF THE ORDER OF ABOUT 13O-26O*F. ARE POSSIBLE TO BE EMPLOYED UNDER CONDITIONS OF OPERATION. PREFERABLY, A CATALYST SUCH AS AN ACTIVATED ALUMINA CATALYST IS USED. PURITIES OF 99.2 WEIGHT PERCENT HAVE BEEN OBTAINED.

Treatment of waste gases

Abstract: 1,211,033. Removing SO 2 from waste gases. ONTARIO RESEARCH FOUNDATION. 10 Jan., 1969 [11 Jan., 1968], No. 1741/68. Heading C1A. Sulphur dioxide containing effluent gas is contacted with a reducing gas comprising H 2 S in the presence of a catalyst at a temperature of 50- 150‹ C. whereby the SO 2 is at least partially reduced to sulphur in accordance with the equation: and the sulphur is deposited on the catalyst, and removing the sulphur from the catalyst at least partially by reaction with carbon monoxide at a temperature of from 250-500‹ C. in order to provide regenerated, substantially sulphur free catalyst. The reaction with carbon monoxide preferably occurs at 300-450‹ C. The carbonyl sulphide produced may in turn be hydrolysed to CO 2 and H 2 S which is recycled, further H 2 S being produced if a mixture of CO and H 2 is used for removing the sulphur, steam (removing the necessity for subsequent hydrolysis) and an inert gas, such as N 2 , may also be present. Sufficient H 2 S is used in order to react with all the SO 2 , sufficient CO with or without H 2 is used to react with 2/3 of the sulphur produced, the rest being removed as sulphur vapour in the COS and subsequently removed; sufficient steam is used to hydrolyse all the COS produced. A continuous process for the removal of the catalyst from the sulphur depositing zone to the sulphur removing zone and: thereafter recycling the catalyst, is described. Catalysts disclosed for the sulphur producing stage are Pd, Pt, Rh, promoted iron oxide but preferably activated alumina or bauxite is used. This stage may be broken up into 2 parts: (a) reaction with H 2 S at 250-400‹ C. (b) completion of the reaction at 50-150‹ C. Some CS 2 may be produced especially if hydrocarbons are present in the CO or H 2 . This need not be hydrolysed since CS 2 will reduce SO 2 to S if recycled.

Vapor phase process for production of n n'-disubstituted piperazines

Abstract: N,N''-DISUBSTITUTED PIPERAZINES ARE PREPARED IN A VAPOR PHASE PROCESS AT ATMOSPHERIC PRESSURE BY CYCLODEHYDRATION OF THE CORRESPONDING N-SUBSTITUTED ETHANOLAMINE IN THE PRESENCE OF AN ACTIVATED ALUMINA CATYLST.

Method and catalyst for production of nitrfles

Abstract: 1,133,216. Dehydrogenation catalysts. HALCON INTERNATIONAL Inc. 17 Dec., 1965 [18 Dec., 1964], No. 53640/65. Heading B1E. A dehydrogenafion catalyst comprises MoO 3 or WO 3 on activated alumina e.g. eta or gamina alumina in combination with antimony, tin, titanium or (when the catalyst is MoO 3 ) tungsten oxide. The alumina has a purity of at least 99% and a surface area of at least 10 m 2 /gm. The Al 2 O 3 may be activated by heating at 500-2000‹C. Conventional preparative details are provided.

Process for reducing the loss due to abrasion of alumina extrudates and of extruded catalysts based on alumina

Abstract: 1,245,654. Alumina extrudates. KONINKLIJKE ZWAVELZUURFABRIEKEN V/H KETJEN N.V. 17 Sept., 1968 [4 Oct., 1967], No. 44115/68. Heading C1A. [Also in Division B1 Alumina extrudates are calcined for at least 1 hour at 450-850‹ C., wetted with water suitably in an amount of between 50 and 100% wt. calculated on the weight of calcined extrudate, and then subjected to attrition treatment, dried and calcined in order to increase the abrasion resistance of the alumina. The attrition treatment may comprise a tumbling of the calcined extrudates in the drum of a concrete mixer rotating at 60-80 r.p.m. or may comprise a vibrational treatment in a closed container at a frequency of 20-1000 vibs./min. The attrition treatment normally lasts at least 10 minutes and is continued until between 0A2 and 1% wt. Al 2 O 3 has been removed. The tumbled or vibrated extrudates may be treated with a mineral acid, e.g. HCl, to dissolve 3-5% wt. Al 2 O 3 before the drying and calcining steps. Alumina extrudates of the present invention may be impregnated with platinum salts, dried and calcined to form catalysts. Alternatively, an activated alumina extrudate may be impregnated with platinium salts, dried and calcined and then treated by the method described above.

A study of the sorption characteristics at the solution-solid interface, and the hydrogen bonding characteristics of a series of para-substituted phenols

Abstract: A characterisation of the activated alumina used in the sorption studies has been attempted from results obtained by X-ray diffraction techniques, low temperature nitrogen sorptions and sorptions from the liquid phase. The sorption characteristics at an alumina-dioxan interface of a series of 4-substituted phenols (phenol, 4-methyl-, 4-t-butyl-, 4-chloro-, 4-nitro-, and 4-cyano-phenols) have been determined at 35 C.; solubilities in dioxan measured at 35 C.; experimental adsorption isotherms constructed and sorption saturation values estimated. In order to compare the sorptive affinity of the alumina surface for the phenols an index of sorption has been defined as "the number of moles of phenol sorbed at constant relative mole fraction of phenol in the mobile phase", and it has been demonstrated that this index can be related logarithmically to the Hammett sigma constant for the appropriate 4-substituent.The effects of 4-substitution on properties of the OH bond which reflect its hydrogen bonding tendency have been examined, such as association to dioxan in solution. Absorbance measurements in the near ultra-violet have enabled association constants in solution for the process substituted phenol + dioxin ↔ complex to be determined at 25 C. and 55 C. Comparisons have been made with other relevant characteristics of the OH bond, for example acidity, polarity and near infra red stretching frequency, again showing (as with the hydrogen bonding association constants) good correlation with the Hammett structural parameter. The results obtained suggest that in the sorption of 4-substituted phenols from dioxan solution onto an activated alumina the forces on the surface are the dominant ones, since the phenols are not adsorbed as complexes but as discreet molecules. Interaction with the surface appears to be through the mechanism of hydrogen bonding and the phenol molecules probably assume a vertical orientation on localised sorption sites.