Abstract:
A process for separating a component from a feed mixture comprising an aqueous solution of a mixture of different components, such as a mixture of saccharides, in which the mixture is contacted with an adsorbent comprising a crystalline aluminosilicate which selectively adsorbs a component from the feed mixture. The adsorbed component is then recovered by contacting the adsorbent with a desorbent material such as water to effect the desorption of the adsorbed component from the adsorbent. There is an undesirable tendency for the silicon constituent of the crystalline aluminosilicate to dissolve in the aqueous system. The improvement to the process comprises contacting the desorbent, and/or the feed mixture, with a bed of silica gel prior to contacting the feed mixture with the adsorbent. This effects a substantial reduction in the undesirable dissolution.
Abstract:
A catalytic composite of improved activity and a method of manufacture is disclosed. The catalytic composite is particularly effective with respect to the transalkylation of toluene. The catalytic composite comprises a zeolite of the mordenite crystal structure in from about a 1:3 to about a 3:1 weight ratio with a refractory inorganic oxide. The catalytic composite is characterized by a method of preparation which comprises subjecting zeolite of the mordenite crystal structure, with a sodium content of less than about 5 wt. % as Na.sub.2 O, to an aqueous ammoniacal treatment at a pH of at least about 9.5 in admixture with a substantially acid anion-free refractory inorganic oxide.
Abstract:
An improved method of preparing silica-alumina macrospheres is disclosed. An alkali metal silicate solution is acidified with a strong mineral acid and a weak organic acid. The resulting silica sol is admixed with an acidic alumina sol and urea and the mixture is dispersed as droplets in a hot oil bath with the formation of firm spheroidal hydrogel particles. The method insures the formation of firm hydrogel particles which will retain their structural integrity during further processing. The hydrogel spheres are aged, washed, dried and calcined in accordance with prior art methods.
Abstract:
A catalytic composite of improved activity and a method of manufacture is disclosed. The catalytic composite is particularly effective with respect to the transalkylation of toluene. The catalytic composite comprises a zeolite of the mordenite crystal structure in from about a 1:3 to about a 3:1 weight ratio with a refractory inorganic oxide. The catalytic composite is characterized by a method of preparation which comprises subjecting zeolite of the mordenite crystal structure, with a sodium content of less than about 5 wt. % as Na.sub.2 O, to an aqueous ammoniacal treatment at a pH of at least about 9.5, and thereafter admixing said zeolite with said refractory inorganic oxide.
Abstract:
A catalytic composite comprising a Group VIB and a Group VIII metal or metal oxide on a silica-alumina support or carrier material. A catalytic composite particularly useful for the hydrotreating or hydrorefining of petroleum hydrocarbon fractions results from the use of a silica-alumina support or carrier material formed by the gelation of a suspension of an insoluble basic aluminum sulfate in an acidic silica sol.
Abstract:
A method of preparing spheroidal alumina particles of improved physical stability is disclosed. Alumina hydrogel particles prepared by the oil-drop method are aged in the forming oil at atmospheric pressure conditions and at a temperature of from about 95.degree. to 105.degree. C. until the hydrogel spheres achieve a pH in excess of 6 to about 7.5. The forming oil is thereafter displaced with an ammonium salt-buffered aqueous ammoniacal solution, and the hydrogel spheres aged therein for a brief period. After further aging in an aqueous ammoniacal solution in accordance with prior art practice, the spheres are water-washed, dried and calcined.
Abstract:
A process for the transalkylation of alkylaromatic hydrocarbons is disclosed. Transalkylation of alkylaromatic hydrocarbons, such as toluene, is effected at transalkylation conditions in contact with a catalytic composite characterized by a method of preparation whereby a zeolite of the mordenite crystal structure with a sodium content of less than about 5 wt. % as Na.sub.2 O is subjected to an aqueous ammoniacal treatment at a pH of at least about 9.5 and calcined in intimate admixture with a refractory inorganic oxide to form a catalytic composite therewith.
Abstract:
A method is disclosed for effecting a uniform distribution of catalytically active metallic component over substantially all of the available surface area of a carrier material in a crystallite size of less than about 25 Angstroms. The innovative feature is in the use of a sulfur-containing organic acid as a complexing agent for the catalytically active metallic component in an impregnating solution adjusted to a pH of from about 5 to about 7.
Abstract:
A method of preparing high surface area-high average bulk density spheroidal alumina particles is disclosed. Spheroidal alumina hydrogel particles prepared by the oil drop method are aged in an aqueous ammoniacal solution containing from about 4 to about 20 wt. % ammonium salt, and thereafter water-washed, dried and calcined to yield high surface area spheroidal alumina particles having an average bulk density of from about 0.6 to about 0.8 grams per cubic centimeter.
Abstract:
A stoichiometric amount of aluminum is commingled with hydrochloric acid in an aqueous media to provide a final reaction mixture containing from about 10 to about 14 wt. % aluminum in from about a 1:1 to about 1.5:1 ratio with the chloride anion content thereof. The mixture is treated in the presence of a soluble salt of cobalt or nickel at conditions effecting substantially complete digestion of the aluminum.