| 摘要 |
Crystalline metal alumino-silicates having uniform pore openings of 6-15 are used as catalysts in the conversion of hydrocarbons to hydrocarbons of different molecular weight. The alumino-silicate may be sodium aluminosilicate or may contain other metal ions introduced by ion exchange. The preferred compounds are of the formula Me2On.Al2O3.2.7SiO2 in which Me is a metal of valency n, and may be sodium with or without potassium, calcium, cobalt, molybdenum, vanadium zirconium, tungsten, nickel, copper, magnesium, chromium, iron, silver, gold, platinum, palladium, zinc, cadmium, rare earths, mercury, lead or other metal, e.g. of Groups II, VI, VII or VIII. About 2/3 of the sodium may be replaced by the other metal. The sodium alumino-silicate is prepared by treating a sodium silicate solution having a molar ratio of soda to silica of 0.5-2.0 : 1, preferably sodium metasilicate, with a sodium aluminate solution in which the soda to alumina molar ratio is from 1-3 : 1 in proportions such that the silica to alumina molar ratio in the final mixture is 2.2-10 : 1. The slurry formed should have a pH above 12 and contain 2-6 equivalents of sodium per litre. The paste obtained is heated to 180-215 DEG F. for a period up to 200 hours to produce crystals of the desired interstitial dimensions. The solid may then be ion-exchanged by treatment with two portions of a solution of a metal salt in water or aqueous alcohol. Finally the material is dried at 225-250 DEG F. and calcined at 400-1000 DEG F. The catalyst may have a surface area of 200-400 square metres per gram and is readily regenerated by oxidation. The cracking of hydrocarbons can be effected in the presence of the above catalysts, particularly magnesium alumino-silicates having a uniform pore opening of about 13 at 800-1000 DEG F. and 0-200 p.s.i.g.ALSO:In reactions involving polymerization, aromatization of unsaturated aliphatics, hydrogen transfer between hydroaromatic compounds and olefines to form aromatics and saturated hydrocarbons, or alkylation of aromatic hydrocarbons, a catalyst is employed which is a crystalline metal alumino-silicate having uniform pore openings of 6-15 . The catalyst is preferably a sodium alumino-silicate of the formula Na2O.Al2O3.2-7SiO2 in which part, e.g. two-thirds, of the sodium may be replaced by other metals such as potassium, calcium, cobalt, molybdenum, vanadium, zirconium, tungsten, nickel, copper, magnesium, chromium, iron, silver, gold, platinum, palladium, zinc, cadmium, rare earths, mercury or lead (see Group III). The polymerization of normally gaseous and low-boiling liquid olefins such as ethylene, propylene, the butylenes and amylenes to hydrocarbons boiling in the C5-400 DEG F. range or the polymerization of higher olefines such as decylene may be effected at atmospheric-1000 p.s.i. and 300-650 DEG F. In an example: (11) propylene is polymerized to C5-400 DEG F. high octane material over a 13 pore size sodium alumino-silicate at 500 DEG and 550 DEG F., 125 p.s.i.g., and a W.H.S.V. of 0.2. The aromatization of C2-C7 olefines, diolefines or acetylenes may be effected at 350-850 DEG F. and 0-750 p.s.i.g. at a space velocity of 0.5-5 w./w./hr. The catalyst preferably has a surface area of 200-700 square metres per gram and is an adsorbent for the aromatic products. The products are recovered by desorption such as by steaming, evacuation or purging with a suitable gas or vapour at elevated temperature; in fluidized operation the catalyst may be continuously removed and desorbed in a separate vessel. The aromatisation of hydroaromatics is effected in the presence of a hydrogenacceptor such as an olefine in which case the aromatic hydrocarbon formed may also be alkylated by the olefine; when cyclic olefines are aromatized, they act as their own hydrogenacceptors and form naphthenes as well as aromatics. Suitable hydroaromatics include cyclohexane, cyclohexene, decalin, tetralin, phenylcyclohexane, and dicyclohexyl. In examples: (12) n-pentene is aromatized at 400 DEG F. and atmospheric pressure and 0.06 vol./vol./hr. over a sodium alumino-silicate of pore size 13 to give 61.8% conversion of the pentene adsorbed to aromatics and higher boiling non-aromatics; (16) cyclohexane is aromatized in the presence of propylene over a calcium alumino-silicate of pore size 10 to give mostly di-isopropylbenzene by propylation of the benzene formed with excess propylene: (17) cyclohexene is converted to benzene, cyclohexane and cyclopentene over calcium, zinc, sodium and potassium alumino-silicates of 13 pore size. The alkylation of toluene with propylene is effected in Example (10) over a sodium aluminosilicate and a magnesium-sodium (about 76% sodium replaced) alumino silicate at 850 DEG F. and atmospheric pressure with a toluene feed rate of 0.64 vol./vol./hr. and 5 mols. of propylene per mol. of toluene. |
