摘要:
Palladium or platinum is deposited on a low acidity silica polymorph/silicalite/high silica zeolites to yield a supported catalyst particularly useful in the hydrogenation of acetylenes and diolefins. The catalyst has a decreased tendency to promote polymerization which causes fouling than previously used alumina catalysts.
摘要:
A reagent material useful for converting a contaminated waste material, which is environmentally unacceptable, to a relatively harmless granular substance which is environmentally acceptable. The reagent material is comprised of an effective amount of alumina, silica, a hydroxide, or hydroxide precursor, of an alkali metal, calcium oxide, and a medium to large pore zeolitic material. The method involves blending an effective amount of the reagent material with the waste material and allowing it to dry without setting, thereby resulting in an environmentally acceptable particulate substance.
摘要:
A process for the treatment of a hydrogel by contact thereof with an aqueous solution containing from about 0.1 to 20 percent, by weight, of a water soluble mono- or polycarboxylic acid, preferably one which contains from 1 to about 12 carbon atoms, and more preferably from about 2 to about 8 carbon atoms. Suitably, the acid treatment can be incorporated with a wash step which removes the sulfates and other soluble salts, as well as the bayerite, or the acid treatment can be employed subsequent to a wash step, prior to, or simultaneously with a pore volume extending step. The hydrogel can thus be subsequently contacted and separately treated with the acid-containing aqueous solution to remove the bayerite, or the acid can be dissolved in a solution which also contains certain critical amounts of specified type of water soluble polymer in a pore volume extending step.
摘要:
A process for the formation of a catalyst of predetermined pore size distribution and pore volume from an alumina hydrogel formed and obtained by precipitation from a solution containing a hydrous form of alumina in 1-5 wt. % concentration and an anion that is soluble in an alkaline solution and forms an aluminum salt, at pH 8-12, and temperature ranging about 15.degree. F.-120.degree. F., and then extended by contact with a solution of a water-soluble polymer containing 2 to about 24 monomer units from the group consisting of (a) polyethylene glycols, (b) polypropylene glycols, and (c) polyethylene amines sufficient to absorb the polymer and displace water from the pores until the weight ratio of polymer:alumina ranges about 0.5:1 to about 4:1. A metal hydrogenation component, or components, suitably a Group VI-B or Group VIII metal, or both, can be added during the polymer extending step, if desired, by adding a soluble compound, or salt of the desired metal, or metals, to the polymer containing solution. In either event, the polymer is removed by solvent extraction, dried and calcined to form gamma alumina.
摘要:
A synthetic halloysite which is substantially iron-free is obtained by crystallization from a reaction mixture containing hydrous alumina gel and aqueous silica sol. Metal substituted synthetic halloysites can be prepared by coprecipitation of metal hydroxides with the alumina gel.
摘要:
A synthetic halloysite which is substantially iron-free is obtained by crystallization from a reaction mixture containing hydrous alumina gel and aqueous silica sol. Metal substituted synthetic halloysites can be prepared by coprecipitation of metal hydroxides with the alumina gel. Hydrocarbons are converted over cracking catalysts derived from these halloysites.
摘要:
An improved method is provided for the preparation of organic cation-containing zeolites and their thermal decomposition products, by adding the organic templating agent to a preformed aluminosilicate gel containing less than a specified amount of water and a low alkali metal content, and maintaining the mixture at crystallization conditions until the crystalline aluminosilicate zeolite is formed.
摘要:
A process for rejuvenating crystalline aluminosilicayte zeolite-containing catalysts which have become at least partially deactivated through use in a hydrocracking process. Used, deactivated catalysts are treated with ion-containing solutions, particularly those containing hydrogen ions and hydrogen precursors, at a pH of from 3.5 to about 9, such that the alkali metal content of the catalyst is substantially reduced to thereby rejuvenate the catalyst to at least its original fresh activity in a hydrocracking process.
摘要:
A process for the formation of a catalyst of predetermined pore size distribution and pore volume of precipitation and formation of an alumina hydrogel from a solution which contains a hydrous form of alumina, in 1-5 wt. % concentration, and an anion that is soluble in an alkaline solution and forms an aluminum salt, at pH ranging about 8-12, and at temperature ranging about 15.degree. F.-120.degree. F. The alumina hydrogel is separated from the solution and washed in a pore volume extending step by contact with a solution of a water soluble polymer containing from about 2 to about 24 monomer units from the group consisting of (a) polyethylene glycols, (b) polypropylene glycols, and (c) polyethylene amines sufficient to absorb the polymer into the pores of the alumina hydrogel and displace water from the pores until the weight ratio of polymer:alumina within the hydrogel ranges from about 0.5:1 to about 4:1. Metal hydrogenation components, suitably a Group VI-B or Group VIII metal, or both, can be added during the hydrogel formation step (i.e. by cogellation), during the pore volume extending step, or after the alumina is formed, dried and calcined.