Abstract:
A method of making caprolactam from aminohexanoic acid or aminohexanoate ester comprising the steps of: (a) obtaining a reactor containing at least one catalyst, the catalyst being a metal oxide having acid-base-paired active sites; (b) charging a reaction feed into the reactor, the reaction feed containing a reactant, which is either amniohexanoic acid or C.sub.1 to C.sub.12 alkyl aminohexanoate ester, and a solvent; (c) reacting the reaction feed at a reaction temperature between 140.degree. and 300.degree. C. and a reaction pressure between 10 and 100 atm, to form a product stream; and (d) separating caprolactam from the product stream. The metal oxide catalyst is prepared from a process comprising the steps of: (a) dissolving at least a metal salt, which is not a metal oxide, in a solvent to form a metal salt solution, wherein: (i) the metal salt contains a metal element selected from the group consisting of silicon, titanium, tin, barium, calcium, magnesium, aluminum, and zinc; (ii) the solvent is selected from the group consisting of water, alcohol, ether, and mixtures thereof, and (iii) the metal salt is a salt which is soluble in the solvent; (b) adjusting the pH of the metal salt solution to be between 8 and 11, to thereby cause a precipitation of metal hydroxide; and (c) calcining the metal hydroxide at 300.degree. to 1,000.degree. C. to form a metal oxide.
Abstract:
A stackable modular personal computer structure comprises a lowermost frameworks, a plurality of intermediate frameworks, an uppermost framework and an upper cover; the frameworks and the upper cover stacked with each other in a sequence; all the frameworks have the first internal engaging structure inside the tops thereof respectively, the intermediate frameworks, the uppermost framework and the upper cover each have the second internal engaging structure inside the bottoms thereof respectively; the bottoms of each of the intermediate and the uppermost frameworks has a hole especially for electric wires to pass through to enable the modular personal computer so that a consistent outlook for the computer structure can be obtained.
Abstract:
A stackable modular personal computer structure, comprising a plurality of framework; the plural frameworks stacked to combine with each other in a sequence; a bottom of each other framework above the first framework which is mounted on a lowest layer has a hole for allowing at least one electric wire to be passed through to enable the electric wires of the modular personal computer and a combination structure of each layer are all hid inside the frameworks so that an identical outlook can be obtained.
Abstract:
The present invention provides a methanation catalyst prepared by depositing Pt and Ru on a metal oxide carrier by incipient wetness impregnation or precipitation deposition, drying and calcining the deposited carrier to obtain a Pt—Ru/metal oxide catalyst. This catalyst can selectively catalyze methanation of CO, wherein hydrogen and CO in a hydrogen-rich reformate or synthesis gas are reacted to form methane and water, thereby the CO concentration in the hydrogen-rich reformate is reduced.
Abstract:
An improved process for the preparation of acetic esters is disclosed. It comprises a fixed bed reaction and a catalytic distillation. The fixed bed reaction comprises the steps of: (a) charging acetic acid and alcohol into a fixed bed reactor under a predetermined reaction condition; and (b) reacting the esterification reactants in the fixed bed reactor. The fixed bed reactor contains acidic catalysts that are present in a solid phase, and the reaction condition is controlled such that (i) the reactants and the products co-exist in a gas-liquid two-phase equilibrium in the fixed bed reactor and that (ii) at least one component of the reactants is present in one phase and at least one component of the products is present in another phase. The catalytic distillation comprises the steps of: (1) charging acetic acid from top of a catalytic distillation column and the reaction products from the fixed bed reactor from the bottom of the catalytic column in a counter-flow manner; and (c) continuously removing acetic ester and water from the top of the catalytic distillation column, and continuously removing acetic acid from the bottom of the catalytic distillation column. The acetic acid removed from the catalytic distillation column is fed into the fixed bed reactor. Very high alcohol conversion and essentially alcohol free product can be obtained at substantially reduced height of the catalytic distillation column.
Abstract:
The present invention provides a methanation catalyst prepared by depositing Pt and Ru on a metal oxide carrier by incipient wetness impregnation or precipitation deposition, drying and calcining the deposited carrier to obtain a Pt—Ru/metal oxide catalyst. This catalyst can selectively catalyze methanation of CO, wherein hydrogen and CO in a hydrogen-rich reformate or synthesis gas are reacted to form methane and water, thereby the CO concentration in the hydrogen-rich reformate is reduced.
Abstract:
A method for preparing ester end-capped polyalkylene ether is disclosed. Cyclic ether monomers are subjected to ring-opening polymerzation at a temperature of 20.degree.-80.degree. C. and a pressure of 0-10 atm in the presence of a solid acid serving as catalyst and a mixture of acid and acid anhydride serving as a promoter. The solid acid is an oxide of group III and group IV elements and has been modified by sulfuric acid, ammonium sulfate or ammonium sulfite.
Abstract:
A method for preparing ester end-capped polyalkylene ether is disclosed. Cyclic ether monomers are subjected to ring-opening polymerization at a temperature of 10.degree.-80.degree. C. and a pressure of 0-10 atm in the presence of a solid acid of a mixed oxide of group III and group IV elements serving as catalyst and a mixture of acid and acid anhydride serving as molecular weight moidifier. The group III and group IV elements used should have a Ho index of +3.0 to -10.0.