摘要:
A process is provided for the preparation of an indole from aniline or a derivative thereof and a polyhydric alcohol. The reaction is carried out in the presence of a catalyst composed of a carrier having a specific surface area of at least 10 m.sup.2 /g and silver supported on the carrier. The catalyst also contains as an additional component a specific amount of at least one element selected from Co, Fe and Ni. Deterioration in catalytic performance of the catalyst during the reaction and its regeneration are therefore minimized.
摘要:
In a process for preparing an indole by reacting an aniline with a diol, a catalyst the activity of which has been reduced through its use in the reaction is brought into contact with an inert gas containing 5 vol. % or less of oxygen so that the catalyst is regenerated for its repeated utilization. The activity of the regenerated catalyst is enhanced further when it is subjected to a reducing treatment for activation upon its reutilization.
摘要:
Disclosed herein is a preparation process for an indole, which process comprises subjecting an N-(.beta.-hydroxy)-alkylaniline, in the presence of a catalyst and at a super-atmospheric pressure, to a gas-phase catalytic reaction. The present process improves the selectivity of the reaction and the service life of the catalyst.
摘要:
Disclosed herein is to react an aniline and an ethylene glycol at a superatmospheric pressure in preparing an indole by subjecting the aniline and ethylene glycol to a gas-phase catalytic reaction in the presence of a catalyst, thereby improving the selectivity of the reaction and the service life of the catalyst.
摘要:
A method for preparing an unsaturated compound mainly comprising monoolefins, or a mixture of .alpha., .beta.-unsaturated nitriles and monoolefins comprises coming a mixed gas which comprises paraffins and oxygen, or paraffins, oxygen and ammonia in contact with a catalyst which comprises (1) an oxide of phosphorus and (2) at least one oxide selected from the group consisting of indium oxide and tin oxide or comprises, in addition to the foregoing catalytic components, (3) at least one oxide selected from the group consisting of vanadium oxide, tungsten oxide and molybdenum oxide. The method makes it possible to prepare monoolefins, or a mixture of .alpha., .beta.-unsaturated nitriles and monoolefins in high yield and high selectivity from cheap starting materials, parafins.
摘要:
A composite oxide catalyst represented by the general formula: Mo-V-P-X-Y (wherein X represents at least one element selected from the group consisting of Sb, Cu, Co, Bi and As; Y represents at least one element selected from the group consisting of K, Rb, Cs and Tl) and a method for preparing methacrylic acid through gas phase catalytic oxidation of methacrolein with molecular oxygen in the presence of the foregoing catalyst are herein disclosed. The catalyst exhibits excellent catalytic activity, selectivity to methacrylic acid, catalytic stability and lifetime.
摘要:
Preparation process of indole from aniline and ethylene glycol. Upon preparing indole by reacting aniline and ethylene glycol in a gas phase and in the presence of a catalyst, ethylene glycol is charged in portions to a multiplicity of catalyst stages formed by dividing a catalyst bed and connected in series. This divided supply of ethylene glycol permits the suppresing of the decomposition of ethylene glycol, even if the molar ratio of feed aniline to total feed ethylene glycol is small. The above process permits making the yield of indole large and reducing the amount of unreacted aniline to be separated and recovered from the reaction effluent.
摘要:
A method for economically concentrating an acrylamide aqueous solution by catalytic hydration without substantial deterioration in the product. According to the method, an acrylamide aqueous solution obtained from catalytic hydration, is concentrated by distillation while maintaining the solution in good contact with at least 0.1 mole. or more of air per mole of water distilled from the acrylamide aqueous solution.
摘要:
A method for preparing an unsaturated compound mainly comprising monoolefins, or a mixture of .alpha., .beta.-unsaturated nitriles and monoolefins comprises coming a mixed gas which comprises paraffins and oxygen, or paraffins, oxygen and ammonia in contact with a catalyst which comprises (1) an oxide of phosphorus and (2) at least one oxide selected from the group consisting of indium oxide and tin oxide or comprises, in addition to the foregoing catalytic components, (3) at least one oxide selected from the group consisting of vanadium oxide, tungsten oxide and molybdenum oxide. The method makes it possible to prepare monoolefins, or a mixture of .alpha., .beta.-unsaturated nitriles and monoolefins in high yield and high selectivity from cheap starting materials, parafins.
摘要:
An aqueous solution of acrylamide obtained by catalytic hydration of acrylonitrile in the presence of a copper-based catalyst is purified by the steps, in sequence, of (a) removal of the unreacted acrylonitrile, (b) removal of copper, (c) treatment under basic conditions, (d) cation exchanging treatment and (e) weakly basic anion exchanging treatment. The acrylamide obtained by this process has good storage stability. An acrylamide polymer produced from this monomer is useful as a flocculant having a reduced content of the unreacted monomer, a high molecular weight and excellent solubility in water.