Abstract: The present disclosure relates to a multi-sandwich composite catalyst and a preparation method and application thereof. The present disclosure provides a preparation method of a multi-sandwich composite catalyst, comprises the following steps: sequentially depositing a first layer oxide, a first active metal, an oxide interlayer, a second active metal and a surface oxide on a template, and sequentially performing calcination and reduction, thereby obtaining a multi-sandwich composite catalyst; wherein the first active metal and the second active metal are different kinds of active metals. In the present disclosure, a multi-sandwich structure is formed by depositing the oxides and active metals alternately, so that the position and spacing distance of the active centers can be precisely controlled. The multi-sandwich composite catalyst prepared by the method provided described herein has a higher conversion than that of a catalyst without an interlayer when used for the catalytic reaction.

Abstract: The present disclosure relates to a multi-sandwich composite catalyst and a preparation method and application thereof. The present disclosure provides a preparation method of a multi-sandwich composite catalyst, comprises the following steps: sequentially depositing a first layer oxide, a first active metal, an oxide interlayer, a second active metal and a surface oxide on a template, and sequentially performing calcination and reduction, thereby obtaining a multi-sandwich composite catalyst; wherein the first active metal and the second active metal are different kinds of active metals. In the present disclosure, a multi-sandwich structure is formed by depositing the oxides and active metals alternately, so that the position and spacing distance of the active centers can be precisely controlled. The multi-sandwich composite catalyst prepared by the method provided described herein has a higher conversion than that of a catalyst without an interlayer when used for the catalytic reaction.

Abstract: A continuous slurry-bed tank reactor, comprising a tank reactor body, an agitator, and tubular separation membranes. A method of using the continuous slurry-bed tank reactor comprising adding a catalyst, feeding reactants, stopping feeding the reactants, starting a heating system, changing directions of the reactants flowing through the tubular separation membranes.

Abstract: An aromatization catalyst and preparation process and use thereof is set forth. The catalyst comprises an inorganic oxide and a modified Ga-ZSM-5 zeolite, which comprises a modified ZSM-5 zeolite with a hierarchical macro-meso-microporosity and gallium deposited in channels of and/or on surfaces of the modified ZSM-5 zeolite. The hierarchical porosity of the modified ZSM-5 zeolite in the catalyst can reduce diffusion resistance of products during the aromatization reaction, thereby retarding carbon depositing rate and substantially improving catalytic activity, aromatic hydrocarbon selectivity, stability and lifetime of the catalyst. When being used in aromatization of propane, the catalyst exhibits a high stability, a lifetime of more than 320 hours, and a selectivity to aromatic hydrocarbons of up to 73.3 wt. %.

Abstract: The disclosure relates to a process for continuously producing polyoxymethylene dimethyl ethers at low temperature, pertains to the technical field of polyoxymethylene dimethyl ether preparation processes, and solves the technical problem of continuous production of polyoxymethylene dimethyl ether. A membrane separation element with precisely controlled pores in membrane is used to realize a direct separation of the feedstocks from the catalyst within the reactor, and effectively reduce the permeation resistance of the separation membrane tube. By oppositely switching the flowing direction of liquid reaction materials, the adhesion of the catalyst to the separation membrane tube is inhibited, and some particles stuck in separation membrane tube are removed, which ensures the continuous operation of the reaction process and allows a molecular sieve catalyst to exhibit its advantage of long catalytic life.

Abstract: The present invention provides a method for preparing gasoline and aromatics by using Fischer-Tropsch synthesis exhaust. The method includes conducting an olefin conversion reaction on Fischer-Tropsch synthesis exhaust under the action of a first molecular sieve catalyst. A first refrigeration or cooling is conducted on an obtained product to obtain ultralow sulfur-containing gasoline and first-stage reaction gas. An alkaline aromatization reaction is conducted on the first-stage reaction gas under the action of a second molecular sieve catalyst. A second refrigeration or cooling is conducted on an obtained product to obtain aromatics. After the olefin conversion reaction, a gasoline component is separated and residual alkanes enter a second-stage fluidized bed reactor for the alkane aromatization reaction to produce aromatics.

Abstract: The disclosure relates to a process for continuously producing polyoxymethylene dimethyl ethers at low temperature, pertains to the technical field of polyoxymethylene dimethyl ether preparation processes, and solves the technical problem of continuous production of polyoxymethylene dimethyl ether. A membrane separation element with precisely controlled pores in membrane is used to realize a direct separation of the feedstocks from the catalyst within the reactor, and effectively reduce the permeation resistance of the separation membrane tube. By oppositely switching the flowing direction of liquid reaction materials, the adhesion of the catalyst to the separation membrane tube is inhibited, and some particles stuck in separation membrane tube are removed, which ensures the continuous operation of the reaction process and allows a molecular sieve catalyst to exhibit its advantage of long catalytic life.

Abstract: A continuous slurry-bed tank reactor, comprising a tank reactor body, an agitator, and tubular separation membranes. A method of using the continuous slurry-bed tank reactor comprising adding a catalyst, feeding reactants, stopping feeding the reactants, starting a heating system, changing directions of the reactants flowing through the tubular separation membranes.

Abstract: A catalyst for the preparation of dimethyl carbonate from urea and methanol having a composition on weight base of: active component of from 20 to 50 wt %, and carrier of from 80 to 50 wt %, and prepared by equal-volume spraying and impregnating method is disclosed. The method for the synthesis of dimethyl carbonate can be carried out in a catalytic rectification reactor, said method comprising: (1) dissolving urea in methanol to form a methanol solution of urea; and (2) feeding the methanol solution of urea and methanol counter-currently into the reaction zone, wherein the reaction is carried out at conditions including reaction temperature of from 120° C. to 250° C., reaction pressure of from 0.1 MPa to 5 MPa, kettle bottom temperature of from 70° C. to 210° C., stripping section temperature of from 70° C. to 250° C., rectifying section temperature of from 70° C. to 280° C., and reflux ratio of from 1:1 to 20:1.