39results about How to "Reduce internal diffusion resistance" patented technology

A catalyst for aromatizing paraffin is a non-noble metal modified nano-class zeolite molecular sieve, which is composed of MFI-type zeolite molecular sieve as carrier and the Zn and Ga as active component. It has high catalytic activity, selectivity and stability. Its preparing process is also disclosed.

The invention relates to the fields of catalyst technologies and fine chemical engineering, and in particular relates to a hydrogenation catalyst. The catalyst comprises a carrier and active components, wherein the carrier is mesoporous carbon pretreated by a sodium hypochlorite solution; and the active components comprise metal ruthenium and metal tin. A preparation method of the hydrogenation catalyst comprises the following steps of: soaking the mesoporous carbon in the sodium hypochlorite solution, washing the soaked mesoporous carbon by distilled water, and then filtering the washed mesoporous carbon; and soaking the carrier, namely the mesoporous carbon, by a salty solution containing the metal ruthenium and the metal tin, then washing the soaked carrier by distilled water, and performing suction filtration on the washed carrier. The invention also discloses application of the hydrogenation catalyst to preparation of 10-hydroxydecanoate. The hydrogenation catalyst has the advantages that the catalyst carrier adopts the mesoporous carbon, and compared with active carbon, the mesoporous carbon enables the target product yield to be obviously improved; compared with a catalyst with an inorganic oxide carrier, the catalyst has the advantage that the active components, namely the ruthenium and the thin, in the waste catalyst are easy to recycle; due to proper passageways, the inner diffusion resistance can be reduced, and the reaction rate is improved; by pretreatment of the sodium hypochlorite, the activity of the catalyst is obviously improved; and the hydrogenation catalyst has great industrial prospect.

The invention discloses a rapid sanitary appliance production method which includes the steps: grouting and forming: pouring slurry into a mold, demolding to form a sanitary appliance mud blank; microwave drying: conveying the sanitary appliance mud blank into a microwave drying oven to dry the mud blank for 3-6 hours. Microwave drying stages sequentially include a slow drying stage, an accelerated drying stage, a rapid drying stage and a cooling stage. The sanitary appliance mud blank is dried by the aid of a microwave drying mode, a drying period is controlled within the range from 3 hours to 6 hours and reduced to a large extent, and the production efficiency is improved. The method adopts four microwave drying stages, so that the sanitary appliance mud blank is slowly dried, dried in an accelerated manner, rapidly dried and cooled, and the drying qualification rate of sanitary appliances is effectively increased and reaches 97%.

The invention relates to a preparation method of oxalate by CO gas phase coupling synthesis using a regular catalyst. In the method, a fixed bed reactor is adopted, a catalyst bed consists of a regular structural catalyst loaded with noble metal; CO and vaporized nitrite are introduced into a reactor for reacting on the regular catalyst so as to generate the oxalate at the conditions that the pressure is 0.1-2MPa, the reaction temperature is 80-200 DEG C, and N2 is taken as a carrier gas, wherein the volume ratio of the materials is as follows: N2:CO:nitrite is 20-80:5-60:10-40, and the retention time is 0.5-10 hours. The method of the invention improves mass transfer efficiency of the reaction materials between the gas phase and the solid phase or among the gas phase, the liquid phase and the solid phase, increases the contact area of the reaction materials and the catalyst and reduces the usage amount of the catalyst in the noble metal, wherein the usage amount of the catalyst noble metal Pd is saved by more than 86%. The method of the invention has the characteristics of high catalyst activity, low cost, convenient and fast replacement and the like, and is beneficial for realizing large-scale engineered application.

The invention discloses a monolithic cluster alumina supported catalyst and an application thereof. A supporter contains a hierarchical-structure alumina coating and a monolithic porous ceramic matrix, wherein the hierarchical-structure alumina coating is a micron-sized cluster substance formed by laminating blades with nano-thickness and is of a flower-like structure.

The invention discloses a ZSM-5 molecular sieve and a synthesizing method thereof. The synthesizing method comprises the following steps of (1) adjusting the activity of an aluminum source, performing inert treatment on the active aluminum source, and activating the inert aluminum source; (2) adding a template agent into a silicon source solution, stirring the treated aluminum source solution, dripping into the silicon source solution, adding a crystal seed, and preparing into a uniform gel; (3) hydrothermally crystallizing the prepared gel for 1 to 200h at the temperature of 100 to 200 DEG C, filtering a crystallized solid, washing, drying, and calcining, so as to obtain the ZSM-5 molecular sieve, wherein the active aluminum source is one or several of a group formed by aluminum sulfate, aluminum chloride, aluminum nitrate and aluminium isopropoxide; the inert aluminum source is one or several of a group formed by pseudo-boehmite, sodium metaaluminate, aluminium hydroxide and metal aluminum. Thin sheet type ZSM-5 zeolite has the advantages that the straight pore channel is very short, the inner diffusion drag is small, the agglomeration of crystal grains is avoided, and the thin sheet type ZSM-5 zeolite is favorable for processing wearproof catalysts.

The invention belongs to the technology of catalysts in the field of fine chemical engineering, and particularly relates to a catalyst used for preparing 1-amino-anthraquinone from 1-nitroanthraquinone by hydrogenation and a preparation method and application of the catalyst. Mesoporous carbon is added into ethylenediamine aqueous solution to be dipped, then, saline solution containing palladium and silver is used for dipping a carrier which is mesoporous carbon, and reduction, washing and filtering are carried out to obtain a Pd-Ag / mesoporous carbon catalyst. The above hydrogenation catalyst is used for preparing the 1-amino-anthraquinone from the 1-nitroanthraquinone by hydrogenation, a reaction condition is moderate, and product selectivity is high.

The invention relates to a palladium-loaded mesoporous carbon catalyst, which is characterized in that the mesoporous carbon is pretreated before loading palladium, and the treatment method includes one of the following steps or a combination thereof: (1) adding mesoporous carbon to 10%-30 % peroxide solution for 1-24 hours, washing to remove peroxide; (2) adding mesoporous carbon to 1-6M hydrochloric acid solution and soaking for 1-24 hours, washing to remove hydrochloric acid. In addition, the present invention also relates to the application of the catalyst to the preparation of 4,4'-diaminostilbene-2,2'-disulfonic acid (DSD acid). According to the invention, the catalyst carrier is pretreated to improve catalyst activity and reduce catalyst consumption; the process conditions are optimized to effectively improve the conversion rate of DNS acid into DSD acid, and maintain the high selectivity of the product DSD acid.