283results about How to "Maintain catalytic activity" patented technology

The invention discloses a method for regenerating and maintaining the activity of an ionic liquid catalyst, and the method comprises the following step of adding hydrogen halide or halohydrocarbon in an acidic ionic liquid catalyst or alkylation reaction raw material during the alkylation reaction process, and the ionic liquid catalyst is used for catalyzing alkylation of C4 alkene and alkane. And the invention also provides a method for producing alkylate by using alkylation reaction, and the method comprises the following step of adding the hydrogen halide or the halohydrocarbon in the acidic ionic liquid catalyst or the alkylation reaction raw material during the alkylation reaction process, and the regeneration of the ionic liquid catalyst and the continuous production of the alkylateare realized by adding B acid lost during the alkylation reaction process of the ionic liquid catalyst. The invention can effectively prolong the service life of the acidic ionic liquid catalyst, andthe treatment capacity of the raw materials can reach more than 1000 times of consumption of the ionic liquid; and the method has no influence to the quality of the alkylate, is simple and convenientin operation, and has higher industrial practicability.

The invention provides a catalyst for continuously producing butanedioic anhydride by maleic anhydride hydrogenation. The catalyst is a nickel loaded catalyst prepared by an equivalent-volume impregnation method, wherein in the catalyst, the content of nickel is 13 to 20 weight percent, the content of accelerating agent is 1 to 7 weight percent, and a carrier is a composite oxide of SiO2 and Al2O3 or SiO2-Al2O3. A preparation method for the catalyst comprises the following steps: impregnating impregnation solution blended by ammonia water and active metal salt solution on a carrier subjected to baking pretreatment at a temperature between 400 and 800 DEG C by the equivalent-volume impregnation method to form the catalyst through drying, baking and reducing treatment. The catalyst is applied to continuously preparing the butanedioic anhydride by maleic anhydride hydrogenation on a fixed bed reactor, the conversion rate of maleic anhydride is more than or equal to 99.98 percent, and theselectivity of the butanedioic anhydride is more than or equal to 98.85 percent. The catalyst achieves the technical-scale continuous production of the butanedioic anhydride, and has the advantages of high activity, good selectivity, high yield (more than or equal to 98.83 percent) and long service life.

Disclosed are a hydrothermally stable porous molecular sieve catalyst and a preparation method thereof. The catalyst consists of a product obtained by the evaporation of water from a raw material mixture comprising a molecular sieve having a framework of Si-OH-Al-, a water- insoluble metal salt and a phosphate compound. The catalyst maintains its physical and chemical stabilities even in an atmosphere of high temperature and humidity. Accordingly, the catalyst shows excellent catalytic activity even when it is used in a severe process environment of high temperature and humidity in heterogeneous catalytic reactions, such as various oxidation / reduction reactions, including catalytic cracking reactions, isomerization reactions, alkylation reactions and esterification reactions.