34results about How to "Reduce coke inactivation" patented technology

The invention relates to a preparation method of a thin-layer nano flaky total-silicon molecular sieve for preparing caprolactam. The preparation method comprises the following steps: uniformly stirring a silicon source and an alkali source to obtain a mixture I; dissolving a template agent in a mixed solution of deionized water and ethanol to obtain a mixture II, and gradually dropwise adding the mixture I into the mixture II to be stirred to obtain a mixture III, and stirring the mixture III in a water bath to obtain initial gel; dynamically crystallizing the initial gel in a closed reaction kettle, and washing and drying the initial gel to obtain the thin-layer nano flaky total-silicon molecular sieve. The preparation method has the advantages of low cost, small energy consumption, high conversion rate, no pollution and capability of realizing industrial production.

The invention discloses a phosphorus-containing MFI structure molecular sieve and a preparation method thereof, wherein the n(SiO2) / n(Al2O3) of the molecular sieve is more than 18 and is less than 70,the phosphorus content (calculated as P2O5) of the molecular sieve is 1-15 wt% by using the dry base weight of the molecular sieve as the reference, the volume of the mesopores of the molecular sieveaccounts for 40-70% of the total pore volume, the volume of the mesopores with the pore size of 2-20 nm accounts for more than 85% of the total mesopore volume, the amount of the strong acid of the molecular sieve accounts for 45-75% of the total acid amount, and a ratio of the acid B to the acid L is 8-30. According to the present invention, with the catalyst or the auxiliary agent prepared by using the phosphorus-containing MFI structure molecular sieve as the active component, the propylene yield and the propylene selectivity can be effectively increased in the catalytic cracking or catalytic cracking reaction of petroleum hydrocarbons while the yield of BTX can be increased.

The invention relates to a preparation method of 4-hexene-3-ketone by virtue of dehydration of 4-hydroxy-3-hexanone, and the method is mainly used for solving the problems in the prior art that the catalyst activity is low, the reaction temperature is high and the space velocity is low. The technical scheme adopted by the invention is as follows: according to the preparation method, 4-hydroxy-3-hexanone which is used as a raw material, is contacted with a catalyst so as to generate 4-hexene-3-ketone under the condition that the reaction temperature is 200-400 DEG C, and the space velocity relative to the liquid weight of 4-hexene-3-ketone is 0.5-15h<-1>, wherein the catalyst comprises the following components in parts by weight: a), 40-95 parts of ZSM-11 molecular sieve with the silicon aluminum mole ratio (SiO2 / Al2O3) of 20-300 and the crystal particle diameter of equal to or less than 5 microns and b), 5-6 parts of binding agent, and the ZSM-11 molecular sieve is at least subjected to once acid pickling, so that the problems in the prior art are better solved, and the method can be used in the industrial production of 4-hexene-3-ketone prepared by utilizing 4-hydroxy-3-hexanone.