31results about How to "High isomer selectivity" patented technology

A kind of preparation method of 3,5,5-trimethyl-3-cyclohexene-1-ketone: with 3,5,5-trimethyl-2-cyclohexene-1-ketone (α-IP) As a raw material, the former nitrogen phosphatrane base is used as a catalyst, and reactive distillation technology is used to carry out isomerization reaction to prepare 3,5,5-trimethyl-3-cyclohexene-1-ketone (β-IP), product β The purity of ‑IP can reach 99.5wt%‑99.8wt%, and the reaction selectivity can reach 99.2%‑99.9%. The process has the advantages of less catalyst consumption, high selectivity, no alkali precipitation, less high boiling matter, etc., and is an efficient synthesis process.

The invention provides a low-cost method for synthesizing ZSM-48 molecular sieve with low silicon-aluminum ratio. The method utilizes double templates to synthesize low-silicon-aluminum ratio ZSM-48 molecular sieves at low cost. Compared with the existing method for preparing low-silicon-aluminum ratio ZSM-48 molecular sieves, the use of double templates reduces the cost of templates and shortens the time. Crystallization time, efficient synthesis of high-crystallinity low-silicon-alumina ratio pure phase ZSM-48 molecular sieves, and easier and more effective removal of templates, increased molecular sieve specific surface area, pore volume, pore size and acid content, and more effectively carried out Hydroisomerization reaction to improve isomerization selectivity. The molecular sieve has high application value and prospect in the field of hydroisomerization dewaxing.

The invention relates to a preparation method for a C5 and C6 alkane isomerization catalyst. The preparation method comprises the following steps: (1) mixing, kneading, extruding and forming mordenite, an inorganic binder, methylcellulose and a nitric acid solution, and performing drying and roasting to obtain a carrier; (2) soaking the carrier in the step (1) in hydrophobic organic amine-alcohol solution, and adding organic amine according to 20%-150% (a molar fraction) of total acid amount of the carrier detected by NH3-TPD, wherein the weight of a soaking solution is 1.2-3 times that of the carrier; (3) drying the soaked carrier, and controlling the drying temperature to be 0-100 DEG C before and after a low-temperature desorption peak detected by NH3-TPD; and (4) performing ion exchange on a VIII-family metal precursor for the carrier dried in step (3), and performing drying and roasting to obtain the catalyst. According to the catalyst prepared by the preparation method, noble metals are highly dispersed, and are uniformly distributed inside the catalyst; and the catalyst is used for C5 and C6 alkane isomerization reaction, so that a normal-alkane conversion rate is high and isomeric selectivity is good.

The invention discloses a preparation method of a loading type bimetallic catalyst with a highly-dispersing active center and belongs to the technical field of active center structure control of the loading type catalyst. In the catalyst, the active center is loaded on aluminium oxide modified in situ by hydrotalcite, and a trivalent additive metal is introduced into a hydrotalcite layer plate by utilizing the adjustable characteristic of metal cations of the hydrotalcite layer plate. When the hydrotalcite layer plate is topologically transformed into the layered bimetallic oxide in the process of roasting reduction, due to the confinement action of lattices of the hydrotalcite layer plate, the additive metal embedded into the hydrotalcite layer plate is controlled to grow in the process of roasting reduction. The control for the dispersing state of the active center of the metal is realized by the lattice induction action of the platinum at the active center of the metal on the layer plate by the hydrotalcite layer plate.