41results about How to "Shorten the crystallization cycle" patented technology

The invention relates to a preparation method of a ZSM-5 molecular sieve. The method comprises performing solid-phase thermal crystallization of a ZSM-5 molecular sieve precursor to obtain a sodium-type ZSM-5 molecular sieve. The preparation method of the ZSM-5 molecular sieve is high in reaction speed and short in crystallization time, is high in single-reactor yield and production efficiency, and is not limited by silicon-aluminum sources. According to the invention, the prepared ZSM-5 molecular sieve has advantages of nanoscale, high crystallization degree, and excellent physical and chemical performance.

The invention discloses a method for synthesizing a beta molecular sieve by utilizing a beta molecular sieve mother solution. The method comprises the following steps: performing equal-pH coprecipitation on a crystallized mother solution and dilute acid parallel flow to synthesize silica gel in bottom water containing a gel accelerator, adding a template-agent-containing BETA molecular sieve milled by a colloid mill to serve as a seed crystal, and performing hydrothermal crystallization to synthesize the BETA molecular sieve according to the ratio of low addition amount of organic template agents. According to the production method disclosed by the invention, the batching amount of a fresh silicon source and the template agent in beta molecular sieve synthesis is reduced, and due to the existence of a molecular sieve microcrystal, the crystallization process of the molecular sieve is accelerated, and the crystallization period is shortened. Moreover, the synthesized beta molecular sieve is high in crystallinity degree, the milled seed crystal contains lots of micro grains and organic template agents with secondary structures, the crystallization induction period can be effectively shortened, and the use amount of the template agent is reduced. Therefore, the synthetic cost is greatly reduced.

The invention discloses a method for preparing a zeolite molecular sieve through quick crystallization of dry glue, and relates to the field of molecular sieve solid phase synthesis. The method specifically comprises the following steps: adding an aluminum source and a fluoride into a silicon-aluminum type molecular sieve mother solution for crystallizing to obtain a silicon-aluminum type molecular sieve guiding agent; adding an alkali source, a silicon source, a template agent R and deionized water into the silicon-aluminum type molecular sieve guiding agent, uniformly carrying out mixing, and then carrying out drying to obtain dry glue powder; and crystallizing the dry glue powder in a steam atmosphere in a continuous crystallization kettle to obtain the zeolite molecular sieve, whereinthe crystallization time is 2-10 hours. The guiding agent disclosed by the invention is obtained by secondary crystallization, and is high in activity and strong in guiding action, so that the usage amount of the template agent can be reduced, crystallinity can be improved, generation of hybrid crystal phases formed by solid-phase synthesis is avoided, and the crystallization period is shortened.The continuous crystallization kettle can be used for continuous production without need of cooling and pressure relief, so that the required crystallization time is short, and efficiency and yield are high. The prepared zeolite molecular sieve is good in stability, high in crystallinity and high in silicon-aluminum ratio.

The invention introduces a preparation method of modified HEU type zeolite and an application of the modified HEU type zeolite as a nitrogen selection adsorbent. The preparation method comprises the following steps of uniformly mixing SiO2 with Al2O3, Na2O, K2O and H2O according to the mole ratio of the SiO2 to the Al2O3, to the Na2O, to the K2O and to the H2O being (8-20) to 1 to (0.5-3) to (0.5-3) to (300-800) to obtain initial aluminosilicate sol, then adding artificial synthesis structure induction species of which the mass percentage is about 1-20%, performing low-temperature ageing, performing high-temperature crystallization, performing solid-liquid separation, and performing drying so as to obtain high-crystallinity HEU type zeolite. According to the preparation method disclosed by the invention, the crystallization period can be greatly shortened and can be shortened to 12h, and besides, the synthesized HEU type zeolite can be guaranteed to have small and uniform grain size (1-3[mu]m); and after ion exchange modification, different ion exchange modified adsorbents can be obtained, and the selective adsorption capacity of the adsorbents to N2 in N2 / CH4 mixed gas is obviously improved and can be improved by 2-15 times.