Preparation method of multistage pore passage composite molecular sieve adsorbent

Abstract

The invention relates to a preparation method of a multistage pore passage composite molecular sieve adsorbent for overcoming a phenomenon that volatile organic compounds pollute environment. Silicon sol, tetraethoxysilane, aluminum sulfate, sodium hydroxide, hydrochloric acid, hexamethonium bromide, hexadecyl trimethyl ammonium bromide and deionized water are used as raw materials, and the preparation method comprises the steps of synthesizing a ten-ring microporous molecular sieve firstly, then synthesizing a micropore-mesoporous molecular sieve, and finally performing procedures of heating in a thermostat, crystallization reaction in a reaction kettle, quenching, vacuum drying, and high-temperature roasting, thereby obtaining the multistage pore passage composite molecular sieve adsorbent. The preparation method has advanced process and accurate and full data, and the prepared multistage pore passage composite molecular sieve adsorbent has the grain diameter of less than or equal to 1.5 microns, the pore passage diameter of less than and equal to 2.83nm and the purity up to 96%; the multistage pore passage composite molecular sieve adsorbent can be directly used as a volatile organic compound adsorbent, or can be matched with multiple chemical substances to serve as an adsorbing material; the preparation method of the multistage pore passage composite molecular sieve adsorbents is ideal.

Description

technical field [0001] The invention relates to a preparation method of a multi-stage pore composite molecular sieve adsorbent, belonging to the technical field of adsorbent preparation and application. Background technique [0002] Volatile organic compounds, referred to as VOCs, refer to organic compounds with a boiling point lower than 260°C under normal pressure, mainly including alkanes, aromatic hydrocarbons, esters, and aldehydes. VOCs mainly come from petrochemical, pharmaceutical synthesis, coatings, printing, Shoemaking, electronic component manufacturing, and automobile exhaust are air pollutants with large emissions, and are flammable and explosive, which will pose a huge threat to production and transportation safety; some of these VOCs are extremely carcinogenic and genotoxic , and even damage the central nervous system and liver; VOCs will also undergo photochemical reactions with NOx under the action of light to form photochemical smog and cause secondary pol...

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Problems solved by technology

[0003] How to control and purify volatile organic compounds (VOCs) is a top priority. At present, the most commonly used method is adsorption, such as using microporous zeolite and activated carbon as adsorbents. However, due to the small pore size and narrow pore volume of microporous zeolite, it is difficult The diffusion adsorption capacity of VOCs is weak and it is difficult to desorb, and it is easy to generate carbon deposition to block the pores, resulting in the deactivation of the adsorbent, and cannot play the role of governance and purification; mesoporous molecular sieves have large pore volume, pore size and specific surface area. It is very beneficial for the VOCs adsorption of macromolecules. For example, the patent CN103495405A introduces a mesoporous molecular sieve adsorbent, but the acid-alkalinity and stability of mesoporous molecular sieves cannot reach the level of microporous molecular sieves; the current treatment and purification of VOCs There are still many disadvantages in the method and adsorption materials, and they are still under continuous research.

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