Preparation method of solid like phase VOCs degradation high silicon ZSM-5 molecular sieve with controllable crystal grain size

Abstract

The invention discloses a preparation method of a solid like phase VOCs degradation high silicon ZSM-5 molecular sieve with controllable crystal grain size. The preparation method comprises followingsteps: 1, a silicon source, an alkali source, a template, ZSM-5 molecular sieve crystal seed, and water are mixed to obtain a gel; 2, the gel obtained in step 1 is introduced into a reaction vessel for hydro-thermal treatment, after reaction, solid liquid separation, washing, drying, and roasting are carried out to obtain a molecular sieve raw powder; and 3, the molecular sieve raw powder is addedinto an ammonium salt solution for ion exchange so as to obtain an ammonium type ZSM-5 molecular sieve, and then roasting is carried out to obtain a HZSM-5 molecular sieve. The preparation method iscapable of increasing product single vessel yield, reducing production cost, reducing mother liquor waste water discharge, and realizing molecular sieve green synthesis; the prepared ZSM-5 high silicon molecular sieve possesses special sphere appearance; and when the ZSM-5 high silicon molecular sieve is adopted in VOCs decomposition, adsorption capacity is high, the hydrophobicity is high, and regeneration is easily realized.

Description

technical field [0001] The invention belongs to the technical field of molecular sieve preparation, and in particular relates to a method for preparing a solid-phase VOCs-like degradable high-silicon ZSM-5 molecular sieve with controllable grain size. Background technique [0002] Volatile organic compounds (VOCs) refer to organic compounds with a saturated vapor pressure greater than 0.13kPa under standard conditions, including more than 300 organic compounds such as hydrocarbons, aldehydes, ketones, alcohols, ethers, esters, and heteroatom-substituted hydrocarbons. VOCs in the atmosphere have the characteristics of various types, wide sources, high toxicity, relatively low concentration but large total pollutants. Adsorption method is one of the main VOCs purification methods. Compared with other methods, adsorption method has the advantages of mature technology, simple operation, low energy consumption, and high purification efficiency. It is suitable for VOCs purificatio...

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Problems solved by technology

In the entire zeolite rotor adsorption and concentration technology, the hydrophobic zeolite molecular sieve used for adsorption and concentration is the core of the technology. The advantages of zeolite molecular sieve as a hydrophobic adsorption material are becoming more and more obvious. At present, there are many patents at home and abroad involving zeolite. Reports on molecular sieves used as adsorbents for the treatment of VOCs mainly include US6281406B1, US4705909, CN1781885A, CN11055906A, CN1280977A, CN1749226A, CN201710375783, etc. When the molecular sieves synthesized in the above patents are used as adsorbents, there are the following main defects: (1) Molecular sieves When used as an adsorbent, some inorganic or organic materials need to be added as a binder, which results in cumbersome product synthesis steps and the need to add toxic and harmful substances in the process, which is not conducive to industrial production; (2) Molecular sieve is the largest adsorbent The most difficult point is the regeneration problem, which is not mentioned in the above-mentioned patents; (3) the templating agent used in the molecular sieve synthesis is expensive, and the follow-up treatment is complicated, resulting in high cost of the adsorbent, and most of the synthesis is still in hydrothermal conditions, and there is no report on the preparation of high-silicon ZSM-5 molecular sieves in a solid-like system.

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