A kind of preparation method and application of metal Ni-doped hierarchical porous ZSM-5 molecular sieve

Abstract

The invention discloses a preparation method and application of Ni-doped hierarchical porous ZSM-5 molecular sieve. The preparation method includes the steps of pretreating a molecular sieve, namely roasting to remove a templating agent and water; etching the molecular sieve with HF (hydrofluoric) acid solution to generate a hierarchical porous structure; loading high-activity metallic nickel by impregnation; carrying out sheeting and screening. Application of the molecular sieve herein in catalytic quick pyrolysis of biomass is also disclosed. The zeolite HZSM-5 that is low in price and easyto obtain is used herein as a matrix; desilication and dealumination treatment is performed while fiver-membered and ten-membered ring intersection micro porosity of the matrix is utilized, so that hierarchical pores good for entering of macromolecules are generated. The preparation method herein allows acid site distribution to be reduced at the premise of pore expansion; on such basis, the low-price metallic nickel with high hydrogen transfer capacity is added, so that high passing rate and high conversion rate of macromolecules during catalysis are achieved. A catalyst prepared via the preparation method has the advantages of low price, good access convenience, and simple process, is mainly applicable to the catalytic pyrolytic test of biomass or coal, and has a good prospect of catalytic reforming of pyrolytic volatiles.

Description

technical field [0001] The present invention relates to a method for preparing a highly active catalyst, which is a method for preparing a highly active catalyst through the joint action of metal and etching HZSM-5, specifically a method for preparing a metal Ni-doped multi-stage porous ZSM-5 molecular sieve , and metal Ni-doped hierarchical porous ZSM-5 molecular sieves are used for catalytic fast pyrolysis of biomass, which belongs to the field of catalytic material modification. Background technique [0002] Biomass is a renewable resource that is abundant worldwide and offers the prospect of liquid transport materials replacing fossil fuels. Due to the high oxygen content of bio-oil, poor stability is considered to be a major issue in the difference between bio-oil and hydrocarbon fuels. So far, the catalytic deoxygenation technology of bio-oil has been widely studied and applied, and it is considered to be an effective way for deoxidation and upgrading. Catalytic crac...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the technical defects of reducing active sites and weak catalytic ability by using conventional HZSM-5 desiliconization or dealumination method to expand holes, and propose a kind of metal Ni-doped hierarchical porous ZSM-5 molecular sieve. The preparation method uses HF acid etching on the molecular sieve carrier to simultaneously desilicate and dealuminate to reduce the catalytic reaction resistance and load highly active metals to increase cracking and hydrogen transfer capabilities to increase the yield of aromatics

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