Catalyst for improving content of cycloalkane in tar through microwave pyrolysis of low-rank coal as well as preparation method and application of catalyst

Abstract

The invention provides a catalyst for improving the content of cycloalkane in tar through microwave pyrolysis of low-rank coal as well as a preparation method and application of the catalyst, belonging to the technical field of microwave catalytic pyrolysis of low-rank coal. According to the catalyst for improving the cycloalkane content in the tar through microwave pyrolysis of the low-rank coal, catalytic active substances play a main catalytic role, and a cocatalyst can improve the connecting capacity of a catalyst carrier and the catalytic active substances, so the catalytic active substances are not leached in a reaction process, and the stability and the service life of the catalyst are improved; and the catalyst carrier has a high dielectric coefficient and a large specific surface area, can effectively improve the microwave absorption capability of the whole catalyst, improves a heating rate, accelerates a reaction speed, promotes a pyrolysis reaction, promotes the generation of small molecular free radicals, and increases the yield of pyrolysis tar and the content of cycloalkane in the pyrolysis tar.

Description

technical field [0001] The invention relates to the technical field of microwave catalytic pyrolysis of low-rank coal, in particular to a catalyst for increasing the content of naphthenes in tar through microwave pyrolysis of low-rank coal, a preparation method and application thereof. Background technique [0002] Coal tar obtained from low-rank coal pyrolysis contains a variety of high value-added products such as normal alkanes, cycloalkanes, aromatic hydrocarbons, phenols, and naphthalene compounds. Especially naphthenes, because of their high activation energy of autoxidation and large calorific value, are very suitable as raw materials for the synthesis of high-stability aerospace fuels. In addition, naphthenes are mostly used in the synthesis of high-quality lubricating oils and as intermediates in pharmaceutical synthesis. [0003] The content of heavy components in the tar obtained by the traditional coal pyrolysis process is relatively high, usually 40-50wt%, and t...

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Problems solved by technology

Studies have shown that catalysts suitable for microwave pyrolysis of low-rank coal include metal catalysts, molecular sieve catalysts, and carbon-based catalysts. Among them, molecular sieve catalysts and carbon-based catalysts have rich physical pore structures and large specific surface areas. , so it is often used as a catalyst carrier, but molecular sieves are expensive, and it is easy to deactivate the catalyst due to carbon on the surface of the catalyst; metal catalysts include alkali metals and alkaline earth metals, transition metals, iron-based catalysts and natural minerals, but alkali metals will be in the catalyst. Cross-linking with coal molecules during pyrolysis is not conducive to the formation of tar; iron-based catalysts and some transition metals synthesized by general methods can promote the yield of microwave pyrolysis tar, but most of them can promote the production of benzene series , while the promotion effect on the formation of naphthenes is very weak

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