Method for preparing carbon molecular sieve based on petroleum coke

Abstract

The invention belongs to the technical field of chemical industry production, and particularly relates to a method for preparing a carbon molecular sieve based on petroleum coke. The preparation method includes the following steps of: mixing and grinding petroleum coke and nano-silica, carrying out carbonization, excitation and carbon deposit to obtain the carbon molecular sieve. According to theinvention, nano-silica is doped in petroleum coke and formed of silicon carbide filled in the petroleum coke pore structure during high temperature treatment, so that the obtained carbon molecular sieve has higher strength; meanwhile, the filling of the nano silica can also generate carbon monoxide gas in the process of being reduced by carbon, and can reduce the pore shrinkage of the petroleum coke caused by polycondensation during the releasing process, thereby ensuring that the obtained carbon molecular sieve has a more dense pore structure.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a method for preparing a petroleum coke-based carbon molecular sieve. Background technique [0002] Petroleum coke is a product obtained by separating light and heavy oils through distillation of crude oil, and then transforming heavy oils through thermal cracking. In essence, petroleum coke is a partially graphitized carbon form. From the appearance, it is Irregular shape, different sizes of black lumps (or granular), with metallic luster, the particles have a porous structure, the main element is carbon, and the rest are hydrogen, oxygen, nitrogen, sulfur and metal elements. Melting, in the prior art, is widely used in metallurgy, chemical industry and other industries as electrodes or raw materials for producing chemical products. [0003] At present, although petroleum coke is also divided into several categories due to different uses, there is no pet...

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Problems solved by technology

[0003] At present, although petroleum coke is also divided into several categories due to different uses, there is no petroleum coke specially used for the production of activated carbon. Therefore, when using petroleum coke to prepare activated carbon, the necessary selection of petroleum coke must be made. , the selection of crude oil alone is not enough, it should be necessary to evenly add pore-forming agents in the coking raw materials, the pore-forming agents can be evenly dispersed in the coking raw materials, most of these pore-forming agents are solidified and carbonized It decomposes and escapes at high temperature, thereby leaving interconnected pores in the petroleum coke matrix. The size and uniformity of these pores are controlled by the pore-forming agent. However, after high-temperature treatment, the pore-forming agent is lost. , the structural strength of activated carbon cannot reach a higher level

In addition, during the high-temperature calcination process of petroleum coke, the carbon-hydrogen bond is broken, the hydrogen content is reduced, and the carbon atoms are released from the bonded state, which makes the volume of petroleum coke shrink, resulting in a decrease in the porosity of petroleum coke