Method for preparing nano-porous carbon molecular sieve with high specific surface area by petroleum coke

Abstract

The invention is a preparation method of high specific area nano-holed carbon molecular screen by petrol coke, and is an improvement of preparation method of molecular screen. Mainly raw material of this method-petrol coke which is the byproduct of refining petrol will take a process consist of comminution, charring, activation, heat polycondensation to produce a high specific area, uniform diameter of holes and carbon framed molecular screen. The carbon molecular screen produced in above ways has got following characteristic: (1) high reaction activity; (2) product selective; (3) strongly anti-carbon-accumulation. The device and techniques of this invention is simple and the product is of rational rate of performance to price which is capable of widely application.

Description

technical field [0001] The invention designs a method for preparing nanoporous carbon molecular sieve with high specific surface area from petroleum coke, which belongs to the improvement of the preparation method of molecular sieve. It mainly uses petroleum coke, a by-product of petroleum refining, as raw material, and prepares carbon-based molecular sieves with large specific surface area and uniform pore size distribution through the process of crushing, carbonization, activation and thermal condensation. Background technique [0002] Molecular sieves refer to a class of substances with pores close to the size of the adsorbed molecules and with uniform pore size distribution. The most commonly used in industry are zeolite molecular sieves. Utilize its screening ability to achieve the purpose of refining various petroleum products in the field of catalysis. The application of zeolite molecular sieve in industrial production has a certain history, but it has some insurmou...

AI Technical Summary

Problems solved by technology

The application of zeolite molecular sieve in industrial production has a certain history, but it has some insurmountable defects: (1) The specific surface area is small, usually 400-600m 2 / g, so the number of corresponding surface atoms is small, and most of the adjacent atoms are saturated bonds and less unsaturated bonds, so the activity in catalytic reactions is low; (2) the pore volume and porosity of zeolite molecular sieves are small, The corresponding adsorption capacity is also small, especially the adsorption capacity for macromolecules is poor, which is unfavorable for the activation of macromolecules; (3) due to the large crystal grains and long channels of zeolite molecular sieves, the diffusion resistance in microcrystals is large; (4) zeolite The specific surface area of ​​molecular sieves is small, and the number of unit cells exposed to the outside is small, resulting in correspondingly fewer molecules entering and exiting the pores, which is not conducive to the rapid entry and exit of reactant or product molecules into the molecular sieve channel, which is not good for reactions limited by diffusion, and the conversion rate is low; (5) Since the product enters and exits the pores for a long time, it is easy to accumulate in the pores and cause carbon deposition, thereby reducing the service life of the molecular sieve