Method for synthesizing 5A dewaxing molecular sieve from bentonite

Abstract

The invention provides a method for synthesizing a 5A dewaxing molecular sieve from bentonite, belonging to the field of synthesis and processing of molecular sieves. The technical scheme is as follows: the method comprises the following steps: activation of bentonite, surface modification of bentonite, purification of bentonite, synthesis of 4A molecular sieve, synthesis of 5A molecular sieve, and synthesis of dewaxing molecular sieve. By using the cheap raw material bentonite, the synthesized molecular sieve has high yield and good quality. The n-heptane adsorption capacity of the obtained 5A dewaxing molecular sieve is higher than 25%, and the dewaxing efficiency is greater than 98.5%. The method has the advantages of low production cost, controllable preparation process and no environment pollution, and is suitable for large-scale production.

Description

technical field [0001] The invention belongs to the field of synthesis and processing of molecular sieves, in particular to a method for synthesizing 5A type dewaxing molecular sieves from bentonite. Background technique [0002] Molecular sieve is a frame-like aluminosilicate crystal with a special pore structure, composed of [SiO 4 ] and [AlO 4 ] tetrahedrons form a framework with uniform and regular channels and wide internal cavities. There are metal ions (such as potassium, sodium, calcium, copper, etc.) in the molecular sieve lattice to balance the excess negative charges in the silicon-aluminum tetrahedron, and It plays the role of adjusting the pore size of the molecular sieve. [0003] Due to its unique adsorption and separation, ion exchange performance and good chemical stability, molecular sieves are widely used in petroleum, chemical, food, medicine, machinery, electronics, etc. , aviation and other industries. Statistics show that the market demand for A-ty...

AI Technical Summary

Problems solved by technology

[0008] There are some problems in the production method of above-mentioned synthetic molecular sieve: (1) the cost of synthesizing molecular sieve with chemical raw material is higher; The cost of raw materials for producing molecular sieves is comparable, and it is difficult to guarantee the quality of molecular sieves if poor quality kaolin is used to produce molecular sieves

However, the produced 5A type dewaxing molecular sieve has an adsorption capacity of n-heptane of less than 20%, and a dewaxing efficiency of less than 98%.