Deep analysis of molecular sieves 13X and 13X APG

2025-07-26

In the field of gas separation and purification, molecular sieves have become the core material of the industry due to their unique adsorption properties. Molecular sieve 13X series, as an important adsorbent, is widely used in industrial scenarios due to its excellent performance. This article will provide an in-depth analysis of the core differences, technical advantages, and typical applications of molecular sieve 13X and its upgraded version molecular sieve 13X APG, to help you make accurate choices.
1、Molecular sieve 13X: basic macroporous adsorbent
Belonging to the X-type zeolite structure, with a pore size of approximately 10 Å (1nm), sodium ions (NaE) are the key exchangeable cations.
Core features:
# Large pore size: Capable of adsorbing molecules with a critical diameter less than 10 Å (such as propane and propylene).   
# High polarity: Strong affinity for polar molecules such as H₂O, CO₂, H₂S.   
# Basic performance: Standard equilibrium water adsorption capacity>25%.
 
Typical applications:
* Deep air dryness (dew point<-70 ° C);
* Natural gas, refinery gas desulfurization (H₂S) and decarbonization (CO₂);
* Pre purification of CO₂ and moisture before air separation for oxygen/nitrogen production;
* Refrigerant drying;
* Drying of general industrial gases and liquids.
 
2、Molecular Sieve 13X APG: High Performance Upgraded Version
13X APG is a formula and process optimization based on conventional molecular sieve 13X.
Core optimization direction and advantages:
# Stronger compressive strength:
By optimizing adhesives or molding processes, the mechanical strength of particles can be significantly improved (usually more than 10% higher than molecular sieve 13X), reducing pulverization during operation, lowering bed pressure drop and equipment wear, and extending lifespan.   
# Higher adsorption capacity:
Optimizing the pore structure or surface properties can provide higher equilibrium adsorption capacity or faster adsorption kinetics under the same conditions (especially for water and CO₂), improving the treatment efficiency of unit molecular sieves.   
# Better pollution resistance:
Enhance tolerance to certain hydrocarbons or impurity molecules and reduce the rate of performance degradation caused by co adsorption or poisoning.   
# More stable performance:
After multiple adsorption regeneration cycles, the specially treated 13X APG exhibits higher performance retention and longer lifespan.
 
Application scenarios (focusing on high-performance requirements):
* High pressure or high flow rate conditions: Such as high-pressure natural gas desulfurization and decarbonization, PSA/VPSA oxygen/nitrogen production units, which can withstand greater airflow impact with high intensity.   
* Deep drying with extremely high dew point requirements, such as electronic specialty gas, precision instrument protection gas, and polyurethane raw material gas.   
* Devices that require long-term operation: reduce downtime and replacement frequency, and lower operating costs.   
* Handling gases containing trace amounts of heavy hydrocarbons or impurities: better stability ensures long-term performance.   
* Applications sensitive to device pressure drop: Low pulverization rate means more stable low bed pressure drop.
3、So how to choose a more suitable molecular sieve?
Selection molecular sieve 13X:
*Mild operating conditions (normal/low pressure, moderate flow rate).   
*The gas is relatively clean with low impurity content.   
*The requirements for operating life and replacement frequency are not strict.   
*Budget sensitive, pursuing the lowest initial cost.
Select molecular sieve zeolite 13X APG:
*High pressure operations (such as natural gas processing, PSA/VPSA).   
*High gas flow rate or frequent switching (which can easily cause bed disturbance).   
*Require extremely low dew point or extremely high purification degree.   
*The gas contains trace amounts of heavy hydrocarbons or other potential pollutants.   
*Long term stable operation is required to minimize downtime to the greatest extent possible.   
*Strict requirements are placed on the pressure drop control of the bed layer.   
*Although the initial cost is high, it places greater emphasis on long-term operational reliability and total cost of ownership (TCO).
 
4、In depth analysis of application cases
# Pre purification of air separation unit:
*Challenge: The air contains H₂O and CO₂, which can freeze and block in the low-temperature distillation tower.   
*Advantages of zeolite 13X APG: Working under high pressure at the outlet of the air compressor, its high strength ensures low pulverization; High capacity and dynamics ensure deep removal of CO₂/H₂O, protecting expensive cold boxes; Long lifespan reduces maintenance. Zeolite 13X may pulverize faster under high pressure, increasing risk.
 
# Natural gas desulfurization and decarbonization (meeting pipeline transportation standards):
*Challenge: High pressure, H₂ S/CO₂/moisture and trace heavy hydrocarbons.   
*Advantages of zeolite13X APG: High compressive strength to withstand pipeline pressure; Enhanced resistance to pollution and better tolerance to heavy hydrocarbons; High capacity ensures processing efficiency; Stability assurance ensures long-term compliance and operation. Zeolite 13X may fail faster under high pressure and complex components.