The 5A molecular sieve provided by our company refers to calcium A-type aluminosilicate. 5A molecular sieve can adsorb molecules whose critical diameter is not larger than 5A. All molecules that can be adsorbed on 3A and 4A molecular sieves can be adsorbed on 5A. N-alkanes can be separated from branched and cyclic alkanes by a selective adsorption process. It is currently used industrially in the large-scale separation process of n-isoparaffins. 5A molecular sieve can also be used for hydrogen production by pressure swing adsorption.