4a zeolite at 110 ° C ambient temperature drying Can be activated

4A, can adsorb water, methanol, ethanol, hydrogen sulfide, sulfur dioxide, carbon dioxide, ethylene, propylene and other low molecular weight compounds as pore molecular sieve 4A, air separate unit molecular sieve does not activated molecular sieves adsorb any molecular diameter greater than 4A (including propane), a high selectivity for water adsorption properties any other molecule, is one of the varieties of industrial zeolite largest amount. 110 ° C for water evaporation is a large space, but it is impossible to zeolite pore water rush out. Therefore, generally zeochem molecular sieves used in a laboratory muffle furnace dehydrated drying can be activated at a temperature of 350 ° C, dried 8 hours at atmospheric pressure (if the vacuum pump can be dried for 5 hours at 150 ° C in the case of the exhaust). The activated molecular sieve in air cooled to 200 ° C (about 2 minutes) and immediately stored in a desiccator. If the conditions applied during the cooling and preservation of dry nitrogen to prevent moisture in the air is absorbed again. Old post contaminants using molecular sieve, activated not only when the temperature of 450 ° C up to, but also to pass into the steam or inert gas (nitrogen) to replace sieve out the other substances.