METHOD FOR REGENERATION OF SILVER FORMALDEHYDE PRODUCTION CATALYST Russian patent published in 2004 - IPC

FIELD: industrial organic synthesis catalyst.

SUBSTANCE: invention aims at regenerating exhausted silver catalyst through removal of coke and iron-containing deposits followed by restoration of level of silver in catalyst to its initial value and subsequent activation of catalyst, loss of silver in the course of catalyst regeneration being excluded. For that, exhausted silver catalyst, calcined by the aid of coke deposits to remove iron-containing compounds from the surface of catalyst, after restoration of silver level and activation, is treated with 10-20% nitric acid with specified amount of silver nitrate needed to restore initial silver level at 100-120^оС and pH value adjusted to 1-2. Catalyst is then separated from silver nitrate-containing treatment solution, from which iron-containing compounds are then removed by adding ammonia solution followed by filtration. Filtered hot silver nitrate-containing solution is used for additional activation of catalyst involving subsequent evaporation, drying, calcination, and cooling.

EFFECT: enabled repetitive regeneration of catalyst, simplified regeneration technology, and excluded loss of silver.