Method of restoring catalytic activity to a spent hydrotreating catalyst, the resulting restored catalyst, and a method of hydroprocessing

A method of restoring catalytic activity to a spent non-additive based hydrotreating catalyst, said method comprises:

• providing said spent hydrotreating catalyst having a first carbon concentration;
• reducing the concentration of carbon on said spent hydrotreating catalyst to provide a carbon-reduced catalyst having a second carbon concentration that is less than said first carbon concentration;
• exposing said carbon-reduced catalyst to a solution comprising a chelating agent and a solvent for an aging time period from about 10 hours to about 900 hours during which time period said chelating agent reacts with and re-disperses catalytically active metals present in said spent non-additive based hydrotreating catalyst, thereby resulting in an aged catalyst having incorporated therein said chelating agent and said solvent and re-dispersed catalytically active metals;
• exposing said aged catalyst to conditions including a drying temperature of from 90° C. to 200° C. so as to remove from said aged catalyst a portion of said solvent without removing a significant portion of said chelating agent from said aged catalyst thereby resulting in a dried aged catalyst;
• and
• Sulfur treating said dried aged catalyst without prior exposure to a calcination temperature exceeding 400° C., to yield a restored catalyst.

A method, comprising:

• providing a spent non-additive based hydrotreating catalyst further containing carbon;
• removing a portion of said carbon from said spent hydrotreating catalyst to thereby provide a carbon-reduced catalyst;
• incorporating a chelating agent into said carbon-reduced catalyst by exposing said carbon-reduced catalyst to a solution comprising said chelating agent and a solvent;
• aging the resulting chelant-incorporated carbon-reduced catalyst for an aging time period from about 20 hours to about 600 hours during which time period said chelating agent reacts with and re-disperses catalytically active metals present in said spent non-additive based hydrotreating catalyst, to thereby provide an aged catalyst;
• drying said aged catalyst at a drying temperature so as to remove from said aged catalyst a portion of said solvent without removing a significant portion of said chelating agent from said aged catalyst thereby resulting in a dried aged catalyst;
• and
• Sulfur treating said dried aged catalyst without prior exposure to a calcination temperature exceeding 400° C., to yield a restored catalyst.