Methods for injecting catalyst into a polymerization reactor

A method of forming polypropylene, comprising;

• providing a conduit having at least one catalyst valve, a first propylene stream inlet and a second propylene stream inlet, the conduit being operably connected to a polymerization vessel;
• introducing a catalyst to the conduit;
• passing the catalyst through the conduit to the polymerization vessel;
• introducing a first propylene stream comprising propylene monomers to the conduit through a first propylene conduit having a first propylene valve to provide a mixed catalyst stream;
• closing the catalyst valve and the first propylene valve;
• introducing a second propylene stream to the conduit through a second propylene conduit having a second propylene valve;
• passing the second propylene stream through the conduit to the polymerization vessel;
• removing at least a first section of the conduit;
• and
• replacing the first section of the conduit with a second conduit section.

A method of forming polypropylene, comprising;

• providing a first conduit having a catalyst inlet, a first propylene stream inlet, and a second propylene stream inlet located downstream of the first propylene stream inlet, the first conduit being operably connected to a polymerization vessel;
• introducing a catalyst to the first conduit through the catalyst inlet;
• passing the catalyst through the first conduit to the polymerization vessel;
• introducing a first propylene stream to the first conduit to provide a mixed catalyst stream downstream of the catalyst inlet;
• stopping the flow of the catalyst passing through the first conduit;
• introducing a second propylene stream to the first conduit through the second propylene stream inlet;
• passing the catalyst through a third conduit to the polymerization vessel;
• and
• replacing a first section of the first conduit with a second conduit section.