Process and system for setting up impact copolymer polypropylene production and process and system for producing the same
AssigneeLummus Novolen Technology GmbH
InventorsStefan Bangerth, Sarah Froelich, Oliver Marco Ruhl
Life of this patent
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Abstract
Embodiments disclosed herein relate to a use of propane contained in a propylene feedstock for setting up impact copolymer polypropylene production in at least two polymerization zones comprising accumulating the propane in a first polymerization zone (2, 5) during a parallel operation mode of the first polymerization zone (2, 5) and a second polymerization zone (7, 10) producing respective propylene polymers. Embodiments disclosed herein also relate to a process and a system for setting up impact copolymer polypropylenes production.
Claims15
A process for setting up impact copolymer polypropylene production in at least two polymerization zones, the process comprising:
- feeding a first propylene stream (1a) comprising propane to a first polymerization zone (2, 5), thereby producing a first product (3a) comprising a first propylene polymer and a first carrier fluid;
- recycling a first reactor recycle stream (4) to the first polymerization zone (2, 5);
- feeding a second propylene stream (6a) comprising propane to a second polymerization zone (7, 10) operated in an operation mode parallel to the first polymerization zone (2, 5), thereby producing a second product (8a) comprising a second propylene polymer and a second carrier fluid;
- recycling a second reactor recycle stream (9) to the second polymerization zone (7, 10);
- recycling a carrier fluid recycle stream (26) comprising the first carrier fluid and the second carrier fluid to the first polymerization zone (2, 5) and to the second polymerization zone (7, 10);
- once a total propane content in the first reactor recycle stream (4) and the second reactor recycle stream (9) attains a first threshold, switching the operation mode from the parallel operation mode to a serial operation mode;
- transferring propane accumulated in the first polymerization zone (2, 5) to the second polymerization zone (7, 10);
- and
- once the propane content in the second reactor recycle stream (9) reaches a second threshold higher than the first threshold, stopping recycling the carrier fluid recycle stream (26) to the first polymerization zone (2, 5).
A system for setting up impact copolymer polypropylene production in at least two polymerization zones, the system comprising:
- a first polymerization zone (2, 5) configured to convert a first propylene stream (1a, 1b) comprising propane to a first product (3a) comprising a first propylene polymer and a first carrier fluid;
- a second polymerization zone (7, 10) configured to be operated in an operation mode parallel to or serial with the first polymerization zone (2, 5) and convert a second propylene stream (6a, 6b) comprising propane to a second product (8a) comprising a second propylene polymer and a second carrier fluid;
- a recycle line (26) for recycling, in the parallel operation mode, a carrier fluid recycle stream (26) comprising the first carrier fluid and second carrier fluid to the first polymerization zone (2, 5) and to the second polymerization zone (7, 10);
- a controller configured to, once a total propane content in a first reactor recycle stream (4) and a second reactor recycle stream (9) attains a first threshold, switch the operation mode from the parallel operation mode to the serial operation mode;
- and
- at least one transfer line (29) for transferring propane accumulated in the first polymerization zone (2, 5) to the second polymerization zone (7, 10),
- wherein the controller is further configured to, once the propane content in the second reactor recycle stream (9) reaches a second threshold higher than the first threshold, stop recycling the carrier fluid recycle stream (26) to the first polymerization zone (2, 5).
Use of propane contained in a propylene feedstock for setting up impact copolymer polypropylene production in at least two polymerization zones, comprising accumulating the propane in a first polymerization zone (2, 5) and a second polymerization zone (7, 10) during a parallel operation mode thereof producing respective propylene polymers, and transferring the propane accumulated in the first polymerization zone (2, 5) to the second polymerization zone (7, 10) during a serial operation mode.
Dependencies are inferred from the claim text.