Abstract: A method of crystallizing a plurality of crystallizable polymer pellets includes a step in which the pellets are contacted with a temperature adjusting fluid in a crystallizer. The fluid adjusts the temperature of the pellets by having a temperature sufficient to allow at least partial crystallization of the plurality of polymeric pellets while maintaining the average pellet temperature of the plurality of pellets below the melting temperature of the pellets. A crystallizer implementing the methods of the invention is also provided.

Abstract: A method of crystallizing polymeric pellets includes a step in which a plurality of polymeric pellets are introduced into a crystallizer. While within the crystallizer, the plurality of pellets is contacted with a plurality of solid additives for the purpose of adjusting the average pellet temperature. The plurality of solid additives adjusts the temperature of the pellets by having a temperature sufficient to allow at least partial crystallization of the plurality of polymeric pellets while maintaining the average pellet temperature below the melting temperature. Finally, the plurality of polymer pellets is removed from the outlet of the crystallizer.

Abstract: Energy savings are realized during the commercial production of polyethylene terephthalate by partially cooling polyethylene terephthalate pellets exiting a solid stating reactor by contact with water, and using the residual heat stored in the pellets to vaporize associated water to form dry pellets.

Abstract: Strands of molten polyethylene terephthalate (PET) from a PET polycondensation reactor are solidified, pelletized, and cooled only to a temperature in the range of 50° C. to a temperature near the polymer Tg by contact with water. The still hot pellets are conveyed, optionally followed by drying to remove water, to a PET crystallizer. By avoiding cooling the amorphous pellets to room temperature with water and cool air, significant savings of energy are realized.

Abstract: Considerable energy savings may be realized by recovering heat from hot PET pellets exiting a solid state polymerization reactor, and using this heat to heat cool pellets entering the crystallizer or solid state polymerization reactor. The heat may be transferred from hot to cool pellets employing a heat exchanger.

Abstract: There are disclosed polyester processes using a pipe reactor and corresponding apparatuses. In particular, there are disclosed processes and corresponding apparatuses including an esterification pipe reactor operated in an upflow or downflow mode, especially in a regime including stratified flow.

Abstract: There are disclosed polyester processes using a pipe reactor and corresponding apparatuses. In particular, there are disclosed processes and corresponding apparatuses including an esterification pipe reactor operated in an upflow or downflow mode, especially in a regime including stratified flow.