Solid phase continuous polymerisation of polyethylene terephthalate (PET) reactor and process
OwnerGiuliano Cavagliainventor
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Abstract
A reactor and a process for solid phase continuous polymerization of polyethylene terephthalate (PET) in order to achieve an increase of the intrinsic viscosity (I.V.) of a low molecular weight PET pre-polymers flow. A plurality of fluidized stages in series (109; 309) are provided and said PET pre-polymers flow is fed into said fluidized stages in series (109; 309). An inert gas flow is fed either in cross-flow or in counter-current flow with respect to the PET pre-polymers flow.
Claims51
A reactor for solid phase continuous polymerisation of polyethylene terephthalate (PET), comprising:
- a casing;
- a feeding line to feed a low molecular weight PET pre-polymers flow into said reactor;
- a gas line to feed, through supply valves, a gas into said reactor;
- a discharging line inferiorly connected to the bottom of the reactor to discharge the polymerised product;
- a circuit connected to the reactor to purify the gas and to recover pre-polymer particles by means of a proper separator;
- wherein, said casing of said reactor is horizontally arranged;
- and
- wherein, inside said reactor, means are provided to generate a plurality of fluidised stages in series to cause an increase of the intrinsic viscosity (I.V.) of said PET pre-polymers flow;
- and
- wherein in correspondence with each fluidised stage a sufficient gas flow is generated by said supply valves, each valve being equipped with a heating device,
- wherein said I.V. increase of said PET pre-polymers flow is ≧0.06 dl/g.
A process for solid phase continuous polymerisation of polyethylene terephthalate (PET), comprising the steps of:
- feeding a low molecular weight PET pre-polymers flow into a horizontally arranged reactor through a feeding line;
- feeding a gas into said reactor through a gas line in cross-flow or in counter-current flow with respect to said PET pre-polymers flow,
- carrying out said polymerisation in a plurality of fluidised stages in series generated inside said reactor to cause an increase of the intrinsic viscosity (I.V.) of ≧0.06 dl/g of said PET pre-polymers flow, and
- bringing at the desired temperature the gas flowing through supply valves, each valve being associated to a fluidsed stage and being equipped with a heating device.
Dependencies are inferred from the claim text.