The invention relates to a pyrolytic reaction device technology and the field of plastic
pyrolysis, in particular to a PET (
polyethylene glycol terephthalate)
steam pyrolysis method and device, and the device comprises a
mixed gas inlet
system, a PET
powder feeding
system, a pyrolytic
reaction system, a high and low temperature partition
separation system and the like.
Water vapor,
nitrogen and auxiliary agent gas are mixed through a three-way gas inlet
system and enter the pyrolytic
reaction system from the bottom end of the pyrolytic device; pET
raw material powder is arranged at the upper part of the
mixed gas inlet system, is continuously fed through conveying of
nitrogen with the temperature lower than 100 DEG C, and enters the pyrolytic
reaction system; under the action of the
mixed gas, fluidizing the PET at the temperature of 400-600 DEG C, carrying the PET by
airflow and lifting the PET upwards; in the lifting process, the pyrolytic reaction starts to be carried out and is gradually and completely converted into high-temperature pyrolytic steam; high-temperature
pyrolysis steam enters a high-low temperature partition
separation system from the
tail of a
pyrolysis reaction system, the temperature of the high-temperature pyrolysis steam is reduced, the steam enters a high-temperature
cyclone separator with the temperature of 300-200 DEG C, deposition and collection of a product TPA (
terephthalic acid) are achieved, then the temperature of the pyrolysis steam is reduced to the
room temperature, and pyrolysis liquid and pyrolysis non-condensable gas are collected. The method and the device can effectively overcome the defects of high coking amount, complex product, difficult reaction control and the like in the conventional PET pyrolysis process, and can directionally prepare high-yield and high-purity TPA.