HWAHAK KONGHAK, Vol.18, No.6, 479-488, December, 1980
폐폴리에스터회수 공정에 관한 연구
A Study on Recycling Process of Polyester Waste
초록
페폴리에스터를 회수, 재이용하기 위하여 해중합 공정을 개선한 연속식 2단계 Alcoholysis 공정에서 BHET 단량체로 해중합되는 것을 연구하였다. 실험장치로는 폐 PET를 235 ℃에서 BHET 단량체에 용해시키기 위한 3.4 l용 해조, EG가열을 위한 예열기와 용해된 폐 PET와 EG의 반응을 위한 2.75 l반응기를 사용하였다. 반응온도（220 ℃∼260 ℃）, 체류시간(5∼30분) 및 환류비(1:1∼3:1)가 각각 평균 중합도에 미치는 영향을 실험적으로 조사하였으며, 이를 분석 검토한 결과 240 ℃∼250 ℃ 반응온도, 환류비 2:1와 10분의 체류시간이 평균 중합도 측면에서 최적 조건임을 알 수 있었다. 이때 얻을 수 있는 평균중합도는 1.5∼1.7정도이어서 PET 재중합에 사용될 수 있으리라 믿어진다.
Recycling of PET waste was studied by employing depolymerization to a lower molecular -weight monomer or oligomer（BHET） in a continuous two stage alcoholysis process. A dissolver of 3.4 l capacity was used for dissolving PET waste in BHET at 235 ℃, a preheater for heating EG, and a 2.75 l tubular reactor, equipped with a perforated plate for good mixing, for depolymerization reaction of dissolved PET waste in BHET with EG.
The effect of reaction temperature, residence time, and recycle ratio on the average degree of polymerization of depolymerized oligomer were experimentally investigated. It was found that the optimum conditions were as follows : reaction temperature of 240∼250 ℃, residence time of 10 min, and recycle ratio of 2 : 1 Under the optimum operating conditions the average degree of polymerization of depolymerized oligomer ranged from 1.5 to 1. 7 which appears low enough to be used in repolymerizing to PET.
The effect of reaction temperature, residence time, and recycle ratio on the average degree of polymerization of depolymerized oligomer were experimentally investigated. It was found that the optimum conditions were as follows : reaction temperature of 240∼250 ℃, residence time of 10 min, and recycle ratio of 2 : 1 Under the optimum operating conditions the average degree of polymerization of depolymerized oligomer ranged from 1.5 to 1. 7 which appears low enough to be used in repolymerizing to PET.