PROCESS FOR RECYCLING WASTE POLYESTER MATERIAL

DE602020051638T2Active Publication Date: 2025-05-21AVANTGARDE SHANGHAI ENVIRONMENTAL TECH CO LTD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
DE602020051638
Authority / Receiving Office
DE · DE
Patent Type
Patents
Current Assignee / Owner
Priority Date
2019-07-10
Filing Date
2020-02-24
Publication Date
2025-05-21
Estimated Expiration
2040-02-24

AI Technical Summary

Technical Problem

The existing methods for recycling waste polyester using the alcoholysis method face challenges with long depolymerization times and high dosages of alcoholysis agents due to solid-liquid heterogeneous reactions, leading to increased energy consumption and equipment input.

Method used

The method involves pretreating waste polyester by dewatering and deoxidizing it, then melting it and adding ethylene glycol as the alcoholysis agent, allowing for a homogeneous liquid-liquid reaction in the alcoholysis tank, which accelerates the depolymerization process and reduces viscosity, followed by a transesterification step to produce Dimethyl Terephthalate (DMT).

Benefits of technology

This approach significantly shortens the depolymerization time, improves the purity and yield of Bis(2-hydroxyethyl) terephthalate (BHET), and results in higher purity and yield of DMT, while reducing the risk of side reactions and energy consumption.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

A method for recycling waste polyester, in particular to a method for recycling waste polyester by a modified alcoholysis method to recycle waste polyester to prepare dimethyl terephthalate (DMT), is provided and belongs to waste polyester recycling technology field. The waste polyester after dewatering and deoxygenation treatment is used as a raw material, in the step of feeding in melted state the alcoholysis agent is added in the melted waste polyester for preliminary alcoholysis, and the alcoholysis agent is ethylene glycol. On one hand, alcoholysis reaction occurs when the waste polyester raw material are melted, and at the same time, the viscosity of the melted material is reduced. Thus, the melted material remains melted at the alcoholysis temperature and is not easy to solidify again after entering the alcoholysis tank, ensuring that the alcoholysis is carried out under homogeneous conditions.
Need to check novelty before this filing date? Find Prior Art