US 11,655,351 B2
Method for recycling waste polyester with continuous alcoholysis and transesterification
Huayu Fang, Shanghai (CN); Enbin Zhu, Shanghai (CN); Dubin Wang, Shanghai (CN); Guoqing Yu, Shanghai (CN); Jincheng Chen, Shanghai (CN); Tianyuan Li, Shanghai (CN); Jiantong Wu, Shanghai (CN); Jianhua Chen, Shanghai (CN); and Shengyao Lin, Shanghai (CN)
Filed by AVANTGARDE (SHANGHAI) ENVIRONMENTAL TECHNOLOGY CO., LTD., Shanghai (CN)
Filed on Sep. 7, 2020, as Appl. No. 17/13,671.
Application 17/013,671 is a continuation in part of application No. PCT/CN2020/076455, filed on Feb. 24, 2020.
Prior Publication US 2021/0024717 A1, Jan. 28, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. C08J 11/16 (2006.01)
CPC C08J 11/16 (2013.01) [C08J 2367/00 (2013.01)] 12 Claims
 
1. A method for recycling waste polyester with continuous alcoholysis and transesterification comprising:
material pretreatment: drying and deoxygenating waste polyester material to obtain waste polyester as raw material;
alcoholysis: after the material pretreatment, the waste polyester raw material, an alcoholysis agent and an alcoholysis catalyst are continuously fed into a first alcoholysis tank in the melted state for a first alcoholysis to obtain a melt A, and then the melt A is continuously fed into a second alcoholysis tank for a second alcoholysis through a delivery pump to obtain alcoholysis product, wherein the first alcoholysis tank and the second alcoholysis tank are connected in series; wherein the conveying amount of the waste polyester is adjusted by the speed of a screw extruder which is controlled based on the liquid level of the first alcoholysis tank, and the speed of the delivery pump is controlled based on the liquid level of the second alcoholysis tank;
transesterification: including carrying out transesterification reaction in the transesterification tank to obtain a transesterification product, and crystallization, separation and purification of raw dimethyl terephthalate (DMT);
wherein the transesterification tank includes a first transesterification tank and a second transesterification tank, the first transesterification tank and the second transesterification tank are connected in series;
the alcoholysis product, the transesterification agent, and the transesterification catalyst are continuously fed into the first transesterification tank in the melted state for the first transesterification to obtain the transesterification product;
the second transesterification tank is configured to place the transesterification product that is continuously fed from the first transesterification tank for a second transesterification.