公开(公告)号：US20030225299A1

公开(公告)日：2003-12-04

申请号：US10424042

申请日：2003-04-24

Applicant: Tsukishima Kikai Co., Ltd.

Inventor： Jinichi Yazaki ,  Kozaburo Sakano ,  Nobuyuki Funakoshi ,  Kazuho Tanaka

IPC: C07C051/09

CPC classification number: C07C51/43 ,  C07C51/09 ,  C07C51/412 ,  C07C51/47 ,  C08J11/24 ,  C08J2367/02 ,  Y02W30/706 ,  C07C63/28 ,  C07C63/26

Abstract: This invention provides a process a process for recovering terephthalic acid from pulverized products of spent polyethylene terephthalate. This process comprises (1) a decomposition reaction step where the pulverized products of spent polyethylene terephthalate are continuously subjected to decomposition reaction in ethylene glycol in the presence of alkali, which is equimolar or excessmolar relative to the polyethylene terephthalate, so that salt of terephthalic acid and ethylene glycol can be continuously obtained; (2) a solid-liquid separation, dissolution, impurities-removing step where the ethylene glycol is separated from decomposition reaction slurry of salt of terephthalic acid and ethylene glycol, and the solid salt of terephthalic acid is dissolved into water, while insoluble impurities are removed; (3) a neutralization, crystallization step, where solution of said salt of terephthalic acid is neutralized with acid so that terephthalic acid can be crystallized; (4) a solid-liquid separation, washing stop where slurry of terephthalic acid crystals is subjected to solid-liquid separation so that the terephthalic acid crystals can be obtained and washed; and (5) a drying, pulverization step where the washed terephthalic acid crystals are dried and pulverized

Abstract translation: 本发明提供一种从废聚对苯二甲酸乙二醇酯的粉碎产物中回收对苯二甲酸的方法。 该方法包括：（1）分解反应步骤，其中废聚对苯二甲酸乙二醇酯的粉碎产物在相对于聚对苯二甲酸乙二醇酯等摩尔或过量的碱的存在下在乙二醇中连续进行分解反应，使得对苯二甲酸的盐 可连续获得乙二醇; （2）从对苯二甲酸和乙二醇盐的分解反应浆液中分离出乙二醇和对苯二甲酸的固体盐的固液分离，溶解，杂质去除步骤溶解在水中，不溶性杂质为 删除 （3）中和，结晶步骤，其中所述对苯二甲酸盐的溶液用酸中和，使对苯二甲酸可以结晶; （4）固液分离，其中对苯二甲酸晶体的浆液进行固液分离以使得可以获得和洗涤对苯二甲酸晶体的洗涤停止; 和（5）干燥，粉碎步骤，其中将洗涤的对苯二甲酸晶体干燥并粉碎

公开(公告)号：US3378236A

公开(公告)日：1968-04-16

申请号：US58989066

申请日：1966-10-27

Applicant: TSUKISHIMA KIKAI CO

Inventor： TATUSI KASAI

IPC: B01D9/00

CPC classification number: B01D9/0018 ,  B01D9/0036

Abstract: 1,161,474. Growing crystals. TSUKISHIMA KIKAI CO. Ltd. 26 Oct., 1966 [27 Oct., 1965], No. 47996/66. Headings BIB, B1C, B1D and BIG. A crystallizer comprises a tube having a fixed lower part 2, and a rotatable upper part 3 carrying inner impeller blades 4 and outer blades 7 creating a circulation through the tube. When crystal have .grown to a predetermined size they separate from the circulating flow, fall into the classifying leg 9 and are withdrawn at 10, while the liquid from which they have been removed moves upwardly outside the baffle 11 and is discharged at 12 for re-heating and re-cycling through inlet 1. Solvent vapour leaves at 13 to waste or recovery. The impeller blades are so pitched and dimensioned that the mass flow rate of the magma is the same up the tube and downward outside it, and the impeller is driven so that the crystals fall faster than the descending liquid while the inner impeller 4 assist the upward flow only sufficiently to compensate for the .resistance of .the tube support; in consequence wear of the crystals is much reduced. In another embodiment (Fig. 3, not shown) the draft tube has three parts of which the middle (22) rotates and overlaps the lowest (21) which is smaller in diameter and may contain an additional impeller (24). The outer impeller (7) in this case has a greater mass flow than the inner (4) so that part of the liquid containing the smaller crystals circulates through the annular gap between the tube portions (21), (22) while part ascends through k the lowest tube portion (21) depositing in the bottom of the apparatus crystals which have reached a predetermined uniform size.