SU1091851A3 - Method for treating reaction mother liquor in therephthalic acid production - Google Patents

Abstract

1. METHOD FOR TREATING A REACTIVE MEMBER TREATMENT FOR MANUFACTURING TEROFETTIC ACID obtained by oxidizing p-xylene with molecular oxygen in the presence of a catalyst — a salt of a heavy metal in acetic acid, followed by separating the resulting target acid from the mother liquor by filtration or centrifuging and treating it with an acetic acid and treating the resulting acid by treating the resulting acid by treating the acetic acid. at an elevated temperature, characterized in that, in order to simplify the technology, the mother liquor is sent to a tubular heater consisting of one or several pipes with a volumetric rate of 1.992255 at a temperature of 120-350 ° C and then into a separation chamber connected to one end of the heat exchanger, in which a reduced pressure of 20-500 mm Hg is maintained, after which a separate a gaseous phase consisting of acetic acid and water, which is condensed separately; and a solid phase consisting of a salt of an i-sth metal, terephthalic acid, and reaction by-products in the form of a discrete powder or an easily ground mass. 2. A method according to claim 1, characterized in that the uterine plant is sent to the heat exchanger after concentrating the evaporation of a portion of the acetic acid from the solution. 00 ate

Description

Il

This invention relates to cnoci / Ov treatment of a reactive mother liquor during the manufacture of a teref; ; rieic acid is oxidized by p-xylyl a.

During the washed production of terephthalic acid (TCh) from t as catalysis. The mountain is used (1p, salts of heavy meta / s are used, for example, salts of Co or Mie 5 or CNsecb salts. Oxidation is carried out by molecular oxygen in a medium of lower carbolic acid, usually acetic acid,

The resulting TPA is precipitated in the reaction solution and recovered by separating the fillet, tinting or centrifuging. The uterine suspension thus obtained contains, in addition to the solvent, a catalyst. TPA and reaction by-products (water, isophthalic; and acid, benzoic acid, polymers).

Aliphatic ketones Clj or aromatic hydrocarbons 21 are added to the mother liquor to further extract the terephthalic acid.

The mother liquor is first evaporated to recover the main mass of the solvent, then the syringe is evaporated on a thin-film evaporator to extract the solid solvent.

The resulting thickener hardens after cooling. 1; en. Extrast Solid Catalyst: -; Fired for regeneration.

The disadvantages of this method are the unreliability of operation of the film evaporator, the need for pretreatment of the solid residue formed after evaporating 11G1-; and the solvent to extract the catalyst 5 and also the initial amount (8-10%) of the residual solvent,

The use of ketones and aromatic compounds creates an additional 1 t; 2 technological difficulties; C1 with the separation of aliphatic ketones or aromatic hydrocarbons from acetic acid.

The purpose of the invention is to simplify the part of the processing of the uterine solution during the production of T :: -phthalic acid.

The goal is achieved by tlm that according to cnoc (j6y pererab.p; kch r -; - promotional stock solution pooiz 0, k; tv ;; terephthalic number, semi-mycium :: sour; 1 (p-xylol MOJieKy / rye kis; ioii,) .iiir-; and in the presence of catalys h5ato; -l - if; willing:) 1 o metal: a: nc-) acetic acid}, followed by: noyiyqOHfioi: p.e. Kjir: ioTiv from quot;} ();) (by (rilgrape ;; or tsen1 rI (1) vani and processing) Kiui MatthewS) pacTij./ipa at logging i temperature, -;

the solution is directed to the heat exchanger: l 1: L1 ,, cocToniiriui from one; o1 or niCo. iijRiix: ri) y6, reads the text from: to (pc; cond; 99-223) at a temperature of 1205 zrPS, l then in 11p; 1elit1; ry chame1 ;;y,;:; ii-M; H c; i n uk s k (| W; j; otio- r.Mii; viK ,:, and KOTOJ ON;::; about: 1, holding iia-cK 1nizh: p1noe lanz; s11is 20 ZOi -g. rt followed by u :; chambers 0 НЫ1 о :; т 1; 1 Тdel about the main phase, with an extract from vinegar: ACID), and water.

KO7Ou condense OTLS, Ng) EUT. and

1i}) lu | o phase, C (.) Containing from salt t, ;; oio msssalla-, terephthalic acid zoy

5 and g; bypass reactions in the form of l. -Cpst; -and: Go noiK-iiKa KHt; Effortless pazm: l11 aems of mass.

: epe; i 11:) lacsi and m etopevvik maro4: jiij raskvor can be scooped up {:: o: ln iiyieM ptivaptg Lstm ukiVCiiiH xiicncjTi.i from razrl.

Constructions l 1a:; ogichn :) apparatus (pchisail i-;: at (; nte USA 13.

; 1 month 1-9. p-Cygno, g; oxide; ; | 11T with isgi / h sotnnii and An - elIHc of a catcher of acetic acid acetate: a and igrgnsha and as an accelerator - n cpe / ie uklusn, /, 1. Losls zazeri; e 1n

: reactions) 1СЯ кц -: he; - and the mixture - :) is led; |, ponifriff; -p; olani with the aim of: dellsmch: :( mut; e1P: oh tereft.nearly sour1; 1,: ok, p) Vinegar: .ii ;; ps;: right, KoiojjaH yes: and: C connection -. i with. LL TV Qg; ok {b.istoatl

. , i-) l yi, LONG GL1KIM way of the uterus; 1b; nd jjHc r; ioj} c:; icT) iiT of volatile comunee Toi (acetic acid hislota and water) and velochev11; ops NTO (terZfta lev kis -

, lot,) h 1,; with products and components: 1: clt; i; and ch hora mountain).

Ml hstch n;) Y rlstpor serves n heatballs; H1IK J, I; u nakrc; iaio) Parsm to Z, ls; ns1Y temperature; - further divided by

} H / :; i, i; VHi xaNiepv liKyrpn which is sub-type; -:: n; 1e: l: pony / xnvy pressure. Ninar.,) N; s, options for;: ayuts) s conllll ii szhizhlyuts. and hard com; c) b: nty ck: node mc via KJiana ;; In the 3 portions of the section, the chambers of the chamber were separated. The solid substance is a discrete powder. The composition of the feed is given in table. one . In tab. 2 conditions for the implementation of the method. Example 10. Processing the matte solution is carried out on a wide scale using a double heating tube. Inner:; The pipe diameter is 52.9 mm and the length is 48 m. The separation gauge is 4 m. Processing is carried out under the following operating conditions: Input of raw materials Flow rate, kg / h 10 Non-volatile 1.component, kg / h (wt.%) 256 (23.8 Volatile component Acetic acid, kg / h 776 (95 ) Water, kg / h Total, kg / h (%) 817 (76.2) Coolant used: vapor 151 C. The volumetric velocity at the outlet of the pipe is 1805 m / h. Separating chamber: volume 4 m, pressure 500 mm Hg. The following results were obtained: Continuity of operation. Flow rate, kg / h 242.8 Yield (dry matter),% 95 Residual liquid,% 1.8 Example 11. Installed at a large industrial scale, in one The housing of which contains 55 tubes of an internal diameter of 9.2 and a length of 5 m each (case diameter 305 mm). The operation was carried out under the following operating conditions: Input of raw materials Flow rate, kg / h 1335 Non-volatile component. kg / h ( wt.%) 318 (23.8) Volatile component: Acetic acid, kg / h (%) 966 (95) Water, kg / h (%) Total, kg / h (wt.%) 1017 (76.2) Heat carrier used: steam,. Volumetric velocity at the outlet of pipes: 2255 Separating chamber: capacity (pressure 200 mm Hg) The results obtained are as follows: Continuity of operationYes Flow rate, kg / h292 Yield (dry matter), wt.% 92 Residual liquid, in e c.% 1.4 The proposed method allows continuous solid components to be extracted from the reaction masterbatch during production TPA in the form of a powder or an easily ground mass that contains a small amount of acetic acid. In this way, the proportion of acetic acid is circulated and reused (1H acid can be drastically increased, and the removal of 1P1e and reuse of catalyst components becomes simpler. Table 1

23.8 23.8 48.5 23.8 23.8

76.2

2.52

0.13

76.2 3.89 0.19

51.5 2.16 0.02

76.2 0.65 0.03

76.2 2.52 0.13

With pre-evaporation. Speed Example of the p 5 internal diameter 1 mm

3.3

2

5.11

4.2

3

0.85

four

3.3

five

0.8

6

3.3

7

equals

0,2D

1 .6 Temperature of the heating tube. In other temperatures of the heating medium.

Continued table. Experiments temperature is

Claims (2)

1. METHOD FOR PROCESSING A REACTOR UTERINE SOLUTION IN THE PRODUCTION OF TERPHTHALIC ACID obtained by oxidation of η-xylene with molecular oxygen in the presence of a catalyst - a salt of a heavy metal in an acetic acid medium, followed by separation of the obtained target acid from the mother liquor by filtration or centrifugation and processing of the mother liquor during processing higher temperature, characterized in that, in order to simplify the technology, the mother liquor is sent to a tubular heater, consisting of one or more pipes, with a bulk velocity of 1.992255 m ³ / h at a temperature of 12O-35O ° C, and then into a separation chamber connected to one end of the heat exchanger, in which a reduced pressure of 20-500 mm Hg is maintained, and then from the chamber the separately formed gaseous phase, consisting of acetic acid and water, which is condensed separately, and the solid phase, consisting of a salt of a heavy metal, terephthalic acid and reaction by-products in the form of a discrete powder or an easily grinded mass, are removed. 2. The method of pop. 1, characterized in that the mother liquor is sent to the heat exchanger after concentration by evaporation of part of acetic acid from the solution.