CN1120967A - Processing method of filter residue from the refinement of crude DMT - Google Patents
Processing method of filter residue from the refinement of crude DMT Download PDFInfo
- Publication number
- CN1120967A CN1120967A CN 94116949 CN94116949A CN1120967A CN 1120967 A CN1120967 A CN 1120967A CN 94116949 CN94116949 CN 94116949 CN 94116949 A CN94116949 A CN 94116949A CN 1120967 A CN1120967 A CN 1120967A
- Authority
- CN
- China
- Prior art keywords
- dmt
- dmi
- crystallizer
- fractions
- filtrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The said processing method includes filterate distillation, residue distillation, DMT separation, DMI separation and other process. During DMT separation and DMI separation, film crystallizer and other equipment with high separation efficiency are used and this results in high product quality. The present invention is used in the DMT refining process.
Description
Wei Dengfa (Witten) produces in dimethyl terephthalate (DMT) (DMT) process, and thick DMT need make with extra care, so that remove wherein isomers DMIP (DMI), repefral impurity such as (DMO).The DMT process for refining is that thick DMT is dissolved in the methyl alcohol, by the method for crystallisation by cooling or vacuum cooled crystallization, the DMT crystallization is separated out, and most of DM1, DMO leaves in mother liquor; Separate through centrifugal filtration again, DMT and isomers DMI, DMO branch are opened.Present DMT process units both domestic and external has two-stage method vacuum crystallization flow process (as domestic chemical fibre factory, Liaoyang, Tianjin petrochemical corporation (complex)), and one-stage process crystallization flow process in the back of improvement is also arranged; Continuous crystallisation technology is promptly arranged, periodic crystallisation technology is also arranged.Which kind of technological process all has the filtrate after the Separation of Solid and Liquid, and these filtrates must be distilled processing, reclaims wherein methyl alcohol and the useful material of part.Distillation test residue mainly contains DMT15～30%, DMI40～50%, DMO3.0～8.0%; When DMT content＞15%, generally raffinate is returned crystallizing tank, so that further extract DMT wherein.When DMT content≤15%, in order to improve crystalline rate, generally just no longer utilize this part material, but send to burning (see polyester industrial, 1990, the fourth phase, 27～28 pages).Obviously present this processing method is not reasonably utilized wherein utility-DMT, DMI; Except that DMT, DMI also is a kind of important chemical material, and DMI can be as the additive of polyester after sulfonation is handled, the polyester of properties such as preparation highly shrinkable polyester, shape memory polyester.
The objective of the invention is to design a kind of membrane type crystal separating technology, in thick DMT subtractive process, the residue of filtrate distillation further separates, and reclaims wherein utility DMT, DMI.
Processing method provided by the invention comprises four operations such as filtrate distillation, residue distillation, DMT separation, DMT separation.At the filtrate distillation process, methyl alcohol in the filtrate is separated recycling, the part of remaining residue is sent to filtrate residue distillation process, residue is separated into＜180 ℃ of fractions, 180～240 fractions,＞240 ℃ of three kinds of fractions such as fraction, send the DMT production system back to less than 180 ℃ of fractions, discard burning greater than 240 ℃ of fractions, 180～240 ℃ of fractions send DMT, DMI separation circuit; It is characterized in that separation circuit at DMT, 180～240 ℃ of fraction temperature are controlled to send under 80～100 ℃ among the batch (-type) membrane type crystallizer I carry out crystallization treatment, make DMT at first on the crystallizer inwall, form epitaxial by cooling, uncrystallized solution is discharged crystallizer I and is delivered to the DMI separation circuit, collects the epitaxial melting temperature greater than 130 ℃ component DMT and send the DMT refining system back to; DMI Crystallization Procedure, feeding temperature are controlled at 40～70 ℃, and make it be cooled to 30～40 ℃, after the DMI epitaxial appears in membrane type crystal device II, discharge not that crystal solution discards burning, and the heating crystallizer is to the fusion of DMI epitaxial, collect fusing point greater than 66 ℃ DMI component.
Wherein membrane type crystal device I, II are the vertical tube-type structure, constitute by top feed space, middle part crystallized region, bottom discharge chamber three parts, the shell of middle part crystallized region is provided with heat-conducting fluid and imports and exports, heat-conducting fluid passes through in shell side, the inside of shell evenly distributed crystallizer, top feed space, bottom discharge chamber are communicated with by crystallizer, and crystallizer is fixed on the upper and lower distribution grid, and crystallized stock passes through in tube side.
Processing method provided by the invention further specifies in conjunction with the accompanying drawings.
Description of drawings:
Fig. 1. filtrate residue treatment flow process
1-filtrate destilling tower 1.1-filtrate 1.2-filtrate residue 1.3-methyl alcohol
1.4-filtrate residue jar
2-filtrate residue destilling tower 2.1-high-boiling components 2.2-180～240 fraction 2.3-＜180 ℃ fractions
2.4-180～240 ℃ of fraction storage tanks
3-membrane type crystal device I 3.1-＞130 ℃ of fraction 3.2-DMI pregnant solution 3.3-DMI enrichment flow containers
4-membrane type crystal device II 4.1-DMI product 4.2-mother liquor 4.3-＜66 ℃ of components
Fig. 2. membrane type crystal device structure chart
4.1-feed space 4.2-overflow 4.3-charging aperture
4.4-last distribution grid 4.5-heat-conducting fluid goes out 4.6-crystallized region shell
4.7-crystallizer 4.8-thermal medium goes out distribution grid under the 4.9-
4.10-discharge chamber 4.11-discharging opening
(1) earlier filtrate (1.1) is delivered to filtrate destilling tower (1) with pump, steams the methyl alcohol (1.3) in the filtrate, and send Return the DMT esterification step or thick DMT crystal system is recycling; Filtrate destilling tower (1) adopts packed tower, column plate 10～20,50～90 ℃ of operating temperatures are collected the methyl alcohol fraction. Residue part (1.2) at the bottom of the tower is sent the refining system of DMT back to System, a part is delivered to raffinate storage tank (1.4).
(2) residue of being made by residue storage tank (1.4) is delivered to residue destilling tower (2), and the residue destilling tower is packed tower, tower 20～70 of plates, operating pressure are negative pressure 60～200mm mercury column, and reflux ratio 2～7 is carried out batch distillation, 180 ℃ Return DMT production system oxidation operation with foreshot (2.3); Discard burning, 180 greater than 240 ℃ fractions (2.1)～240 ℃ fraction (2.2) send the DMI separation circuit.
(3) 180～240 ℃ of fractions of residue distillation process (2.2) are delivered to by storage tank (2.4) under 80～100 ℃ of temperature Among the membrane type crystal device I (3), the control system temperature is carried out crystallization under 50～100 ℃, form at the crystallizer inwall The DMT epitaxial, and crystal solution does not enter storage tank (3.3) for the DMI pregnant solution. And then make crystallizer rising temperature to 130 ℃, Still drain into DMI enrichment storage tank (3.3) less than the liquid (3.2) before 130 ℃, the DMT crystal heats up molten more than 130 ℃ Melt the DMT refining step that thing (3.1) returns the DMT production system.
The method that this operation also can adopt the solubilizer cooling that DMT is separated namely adds in 180～240 ℃ of fraction materials Enter 60% ethanol, it is dissolved each other, reduce then temperature to 10～30 ℃, DMT is separated out in solution, and knot not Brilliant part steams earlier etoh solvent, send the DMI separation circuit residual fraction again.
(4) pregnant solution in the DMI pregnant solution storage tank (3.3) is carried membrane type crystallizer II (4) with pump, make system 20～50 ℃ of following crystallizations, on the crystallizer inwall, form the DMI epitaxial, the uncrystallized mother liquor (4.2) of draining is then done him and is used, make the epitaxial on the crystallizer be warming up to 66 ℃ of fusions again, deliver to DMI enrichment flow container less than 66 ℃ liquid (4.3) recovery, the epitaxial fused mass (4.1) that is higher than 66 ℃ is product DMI.
Membrane type crystal device provided by the present invention (I, II) is a pipe type membrane type crystal device (consulting Fig. 2).The membrane type crystal device partly is made up of feed space, discharge chamber, crystallized region etc., and its profile is a upright cylinder.Feed space (4.1) is on top, the shell of feed space shell and crystallized region (4.6) links to each other, feed space is provided with charging aperture (4.3) and material overfall (4.2), press definite shape in the crystallized region (as triangle, regular hexagon etc.), arranging crystallizer (4.7), crystallizer (4.7) is installed on, orifice plate (4.4,4.9), feed space (4.1) and discharge chamber (4.10) are communicated with by crystallizer, and crystallized region (4.6) shell is provided with heat-conducting fluid and imports and exports (4.5,4.8), heat-conducting fluid passes through in shell side, crystallization medium flows in crystallizer (4.7), and discharge chamber (4.10) is in the crystallizer bottom, and discharge chamber (4.10) shell links to each other with the crystallized region shell, discharge chamber is coniform, discharging opening (4.11) is in the lower end, and crystallizer I is identical with the structure of crystallizer II, the material selection stainless steel.
Filtrate draff processing method provided by the invention, technology is simple, and is easy and simple to handle, can reclaim useful industrial chemicals DMT, DMI effectively from residue, has higher economic value.
Embodiment 1:
1) filtrate destilling tower: packed tower, 17 of theoretical trays, 70 ℃ of tower top temperatures, filtrate 5000 grams, the overhead reflux ratio is 3, steams methyl alcohol 3500 grams, raffinate 1500 grams.
2) filtrate residue distillation: packed tower, 50 of theoretical trays, reflux ratio is 2, intermittently operated, negative pressure (pressure 100～200mm mercury column) must be less than 180 ℃ of fractions, 145 grams, and greater than 240 ℃ of fractions, 200 grams, 180～240 ℃ of fractions 1135 restrain.
3) DMT separates: get 180～240 ℃ of fractions, 610 grams and carry out in membrane type crystal device I, 95 ℃ of feeding temperatures, chilling temperature to 55 ℃ gradually, temperature fall time 100 minutes, treat to remove after the DMT epitaxial forms not crystallization raffinate 156 grams, be warming up to gradually more than 130 ℃ again, isolate the DMT190 gram, less than 130 ℃ of liquid, 255 grams, adding not, crystallization raffinate 156 grams are total to such an extent that DMI pregnant solution 411 restrains.
4) DMI separates: DMI pregnant solution 411 grams, and 65～75 ℃ of temperature, input membrane type crystal device II adjusts the heat-conducting fluid temperature and makes crystallizer remain on 50～60 ℃, crystallization 110 minutes, removing not, crystallization raffinate 41 restrains and removes.Crystallizer II temperature is heightened to 65 ℃,, collected product DMI158 gram more than 65 ℃, less than the 200 gram reuses of 65 ℃ of components, loss 11 grams crystal constant temperature 20 minutes.
Product DMI forms: DMI content 97.3%, DMT2.6%, other 0.1%, one way product yield 87.55%.
Embodiment 2:
1) filtrate destilling tower: packed tower, 17 of theoretical trays, 80 ℃ of tower top temperatures, filtrate 5500 grams, the overhead reflux ratio is 3, steams methyl alcohol 3850 grams, raffinate 1650 grams.
2) filtrate residue distillation: packed tower, 50 of theoretical trays, reflux ratio is 2, intermittently operated, negative pressure (pressure 100～200mm mercury column) must be less than 180 ℃ of fractions, 159 grams, and greater than 240 ℃ of fractions, 220 grams, 180～240 ℃ of fractions 1248 restrain.
3) DMT separates: get 180～240 ℃ of fractions, 559 grams and carry out in membrane type crystal device I, 95 ℃ of feeding temperatures, chilling temperature to 53 ℃ gradually, temperature fall time 100 minutes, treat to remove after the DMT epitaxial forms not crystallization raffinate 138 grams, be warming up to gradually more than 130 ℃ again, isolate the DMT179 gram, less than 130 ℃ of liquid, 242 grams, adding not, crystallization raffinate 138 grams are total to such an extent that DMI pregnant solution 380 restrains.
4) DMI separates: DMI pregnant solution 380 grams, and 65～75 ℃ of temperature, input membrane type crystal device II adjusts the heat-conducting fluid temperature and makes crystallizer remain on 50～60 ℃, crystallization 110 minutes, removing not, crystallization raffinate 32 restrains and removes.Crystallizer II temperature is heightened to 65 ℃,, collected product DMI144 gram more than 65 ℃, less than the 186 gram reuses of 65 ℃ of components, loss 12 grams crystal constant temperature 20 minutes.
Product DMI forms: DMI content 97.1%, DMT2.8%, other 0.1%, one way product yield 89.94%.
Claims (1)
- The processing method of filtrate residue in a kind of thick DMT subtractive process, comprise operations such as filtrate distillation, residue distillation, DMT separation, DMI separation, at the filtrate distillation process, methyl alcohol in the filtrate is separated recycling, the part of remaining residue is sent to filtrate residue distillation process, residue is separated into＜180 ℃ of fractions, 180～240 fractions,＞240 ℃ of three kinds of fractions such as fraction, send the DMT production system back to less than 180 ℃ of fractions, discard burning greater than 240 ℃ of fractions, 180～240 ℃ of fractions send DMT, DMI separation circuit; It is characterized in that separation circuit at DMT, 180～240 ℃ of fraction temperature are controlled to send under 80～100 ℃ among the batch (-type) membrane type crystallizer I carry out crystallization treatment, make DMT at first on the crystallizer inwall, form epitaxial by cooling, uncrystallized solution is discharged crystallizer I and is delivered to the DMI separation circuit, collect the epitaxial melting temperature greater than 130 ℃ component DMT, and send the DMT refining system back to; DMI Crystallization Procedure, feeding temperature are controlled at 40～70 ℃, and make it be cooled to 30～40 ℃, after the DMI epitaxial appears in membrane type crystal device II, discharge not that crystal solution discards burning, and the heating crystallizer is to the fusion of DMI epitaxial, collect fusing point greater than 66 ℃ DMI component;Wherein membrane type crystal device I, II are the vertical tube-type structure, constitute by top feed space, middle part crystallized region, bottom discharge chamber three parts, the shell of middle part crystallized region is provided with heat-conducting fluid and imports and exports, heat-conducting fluid passes through in shell side, the inside of shell evenly distributed crystallizer, top feed space, bottom discharge chamber are communicated with by crystallizer, and crystallizer is fixed on the upper and lower distribution grid, and crystallized stock passes through in tube side.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 94116949 CN1120967A (en) | 1994-10-18 | 1994-10-18 | Processing method of filter residue from the refinement of crude DMT |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 94116949 CN1120967A (en) | 1994-10-18 | 1994-10-18 | Processing method of filter residue from the refinement of crude DMT |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1120967A true CN1120967A (en) | 1996-04-24 |
Family
ID=5038174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 94116949 Pending CN1120967A (en) | 1994-10-18 | 1994-10-18 | Processing method of filter residue from the refinement of crude DMT |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1120967A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101663483B (en) * | 2007-02-21 | 2012-07-18 | 阿尔弗雷德·凯驰两合公司 | Motor pump unit particularly for a high-pressure cleaning device |
-
1994
- 1994-10-18 CN CN 94116949 patent/CN1120967A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101663483B (en) * | 2007-02-21 | 2012-07-18 | 阿尔弗雷德·凯驰两合公司 | Motor pump unit particularly for a high-pressure cleaning device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3934168B2 (en) | Purification method of bisphenol A | |
| DE1468705A1 (en) | Process for the recovery of para-xylene | |
| US2245404A (en) | Manufacture of succinic anhydride | |
| CN102781913A (en) | Method of manufacturing epsilon-caprolactam | |
| KR20190132344A (en) | Distillation of dimethyl sulfoxide, and multistage distillation column | |
| CN101323554A (en) | Solid-liquid separation process | |
| CN106943775B (en) | Device and method for continuously separating solid phase from liquid phase in caprolactam distillation heavy residual liquid | |
| EP1284962B1 (en) | Method for obtaining pure n-vinyl pyrrolidone | |
| CN107750181B (en) | Semi-continuous crystallization method and apparatus | |
| CN1120967A (en) | Processing method of filter residue from the refinement of crude DMT | |
| CN1020587C (en) | Process for preparing p-xylene with at least 99.5% pureness | |
| US9095783B2 (en) | Arrangement and method for producing high-purity crystals | |
| CN111099953B (en) | Separation and purification method of isomer | |
| EP0067224B1 (en) | Process for producing dibenzofuran | |
| EP0354433A2 (en) | Process for separating substances by cool chrystallization | |
| US5344618A (en) | Crystal refining apparatus | |
| US2868830A (en) | Separation by crystallization | |
| CN217489767U (en) | Crystallizer and device for producing phase-change wax | |
| CN114669077B (en) | Purification system and purification method of 2-methylnaphthalene | |
| US2207752A (en) | Process for crystallizing naphthalene | |
| EP4321500A1 (en) | Method and installation for the production of a monomer by depolymerization of the corresponding polymer | |
| CN1136188C (en) | Industrial high purity 1-naphthylamine and its preparing method | |
| KR19990076779A (en) | Purification method of crystalline substance | |
| US3755390A (en) | Process for continuously separating glycerides | |
| RU1811524C (en) | Method of 4-acetoxystyrene purification |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C01 | Deemed withdrawal of patent application (patent law 1993) | ||
| WD01 | Invention patent application deemed withdrawn after publication |