CN102372591B - Crystallization method for p-xylene production - Google Patents
Crystallization method for p-xylene production Download PDFInfo
- Publication number
- CN102372591B CN102372591B CN201010262041.XA CN201010262041A CN102372591B CN 102372591 B CN102372591 B CN 102372591B CN 201010262041 A CN201010262041 A CN 201010262041A CN 102372591 B CN102372591 B CN 102372591B
- Authority
- CN
- China
- Prior art keywords
- xylol
- crystallization
- crystallizer
- filtrated stock
- crystal
- 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.)
- Active
Links
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a crystallization method for p-xylene production, and mainly aims to solve the problem of large energy consumption during crystallization separation in existing technologies. According to the method, a slurrying trough is arranged, and a p-xylene crystal obtained from a secondary crystallization process can be slurried so as to enter a first crystallizer, in which a clear mother solution enters the slurrying trough. The technical method of the invention well solves the above problem, and can be used for the industrial production of p-xylene.
Description
Technical field
The present invention relates to a kind of crystallization method of producing p-Xylol.
Background technology
P-Xylol is the important source material of polyester industrial, mainly for the production of pure terephthalic acid (PTA) or pure terephthalic acid's dimethyl ester (DMT), and then removing to produce polyester (PET) by PTA and DMT, separating mixed dimethyl is the main production method of p-Xylol.Xylol is mainly comprised of p-Xylol, m-xylene, o-Xylol and ethylbenzene, and the boiling point between each component differs very little, larger but fusing point differs, and can adopt crystallization process separating paraxylene.
Patent US5448005 discloses a kind of crystallization method by being rich in the xylol raw material production p-Xylol of p-Xylol, the method obtains highly purified p-Xylol product by the separation of first step crystallisation process, and reclaims remaining p-Xylol in crystalline mother solution by second stage crystallisation process.Because the purity of p-Xylol crystal product depends on solid-liquid separation efficiency, and the service temperature of second stage crystallisation process is lower, gained magma temperature is also lower, be unfavorable for solid-liquid separation, thereby the highly purified p-Xylol crystal of difficult acquisition, therefore, in this patent, the p-Xylol crystal of second stage crystallisation process gained all melts, and then turns back to first step crystallisation process and carry out recrystallization to improve the purity of p-Xylol product.From the angle of energy utilization, first refrigeration obtains crystal, then melts crystal and freezes and carry out recrystallization, and the Crystallizing process energy consumption of this patent is increased.
Summary of the invention
Technical problem to be solved by this invention is the large problem of energy consumption existing in the crystallization method of existing production p-Xylol, and a kind of crystallization method of production p-Xylol of novelty is provided.The method has been saved Crystallizing process energy consumption.
In order to solve the problems of the technologies described above, the technical solution used in the present invention is as follows: a kind of crystallization method of producing p-Xylol, comprises the following steps:
A) xylol carries out crystallization in first step crystallizer, after the clear mother liquor overflow of crystallization on crystallizer top, enters in slurrying tank, and the magma in crystallizer obtains p-Xylol crystal I and crystallization filtrated stock I after the first solid-liquid separator separation;
B) p-Xylol crystal I melts after heat exchange, and the p-Xylol of 5～30% weight returns to the first solid-liquid separator as washings, and the p-Xylol of 70～95% weight is discharged as product;
C) crystallization filtrated stock I is divided into two strands, and first gang of crystallization filtrated stock I that accounts for 5～95% weight enters in slurrying tank, and second gang of crystallization filtrated stock I that accounts for 5～95% weight enters and in the crystallizer of the second stage, carry out crystallization;
D) magma in the crystallizer of the second stage obtains p-Xylol crystal II and crystallization filtrated stock II through the second solid-liquid separator separation;
E) p-Xylol crystal II enters in slurrying tank, turns back in first step crystallizer after the mixing of materials in slurrying tank;
F) crystallization filtrated stock II is divided into two strands, and first gang of crystallization filtrated stock II that accounts for 5～95% weight turns back in the crystallizer of the second stage, after second gang of crystallization filtrated stock II that accounts for 5～95% weight and the heat exchange of xylol raw material, discharges;
Wherein, after xylol raw material and second gang of crystallization filtrated stock II heat exchange, enter in slurrying tank, the clear mother liquor of crystallization is 0.1: 1～10: 1 with the ratio of the weight of second gang of crystallization filtrated stock I.
In technique scheme, the service temperature of first step crystallizer is higher than the service temperature of second stage crystallizer; The service temperature of first step crystallizer is-65～13 ℃; The service temperature of second stage crystallizer is-65～13 ℃; The service temperature of slurrying tank is higher than the service temperature of first step crystallizer; Solid-liquid separator is centrifuge separator or crystal washing tower; In xylol, p-Xylol concentration is greater than 20%; The purity of p-Xylol product is at least 99.5%.
In technique scheme, the object that slurrying tank is set is by regulating service temperature and the magma residence time therein of slurrying tank, makes p-Xylol crystal experience therein crystal slaking and crystal sweating process to improve crystal purity.In crystal maturing process, large crystal continues to grow up, and little crystal melts, and the macrobead crystal obtaining will be conducive to follow-up solid-liquid separation process, and crystal purity can be higher.In crystal sweating process, thereby the impurity of crystals will flow out and improves crystal purity after melting.Because the magma after pulp will turn back to first step crystallizer, thereby, the fine crystals having melted in slurrying tank will be in the first step crystallizer recrystallization, thereby can not cause the loss of crystal product, crystal purity can be improved because of recrystallization on the contrary.Arrange after slurrying tank, second stage crystallisation process gained p-Xylol crystal does not just need whole fusings, but after pulp, enters in first step crystallizer, thereby has greatly saved the energy consumption of sepn process.Inevitably some thin brilliant existence in crystallizer, degree of supersaturation is the impellent of crystallisation process, in the thin brilliant process growing, will consume a part of degree of supersaturation, thereby make other larger crystal be difficult to grow into larger crystal, thereby can reduce the mean particle size of whole crystal product, be unfavorable for follow-up solid-liquid separation process.Because the magma in first step crystallizer obtains crystal product after solid-liquid separation, therefore need to eliminate the thin crystalline substance in first step crystallizer.Part magma in first step crystallizer in crystallizer through clarification after, can form on crystallizer top the clear mother liquor of crystallization, the clear mother liquor of these crystallizations is not real clear mother liquor, wherein must contain a large amount of thin crystalline substances, the clear mother liquor overflow of this part crystallization is gone out to crystallizer, be about to thin crystalline substance and shifted out crystallizer, thus make that in crystallizer, other larger crystal can be grown larger.Containing the thin brilliant clear mother liquor of crystallization, enter slurrying tank, after the xylol raw material higher with temperature mixes, temperature raises, contained thin crystalline substance will melt, and the p-Xylol after fusing is separated out recrystallization when turning back to first step crystallizer, can not cause the loss of p-Xylol.
Use the crystallization method of production p-Xylol of the present invention to produce p-Xylol, compared with prior art, the energy consumption for cooling of sepn process has reduced more than 19%, and the purity of p-Xylol product reaches 99.9%, has obtained good technique effect.
Accompanying drawing explanation
Fig. 1 is the schematic flow sheet of the crystallization method of existing production p-Xylol.
Wherein, 1-raw material; 2-interchanger; 3-first step crystallizer; 4-one-level crystallization magma I; 5-one-level solid-liquid separator; 6-p-Xylol crystal I; 7-one-level crystallization filtrated stock I; 8-melting tank; 9-washings; 10-p-Xylol product; 11-second stage crystallizer; 12-secondary crystallization magma II; 13-secondary solid-liquid separator; 14-p-Xylol crystal II; 15-secondary crystallization filtrated stock II; 16-melting tank.
Fig. 2 is the schematic flow sheet of the crystallization method of production p-Xylol of the present invention.
Wherein, 1-raw material; 2-interchanger; 3-first step crystallizer; 4-one-level crystallization magma I; 5-one-level solid-liquid separator; 6-p-Xylol crystal I; 7-one-level crystallization filtrated stock I; 8-melting tank; 9-washings; 10-p-Xylol product; 11-second stage crystallizer; 12-secondary crystallization magma II; 13-secondary solid-liquid separator; 14-p-Xylol crystal II; 15-secondary crystallization filtrated stock II; 16-slurrying tank; 17 1 the first one-level crystallization filtrated stock I; Second gang of one-level crystallization filtrated stock I of 18-; First gang of secondary crystallization filtrated stock II of 19-; Second gang of secondary crystallization filtrated stock II of 20-; 21-slurrying tank magma; The clear mother liquor of 22-crystallization.
As described in Figure 1, xylol 1, after interchanger 2 is cooling, carries out crystallization in first step crystallizer 3, and the magma 4 in crystallizer 3 carries out solid-liquid separation by the first solid-liquid separator 5, obtains highly purified p-Xylol crystal 6 and crystallization filtrated stock 7.P-Xylol crystal 6 melts in melting tank 8, and a part is washed as the crystal in 9 pairs of the first solid-liquid separators 5 of washings, and a part is discharged as p-Xylol product 10.Crystallization filtrated stock 7 enters in second stage crystallizer 11 and carries out crystallization, and the magma 12 in second stage crystallizer 11 obtains p-Xylol crystal 14 and crystallization filtrated stock 15 through the second solid-liquid separator 13 separation.P-Xylol crystal 14 enters in first step crystallizer 3 after melting in melting tank 16, and crystallization filtrated stock 15 carries out cooling rear discharge by 2 pairs of xylol of interchanger 1.
As described in Figure 2, xylol 1 enters in slurrying tank 16 after interchanger 2 is cooling.The clear mother liquor 22 of crystallization in crystallizer 3 enters in slurrying tank 16 from flow out on crystallizer top, and the magma 4 in crystallizer 3 carries out solid-liquid separation by the first solid-liquid separator 5, obtains highly purified p-Xylol crystal 6 and crystallization filtrated stock 7.P-Xylol crystal 6 melts in melting tank 8, and one is washed as the crystal in 9 pairs of the first solid-liquid separators 5 of washings, and a part is discharged as p-Xylol product 10.Crystallization filtrated stock 7 is divided into two strands, and one crystallization filtrated stock 17 enters in slurrying tank 16, and one crystallization filtrated stock 18 enters and in second stage crystallizer 11, carries out crystallization.Magma 12 in second stage crystallizer 11 obtains p-Xylol crystal 14 and crystallization filtrated stock 15 through the second solid-liquid separator 13 separation.P-Xylol crystal 14 enters in slurrying tank 16, and the magma 21 in slurrying tank 16 returns in first step crystallizer 3.Crystallization filtrated stock 15 is divided into two strands, and one crystallization filtrated stock 19 turns back in second stage crystallizer 11, and one crystallization filtrated stock 20 is crossed 2 pairs of xylol of interchanger 1 and carried out cooling rear discharge.
Below by embodiment, the present invention is further elaborated.
Embodiment
[comparative example 1]
The crystallization method of existing production p-Xylol
As described in Figure 1, in xylol 1, containing 90% p-Xylol, flow is 14864kg/h, after interchanger 2 is cooling, carries out crystallization in first step crystallizer 3, and Tc is 3 ℃.Magma 4 in crystallizer 3 carries out solid-liquid separation by the first solid-liquid separator 5, obtains highly purified p-Xylol crystal 6 and crystallization filtrated stock 7.P-Xylol crystal 6 melts in melting tank 8, and temperature of fusion is 20 ℃, and the p-Xylol of 20% weight washs as the crystal in 9 pairs of the first solid-liquid separators 5 of washings, and the p-Xylol of 80% weight is discharged as p-Xylol product 10.Crystallization filtrated stock 7 enters in second stage crystallizer 11 and carries out crystallization, and Tc is-14 ℃.Magma 12 in second stage crystallizer 11 obtains p-Xylol crystal 14 and crystallization filtrated stock 15 through the second solid-liquid separator 13 separation.P-Xylol crystal 14 enters in first step crystallizer 3 after melting in melting tank 16, and temperature of fusion is 20 ℃.Crystallization filtrated stock 15 carries out cooling rear discharge by 2 pairs of xylol of interchanger 1.The results are shown in Table 1 for it.
[embodiment 1]
The crystallization method of production p-Xylol of the present invention
As described in Figure 2, in xylol 1, containing 90% p-Xylol, flow is 14864kg/h, enters in slurrying tank 16 after interchanger 2 is cooling.Xylol carries out crystallization in first step crystallizer 3, and Tc is 3 ℃.The clear mother liquor 22 of crystallization in crystallizer 3 enters in slurrying tank 16 from flow out on crystallizer top, and the magma 4 in crystallizer 3 carries out solid-liquid separation by the first solid-liquid separator 5, obtains highly purified p-Xylol crystal 6 and crystallization filtrated stock 7.P-Xylol crystal 6 melts in melting tank 8, and temperature of fusion is 20 ℃, and the p-Xylol of 20% weight washs as the crystal in 9 pairs of the first solid-liquid separators 5 of washings, and the p-Xylol of 80% weight is discharged as p-Xylol product 10.Crystallization filtrated stock 7 is divided into two strands, and first strand of crystallization filtrated stock 17 that accounts for 68% weight enters in slurrying tank 16, and second strand of crystallization filtrated stock 18 that accounts for 32% weight enters in second stage crystallizer 11 and carry out crystallization, and Tc is-14 ℃.Magma 12 in second stage crystallizer 11 obtains p-Xylol crystal 14 and crystallization filtrated stock 15 through the second solid-liquid separator 13 separation.P-Xylol crystal 14 enters in slurrying tank 16, and the magma 21 in slurrying tank 16 returns in first step crystallizer 3, and the service temperature of slurrying tank is 6.1 ℃.Crystallization filtrated stock 15 is divided into two strands, and first strand of crystallization filtrated stock 19 that accounts for 63% weight turns back in second stage crystallizer 11, and second strand of crystallization filtrated stock 20 that accounts for 37% weight carries out cooling rear discharge by 2 pairs of xylol of interchanger 1.Wherein, the clear mother liquor 22 of crystallization is 0.67: 1 with the ratio of the weight of crystallization filtrated stock 18.The results are shown in Table 1 for it.
[embodiment 2]
The crystallization method of production p-Xylol of the present invention
The crystallization method that adopts production p-Xylol as described in Figure 2, wherein, the clear mother liquor 22 of crystallization is 0.5: 1 with the ratio of the weight of crystallization filtrated stock 18, and all the other operational conditions are identical with embodiment 1, and the results are shown in Table 1 for it.
Embodiment 3: the crystallization method of production p-Xylol of the present invention
The crystallization method that adopts production p-Xylol as described in Figure 2, wherein, the clear mother liquor 22 of crystallization is 0.33: 1 with the ratio of the weight of crystallization filtrated stock 18, and all the other operational conditions are identical with embodiment 1, and the results are shown in Table 1 for it.
Table 1
[comparative example 1]
The crystallization method of existing production p-Xylol
The crystallization method that adopts production p-Xylol as described in Figure 1, wherein, the service temperature of second stage crystallizer is-3.54 ℃, and all the other operational conditions are identical with comparative example 1, and the results are shown in Table 2 for it.
[embodiment 4]
The crystallization method of production p-Xylol of the present invention
Adopt the crystallization method of production p-Xylol as described in Figure 2, wherein, second strand of crystallization filtrated stock 18 that accounts for 36% weight enters and in second stage crystallizer 11, carries out crystallization, the service temperature of second stage crystallizer is-3.54 ℃, the service temperature of slurrying tank is 6.3 ℃, second strand of crystallization filtrated stock 20 that accounts for 87% weight carries out cooling rear discharge by 2 pairs of xylol of interchanger 1, the clear mother liquor 22 of crystallization is 0.67: 1 with the ratio of the weight of crystallization filtrated stock 18, all the other operational conditions are identical with embodiment 1, and the results are shown in Table 2 for it.
[embodiment 5]
The crystallization method of production p-Xylol of the present invention
The crystallization method that adopts production p-Xylol as described in Figure 2, wherein, the clear mother liquor 22 of crystallization is 0.5: 1 with the ratio of the weight of crystallization filtrated stock 18, and all the other operational conditions are identical with embodiment 4, and the results are shown in Table 2 for it.
[embodiment 6]
The crystallization method of production p-Xylol of the present invention
The crystallization method that adopts production p-Xylol as described in Figure 2, wherein, the clear mother liquor 22 of crystallization is 0.33: 1 with the ratio of the weight of crystallization filtrated stock 18, and all the other operational conditions are identical with embodiment 4, and the results are shown in Table 2 for it.
Table 2
By comparative example, can find out, under the identical rate of recovery, in the present invention, because gained crystal in the crystallizer of the second stage is without recrystallization again after whole fusings, thereby the energy consumption of whole crystallisation process reduces greatly, by thin brilliant elimination of first step crystallizer, the mean particle size of crystal product is also significantly improved, and product purity is higher.
Claims (3)
1. a crystallization method of producing p-Xylol, comprises the following steps:
A) xylol carries out crystallization in first step crystallizer, after the clear mother liquor overflow of crystallization on crystallizer top, enters in slurrying tank, and the magma in crystallizer obtains p-Xylol crystal I and crystallization filtrated stock I after the first solid-liquid separator separation;
B) p-Xylol crystal I melts after heat exchange, and the p-Xylol of 5～30% weight returns to the first solid-liquid separator as washings, and the p-Xylol of 70～95% weight is discharged as product;
C) crystallization filtrated stock I is divided into two strands, and first gang of crystallization filtrated stock I that accounts for 5～95% weight enters in slurrying tank, and second gang of crystallization filtrated stock I that accounts for 5～95% weight enters and in the crystallizer of the second stage, carry out crystallization;
D) magma in the crystallizer of the second stage obtains p-Xylol crystal II and crystallization filtrated stock II through the second solid-liquid separator separation;
E) p-Xylol crystal II enters in slurrying tank, turns back in first step crystallizer after the mixing of materials in slurrying tank;
F) crystallization filtrated stock II is divided into two strands, and first gang of crystallization filtrated stock II that accounts for 5～95% weight turns back in the crystallizer of the second stage, after second gang of crystallization filtrated stock II that accounts for 5～95% weight and the heat exchange of xylol raw material, discharges;
Wherein, after xylol raw material and second gang of crystallization filtrated stock II heat exchange, enter in slurrying tank, the clear mother liquor of crystallization is 0.1:1～10:1 with the ratio of the weight of second gang of crystallization filtrated stock I;
Wherein, the service temperature of first step crystallizer is higher than the service temperature of second stage crystallizer; The service temperature of first step crystallizer is-65～13 ℃; The service temperature of second stage crystallizer is-65～13 ℃; The service temperature of slurrying tank is higher than the service temperature of first step crystallizer.
2. the crystallization method of production p-Xylol according to claim 1, is characterized in that in xylol raw material, p-Xylol concentration is greater than 20%.
3. the crystallization method of production p-Xylol according to claim 1, is characterized in that the purity of p-Xylol product is at least 99.5%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010262041.XA CN102372591B (en) | 2010-08-23 | 2010-08-23 | Crystallization method for p-xylene production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010262041.XA CN102372591B (en) | 2010-08-23 | 2010-08-23 | Crystallization method for p-xylene production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102372591A CN102372591A (en) | 2012-03-14 |
| CN102372591B true CN102372591B (en) | 2014-03-26 |
Family
ID=45791881
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201010262041.XA Active CN102372591B (en) | 2010-08-23 | 2010-08-23 | Crystallization method for p-xylene production |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102372591B (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103772127B (en) * | 2012-10-25 | 2015-07-08 | 中国石油化工股份有限公司 | Method for producing p-xylene |
| CN103772130B (en) * | 2012-10-25 | 2015-10-21 | 中国石油化工股份有限公司 | The crystallization method of separating paraxylene |
| CN103772131B (en) * | 2012-10-25 | 2015-12-09 | 中国石油化工股份有限公司 | Produce the multistage crystallization method of p-Xylol |
| CN103880586B (en) * | 2012-12-19 | 2015-09-09 | 中国石油化工股份有限公司 | The multistage crystallization method of p-Xylol |
| CN103880585B (en) * | 2012-12-19 | 2015-09-09 | 中国石油化工股份有限公司 | Produce the crystallization method of p-Xylol |
| CN103880581B (en) * | 2012-12-19 | 2015-12-23 | 中国石油化工股份有限公司 | The crystallization method of p-Xylol |
| CN103880582B (en) * | 2012-12-19 | 2015-08-12 | 中国石油化工股份有限公司 | P-Xylol multistage crystallization method |
| CN103880583B (en) * | 2012-12-19 | 2015-12-23 | 中国石油化工股份有限公司 | The Crystallization Separation method of p-Xylol |
| CN104230639B (en) * | 2013-06-17 | 2016-06-08 | 中国石油化工股份有限公司 | The method of suspension crystallization separating paraxylene |
| CN104557424B (en) * | 2013-10-28 | 2016-09-07 | 中国石油化工股份有限公司 | The method of multistage suspension Crystallization Separation paraxylene |
| CN104557433B (en) * | 2013-10-28 | 2017-08-25 | 中国石油化工股份有限公司 | The method of multistage suspension crystallization production paraxylene |
| CN109694341B (en) * | 2017-10-20 | 2020-12-29 | 中国石油化工股份有限公司 | Method for producing dicumyl peroxide |
| CN112225635B (en) * | 2020-11-03 | 2022-09-23 | 中国石油化工股份有限公司 | Device, method and application for crystallization and separation of paraxylene |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1493489A (en) * | 1974-03-11 | 1977-11-30 | Standard Oil Co | Process for the recovery of high purity paraxylene |
| US5448005A (en) * | 1994-04-04 | 1995-09-05 | Mobil Oil Corporation | Crystallization of paraxlene from high purity paraxylene feeds |
| CN101437593A (en) * | 2006-05-24 | 2009-05-20 | 三菱化工机株式会社 | Recovery method and recovery system for crystallization component |
-
2010
- 2010-08-23 CN CN201010262041.XA patent/CN102372591B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1493489A (en) * | 1974-03-11 | 1977-11-30 | Standard Oil Co | Process for the recovery of high purity paraxylene |
| US5448005A (en) * | 1994-04-04 | 1995-09-05 | Mobil Oil Corporation | Crystallization of paraxlene from high purity paraxylene feeds |
| CN101437593A (en) * | 2006-05-24 | 2009-05-20 | 三菱化工机株式会社 | Recovery method and recovery system for crystallization component |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102372591A (en) | 2012-03-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102372591B (en) | Crystallization method for p-xylene production | |
| CN101941883B (en) | Method for preparing p-xylene by separating and crystallizing mixed xylenes | |
| CN101941882B (en) | Method for separating p-xylene from mixed xylene | |
| CN104230638B (en) | Suspension crystallization produces the method for p-Xylol | |
| CN102372590B (en) | Crystallization method for preparing para-xylene from xylol | |
| CN103880585B (en) | Produce the crystallization method of p-Xylol | |
| CN104557433B (en) | The method of multistage suspension crystallization production paraxylene | |
| CN102371081B (en) | Crystallization method with a fine crystal elimination | |
| CN111099954B (en) | Method for producing p-xylene | |
| CN106831301B (en) | Method for separating paraxylene by multistage suspension melting crystallization | |
| CN103880586B (en) | The multistage crystallization method of p-Xylol | |
| CN104557424B (en) | The method of multistage suspension Crystallization Separation paraxylene | |
| CN102371082A (en) | Crystallization method with overflow of clear mother liquor | |
| CN103772131B (en) | Produce the multistage crystallization method of p-Xylol | |
| CN106831311A (en) | Produce the multistage suspension fusion-crystallization method of paraxylene | |
| CN103880582B (en) | P-Xylol multistage crystallization method | |
| CN103664487B (en) | paraxylene crystallization method | |
| CN112679304B (en) | Method for producing p-xylene | |
| CN111099953A (en) | Separation and purification method of isomer | |
| CN104230639B (en) | The method of suspension crystallization separating paraxylene | |
| CN103772130B (en) | The crystallization method of separating paraxylene | |
| CN103880583B (en) | The Crystallization Separation method of p-Xylol | |
| CN103772127B (en) | Method for producing p-xylene | |
| CN103664491B (en) | Production method of p-xylene | |
| CN103880581B (en) | The crystallization method of p-Xylol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |