Device and method for separating 2, 6-xylenol from mixed phenol

Abstract

The invention relates to a device and method for separating 2, 6-xylenol from mixed phenol, in particular to the technical field of separation and purification, and the device sequentially comprises a rectifying section, a separation section and a stripping section from top to bottom; the separation section comprises a feeding side and an extraction side which are adjacent left and right; the volume of the feeding side is larger than that of the extraction side; the specific surface area of the filler used in the rectifying section > the specific surface area of the filler used in the feeding side > the specific surface area of the filler used in the stripping section and the specific surface area of the filler used in the extraction side; the silk screen inclination angle of the filler used in the stripping section > the silk screen inclination angle of the filler used in the rectifying section > the silk screen inclination angle of the filler used in the feeding side and the silk screen inclination angle of the filler used in the extraction side. According to the device provided by the invention, a separation section design mode is adopted, and meanwhile, by virtue of arrangement of the filler with specific parameters, efficient separation of 2, 6-xylenol from the mixed phenol material is realized, meanwhile, the energy consumption in the separation process is remarkably reduced, and efficient and green separation of 2, 6-xylenol is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of separation and purification, and in particular to a device and a method for separating 2,6-xylenol from mixed phenols. Background Art

[0002] At present, 2,6-dimethylphenol is a widely used chemical raw material with broad application prospects in the fields of medicine, dyes, fragrances and polymer materials. Its separation process is affected by many factors. In industrial applications, the separation conditions need to be optimized to improve the yield and product quality.

[0003] For example, CN107556165A discloses a method and device for extracting 2,6-xylenol from crude phenol. The method adopts a two-stage distillation technology, firstly, the crude phenol is subjected to a primary distillation treatment to remove light components lighter than 2,6-xylenol, to prevent the light components from affecting the effect of the subsequent secondary distillation treatment, and to improve the product yield and quality of 2,6-xylenol; and then, secondary distillation treatment is performed under specific operating conditions, especially the operating pressure of the secondary distillation treatment is controlled to be no higher than 5kPa, which increases the relative volatility between 2,6-xylenol and other components in the primary distillation product, facilitates the extraction of high-concentration 2,6-xylenol, and ensures that 2,6-xylenol will not undergo isomerization changes during the distillation process, thereby ensuring the separation effect of 2,6-xylenol.

[0004] However, the traditional double-tower distillation separation process still has problems of high energy consumption and poor separation effect. Summary of the invention

[0005] In view of the problems existing in the prior art, the object of the present invention is to provide a device and method for separating 2,6-xylenol from mixed phenols, so as to solve the problems of high energy consumption and poor separation effect in the traditional double-tower distillation separation process.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a device for separating 2,6-xylenol from mixed phenols, the device comprising, from top to bottom:

[0008] Rectification section, partition section and stripping section;

[0009] The partition section includes a feed side and a withdrawal side adjacent to each other on the left and right;

[0010] The volume of the feed side is greater than the volume of the extraction side;

[0011] The specific surface area of ​​the filler used in the rectifying section>the specific surface area of ​​the filler used on the feed side>the specific surface area of ​​the filler used in the stripping section and the specific surface area of ​​the filler used on the extraction side;

[0012] The wire mesh inclination angle of the packing used in the stripping section is greater than the wire mesh inclination angle of the packing used in the rectification section and greater than the wire mesh inclination angle of the packing used on the feed side and the wire mesh inclination angle of the packing used on the withdrawal side.

[0013] The device provided by the present invention adopts a partition section design and, with the help of the arrangement of fillers with specific parameters, realizes the efficient separation of 2,6-xylenol from mixed phenol materials, while significantly reducing the energy consumption of the separation process, which is conducive to the efficient and green separation of 2,6-xylenol.

[0014] As a preferred technical solution of the present invention, the filler used in the distillation section includes a double-layer wire mesh structured filler.

[0015] Preferably, the specific surface area of ​​the filler used in the rectification section is 1300-1500m 2 / m 3 .

[0016] Preferably, the mesh inclination angle of the packing used in the rectification section is 40-50°.

[0017] As a preferred technical solution of the present invention, the filler used on the feed side includes a double-layer wire mesh structured filler.

[0018] Preferably, the specific surface area of ​​the filler used on the feed side is 900-1100m 2 / m 3 .

[0019] Preferably, the mesh inclination angle of the filler used on the feed side is 25-35°.

[0020] As a preferred technical solution of the present invention, the filler used on the extraction side includes a single-layer wire mesh structured filler.

[0021] Preferably, the specific surface area of ​​the filler used on the extraction side is 500-600m 2 / m 3 .

[0022] Preferably, the mesh inclination angle of the filler used on the extraction side is 25-35°.

[0023] As a preferred technical solution of the present invention, the packing used in the stripping section includes plate corrugated structured packing.

[0024] Preferably, the specific surface area of ​​the filler used in the stripping section is 500-600m 2 / m 3 .

[0025] Preferably, the inclination angle of the packing used in the stripping section is 90°.

[0026] As a preferred technical solution of the present invention, the volume of the feed side is 65-75% of the volume of the partition section, and the remainder is the extraction side.

[0027] In a second aspect, the present invention provides a method for separating 2,6-xylenol from a mixed phenol, the method comprising:

[0028] The mixed phenol is separated through feeding, rectification, stripping and extraction to obtain 2,6-xylenol.

[0029] As a preferred technical solution of the present invention, the mixed phenol includes o-cresol, 2,6-xylenol and m-p-cresol.

[0030] As a preferred technical solution of the present invention, the filler used in the feed includes a double-layer wire mesh structured filler.

[0031] Preferably, the specific surface area of ​​the filler used in the feed is 900-1100m 2 / m 3 .

[0032] Preferably, the mesh inclination angle of the filler used in the feed is 25-35°.

[0033] Preferably, the packing used in the distillation comprises a double-layer wire mesh structured packing.

[0034] Preferably, the specific surface area of ​​the filler used in the distillation is 1300-1500m 2 / m 3 .

[0035] Preferably, the mesh inclination angle of the packing used in the distillation is 40-50°.

[0036] Preferably, the packing used in the distillation comprises a plate corrugated structured packing.

[0037] Preferably, the specific surface area of ​​the filler used in the distillation is 500-600m 2 / m 3 .

[0038] Preferably, the inclination angle of the packing used in the distillation is 90°.

[0039] Preferably, the filler used in the extraction comprises a single layer of wire mesh structured filler.

[0040] Preferably, the specific surface area of ​​the filler used in the extraction is 500-600m 2 / m 3 .

[0041] Preferably, the mesh inclination angle of the filler used in the extraction is 25-35°.

[0042] As a preferred technical solution of the present invention, the feed pressure in the separation is 0.5-1.5 kPaG.

[0043] Preferably, the feed temperature in the separation is 60-80°C.

[0044] Preferably, the tower top pressure during the separation is -90 to -100 kPaG.

[0045] Preferably, the tower top temperature during the separation is 108-110°C.

[0046] Preferably, the side line extraction temperature during the separation is 113-116°C.

[0047] Preferably, the tower bottom temperature during the separation is 123-126°C.

[0048] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0049] The device provided by the present invention can achieve good recovery effect for a given mixed phenol material at a smaller reflux ratio (relative to the two-tower separation process, the reflux ratio of the present invention is reduced by more than 1 / 4), with low energy consumption, less equipment investment, and better product indicators. It has considerable advantages in the separation of this system, with comprehensive energy saving of about 35%, and can save about 30% of equipment investment, especially for sites with limited space. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic diagram of a device for separating 2,6-xylenol from mixed phenols provided in an embodiment of the present invention;

[0051] In the figure: 1-distillation section, 2-feed upper section, 3-feed lower section, 4-stripping section, 5-extraction upper section, 6-extraction lower section.

[0052] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0053] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0054] This embodiment provides a device for separating 2,6-xylenol from mixed phenols, such as Figure 1 As shown, the device comprises, from top to bottom:

[0055] A rectifying section 1, a partitioning section and a stripping section 4;

[0056] The partition section includes a feed side and a withdrawal side adjacent to each other on the left and right;

[0057] The volume of the feed side is greater than the volume of the extraction side;

[0058] The specific surface area of ​​the filler used in the rectifying section 1>the specific surface area of ​​the filler used on the feed side>the specific surface area of ​​the filler used in the stripping section 4 and the specific surface area of ​​the filler used on the extraction side;

[0059] The wire mesh inclination angle of the packing used in the stripping section 4 is greater than the wire mesh inclination angle of the packing used in the rectifying section 1 and is greater than the wire mesh inclination angle of the packing used on the feed side and the wire mesh inclination angle of the packing used on the withdrawal side.

[0060] In the present invention, an oil collecting tank distributor may be optionally arranged between the rectifying section 1 and the partition section and between the partition section and the stripping section 4 to collect the upper liquid and distribute it to the fillers on both sides of the partition.

[0061] In the present invention, distribution pipes may be optionally provided below the reflux port and the feed port of the rectifying section 1 to ensure uniform distribution of the liquid phase for the initial distribution of the reflux.

[0062] In the present invention, a two-stage trough-type liquid distributor may be optionally used between the tower top and the packing of the distillation section 1 to evenly distribute the tower top reflux liquid phase.

[0063] In the present invention, an oil collecting box distributor may be optionally provided between adjacent packings in the rectifying section 1 to collect liquid flowing down from the upper packing and introduce it into the lower packing.

[0064] In the present invention, the feed side is divided into an upper feed section 2 and a lower feed section 3 from top to bottom, the height of the upper feed section 2 is less than the height of the lower feed section 3, and the feed port is arranged between the upper feed section 2 and the lower feed section 3.

[0065] In the present invention, the extraction side is divided into an extraction upper section 5 and an extraction lower section 6 from top to bottom, the height of the extraction upper section 5 is greater than the height of the extraction lower section 6, the side line extraction port is located between the extraction upper section 5 and the extraction lower section 6, and 2,6-xylenol is obtained from the side line extraction port.

[0066] In the present invention, the height between each section in the device can be reasonably designed according to actual industrial requirements. For example, the packed bed height of the distillation section 1 is 4-8m, the packed bed height of the upper feed section 2 is 2-5m, the packed bed height of the lower feed section 3 is 4-8m, the packed bed height of the stripping section 4 is 3-5m, the packed bed height of the upper extraction section 5 is 4-8m, and the packed bed height of the lower extraction section 6 is 2-5m.

[0067] Specifically, the packing used in the distillation section 1 includes double-layer wire mesh structured packing.

[0068] Specifically, the specific surface area of ​​the filler used in the distillation section 1 is 1300-1500m 2 / m 3 , for example, it can be 1300m 2 / m 3 、1320m 2 / m 3 、1340m 2 / m 3 、1360m 2 / m 3 、1380m 2 / m 3 、1400m 2 / m 3 、1420m 2 / m 3 、1440m 2 / m 3 、1460m 2 / m 3 、1480m 2 / m 3 or 1500m 2 / m 3 The above values ​​are not limited to the above values. Other values ​​not listed in the above values ​​also meet the requirements.

[0069] Specifically, the wire mesh inclination angle of the packing used in the distillation section 1 is 40-50°, for example, it can be 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49° or 50°, but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0070] Specifically, the filler used on the feed side includes a double-layer wire mesh structured filler.

[0071] Specifically, the specific surface area of ​​the filler used on the feed side is 900-1100m 2 / m 3 , for example, it can be 900m 2 / m 3 、920m 2 / m 3 、940m 2 / m 3 、960m 2 / m 3 、980m 2 / m 3 , 1000m 2 / m 3 、1020m 2 / m 3 、1040m2 / m 3 、1060m 2 / m 3 、1080m 2 / m 3 or 1200m 2 / m 3 The above values ​​are not limited to the above values. Other values ​​not listed in the above values ​​also meet the requirements.

[0072] Specifically, the wire mesh inclination angle of the filler used on the feed side is 25-35°, for example, it can be 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°, etc., but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0073] Specifically, the filler used on the extraction side includes a single-layer wire mesh structured filler.

[0074] Specifically, the specific surface area of ​​the filler used on the extraction side is 500-600m 2 / m 3 , for example, it can be 500m 2 / m 3 、510m 2 / m 3 、520m 2 / m 3 、530m 2 / m 3 、540m 2 / m 3 、550m 2 / m 3 、560m 2 / m 3 、570m 2 / m 3 、580m 2 / m 3 、590m 2 / m 3 or 600m 2 / m 3 The above values ​​are not limited to the above values. Other values ​​not listed in the above values ​​also meet the requirements.

[0075] Specifically, the mesh inclination angle of the filler used on the extraction side is 25-35°, for example, it can be 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°, but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0076] Specifically, the packing used in the stripping section 4 includes plate corrugated structured packing.

[0077] Specifically, the specific surface area of ​​the filler used in the stripping section 4 is 500-600m 2 / m 3 , for example, it can be 500m 2 / m 3 、510m 2 / m 3 、520m 2 / m 3 、530m 2 / m 3 、540m 2 / m 3 、550m 2 / m 3 、560m 2 / m 3 、570m 2 / m 3 、580m 2 / m 3 、590m 2 / m 3 or 600m 2 / m 3 The above values ​​are not limited to the above values. Other values ​​not listed in the above values ​​also meet the requirements.

[0078] Specifically, the inclination angle of the packing used in the stripping section 4 is 90°.

[0079] Specifically, the volume of the feed side is 65-75% of the volume of the partition section, and the remainder is the production side, for example, it can be 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74% or 75%, etc., but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0080] Further, the present invention provides a method for separating 2,6-xylenol from mixed phenols, the method comprising:

[0081] The mixed phenol is separated by using the aforementioned device for separating 2,6-xylenol from mixed phenol to obtain 2,6-xylenol.

[0082] Specifically, the method comprises the following steps: separating the mixed phenol through feeding, rectification, stripping and extraction to obtain 2,6-xylenol.

[0083] Specifically, the mixed phenols include o-cresol, 2,6-xylenol and m-p-cresol.

[0084] Specifically, the filler used in the feed includes a double-layer wire mesh structured filler.

[0085] Specifically, the specific surface area of ​​the filler used in the feed is 900-1100m 2 / m 3 .

[0086] Specifically, the mesh inclination angle of the filler used in the feed is 25-35°.

[0087] Specifically, the packing used in the distillation includes double-layer wire mesh structured packing.

[0088] Specifically, the specific surface area of ​​the filler used in the distillation is 1300-1500m 2 / m 3 .

[0089] Specifically, the mesh inclination angle of the packing used in the rectification is 40-50°.

[0090] Specifically, the packing used in the distillation includes plate corrugated structured packing.

[0091] Specifically, the specific surface area of ​​the filler used in the distillation is 500-600m 2 / m 3 .

[0092] Specifically, the inclination angle of the packing used in the distillation is 90°.

[0093] Specifically, the filler used in the extraction includes a single-layer wire mesh structured filler.

[0094] Specifically, the specific surface area of ​​the filler used in the extraction is 500-600m 2 / m 3 .

[0095] Specifically, the mesh inclination angle of the filler used in the extraction is 25-35°.

[0096] Specifically, the feed pressure in the separation is 0.5-1.5 kPaG, for example, it can be 0.5 kPaG, 0.6 kPaG, 0.7 kPaG, 0.8 kPaG, 0.9 kPaG, 1 kPaG, 1.1 kPaG, 1.2 kPaG, 1.3 kPaG, 1.4 kPaG or 1.5 kPaG, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0097] Specifically, the feed temperature in the separation is 60-80°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0098] Specifically, the top pressure of the separation tower is -90 to -100 kPaG, for example, it can be -90 kPaG, -91 kPaG, -92 kPaG, -93 kPaG, -94 kPaG, -95 kPaG, -96 kPaG, -97 kPaG, -98 kPaG, -99 kPaG or -100 kPaG, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0099] Specifically, the tower top temperature during the separation is 108-110°C, for example, it can be 108°C, 108.5°C, 109°C, 109.5°C or 110°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0100] Specifically, the side line extraction temperature during the separation is 113-116°C, for example, it can be 113°C, 113.5°C, 114°C, 114.5°C, 115°C, 115.5°C or 116°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0101] Specifically, the bottom temperature of the separation tower is 123-126°C, for example, it can be 123°C, 123.5°C, 124°C, 124.5°C, 125°C, 125.5°C or 126°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0102] Specifically, the reflux ratio in the separation process is determined according to the feed, but for the same feed, the reflux ratio of the present invention is reduced by more than 1 / 4 compared with the separation process of two towers.

[0103] Further, in order to illustrate the good separation effect that can be achieved by the device for separating 2,6-xylenol from mixed phenols provided by the present invention, the following example is used for illustration, as follows:

[0104] In the following examples, the mass percentage composition of the mixed phenols includes:

[0105] o-Cresol 6.5%, 2,6-dimethylphenol 90%, mixed phenols (2,4-cresol, 2,3-dimethylphenol and phenol conjugate) 2%, m-para-cresol 1.5%, others 0.5%.

[0106] Example 1

[0107] This embodiment provides a method for separating 2,6-xylenol from a mixed phenol material, which is as follows:

[0108] The apparatus used is as follows:

[0109] The device comprises, from top to bottom:

[0110] The distillation section, the partition section and the stripping section; the partition section includes a feed side and a withdrawal side adjacent to each other on the left and right; the volume of the feed side is 70% of the volume of the partition section, and the remainder is the withdrawal side; the feed side is divided into an upper feed section and a lower feed section from top to bottom; the withdrawal side is divided into an upper withdrawal section and a lower withdrawal section from top to bottom; the packing bed height of the distillation section is 5m; the packing bed height of the upper feed section is 2m; the packing bed height of the lower feed section is 5m; the packing bed height of the stripping section is 4m; the packing bed height of the upper withdrawal section is 6m; the packing bed height of the lower withdrawal section is 3m;

[0111] The filler used in the rectification section is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used in the rectification section is 1400m 2 / m 3 ; The wire mesh inclination angle of the filler used in the rectification section is 45°;

[0112] The filler used on the feed side is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used on the feed side is 1000m 2 / m 3 ; The inclination angle of the wire mesh of the filler used on the feed side is 30°;

[0113] The filler used on the extraction side is a single-layer wire mesh structured filler; the specific surface area of ​​the filler used on the extraction side is 550m 2 / m 3 ; The mesh inclination angle of the filler used on the extraction side is 30°;

[0114] The packing used in the stripping section is a plate corrugated structured packing; the specific surface area of ​​the packing used in the stripping section is 540m 2 / m 3 ; The inclination angle of the packing used in the distillation section is 90°.

[0115] The separation process is as follows:

[0116] The mixed phenols are separated by the aforementioned device to obtain 2,6-xylenol;

[0117] The feed pressure in the separation is 1 kPaG; the feed temperature in the separation is 70°C;

[0118] The tower top pressure during the separation is -95 kPaG; the tower top temperature during the separation is 109°C; the side line extraction temperature during the separation is 115°C; the tower bottom temperature during the separation is 125°C; and the reflux ratio during the separation is 6.66.

[0119] The indicators and energy consumption of the products obtained during the separation process are detailed in Table 1.

[0120] Example 2

[0121] This embodiment provides a method for separating 2,6-xylenol from a mixed phenol material, which is as follows:

[0122] The apparatus used is as follows:

[0123] The device comprises, from top to bottom:

[0124] The distillation section, the partition section and the stripping section; the partition section includes a feed side and a withdrawal side adjacent to each other on the left and right; the volume of the feed side is 72% of the volume of the partition section, and the remainder is the withdrawal side; the feed side is divided into an upper feed section and a lower feed section from top to bottom; the withdrawal side is divided into an upper withdrawal section and a lower withdrawal section from top to bottom; the packing bed height of the distillation section is 6m; the packing bed height of the upper feed section is 2.4m; the packing bed height of the lower feed section is 6m; the packing bed height of the stripping section is 4.5m; the packing bed height of the upper withdrawal section is 5m; the packing bed height of the lower withdrawal section is 2.5m;

[0125] The filler used in the rectification section is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used in the rectification section is 1350m 2 / m 3 ; The wire mesh inclination angle of the filler used in the rectification section is 48°;

[0126] The filler used on the feed side is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used on the feed side is 1050m 2 / m 3 ; The inclination angle of the wire mesh of the filler used on the feed side is 27°;

[0127] The filler used on the extraction side is a single-layer wire mesh structured filler; the specific surface area of ​​the filler used on the extraction side is 560m 2 / m 3 ; The mesh inclination angle of the filler used on the extraction side is 30°;

[0128] The packing used in the stripping section is a plate corrugated structured packing; the specific surface area of ​​the packing used in the stripping section is 550m 2 / m 3 ; The inclination angle of the packing used in the distillation section is 90°.

[0129] The separation process is as follows:

[0130] The mixed phenols are separated by the aforementioned device to obtain 2,6-xylenol;

[0131] The feed pressure in the separation is 1.2 kPaG; the feed temperature in the separation is 75°C;

[0132] The tower top pressure during the separation is -98 kPaG; the tower top temperature during the separation is 109°C; the side line extraction temperature during the separation is 114°C; the tower bottom temperature during the separation is 124°C; and the reflux ratio during the separation is 6.53.

[0133] The indicators and energy consumption of the products obtained during the separation process are detailed in Table 1.

[0134] Example 3

[0135] This embodiment provides a method for separating 2,6-xylenol from a mixed phenol material, which is as follows:

[0136] The apparatus used is as follows:

[0137] The device comprises, from top to bottom:

[0138] The distillation section, the partition section and the stripping section; the partition section includes a feed side and a withdrawal side adjacent to each other on the left and right; the volume of the feed side is 65% of the volume of the partition section, and the remainder is the withdrawal side; the feed side is divided into an upper feed section and a lower feed section from top to bottom; the withdrawal side is divided into an upper withdrawal section and a lower withdrawal section from top to bottom; the packing bed height of the distillation section is 8m; the packing bed height of the upper feed section is 5m; the packing bed height of the lower feed section is 8m; the packing bed height of the stripping section is 3m; the packing bed height of the upper withdrawal section is 8m; the packing bed height of the lower withdrawal section is 5m;

[0139] The filler used in the rectification section is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used in the rectification section is 1500m 2 / m 3 ; The inclination angle of the wire mesh of the filler used in the rectification section is 50°;

[0140] The filler used on the feed side is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used on the feed side is 1100m 2 / m 3 ; The inclination angle of the wire mesh of the filler used on the feed side is 35°;

[0141] The filler used on the extraction side is a single-layer wire mesh structured filler; the specific surface area of ​​the filler used on the extraction side is 500m 2 / m 3 ; The mesh inclination angle of the filler used on the extraction side is 25°;

[0142] The packing used in the stripping section is a plate corrugated structured packing; the specific surface area of ​​the packing used in the stripping section is 600m 2 / m 3 ; The inclination angle of the packing used in the distillation section is 90°.

[0143] The separation process is as follows:

[0144] The mixed phenols are separated by the aforementioned device to obtain 2,6-xylenol;

[0145] The feed pressure in the separation is 0.5 kPaG; the feed temperature in the separation is 60°C;

[0146] The tower top pressure during the separation is -90 kPaG; the tower top temperature during the separation is 108°C; the side line extraction temperature during the separation is 113°C; the tower bottom temperature during the separation is 123°C; and the reflux ratio during the separation is 6.75.

[0147] The indicators and energy consumption of the products obtained during the separation process are detailed in Table 1.

[0148] Example 4

[0149] This embodiment provides a method for separating 2,6-xylenol from a mixed phenol material, which is as follows:

[0150] The apparatus used is as follows:

[0151] The device comprises, from top to bottom:

[0152] The distillation section, the partition section and the stripping section; the partition section includes a feed side and a withdrawal side adjacent to each other on the left and right; the volume of the feed side is 75% of the volume of the partition section, and the remainder is the withdrawal side; the feed side is divided into an upper feed section and a lower feed section from top to bottom; the withdrawal side is divided into an upper withdrawal section and a lower withdrawal section from top to bottom; the packing bed height of the distillation section is 4m; the packing bed height of the upper feed section is 2m; the packing bed height of the lower feed section is 4m; the packing bed height of the stripping section is 5m; the packing bed height of the upper withdrawal section is 4m; the packing bed height of the lower withdrawal section is 2m;

[0153] The filler used in the rectification section is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used in the rectification section is 1300m 2 / m 3 ; The wire mesh inclination angle of the filler used in the rectification section is 40°;

[0154] The filler used on the feed side is a double-layer wire mesh structured filler; the specific surface area of ​​the filler used on the feed side is 900m 2 / m 3 ; The mesh inclination angle of the filler used on the feed side is 25°;

[0155] The filler used on the extraction side is a single-layer wire mesh structured filler; the specific surface area of ​​the filler used on the extraction side is 600m 2 / m 3 ; The mesh inclination angle of the filler used on the extraction side is 35°;

[0156] The packing used in the stripping section is a plate corrugated structured packing; the specific surface area of ​​the packing used in the stripping section is 500m 2 / m 3 ; The inclination angle of the packing used in the distillation section is 90°.

[0157] The separation process is as follows:

[0158] The mixed phenols are separated by the aforementioned device to obtain 2,6-xylenol;

[0159] The feed pressure in the separation is 1.5 kPaG; the feed temperature in the separation is 80°C;

[0160] The tower top pressure during the separation is -100 kPaG; the tower top temperature during the separation is 110°C; the side line extraction temperature during the separation is 116°C; the tower bottom temperature during the separation is 126°C; and the reflux ratio during the separation is 6.96.

[0161] The indicators and energy consumption of the products obtained during the separation process are detailed in Table 1.

[0162] Comparative Example 1

[0163] The only difference from Example 1 is that the specific surface area of ​​the filler used in the rectification section is 1000m 2 / m 3 .

[0164] Comparative Example 2

[0165] The only difference from Example 1 is that the specific surface area of ​​the filler used on the feed side is 500m 2 / m 3 .

[0166] Comparative Example 3

[0167] The only difference from Example 1 is that the wire mesh inclination angle of the filler used on the extraction side is 50°.

[0168] Comparative Example 4

[0169] The only difference from Example 1 is that the wire mesh inclination angle of the packing used in the rectification section is 90°.

[0170] Comparative Example 5

[0171] The only difference from Example 1 is that the wire mesh inclination angle of the filler used on the feed side is 80°.

[0172] Comparative Example 6

[0173] The only difference from Example 1 is that the inclination angle of the packing used in the stripping section is 45°.

[0174] Comparative Example 7

[0175] The only difference from Example 1 is that the top pressure during separation is 10 kPaG.

[0176] Table 1

[0177] Yield / % purity / % Energy consumption / M*KCAL / HR Example 1 99.05 99.91 0.4712 Example 2 99.03 99.9 0.4715 Example 3 98.99 99.89 0.4812 Example 4 99.01 99.89 0.4852 Comparative Example 1 96.12 95.24 0.5124 Comparative Example 2 95.28 96.12 0.5212 Comparative Example 3 98.25 99.72 0.5014 Comparative Example 4 98.86 99.81 0.4982 Comparative Example 5 95.25 99.44 0.5412 Comparative Example 6 99.01 99.91 0.5672 Comparative Example 7 13.94 23 0.3379

[0178] As shown in Table 1, in the scheme provided by the present invention, the specific pressure, temperature, specifications, purity and yield of the tower internals can be within a very high range, and the energy consumption is relatively balanced. If the parameters of the separation element are changed, the energy consumption and product yield and the indexes are affected to varying degrees due to the failure of some indexes to meet the standards, especially when the pressure is changed, the whole tower is in a chaotic state, which is not conducive to the separation of the target phenol.

[0179] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0180] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0181] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A device for separating 2,6-xylenol from mixed phenols, characterized in that: The device comprises, from top to bottom: Rectification section, partition section and stripping section; The partition section includes a feed side and a withdrawal side adjacent to each other on the left and right; The volume of the feed side is greater than the volume of the extraction side; The specific surface area of ​​the filler used in the rectifying section>the specific surface area of ​​the filler used on the feed side>the specific surface area of ​​the filler used in the stripping section and the specific surface area of ​​the filler used on the extraction side; The wire mesh inclination angle of the packing used in the stripping section is greater than the wire mesh inclination angle of the packing used in the rectification section and greater than the wire mesh inclination angle of the packing used on the feed side and the wire mesh inclination angle of the packing used on the withdrawal side.

2. The device according to claim 1, characterized in that The packing used in the rectification section includes double-layer wire mesh structured packing; Preferably, the specific surface area of ​​the filler used in the rectification section is 1300-1500m 2 / m 3 ; Preferably, the mesh inclination angle of the packing used in the rectification section is 40-50°.

3. The device according to claim 1 or 2, characterized in that The filler used on the feed side includes a double-layer wire mesh structured filler; Preferably, the specific surface area of ​​the filler used on the feed side is 900-1100m 2 / m 3 ; Preferably, the mesh inclination angle of the filler used on the feed side is 25-35°.

4. The device according to any one of claims 1 to 3, characterized in that: The filler used on the extraction side includes a single-layer wire mesh structured filler; Preferably, the specific surface area of ​​the filler used on the extraction side is 500-600m 2 / m 3 ; Preferably, the mesh inclination angle of the filler used on the extraction side is 25-35°.

5. The device according to any one of claims 1 to 4, characterized in that: The packing used in the stripping section includes plate corrugated structured packing; Preferably, the specific surface area of ​​the filler used in the stripping section is 500-600m 2 / m 3 ; Preferably, the inclination angle of the packing used in the stripping section is 90°.

6. The device according to any one of claims 1 to 5, characterized in that: The volume of the feed side is 65-75% of the volume of the partition section, and the remainder is the extraction side.

7. A method for separating 2,6-xylenol from mixed phenols, characterized in that: The method comprises: The mixed phenol is separated through feeding, rectification, stripping and extraction to obtain 2,6-xylenol.

8. The method according to claim 7, characterized in that The mixed phenols include o-cresol, 2,6-xylenol and m-p-cresol.

9. The method according to claim 7 or 8, characterized in that The filler used in the feed includes a double-layer wire mesh structured filler; Preferably, the specific surface area of ​​the filler used in the feed is 900-1100m 2 / m 3 ; Preferably, the mesh inclination angle of the filler used in the feed is 25-35°; Preferably, the packing used in the distillation comprises a double-layer wire mesh structured packing; Preferably, the specific surface area of ​​the filler used in the distillation is 1300-1500m 2 / m 3 ; Preferably, the mesh inclination angle of the packing used in the distillation is 40-50°; Preferably, the packing used in the stripping comprises plate corrugated structured packing; Preferably, the specific surface area of ​​the filler used in the distillation is 500-600m 2 / m 3 ; Preferably, the inclination angle of the packing used in the distillation is 90°; Preferably, the filler used in the extraction comprises a single-layer wire mesh structured filler; Preferably, the specific surface area of ​​the filler used in the extraction is 500-600m 2 / m 3 ; Preferably, the mesh inclination angle of the filler used in the extraction is 25-35°.

10. The method according to any one of claims 7 to 9, characterized in that: The feed pressure in the separation is 0.5-1.5 kPaG; Preferably, the feed temperature in the separation is 60-80°C; Preferably, the tower top pressure during the separation is -90 to -100 kPaG; Preferably, the tower top temperature during the separation is 108-110°C; Preferably, the side line extraction temperature during the separation is 113-116°C; Preferably, the tower bottom temperature during the separation is 123-126°C.

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