CN1305818C

CN1305818C - Apparatus for extracting coarse 1,3-butadiene by double baffle plated tower and method thereof

Info

Publication number: CN1305818C
Application number: CNB2004100364979A
Authority: CN
Inventors: 韩方煜; 方自真; 王浩; 薛振祥; 项曙光
Original assignee: Qingdao Ecss Soft Tech Co Ltd
Current assignee: QINGDAO YIKESI TECHNOLOGY ENGINEERING CO LTD
Priority date: 2004-12-14
Filing date: 2004-12-14
Publication date: 2007-03-21
Anticipated expiration: 2024-12-14
Also published as: CN1789223A

Abstract

The present invention relates to a device and a method thereof for obtaining coarse 1, 3-butadiene by using a double-partition board tower integration process and taking acetonitrile containing water as a solvent for separating butylene from C4 mixtures and removing butyne and recombination parts through extractive distillation. The operation of extractive distillation of the method is carried out in a partition board tower with an upper longitudinal partition board and a lower longitudinal partition board, the inner structure of the partition board tower is divided into a butadiene extractive distillation section, a recombination part removing section, an alkyne extractive distillation section, a middle tower sharing area, a solvent analyzing section, an alkyne distilling section and a lower tower sharing area, wherein liquid phase between the recombination part removing section and the alkyne extractive distillation section is led to a side line tower in order to remove the recombination parts, and the side line tower and relevant components are eliminated when the recombination parts are not removed. The device and the method of the present invention can be used for finishing the operation of traditional twice extractive distillation and partial recombination part removing operation in one tower. The present invention has the advantages of less investment, simple operation and low energy consumption, and thus, the cost of products is reduced.

Description

Two partitioned columns extract the devices and methods therefor of thick 1,3-butadiene

Technical field:

The present invention relates to a kind of extraction thick 1, the devices and methods therefor of 3-divinyl, specifically make solvent and from C 4 mixture, tell butylene by extracting rectifying and remove butine and the devices and methods therefor of thick 1,3-butadiene is obtained in heavy constituent to contain water-acetonitrile with two partitioned column integrated flows.

Technical background:

Industrial thick 1,3-butadiene obtains from the C 4 mixture cut usually.This mixture main component is 1-butylene, iso-butylene, suitable-2-butylene, anti--2-butylene, 1,3-butadiene and a small amount of ethyl acetylene and vinylacetylene.Can adopt and contain water-acetonitrile and make solvent, obtain thick 1 by twice extracting rectifying (comprising the parsing of extracting rectifying and solvent) back, the 3-divinyl: extracting rectifying separates butylene and divinyl for the first time, extracting rectifying is removed butine and vinylacetylene for the second time, needs 4 towers to finish the extracting rectifying process operation twice usually.If removing heavy constituent also needs one and takes off heavies column.Therefore, there is various, the complicated operation of required equipment in existing method, and energy expenditure is big, the outstanding shortcoming that production cost is high.

Summary of the invention:

In order to overcome the shortcoming of prior art, the present invention adopts two partitioned column integrated flow technology, makes above-mentioned twice extracting rectifying and part take off heavy constituent and operates in the tower and finish.Investment reduces, energy expenditure reduces product cost thereby this method makes.

Extracting rectifying of the present invention operates in the partitioned column with two sections wash plate and carries out, and divider upright is installed, and prevents that the liquid of both sides and vapor generation from laterally mixing.The internal structure of partitioned column is divided into the butadiene extraction rectifying section, take off the reorganization segmentation, alkynes extracting rectifying section, tower zone, shared middle part, solvent are resolved section, the alkynes section of steaming and tower zone, shared bottom; The butadiene extraction rectifying section with take off reorganization segmentation, the alkynes extracting rectifying section wash plate by epimere at interval; Solvent parsing section and the alkynes section of steaming are with the wash plate interval of hypomere, by shared middle part tower interregional separate of the cover plate on the alkynes section of steaming with alkynes section of steaming and top; Be provided with the condenser of raffinating oil on butadiene extraction rectifying section top; Be provided with the crude butadiene condenser taking off reorganization segmentation top, when needs take off heavy constituent, be furnished with the conventional distillation operation that the side line tower realizes taking off heavy constituent taking off reorganization segmentation bottom, the side line tower bottom is provided with and takes off the heavies column reboiler, when not needing to take off heavy constituent, remove side line tower and related accessory; Be provided with intermediate reboiler in tower zone, shared middle part, be provided with the alkynes condenser, to reclaim heat at the entrance of the alkynes section of steaming; Be provided with reboiler in tower zone, shared bottom.

Be equipped with structured packing or tower tray in the tower as internals, the column plate internals without limits.The tower tray of design makes the liquid residence time in the tower be no more than 15 minutes, optimal value 10 minutes.

The present invention is similar to the conventional rectification tower, is provided with overhead condenser and tower still reboiler, can move continuously usually.With theoretical plate number hereinafter for to calculate downwards from cat head.

Extracting method of the present invention is: add moisture acetonitrile solvent logistics on partitioned column butadiene extraction rectifying section top, the middle part adds the mixed c 4 logistics, and gaseous stream, condensing reflux are arranged at the top, and obtain the logistics of raffinating oil based on butylene; The material logistics of drawing of coming out at the bottom of the butadiene extraction rectifying section forms the feed back logistics through intermediate reboiler and enters tower zone, shared middle part, in this section realization heat energy recycle, and has gaseous stream to go alkynes extracting rectifying section; Add moisture acetonitrile solvent logistics on the top of alkynes extracting rectifying section, realize the operation of alkynes extracting rectifying; Gaseous stream, condensing reflux are arranged taking off reorganization segmentation top, and obtain product stream based on divinyl; When needs took off heavy constituent, taking off reorganization segmentation lower end had liquid phase stream to introduce the side line tower, has gaseous stream to return and takes off heavies column, obtains the heavy constituent logistics at the bottom of the side line tower; When not needing to take off heavy constituent, can be without the side line tower; Resolve the operation that section realizes steaming divinyl at solvent; Realize steaming the operation of butine and vinylacetylene in the alkynes section of steaming, gaseous stream, condensing reflux are arranged at the top, carbon four alkynes and the vinylacetylene logistics of liquid phase extraction safety content; Realize steaming of alkynes obtaining the pure solvent logistics in shared bottom tower zone, through recovery of heat and modified after recycling.

According to the present invention, finish the butadiene extraction distillation operation at the butadiene extraction rectifying section, from then on the C 4 mixture cut adds at the section middle part, and moisture acetonitrile solvent adds from top, and four streams are arranged at the top.Moisture acetonitrile solvent add-on is adjusted to 4.1～8.9, optimal value 5.2～7.5 with the ratio of C 4 mixture amount.The trim the top of column amount is adjusted to 2.0～5.2, optimal value 2.3～4.0 with the ratio of produced quantity.Butadiene extraction theoretical number of plates of rectifying section 50～110, optimal value 70～100.The solvent feed plate is positioned at theoretical stage 2～8, optimal value 3～6.C 4 mixture fraction charging theoretical stage 25～60, optimal value 35～50.The cat head working pressure is adjusted to 0.42～0.58MPa (A), optimal value 0.45～0.52MPa (A).The cat head service temperature is adjusted to 35～50 ℃, 40～45 ℃ of optimal values.

According to the present invention, finish the extracting rectifying operation of carbon four alkynes and vinylacetylene in alkynes extracting rectifying section: from then on the butadiene stream of carbon containing four alkynes and vinylacetylene enters this section in the section lower end, and moisture acetonitrile solvent adds from top, and backflow is arranged at the top.Solvent adding amount is adjusted to 1.2～3.3, optimal value 1.5～2.8 with the ratio of crude butadiene amount.Quantity of reflux is adjusted to 2.8～5.4, optimal value 3.0～4.8 with the ratio of cat head produced quantity.This pars infrasegmentalis rising tolerance is adjusted to 0.32～0.65, optimal value 0.39～0.58 with the ratio of shared middle part tower district rising tolerance.The setting of this ratio realizes by column internals or cat head vapor phase stream variable valve.This section number of theoretical plate 50～80, optimal value 40～60.The solvent feed plate is positioned at the side line tower and draws theoretical stage 5～20 under the flitch, optimal value 7～12.

According to the present invention, take off the reorganization segmentation finish heavy constituent 1,2-butylene and the carbon five etc. that remove in the crude butadiene product; Backflow is arranged at this section top, and reflux ratio is adjusted to 3.0～6.2, optimal value 4.0～5.8.This section number of theoretical plate 30～60, optimal value 45～55.The cat head working pressure is adjusted to 0.42～0.58MPa (A), optimal value 0.45～0.52MPa (A).The cat head service temperature is adjusted to 35～50 ℃, 38～43 ℃ of optimal values.

According to the present invention, in the time of need taking off heavy constituent, draw material between reorganization segmentation and the alkynes extracting rectifying section and remove the side line tower taking off, this side line tower is finished the operation of extraction heavy constituent, this tower number of theoretical plate 15～35, optimal value 25～32, the feed liquid phasor of drawing of side line tower accounts for 20%～40% of its upper tray decline amount of liquid phase, optimal value 25%～32%.

According to the present invention, realize operations such as heat recuperation and shunting steam flow in shared middle part tower zone, this section number of theoretical plate 3～10, optimal value 4～8.

According to the present invention, resolve section at solvent and finish the solvent parse operation, promptly from solvent, steam divinyl.This section number of theoretical plate 6～20, optimal value 8～15.

According to the present invention, finish the operation that from solvent, steams butine and vinylacetylene in the alkynes section of steaming.From then on the solvent stream of carbon containing four alkynes and vinylacetylene enters the section lower end, and backflow is arranged at the top, and reflux ratio is adjusted to 3.1～6.5, optimal value 3.5～5.3.The ratio that rises tolerance and shared bottom tower zone rising tolerance on the bottom is adjusted to 0.11～0.25, optimal value 0.12～0.20.The setting of this ratio realizes by column internals or section top vapor phase stream variable valve.This section number of theoretical plate 6～16, optimal value 7～13.

According to the present invention, finish the operation that from solvent, steams butine and vinylacetylene in tower zone, shared bottom, make and obtain qualified circulating solvent at the bottom of the tower.This tower section number of theoretical plate 5～13, optimal value 6～10.

Description of drawings:

Fig. 1 is apparatus of the present invention structural principle synoptic diagram.

Fig. 2 is the structural principle synoptic diagram behind apparatus of the present invention remodeling, the i.e. rough schematic view of device when not needing to be temporarily released from one's regular work the product heavy constituent.

Specific embodiments:

Below by embodiment apparatus of the present invention and method are described further.

Embodiment 1:

Apparatus of the present invention partitioned column 1 internal structure is divided into butadiene extraction rectifying section 5, take off reorganization segmentation 32, alkynes extracting rectifying section 6, tower zone, shared middle part 7, solvent are resolved section 8, the alkynes section of steaming 9 and tower zone, shared bottom 10; Butadiene extraction rectifying section 5 with take off reorganization segmentation 32, alkynes extracting rectifying section 6 wash plate 2 by epimere at interval; Solvent is resolved wash plate 3 intervals of section 8 and the alkynes section of steaming 9 usefulness hypomeres, by upper end cover plate 4 the shared middle part tower zone 7 of the alkynes section of steaming 9 with top is separated; Be provided with the condenser 11 of raffinating oil on butadiene extraction rectifying section 5 tops; Be provided with crude butadiene condenser 12 taking off reorganization segmentation 32 tops, when needs take off heavy constituent, be furnished with the conventional distillation operation that side line tower 33 realizes taking off heavy constituent taking off reorganization segmentation 32 bottoms, side line tower 33 bottoms are provided with takes off heavies column reboiler 37; Be provided with intermediate reboiler 15 in tower zone, shared middle part 10, be provided with alkynes condenser 14 at the entrance of the alkynes section of steaming 9; Be provided with reboiler 15 in tower zone, shared bottom 10.

Be on the 49th theoretical stage of the C 4 mixture stream 17 of 54 ℃ the 12248.87kg/h butadiene extraction rectifying section 5 that adds the partitioned column 1 that has 140 theoretical stages altogether with gaseous form with temperature, moisture acetonitrile solvent logistics 16 joins on the 4th theoretical stage, moisture acetonitrile solvent and C 4 mixture weight ratio are 5.8: 1.0, product considers to remove heavy constituent, adopt Fig. 1 flow process, C 4 mixture has the weight percentage of following composition:

Propane 0.43

Propine 0.38

Normal butane 2.00

Trimethylmethane 0.75

Iso-butylene 18.51

1-butylene 15.53

Instead-2-butylene 4.71

Suitable-2-butylene 3.78

1,3-butadiene 52.04

1 0.01

Ethyl acetylene 0.40

Vinylacetylene 0.59

Carbon 5 0.87

Gaseous stream 22, condensing reflux 23 are arranged at partitioned column 1 top, and obtain the logistics 18 of raffinating oil based on butylene.The material logistics 28 of drawing of coming out from 5 ends of butadiene extraction rectifying section enters tower zone, shared middle part 7 through intermediate reboiler 13 formation feed back logistics 29, realizes heat energy recycle in this section, and has gaseous stream to go alkynes extracting rectifying section 6.Add moisture acetonitrile solvent logistics 31 on the top of alkynes extracting rectifying section 6, realize the operation of alkynes extracting rectifying.Be furnished with the conventional distillation operation that side line tower 33 realizes taking off heavy constituent taking off reorganization segmentation 32, gaseous stream 24, condensing reflux 25 are arranged at the top, and obtain the product stream 20 based on divinyl.Taking off reorganization segmentation 32 lower ends has liquid phase stream 34 to introduce side line tower 33, has gaseous stream 35 to return and takes off

reorganization segmentation

32, and 33 ends of side line tower obtain heavy constituent logistics 36.Resolve the operation that section 8 realizes steaming divinyl at solvent.Realize steaming the operation of butine and vinylacetylene in the alkynes section of steaming 9, gaseous stream 26, condensing reflux 27 are arranged at the top, and liquid phase extraction 21 is carbon four alkynes and the vinylacetylene logistics of safe content.10 realize steaming of alkynes in shared bottom tower zone, obtain pure solvent logistics 19, through recovery of heat and modified after recycling.Logistics 30 is the recycle stream of reboiler.

According to Fig. 1, butadiene extraction rectifying section 5 number of theoretical plates 100, take off reorganization segmentation 32 number of theoretical plates 50, alkynes extracting rectifying section 6 number of theoretical plates 50, tower zone, shared middle part 7 number of theoretical plates 16, solvent is resolved section 8 number of theoretical plates 14, the alkynes section of steaming 9 number of theoretical plates 14, shared bottom tower zone 10 number of theoretical plates 10.Moisture acetonitrile solvent logistics 31 joins on the 67th block of plate, and its amount is 1.9: 1.0 with the ratio of cymogene alkene.The amount of liquid of introducing the side line tower accounts for 27% of dropping liq amount.Butadiene extraction rectifying section 5 tops are all 0.495MPa (A) with the working pressure that takes off reorganization segmentation 32 tops.

Take off the divinyl 6386.68kg/h that reorganization segmentation 32 top obtains not contain heavy constituent, purity 98.88% (wt), the rate of recovery 99.0%, carbon containing four alkynes≤20ppm wherein, vinylacetylene≤5ppm.Butadiene extraction rectifying section 5 tops obtain to raffinate oil 5497.44kg/h, wherein contain divinyl≤100ppm.Obtain to contain water-acetonitrile, hydrocarbon content≤50ppm at the bottom of the tower.Meet the requirement of the refining divinyl of postorder workshop section fully.Tower still reboiler thermal load 2.4755 * 10 ⁴MJ/h.Be equivalent to product crude butadiene per ton (having taken off heavy constituent) and consume steam 1.6129t.

Embodiment 2:

Product does not consider to take off heavy constituent, and the partitioned column structure has been removed side line tower 33 and related accessory, adopts Fig. 2 flow process, and all the other are identical with embodiment 1.

Be on the 36th theoretical stage of the C 4 mixture stream 17 of 54.0 ℃ the 13498.4kg/h butadiene extraction rectifying section 5 that adds the partitioned column that has 100 theoretical stages altogether with gaseous form with temperature, moisture acetonitrile solvent logistics 16 joins on the 4th theoretical stage, moisture acetonitrile solvent and C 4 mixture weight ratio are 5.4: 1.0, and C 4 mixture has the weight percentage of following composition:

Propane 0.5047

Propine 0.1019

Normal butane 1.3094

Trimethylmethane 0.3802

Iso-butylene 23.3535

1-butylene 16.6869

Instead-2-butylene 5.1783

Suitable-2-butylene 3.8939

1,3-butadiene 47.5445

1 0.3046

1-acetylene 0.1278

Vinylacetylene 0.5488

Carbon 5 0.0655

According to Fig. 2, butadiene extraction rectifying section 5 number of theoretical plates 60, alkynes extracting rectifying section 6 number of theoretical plates 50, tower zone, shared middle part 7 number of theoretical plates 16, solvent is resolved section 8 number of theoretical plates 14, the alkynes section of steaming 9 number of theoretical plates 14, shared bottom tower zone 10 number of theoretical plates 10.Moisture acetonitrile solvent logistics 31 joins on the 8th theoretical stage, and its amount is 1.6: 1 with the ratio of cymogene alkene.Butadiene extraction rectifying section 5 tops are all 0.52MPa (A) with the working pressure on alkynes extracting rectifying section 6 tops.Alkynes extracting rectifying section 6 tops obtain crude butadiene 7045.30kg/h, purity 94.24% (wt), the rate of recovery 99.0%.Wherein carbon containing four alkynes≤20ppm, vinylacetylene≤5ppm.Butadiene extraction rectifying section 5 tops obtain to raffinate oil 6652.33kg/h, wherein contain divinyl≤100ppm.Obtain the pure water-acetonitrile that contains, alkynes content≤50ppm at the bottom of the tower.Meet the requirement of the refining divinyl of postorder workshop section fully.Tower still reboiler thermal load 2.780 * 10 ⁴MJ/h.Thick product divinyl quite per ton consumes steam 1.6416t.

The present invention compares with the conventional tower flow process owing to adopt highly integrated partitioned column technology, and investment saves 35%, and cost of energy saves 28%.

Claims

1. A device for extracting crude 1,3-butadiene from a double-baffle column, characterized in that the internal structure of the baffle tower is divided into a butadiene extraction and rectification section, a weight removal section, an alkyne extraction and rectification section, Share the middle tower area, solvent analysis section, alkyne distillation section and share the lower tower area; butadiene extraction and rectification section and decombination section, alkyne extraction and rectification section are separated by vertical partitions in the upper section; solvent analysis section The alkyne distillation section is separated from the alkyne distillation section by the vertical partition in the lower section, and the alkyne distillation section is separated from the upper common middle tower area by the cover plate at the upper end of the alkyne distillation section; There is a raffinate condenser; a crude butadiene condenser is installed at the top of the deheavy section. When the deheavy component is required, a side line tower is installed at the bottom of the deheavy section to realize the ordinary rectification operation of the deheavy component. A reboiler for the deheavy fraction tower is installed at the bottom of the side line column. When deheavy components are not needed, the side line tower and related accessories are removed; an intermediate reboiler is installed in the common middle tower area, and a reboiler is installed at the inlet section of the alkyne distillation section. There is an alkyne condenser; there is a reboiler in the common lower column area.

2. The device for extracting crude 1,3-butadiene in a double partition column according to claim 1, characterized in that the partitions are installed vertically to prevent horizontal mixing of liquid and steam on both sides.

3. The device for extracting crude 1,3-butadiene from a double partition tower according to claim 1, characterized in that the tower is equipped with structured packing or trays as internals, and the designed trays allow the liquid in the tower to stay Do not exceed 15 minutes.

4. A method for extracting thick 1,3-butadiene in a double-baffle tower, characterized in that the water-containing acetonitrile solvent stream is added to the upper part of the butadiene extraction and rectification section of the divider tower, and the mixed C4 stream is added in the middle, and the top has The gaseous phase stream, condensed and refluxed, and a raffinate stream mainly composed of butene is obtained; the feed stream from the bottom of the butadiene extraction and rectification section passes through an intermediate reboiler to form a return stream and enters the shared middle tower area. Recycling of heat energy is realized, and there is a gas phase flow to the alkyne extraction and rectification section; water-containing acetonitrile solvent stream is added to the upper part of the alkyne extraction and rectification section to realize the alkyne extraction and rectification operation; there are gas phase streams, Condensate and reflux, and obtain a product stream mainly composed of butadiene; when heavy components need to be removed, the liquid phase flow at the lower end of the heavy removal section is introduced into the side line tower, and the gas phase flow returns to the heavy component tower, and the heavy components are obtained at the bottom of the side line tower Logistics; when there is no need to remove heavy components, the side line tower is not used; the operation of distilling butadiene is realized in the solvent analysis section; the operation of distilling butyne and vinyl acetylene is realized in the alkyne distillation section, and there are gas phase streams at the top, Condensation and reflux, the liquid phase extracts safe content of carbon tetrayne and vinyl acetylene streams; realizes the distillation of alkynes in the common lower tower area, and obtains pure solvent streams, which can be recycled after heat recovery and conditioning.

5. The method for extracting crude 1,3-butadiene in a double-baffle column according to claim 4, characterized in that the butadiene extraction and rectification operation is completed in the butadiene extraction and rectification section, and the addition of aqueous acetonitrile solvent The ratio to the amount of carbon four mixture is adjusted to 4.1-8.9, the ratio of the top reflux to the output is adjusted to 2.0-5.2, the number of theoretical plates in the butadiene extraction and rectification section is 50-110, and the solvent feed plate is located on the theoretical plate 2 to 8, the C4 mixture fraction is fed to a theoretical plate of 25 to 60, the operating pressure at the top of the tower is adjusted to 0.42 to 0.58 MPa (A), and the operating temperature at the top of the tower is adjusted to 35 to 50°C.

6. The method for extracting crude 1,3-butadiene in a double-baffle tower according to claim 4, characterized in that the extraction and rectification operations of carbon tetraacetylene and vinyl acetylene are completed in the alkyne extraction and rectification section, The butadiene stream containing carbon tetraacetylene and vinyl acetylene enters this section from the lower end of this section, and the aqueous acetonitrile solvent is added from the upper part, and there is reflux at the top; the ratio of the amount of solvent added to the amount of crude butadiene is adjusted to 1.2-3.3. The ratio of the flow rate to the output at the top of the tower is adjusted to 2.8-5.4, the ratio of the rising gas volume in the lower part of this section to the rising gas volume in the common middle tower area is adjusted to 0.32-0.65, the number of theoretical plates in this section is 50-80, and the solvent feed plate is located in the side line There are 5-20 theoretical plates under the tower guide plate.

7. The method for extracting crude 1,3-butadiene in a double-baffle tower according to claim 4, characterized in that the removal of the heavy component 1,2-butadiene in the crude butadiene product is completed in the deheavy subsection Diene, 2-butene and C5; there is reflux at the top of this section, and the reflux ratio is adjusted to 3.0-6.2. The operating temperature is adjusted to 35-50°C.

8. The method for extracting crude 1,3-butadiene in a double-baffle tower according to claim 4, characterized in that when deheavy components are required, the material is extracted between the deheavy subsection and the alkyne extraction and rectification section Remove the side line tower, which completes the operation of extracting heavy components. The number of theoretical plates in this tower is 15-35, and the liquid phase volume of the feed material in the side line tower accounts for 20%-40% of the descending liquid phase volume of the upper tray.

9. The method for extracting crude 1,3-butadiene in a double-baffle tower according to claim 4, characterized in that heat recovery and split steam flow operation are realized in the common middle tower area, and the number of theoretical plates in this section is 3-10 .

10. The method for extracting crude 1,3-butadiene in a double partition tower according to claim 4, characterized in that the solvent analysis operation is completed in the solvent analysis section, that is, the butadiene is distilled from the solvent. The number of boards is 6-20.

11. The method for extracting crude 1,3-butadiene in a double-baffle column according to claim 4, characterized in that the operation of distilling butyne and vinyl acetylene from the solvent is completed in the alkyne distillation section, including The solvent flow of carbon tetrayne and vinyl acetylene enters from the lower end of this section, and there is reflux at the top. The reflux ratio is adjusted to 3.1-6.5, and the ratio of the rising gas volume in the lower part to the rising gas volume in the common lower tower area is adjusted to 0.11-0.25. The theoretical plate number of this section is 6~16.

12. The method for extracting crude 1,3-butadiene in a double partition tower according to claim 4, characterized in that the operation of distilling butyne and vinyl acetylene from the solvent is completed in the common lower tower area, and the tower The number of theoretical boards is 5-13.