CN219252166U - Device for improving separation effect of gas separation tower in vinyl acetate production system - Google Patents
Device for improving separation effect of gas separation tower in vinyl acetate production system Download PDFInfo
- Publication number
- CN219252166U CN219252166U CN202320708346.1U CN202320708346U CN219252166U CN 219252166 U CN219252166 U CN 219252166U CN 202320708346 U CN202320708346 U CN 202320708346U CN 219252166 U CN219252166 U CN 219252166U
- Authority
- CN
- China
- Prior art keywords
- liquid
- tower
- section
- branch pipe
- gas
- 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
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The utility model discloses a device for improving the separation effect of a gas separation tower in a vinyl acetate production system, which comprises a reaction liquid collecting tank, an absorption tower and an analysis tower, wherein a reaction liquid output pipeline of the reaction liquid collecting tank and an absorption liquid output pipeline of the absorption tower are converged and then connected to an absorption liquid inlet of the analysis tower through a first heat exchanger, and the analysis liquid output pipeline of the analysis tower returns to the gas separation tower and a three-stage circulating liquid storage tank for storing third-stage circulating liquid of the gas separation tower after sequentially passing through the first heat exchanger and a second heat exchanger. The device for improving the separation effect of the gas separation tower in the vinyl acetate production system reduces the side reaction of the synthesis process and improves the quality of vinyl acetate.
Description
Technical Field
The utility model belongs to the field of vinyl acetate production, and particularly relates to a device for improving the separation effect of a gas separation tower in a vinyl acetate production system.
Background
Vinyl Acetate (VAC) is an important organic chemical raw material, has wide industrial development prospect, the current production method of vinyl acetate comprises an acetylene method, a vinyl method and other methods, wherein the acetylene method is widely used, the vinyl acetate is synthesized by using the acetylene method and comprises two working sections of synthesis and separation, the synthesis working section takes acetylene and acetic acid as raw materials, the vinyl acetate (high-temperature synthesis mixed gas) is catalytically synthesized in a vinyl acetate fluidized bed synthesis reactor through active carbon loaded zinc acetate as a catalyst, the separation working section is that the high-temperature synthesis mixed gas is discharged from the vinyl acetate fluidized bed synthesis reactor and then enters a gas separation tower for separation, and high-boiling-point substances such as acetic acid and vinyl acetate in the high-temperature synthesis mixed gas are liquefied and separated from noncondensable gases such as acetylene and nitrogen, so that the circulating acetylene and the liquefied vinyl acetate and acetic acid are obtained. In order to improve the gas separation effect, the prior measures include: (1) The method has the advantages that the content of vinyl acetate and acetaldehyde in the circulating acetylene is reduced by adding new acetic acid into the circulating liquid in the three-section circulating liquid storage tank, and the method has a certain effect, but increases the load of a subsequent rectifying tower; (2) Closing a liquid discharge valve of a gas-liquid separator of the gas separation tower, thereby avoiding that tail gas of a three-stage circulating liquid storage tank directly enters a vinyl acetate fluidized bed synthesis reactor without washing; (3) And (3) draining the liquid in the gas-liquid separator of the gas separation tower according to the system operation at regular intervals, so as to ensure the normal operation of the gas-liquid separator. However, the existing gas separation tower still has poor separation effect, so that a large amount of unseparated vinyl acetate (with the proportion of 1.0-1.5V%) and acetaldehyde (with the proportion of 6.0-8.0V%) contained in the circulating acetylene enter the vinyl acetate fluidized bed synthesis reactor again to undergo secondary reaction, thereby increasing byproducts, directly affecting the quality of vinyl acetate and the quality of the subsequent product polyvinyl alcohol, and the average number of sudden deterioration times of the synthesis reaction is more than 8 times per year, so that the frequent start and stop causes great economic loss and brings a certain potential safety hazard.
Disclosure of Invention
Aiming at the problems of poor separation effect of a gas separation tower, low purity of circulating acetylene, large load of subsequent rectification operation and the like in the prior art, the utility model provides a device for improving the separation effect of the gas separation tower in a vinyl acetate production system, which reduces side reactions of a synthesis procedure and improves the quality of vinyl acetate.
The utility model relates to a device for improving the separation effect of a gas separation tower in a vinyl acetate production system, which comprises a reaction liquid collecting tank for storing circulating liquid of the gas separation tower, an absorption tower, an analysis tower for releasing the absorption liquid and dissolved gas in the reaction liquid collecting tank, wherein a reaction liquid output pipeline of the reaction liquid collecting tank and an absorption liquid output pipeline of the absorption tower are converged and then connected to an absorption liquid inlet of the analysis tower through a first heat exchanger, and the analysis liquid output pipeline of the analysis tower returns to the gas separation tower and a three-stage circulating liquid storage tank for storing third-stage circulating liquid of the gas separation tower after sequentially passing through the first heat exchanger and a second heat exchanger.
Further, an absorption liquid output pipeline is connected with the bottom of the absorption tower, and a vent pipeline is arranged at the top of the absorption tower.
Further, a first liquid pump for supplying power to the mixed liquid is arranged on the mixed liquid output pipeline between the junction of the reaction liquid output pipeline and the absorption liquid output pipeline and the first heat exchanger.
Further, the mixed liquor output pipeline is connected with the low-temperature liquid inlet of the first heat exchanger, and is connected with the absorption liquid inlet of the resolution tower through the low-temperature liquid outlet of the first heat exchanger, and the absorption liquid inlet of the resolution tower is preferably positioned in the middle of the resolution tower.
Further, a second liquid pump for providing power for the resolving liquid is arranged on the resolving liquid output pipeline between the resolving tower and the first heat exchanger.
Further, a reboiler (the reboiler is used for reheating the desorption liquid, part of components of the desorption liquid are vaporized and returned to the desorption tower to exchange with the desorption liquid entering from the upper part of the desorption tower again) is arranged at the bottom of the desorption tower, a desorption liquid output pipeline is connected with a liquid inlet of the reboiler, a vapor output pipeline of the reboiler is returned to the desorption tower, and a liquid output pipeline of the reboiler is connected with a second liquid pump.
Further, the analysis liquid output pipeline is connected with the high-temperature liquid inlet of the first heat exchanger, is connected with the high-temperature liquid inlet of the second heat exchanger after passing through the high-temperature liquid outlet of the first heat exchanger, and is output through the high-temperature liquid outlet of the second heat exchanger, the low-temperature liquid inlet of the second heat exchanger is connected with the cooling liquid input pipeline (for example, the cooling liquid input pipeline can be a chilled water input pipeline), and the first heat exchanger and the second heat exchanger are respectively a shell-and-tube heat exchanger or a plate heat exchanger, preferably a plate heat exchanger.
Further, the analytic liquid output pipeline is divided into three branch pipes after sequentially passing through the first heat exchanger and the second heat exchanger, the first branch pipe is connected with the analytic liquid inlet of the absorption tower, the second branch pipe returns to the top of the analytic tower, the third branch pipe is divided into a fourth branch pipe and a fifth branch pipe, the fourth branch pipe is connected with the analytic liquid inlet of the tower three-section liquid inlet of the gas separation tower, and the fifth branch pipe is connected with the analytic liquid inlet of the three-section circulating liquid storage tank.
Further, the reaction liquid output pipeline of the reaction liquid collecting tank is connected with the finished product storage tank of the tank area through a fourteenth branch pipe, and preferably, the reaction liquid output pipeline of the reaction liquid collecting tank is separated from the fourteenth branch pipe after passing through a sixth liquid pump.
Further, the gas separation tower sequentially comprises a first tower section, a second tower section and a third tower section from bottom to top, wherein the first tower section is connected with a high-temperature synthesis mixed gas input pipeline, and a first tower section circulating liquid output pipeline of the first gas separation tower section returns to the first tower section after passing through a fifth liquid pump;
the second-section circulating liquid output pipeline of the second section of the gas separation tower is connected with a liquid inlet of a second-section circulating liquid storage tank for storing second-section circulating liquid, and the second-section circulating liquid output pipeline of the second-section circulating liquid storage tank is sequentially divided into a tenth branch pipe and an eleventh branch pipe after passing through a fourth liquid pump and a fourth heat exchanger, the tenth branch pipe returns to the second section of the tower, and the eleventh branch pipe is connected with a reaction liquid inlet of the reaction liquid collecting tank;
the third-section liquid output pipeline of the third section of the gas separation tower is connected with the circulating liquid inlet of the third-section circulating liquid storage tank, the circulating liquid output pipeline of the third-section circulating liquid storage tank is divided into a sixth branch pipe and a seventh branch pipe after passing through a third liquid pump, the sixth branch pipe returns to the third section of the gas separation tower after passing through a third heat exchanger, the seventh branch pipe is divided into an eighth branch pipe and a ninth branch pipe, the eighth branch pipe is connected with the reacting liquid inlet of the reacting liquid collecting tank, and the ninth branch pipe is connected with the second section of the gas separation tower.
Further, the gas output pipeline at the top of the gas separation tower is connected with the gas-liquid separator, the gas output pipeline of the gas-liquid separator is separated into a twelfth branch pipe and a thirteenth branch pipe, the twelfth branch pipe is returned to the vinyl acetate synthesis section, the thirteenth branch pipe is connected to the gas inlet of the absorption tower after passing through the compressor (part of circulating gas output from the gas-liquid separator enters the absorption tower to prevent excessive circulating gas from being stored in the vinyl acetate synthesis section so as to influence the synthesis of vinyl acetate, acetylene and acetaldehyde in the circulating gas entering the absorption tower are absorbed by analytic liquid in the absorption tower, non-condensable gas is discharged from the top of the absorption tower), the liquid discharge pipe of the gas-liquid separator is connected with the three-section circulating liquid storage tank to form a liquid seal, and tail gas carried by the third-section circulating liquid in the three-section circulating liquid storage tank is prevented from returning to the vinyl acetate synthesis section through the liquid discharge pipe (after the third-section circulating liquid enters the three-section circulating liquid storage tank, because the pressure is reduced), and if no liquid seal exists, the overflowed gas returns to the circulating gas and enters the fluidized bed reactor after entering the circulating gas storage tank of the acetylene after passing through the gas-liquid separator, thereby increasing the auxiliary reactor.
The gas separation tower disclosed by the utility model is used for carrying out sectional design and sectional absorption transformation on conventional equipment well known by a person skilled in the art, wherein the first section of the gas separation tower is used for washing catalyst powder contained in high-temperature synthesis mixed gas by using a first section circulating liquid of the first section of the gas separation tower, and the temperature of the first section of circulating liquid is controlled to be 90+/-5 ℃; the second section of the tower is to condense most of high-boiling substances such as acetic acid, vinyl acetate, aldehydes, water and the like, and the temperature of the circulating liquid in the second section is controlled at 18-35 ℃; the third section of the tower is to separate non-condensable acetylene, and the temperature of the circulating liquid in the third section is controlled at-3-1 ℃.
The high-temperature synthesis mixed gas output from the vinyl acetate fluidized bed synthesis reactor comprises about 10V% of acetic acid, about 10V% of vinyl acetate, 0-0.1V% of small amount of crotonaldehyde, 1.0-2.5V% of acetaldehyde, 74.4-77.9V% of acetylene and N 2 、O 2 CO 2 The total amount is 1.0 to 3.0V%, and the flow rate into the gas separation column may be 7000 to 8000Nm 3 And/h) entering a first section of the tower from the bottom of the gas separation tower through a high-temperature synthesis mixed gas input pipeline, contacting with a first section of circulating liquid (mainly acetic acid) on a tower plate in the upward flowing process of the high-temperature synthesis mixed gas, condensing a small amount of acetic acid in the high-temperature synthesis mixed gas to serve as the first section of circulating liquid, washing a small amount of catalyst powder (active carbon of a synthesis section and zinc acetate loaded on the active carbon) in the high-temperature synthesis mixed gas by the first section of circulating liquid, and pressurizing the first section of circulating liquid after separating the catalyst powder through a fifth liquid pump and returning the first section of circulating liquid to the first section of the tower.
The gas rises to the second section of the tower to be in countercurrent contact with the circulating liquid of the second section, most of acetic acid, part of vinyl acetate, crotonaldehyde and the like in the mixed gas are condensed to be used as the circulating liquid of the second section, the circulating liquid of the second section returns to the circulating liquid storage tank of the second section through the circulating liquid output pipeline of the second section of the tower, circulates between the gas separation tower and the circulating liquid storage tank of the second section, the circulating liquid of the second section in the circulating liquid storage tank of the second section is divided into two paths after being cooled by a fourth heat exchanger, one path returns to the second section of the tower through a tenth branch pipe to be in countercurrent contact with the gas rising to the second section of the tower, and the other path is conveyed to the reaction liquid collecting tank through an eleventh branch pipe.
The uncondensed gas continuously rises to a third section of the tower and is in countercurrent contact with third-section circulating liquid (vinyl acetate and a small amount of acetic acid), most of vinyl acetate, acetaldehyde and a trace amount of acetic acid are condensed, the condensed liquid is used as third-section circulating liquid to return to a third-section circulating liquid storage tank through a third-section liquid output pipeline of the tower, meanwhile, the cooled resolving liquid is supplemented to the third section of the tower through a fourth branch pipe, the gas is contacted with the countercurrent rising gas and then enters the third-section circulating liquid storage tank, the third-section circulating liquid in the third-section circulating liquid storage tank is output and then is divided into two paths, one path enters the third section of the tower through a sixth branch pipe and is in countercurrent contact with the gas, and the other path (the third-section circulating liquid in a seventh branch pipe) is used as a working section product to be conveyed to a second section of the tower through an eighth branch pipe or is supplemented to the third section of the tower through a ninth branch pipe, one path of the reacting liquid in the reacting liquid collection tank is used as a finished product to be conveyed to a tank field through a fourteenth branch pipe, and the other path of the reacting liquid is mixed with the absorbing liquid in the absorbing tower is conveyed to the resolving tower.
The gas output from the top of the gas separation tower is separated into a large amount of acetylene through a gas-liquid separator, and in addition, the gas also contains a small amount of nitrogen, oxygen, trace acetaldehyde, carbon dioxide, vinyl acetate and the like, so that the obtained gas containing acetylene (circulating acetylene) can be returned to the synthesis section.
The reaction liquid in the reaction liquid collecting tank comprises most of acetic acid and vinyl acetate, and a small part of water, acetylene, acetaldehyde and the like, and is derived from the reaction product of synthesizing the vinyl acetate by an acetylene method.
The process flow for improving the separation effect of the gas separation tower by using the device comprises the following steps:
(1) After part of circulating acetylene output from the top of the gas-liquid separator enters an absorption tower through a thirteenth branch pipe and a compressor, the descending analysis liquid in the absorption tower (entering the absorption tower through a first branch pipe) exchanges and absorbs the ascending circulating acetylene, most of acetylene and acetaldehyde in the circulating acetylene are absorbed and dissolved to obtain absorption liquid, the reaction liquid in a reaction liquid collecting tank (the reaction liquid component formed by volume percentage comprises 55V of acetic acid, 1.5V of acetaldehyde, 0.04V of water, 43.4V of vinyl acetate and trace amount of acetylene and other impurities) and the absorption liquid in the absorption tower (the absorption liquid component formed by volume percentage comprises 54.5V of acetic acid, 1.0V of acetaldehyde, 0.04V of water, 43.4V of acetylene and trace amount of other impurities) are converged (the merging proportion of the two can be 1:12) are pressurized through a first liquid pump, the temperature of the first heat exchanger is raised to 60-65 ℃ and then enters the analysis tower;
(2) Heating the mixed solution in a resolving tower, so as to release acetylene and acetaldehyde dissolved in the mixed solution, and obtaining degassed resolving solution (the resolving solution comprises vinyl acetate and acetic acid with the volume ratio of about 4:6), wherein the separated acetylene and acetaldehyde are sent to a water washing tower for further treatment through the tower top, the operating pressure in the resolving tower can be 5-10KPa, and the medium temperature can be 57+/-2 ℃ for example;
(3) The analytical solution (the flow rate may be, for example, 2 to 8m 3 And/h) cooling to about 30deg.C in a first heat exchanger by a reboiler and a second liquid pump, cooling to-3-0deg.C in a second heat exchanger, separating the cooled analysis liquid into three paths, one path (flow rate is about 75-85%, such as 80%) entering an absorption tower (operation pressure of the absorption tower can be 40-45KPa, temperature can be-3-0deg.C, for example) through a first branch pipe, absorbing and dissolving acetylene gas and acetaldehyde in circulating gas sent from a gas-liquid separator in the absorption tower to obtain absorption liquid, discharging non-condensable gas in the circulating gas from top of the absorption tower, merging the absorption liquid with the reaction liquid in a reaction liquid collecting tank, and then entering the analysis tower), and the other path (flow rate is about 5-15%, such as 10%) passing throughThe second branch pipe returns to the resolving tower (the impurity gas in the resolving liquid is resolved continuously), the last path (the flow rate is about 5-15%, for example 10%) enters a third circulating liquid storage tank of the gas separation tower or the upper part of the third section of the gas separation tower through a third branch pipe, preferably enters the upper part of the third section of the gas separation tower, when the resolving liquid after cooling completely enters the upper part of the third section of the gas separation tower, the resolving liquid and the third circulating liquid from the third section of the circulating liquid storage tank are in countercurrent contact with the gas phase rising to the third section of the tower in the gas separation tower, and when the gas phase is cooled, most of vinyl acetate (the proportion is about 43.4V% of vinyl acetate in the gas phase), acetaldehyde and trace acetic acid in the gas phase are condensed, and the acetaldehyde and the trace acetic acid are returned to the third section of the circulating liquid storage tank through a third section of liquid output pipeline of the tower; when the cooled analytic liquid is completely fed into the three-section circulating liquid storage tank to be used as the third-section circulating liquid, the analytic liquid is in countercurrent contact with the gas phase of the three-section circulating liquid storage tank of the gas separation tower, and most of vinyl acetate (the vinyl acetate in the gas phase is about 42.5V percent) and acetaldehyde and a trace of acetic acid are condensed in the gas phase at the same time when the gas is cooled, compared with the case that the cooled analytic liquid is completely fed into the upper part of the three-section circulating liquid storage tank of the gas separation tower directly, the cooling and washing effects are slightly poorer, because the cooled analytic liquid is mixed with the liquid in the circulating liquid storage tank after entering the three-section circulating liquid storage tank, the analytic liquid is diluted, and the washing effects are weakened;
(4) The third-stage circulating liquid in the third-stage circulating liquid storage tank (the flow rate may be 80-100m, for example) 3 Dividing the output into two paths, cooling one path (the flow rate is about 90%) to-3-1 ℃ through a sixth branch pipe and a third heat exchanger, returning the cooled path to the third section of the tower, on the premise of ensuring the circulation quantity, conveying the other path (the flow rate is about 10% and the third section of circulating liquid in a seventh branch pipe) to a reaction liquid collecting tank through an eighth branch pipe or supplementing the circulating liquid to the second section of the tower through a ninth branch pipe (supplementing the circulating liquid to the second section of the tower when the tower is started and stopped, fully inputting the circulating liquid to the reaction liquid collecting tank after running stability), returning one part (the flow rate is about 95-97%) of gas-phase circulating acetylene obtained after the gas output from the top of the gas separation tower through a gas-liquid separator to the vinyl acetate fluidized bed reactor through a twelfth branch pipe, and returning the other part (the flow rate is about 3-5% for example)) Delivering the mixture to an absorption tower through a thirteenth branch pipe, wherein the acetylene content in the circulating acetylene is 93.0-96.0V%, the vinyl acetate content is 0.5-1.0V% and the acetaldehyde content is 3.0-5.0V%, the circulating acetylene also comprises nitrogen, oxygen, carbon dioxide and other components, and the liquid (the composition according to the volume percentage comprises 10.0V% of acetic acid, 2.0V% of acetaldehyde, 0.04V% of water, 87.6V% of vinyl acetate, trace acetylene and other impurities) output from the gas-liquid separator is delivered to a three-stage circulating liquid storage tank;
(5) The third-stage circulating liquid supplemented to the second-stage circulating liquid storage tank of the tower and the second-stage circulating liquid from the second-stage circulating liquid storage tank of the gas separation tower are in countercurrent contact with the ascending gas phase of the second-stage circulating liquid storage tank of the gas separation tower, the gas phase is cooled, most of acetic acid (the proportion is about 80V% of acetic acid in the gas phase) and part of vinyl acetate (the proportion is about 18V% of vinyl acetate in the gas phase) in the gas phase are condensed and output from the bottom of the second-stage circulating liquid storage tank of the tower as the second-stage circulating liquid, the second-stage circulating liquid in the second-stage circulating liquid storage tank is divided into two paths, one path (the flow proportion can be 15 percent for example) enters the reaction liquid collecting tank through an eleventh branch pipe, and the other path (the flow proportion can be 85 percent for example) returns to the second-stage circulating liquid storage tank of the tower through a tenth branch pipe.
The utility model has the beneficial effects that:
(1) The reaction liquid in the reaction liquid collecting tank is mixed with the absorption liquid of the gas separation tower after the circulating gas is absorbed by the absorption tower, and then the mixture is analyzed by the analysis tower, so that acetaldehyde, acetylene and some non-condensable gases dissolved in the circulating gas can be removed;
(2) The reaction liquid in the reaction liquid collecting tank is recycled among the gas separation tower, the absorption tower and the analysis tower, so that new reaction liquid is not additionally added into the system, and the production load of a rectification tower (the rectification process is used for separating acetic acid and vinyl acetate) in the subsequent rectification process is not increased;
(3) Because the temperature of the analytic liquid added to the gas separation tower is lower than that of acetic acid added in the prior art, the condensing effect of the gas separation tower on vinyl acetate and acetaldehyde in high-temperature synthesis mixed gas can be improved, so that the content of the vinyl acetate and the acetaldehyde in the circulating acetylene is reduced, the quality of the circulating acetylene is greatly improved, the secondary reaction of synthesis is reduced, and the yield of the vinyl acetate is improved;
(4) Because the liquid outlet of the liquid discharge pipe of the gas-liquid separator extends below the liquid level of the three-section circulating liquid storage tank, the liquid seal is carried out on the liquid discharge pipe of the gas-liquid separator of the gas separation tower, and the tail gas carried by the third-section circulating liquid in the three-section circulating liquid storage tank is prevented from returning to the vinyl acetate synthesis section through the liquid discharge pipe, thereby reducing side reaction during vinyl acetate synthesis, and the gas-liquid separator does not need to be regularly discharged;
(5) Because the acetylene content in the analysis liquid returned to the gas separation tower is lower than the acetylene content in the reaction liquid collecting tank, the reaction liquid in the reaction liquid collecting tank is supplemented when the operation system is stopped and overhauled in the prior art, and the analysis liquid is supplemented in the application, therefore, the concentration of the acetylene gas in the gas separation tower is lower than that in the prior art when the equipment is stopped, the time for nitrogen replacement and the nitrogen consumption (the acetylene content is required to be less than 1% when the nitrogen replacement is stopped) can be shortened when the equipment is stopped, the replacement time can be reduced from about 16 hours to about 10 hours, and 500Nm can be saved per hour 3 The nitrogen consumption is obvious, the energy is saved, the consumption is reduced, the cost is lowered and the efficiency is improved;
(6) In the gas separation device, the reaction liquid in the reaction liquid collecting tank is mixed with the absorption liquid of the absorption tower and exchanges heat with the analysis liquid from the analysis tower in the first heat exchanger, so that self-coupling of heat flow, namely heat and cold flow, namely cold flow, in the gas separation device system and energy recycling are realized, the energy utilization efficiency in the system is improved, and the energy-saving effect is better.
Drawings
FIG. 1 is a schematic diagram of an apparatus for enhancing the separation effect of a gas separation column in a vinyl acetate production system according to the present utility model.
Reference numerals:
l1-reaction liquid output pipeline, L2-absorption liquid output pipeline, L3-analysis liquid output pipeline, L4-emptying pipeline, L5-first branch pipe, L6-second branch pipe, L7-third branch pipe, L9-fourth branch pipe, L10-fifth branch pipe, L11-tower three-section liquid output pipeline, L12-sixth branch pipe, L13-seventh branch pipe, L14-eighth branch pipe, L15-ninth branch pipe, L16-drain pipe, L17-third-section circulating liquid output pipeline, L18-second-section circulating liquid output pipeline, L19-tenth branch pipe, L20-eleventh branch pipe, L21-twelfth branch pipe, L22-thirteenth branch pipe, L23-mixed liquid output pipeline, L24-high temperature synthesis mixed gas input pipeline, L25-tower one-section circulating liquid output pipeline, L26-fourteenth branch pipe, L27-tower two-section circulating liquid output pipeline;
the device comprises a 1-reaction liquid collecting tank, a 2-absorption tower, a 3-first heat exchanger, a 4-resolving tower, a 5-second heat exchanger, a 6-gas separation tower, a 6-1-tower first section, a 6-2-tower second section, a 6-3-tower third section, a 7-third circulating liquid storage tank, an 8-first liquid pump, a 9-second liquid pump, a 10-reboiler, a 11-third heat exchanger, a 12-gas-liquid separator, a 13-third liquid pump, a 14-fourth heat exchanger, a 15-fourth liquid pump, a 16-second circulating liquid storage tank, a 17-compressor, a 18-fifth liquid pump and a 19-sixth liquid pump.
Detailed Description
The utility model is further described below with reference to the drawings and examples.
As shown in fig. 1, the device for improving the separation effect of the gas separation tower in the vinyl acetate production system comprises a reaction liquid collecting tank 1 for storing circulating liquid of the gas separation tower, an absorption tower 2, and a resolving tower 4 for releasing absorption liquid and gas in the reaction liquid collecting tank, wherein a reaction liquid output pipeline L1 of the reaction liquid collecting tank 1 and an absorption liquid output pipeline L2 of the absorption tower 2 are converged and then connected to an absorption liquid inlet of the resolving tower 4 through a first heat exchanger 3, and a resolving liquid output pipeline L3 of the resolving tower 4 sequentially passes through the first heat exchanger 3 and a second heat exchanger 5 and then returns to the gas separation tower 6 and a three-stage circulating liquid storage tank 7 through a third branch pipe L7, a fifth branch pipe L10 and a fourth branch pipe L9.
The absorption liquid output pipeline L2 is connected with the bottom of the absorption tower 2, and the top of the absorption tower 2 is provided with a vent pipeline L4.
The mixed liquid output pipe L23 between the junction of the reaction liquid output pipe L1 and the absorption liquid output pipe L2 and the first heat exchanger 3 is provided with a first liquid pump 8 for supplying power to the mixed liquid.
The mixed liquid output pipe L23 is connected to the low-temperature liquid inlet of the first heat exchanger 3, and is connected to the absorption liquid inlet of the desorption tower 4 via the low-temperature liquid outlet of the first heat exchanger 3, and the absorption liquid inlet of the desorption tower 4 is preferably located in the middle of the desorption tower 4, for example.
A second liquid pump 9 for supplying power to the desorption liquid is provided on the desorption liquid output pipe L3 between the desorption tower 4 and the first heat exchanger 3.
A reboiler 10 is arranged at the bottom of the desorption tower 4, a desorption liquid output pipeline L3 is connected with a liquid inlet of the reboiler 10, a vapor output pipeline of the reboiler 10 returns to the desorption tower 4, and a liquid output pipeline of the reboiler 10 is connected with a second liquid pump 9.
The analytical liquid output pipeline L3 is connected with a high-temperature liquid inlet of the first heat exchanger 3, is connected with a high-temperature liquid inlet of the second heat exchanger 5 after passing through a high-temperature liquid outlet of the first heat exchanger 3, is output through a high-temperature liquid outlet of the second heat exchanger 5, and a low-temperature liquid inlet of the second heat exchanger 5 is connected with a cooling liquid input pipeline (for example, can be a chilled water input pipeline), and the first heat exchanger 3 and the second heat exchanger 5 are respectively a shell-and-tube heat exchanger or a plate heat exchanger, preferably a plate heat exchanger.
The analytical liquid output pipeline L3 is divided into three branch pipes after passing through a reboiler 10, a second liquid pump 9, a first heat exchanger 3 and a second heat exchanger 5 in sequence, wherein the first branch pipe L5 is connected with an analytical liquid inlet of the absorption tower 2, the second branch pipe L6 returns to the top of the analytical tower 4, the third branch pipe L7 is divided into a fourth branch pipe L9 and a fifth branch pipe L10, the fourth branch pipe L9 is connected with an analytical liquid inlet of a tower three-section liquid inlet of the gas separation tower 6, and the fifth branch pipe L10 is connected with an analytical liquid inlet of the three-section circulating liquid storage tank 7.
The fourteenth branch pipe L26 is connected to the product storage tank in the tank area, and preferably the fourteenth branch pipe L26 is branched from the reaction liquid output pipe of the reaction liquid collecting tank 1 after passing through the sixth liquid pump 19.
The gas separation tower 6 sequentially comprises a first tower section 6-1, a second tower section 6-2 and a third tower section 6-3 from bottom to top, wherein the first tower section 6-1 is connected with a high-temperature synthesis mixed gas input pipeline L24, and a first circulating liquid output pipeline L25 of the first gas separation tower section 6-1 returns to the first tower section 6-1 after passing through a fifth liquid pump 18.
The second-stage circulating liquid output pipeline L27 of the second-stage circulating liquid storage tank 16 for storing the second-stage circulating liquid is connected with the liquid inlet of the second-stage circulating liquid storage tank 16, the second-stage circulating liquid output pipeline L18 of the second-stage circulating liquid storage tank 16 is divided into a tenth branch pipe L19 and an eleventh branch pipe L20 after sequentially passing through the fourth liquid pump 15 and the fourth heat exchanger 14, the tenth branch pipe L19 returns to the second-stage circulating liquid storage tank 6-2, and the eleventh branch pipe L20 is connected with the reaction liquid inlet of the reaction liquid collecting tank 1.
The third-section liquid output pipeline L11 of the third section 6-3 of the gas separation tower is connected with the circulating liquid inlet of the third-section circulating liquid storage tank 7, the third-section circulating liquid output pipeline L17 of the third-section circulating liquid storage tank 7 is divided into a sixth branch pipe L12 and a seventh branch pipe L13 after passing through a third liquid pump 13, the sixth branch pipe L12 returns to the third section of the gas separation tower 6 after passing through a third heat exchanger 11, the seventh branch pipe L13 is divided into an eighth branch pipe L14 and a ninth branch pipe L15, the eighth branch pipe L14 is connected with the reacting liquid inlet of the reacting liquid collecting tank 1, and the ninth branch pipe L15 is connected with the second section of the gas separation tower 6.
The gas output pipeline at the top of the gas separation tower 6 is connected with the gas-liquid separator 12, the gas output pipeline of the gas-liquid separator 12 is divided into a twelfth branch pipe L21 and a thirteenth branch pipe L22, the twelfth branch pipe L21 returns to the vinyl acetate synthesis section, the thirteenth branch pipe L22 is connected to the gas inlet of the absorption tower after passing through the compressor 17 (part of circulating gas output from the gas-liquid separator enters the absorption tower to prevent excessive circulating gas from being stored in the vinyl acetate synthesis section so as to influence the synthesis of vinyl acetate, acetylene and acetaldehyde in the circulating gas entering the absorption tower are absorbed by analysis liquid in the absorption tower, noncondensable gas is discharged from the top of the absorption tower), the liquid outlet pipe L16 of the gas-liquid separator is connected with the three-section circulating liquid storage tank 7, and the liquid outlet of the liquid outlet pipe L16 extends to below the liquid level of the three-section circulating liquid storage tank 7 to form a liquid seal, so that tail gas brought by the three-section circulating liquid in the three-section circulating liquid storage tank 7 is prevented from returning to the vinyl acetate synthesis section through the liquid outlet pipe.
Examples
The catalyst powder contained in the high-temperature synthesis mixed gas is washed out by the first circulating liquid at one section of the gas separation tower, and the temperature of the first circulating liquid is controlled to be 90+/-5 ℃; the second section of the tower is to condense most of high-boiling substances such as acetic acid, vinyl acetate, aldehydes, water and the like, and the temperature of the circulating liquid in the second section is controlled at 18-35 ℃; the third section of the tower is to separate non-condensable acetylene, and the temperature of the circulating liquid in the third section is controlled at-3-1 ℃.
The process flow for improving the separation effect of the gas separation tower by using the device comprises the following steps:
(1) The reaction solution in the reaction solution collecting tank 1 (the reaction solution comprises 55V percent of acetic acid, 1.5V percent of acetaldehyde, 0.04V percent of water, 43.4V percent of vinyl acetate, trace acetylene and other impurities) and the absorption solution in the absorption tower 2 (the absorption solution comprises 54.5V percent of acetic acid, 1.0 percent of acetaldehyde, 0.04V percent of water, 43.4V percent of vinyl acetate, trace acetylene and other impurities) are converged (the merging proportion of the two is 1:12), and the obtained mixed solution is pressurized by a first liquid pump 8, heated to 60-65 ℃ by a first heat exchanger 3 and then enters an analysis tower 4;
(2) The mixed solution releases dissolved acetylene and acetaldehyde in the analysis tower 4 to obtain degassed analysis solution (the analysis solution comprises 56V% of acetic acid, 0.04V% of water, 43.9V% of vinyl acetate and trace other impurities according to the volume percentage), and the operation pressure in the analysis tower 4 is about 5-10KPa, and the temperature is 57+/-2 ℃;
(3) Analytical solution (flow 8 m) 3 And/h) cooling to 30 ℃ in the first heat exchanger 3 after passing through the reboiler 10 and the second liquid pump 9, cooling to-3-0 ℃ in the second heat exchanger 5, dividing the cooled analysis liquid into three paths, wherein one path (the flow rate is about 80%) enters the absorption tower 2 (for absorbing acetylene and acetaldehyde in circulating acetylene) through the first branch pipe L5, the operating pressure of the absorption tower is 40-45KPa, the temperature is-3-0 ℃, the other path (the flow rate is about 10%) returns to the analysis tower 4 through the second branch pipe L6, the last path (the flow rate is 10%) enters the upper part of the three sections of the tower of the gas separation tower 6 through the third branch pipe L7 and the fourth branch pipe L9 and is jointly used with the third-section circulation liquid from the third-section circulation liquid storage tank 7The gas rising to the third section of the tower is in countercurrent contact, and the gas is cooled, and meanwhile, the vinyl acetate (the proportion of which is about 43.4V percent of the vinyl acetate in the gas phase), the acetaldehyde and the trace acetic acid in the gas phase are condensed and returned to the third-section circulating liquid storage tank 7 as the third-section circulating liquid;
(4) The third-stage circulating liquid in the third-stage circulating liquid reservoir 7 (flow rate of 90m 3 The output of the gas-liquid separator is divided into two paths, one path (the flow accounting for 90 percent) is cooled to the temperature of minus 3 ℃ to 1 ℃ by a third heat exchanger 11 and then is returned to the third section 6-3 of the tower by a sixth branch pipe L12, the other path is divided into two paths by a seventh branch pipe L13 on the premise of ensuring the circulation quantity, the two paths are conveyed to a reaction liquid collecting tank 1 by an eighth branch pipe L14 or are supplemented to the second section 6-2 of the tower by a ninth branch pipe L15, one part (the flow accounting for 95 percent to 97 percent) of circulating acetylene obtained after the gas output from the top of the gas separation tower 6 passes through a gas-liquid separator 12 is returned to the vinyl acetate fluidized bed reactor by a twelfth branch pipe L21, the other part (the flow accounting for 3 percent to 5 percent) is conveyed to the absorption tower 2 by a thirteenth branch pipe L22, the vinyl acetate content of the circulating acetylene is 0.6V, the acetaldehyde content of the circulating acetylene is 4.3V, and the liquid output from the gas-liquid separator 12 is conveyed to a third-section circulating liquid storage tank 7 by a liquid discharge pipe L16;
(5) The third circulating liquid supplied to the second-stage 6-2 of the column through the ninth branch pipe L15 and the second circulating liquid supplied from the second-stage circulating liquid storage tank 16 are brought into countercurrent contact with the gas rising from the second-stage 6-2 of the gas separation column 6 (through the tenth branch pipe L19), the gas is cooled, most of acetic acid (the ratio of which is about 80V% of acetic acid in the gas phase) and part of vinyl acetate (the ratio of which is about 18V% of vinyl acetate in the gas phase) in the gas phase are condensed and outputted from the bottom of the second-stage 6-2 of the column as the second circulating liquid to enter the second-stage circulating liquid storage tank 16, the second circulating liquid in the second-stage circulating liquid storage tank is divided into two paths, one path enters the reaction liquid collecting tank 1 through the eleventh branch pipe L20 (the ratio of which is 15%), and the other path returns to the second-stage through the tenth branch pipe L19 (the ratio of which is 85%).
The foregoing description of the preferred embodiments of the present utility model has been presented for purposes of illustration and not of limitation. Many variations or modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the utility model. Such changes or modifications are intended to be included within the scope of the appended claims.
Claims (10)
1. The utility model provides an improve device of gas separation tower separation effect in vinyl acetate production system, a serial communication port, it includes reaction liquid collecting vat (1) that is arranged in storing gas separation tower circulation liquid, absorption tower (2), be arranged in releasing absorption liquid and reaction liquid in the reaction liquid collecting vat analysis tower (4), reaction liquid output pipeline (L1) of reaction liquid collecting vat (1) and absorption liquid output pipeline (L2) of absorption tower (2) meet the back and are connected in the absorption liquid import of analysis tower (4) through first heat exchanger (3), analysis liquid output pipeline (L3) of analysis tower (4) return to gas separation tower (6) after first heat exchanger (3), second heat exchanger (5) in proper order and be used for storing three sections circulation liquid storage tank (7) of gas separation tower third section circulation liquid.
2. The device for improving the separation effect of a gas separation tower in a vinyl acetate production system according to claim 1, wherein the analysis liquid output pipeline (L3) is divided into three branch pipes after passing through the first heat exchanger (3) and the second heat exchanger (5) in sequence, the first branch pipe (L5) is connected with an analysis liquid inlet of the absorption tower (2), the second branch pipe (L6) returns to the top of the analysis tower (4), the third branch pipe (L7) is divided into a fourth branch pipe (L9) and a fifth branch pipe (L10), the fourth branch pipe (L9) is connected with an analysis liquid inlet of a tower three-section liquid inlet of the gas separation tower (6), and the fifth branch pipe (L10) is connected with an analysis liquid inlet of the three-section circulating liquid storage tank (7).
3. The device for improving the separation effect of a gas separation tower in a vinyl acetate production system according to claim 1 or 2, wherein a gas output pipeline at the top of the gas separation tower (6) is connected with a gas-liquid separator (12), the gas output pipeline of the gas-liquid separator (12) is separated into a twelfth branch pipe (L21) and a thirteenth branch pipe (L22), the twelfth branch pipe (L21) returns to a vinyl acetate synthesis section, the thirteenth branch pipe (L22) is connected with a gas inlet of the absorption tower (2) after passing through a compressor (17), a liquid discharge pipe (L16) of the gas-liquid separator is connected with a three-section circulating liquid storage tank (7), a liquid outlet of the liquid discharge pipe (L16) extends below the liquid level of the three-section circulating liquid storage tank (7) to form a liquid seal, and tail gas in the three-section circulating liquid storage tank (7) is prevented from returning to the vinyl acetate synthesis section.
4. The device for improving the separation effect of a gas separation tower in a vinyl acetate production system according to claim 1, wherein an absorption liquid output pipeline (L2) is connected with the bottom of the absorption tower (2), and a vent pipeline (L4) is arranged at the top of the absorption tower (2).
5. The apparatus for improving the separation effect of a gas separation column in a vinyl acetate production system according to claim 4, wherein a first liquid pump (8) for supplying power to the mixed liquid is provided on a mixed liquid output pipe (L23) between a junction point of the reaction liquid output pipe (L1) and the absorption liquid output pipe (L2) and the first heat exchanger (3).
6. The apparatus for improving the separation effect of a gas separation column in a vinyl acetate production system according to claim 5, wherein the mixed liquor output pipe (L23) is connected to the low-temperature liquid inlet of the first heat exchanger (3), and is connected to the absorption liquid inlet of the desorption column (4) through the low-temperature liquid outlet of the first heat exchanger (3).
7. The device for improving the separation effect of a gas separation tower in a vinyl acetate production system according to claim 1 is characterized in that a second liquid pump (9) for supplying power to the desorption liquid is arranged on a desorption liquid output pipeline (L3) between the desorption tower (4) and the first heat exchanger (3).
8. The apparatus for improving the separation effect of a gas separation column in a vinyl acetate production system according to claim 7, wherein a reboiler (10) is provided at the bottom of the desorption column (4), a desorption liquid output pipe (L3) is connected to a liquid inlet of the reboiler (10), a vapor output pipe of the reboiler (10) is returned to the desorption column (4), and a liquid output pipe of the reboiler is connected to a second liquid pump (9).
9. The device for improving the separation effect of a gas separation tower in a vinyl acetate production system according to claim 1 or 2, wherein the analysis liquid output pipeline (L3) is connected with a high-temperature liquid inlet of the first heat exchanger (3), is connected with a high-temperature liquid inlet of the second heat exchanger (5) after passing through a high-temperature liquid outlet of the first heat exchanger (3), is output through a high-temperature liquid outlet of the second heat exchanger (5), and is connected with a cooling liquid input pipeline after passing through a low-temperature liquid inlet of the second heat exchanger (5).
10. The apparatus for improving the separation effect of a gas separation column in a vinyl acetate production system according to claim 2, wherein the gas separation column (6) comprises a first column section (6-1), a second column section (6-2) and a third column section (6-3) in this order from bottom to top, the first column section (6-1) is connected with a high temperature synthesis gas mixture input pipeline (L24), a first column section circulating liquid output pipeline (L25) of the first column section of the gas separation column returns to the first column section through a fifth liquid pump (18),
the second-stage circulating liquid output pipeline (L27) of the second-stage circulating liquid storage tank (16) of the gas separation tower is connected with a liquid inlet of the second-stage circulating liquid storage tank (6-2) for storing the second-stage circulating liquid, the second-stage circulating liquid output pipeline (L18) of the second-stage circulating liquid storage tank (16) is divided into a tenth branch pipe (L19) and an eleventh branch pipe (L20) after passing through a fourth liquid pump (15) and a fourth heat exchanger (14), the tenth branch pipe (L19) returns to the second-stage circulating liquid storage tank (6-2), the eleventh branch pipe (L20) is connected with a reaction liquid inlet of the reaction liquid collecting tank (1),
the third-section liquid output pipeline (L11) of the third section (6-3) of the gas separation tower is connected with the circulating liquid inlet of the third-section circulating liquid storage tank (7), the third-section circulating liquid output pipeline (L17) of the third-section circulating liquid storage tank (7) is divided into a sixth branch pipe (L12) and a seventh branch pipe (L13) after passing through a third liquid pump (13), the sixth branch pipe (L12) returns to the third section (6-3) of the gas separation tower (6) after passing through a third heat exchanger (11), the seventh branch pipe (L13) is divided into an eighth branch pipe (L14) and a ninth branch pipe (L15), the eighth branch pipe (L14) is connected with the reaction liquid collecting tank (1), and the ninth branch pipe (L15) is connected with the second section of the gas separation tower (6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320708346.1U CN219252166U (en) | 2023-04-03 | 2023-04-03 | Device for improving separation effect of gas separation tower in vinyl acetate production system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320708346.1U CN219252166U (en) | 2023-04-03 | 2023-04-03 | Device for improving separation effect of gas separation tower in vinyl acetate production system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219252166U true CN219252166U (en) | 2023-06-27 |
Family
ID=86856485
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320708346.1U Active CN219252166U (en) | 2023-04-03 | 2023-04-03 | Device for improving separation effect of gas separation tower in vinyl acetate production system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219252166U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116924877A (en) * | 2023-07-26 | 2023-10-24 | 天津大学 | Process and device for refining recycle gas in vinyl acetate synthesis process |
-
2023
- 2023-04-03 CN CN202320708346.1U patent/CN219252166U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116924877A (en) * | 2023-07-26 | 2023-10-24 | 天津大学 | Process and device for refining recycle gas in vinyl acetate synthesis process |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111302899B (en) | Ammonia and tertiary butanol recovery device and method in cyclohexanone ammoximation production process | |
| CN219252166U (en) | Device for improving separation effect of gas separation tower in vinyl acetate production system | |
| CN104445272A (en) | Comprehensive recycling method of transformation gas condensation liquid containing ammonia gas and carbon dioxide | |
| US11939286B2 (en) | Method for producing vinyl acetate | |
| CN114031580B (en) | Refining device and refining method for low-energy PBAT byproduct tetrahydrofuran | |
| CN105645434A (en) | Comprehensive utilization method of condensed diluted ammonia water containing ammonia gas, carbon dioxide and hydrogen sulfide | |
| CN110256202B (en) | Four-tower four-effect crude methanol refining process method | |
| CN104725191A (en) | Ethylene glycol refining and separating method and system | |
| CN105061187A (en) | A process for continuously producing m-toluic acid | |
| CN115745794A (en) | Process and device for producing vinyl acetate by ethylene method | |
| CN101798265A (en) | Novel method for preparing vinyl acetate from bioethanol | |
| CN204661587U (en) | A kind of energy-saving carbamide production system | |
| CN220176078U (en) | Distillation system for preparing high-quality absolute ethyl alcohol from synthetic gas fermented mash | |
| CN218834066U (en) | Novel separation system for acrylic acid device | |
| CN208182895U (en) | A kind of tetrahydrofuran fractional order reaction separator | |
| CN212102637U (en) | Ammonia and tert-butyl alcohol recovery device in cyclohexanone ammoximation production process | |
| CN105622366A (en) | Device and method for producing polyoxymethylene dimethyl ether DMM3-5 | |
| CN210314061U (en) | Rectification and purification device for synthesizing dimethyl oxalate by carbonylation of coal-made ethylene glycol | |
| CN102452925B (en) | Method for separating acetic acid from water | |
| CN208279528U (en) | A kind of integrated acetylene recycle device | |
| CN112409199A (en) | Continuous production process and device for amino acid methyl ester | |
| CN115672249B (en) | System, method and application for preparing isopropyl ether through isopropanol etherification reaction rectification | |
| CN221107685U (en) | Residual ammonia absorbing device in acetonitrile reactor discharge gas | |
| CN106139823B (en) | A kind of comprehensive reutilization method of coal chemical industry transformation condensate liquid stripping tail gas | |
| CN221867427U (en) | Dilute nitric acid concentrating device for treating gas-liquid-solid three-phase |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |