Method of recovering (meth)acrolein or (meth)acrylic acid and installation intended for this purpose

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of recovering (meth)acrolein or (meth)acrylic acid, including stage of cooling of gaseous reaction mixture containing (meth)acrolein or (meth)acrylic acid obtained by reaction of catalytic oxidation in vapour phase of one or both reagents selected from (A) propane, propylene or isobutylene and (B) (meth)acrolein, with molecular oxygen or gas, containing molecular oxygen, to temperature 140-250°C; contacting of said gaseous reaction mixture with solvent, whose temperature is 20-50°C, in recovery installation for recovering (meth)acrolein or (meth)acrylic acid in solvent, where said recovery installation contains contact zone, where gaseous reaction mixture contacts with solvent, having transversal section of round form and many devices of gaseous reaction mixture supply for supplying gaseous reaction mixture into contact zone, devices of gaseous reaction mixture supply are installed in contact zone at the same height directed towards contact zone centre, gaseous reaction mixture is supplied to contact zone from devices of gaseous reaction mixture supply and is subjected to collision straight in one point of contact zone, and recovery installation does not have device which prevents direct collision of gaseous mixture supplied from devices of gaseous reaction mixture supply. Invention also relates to recovery installation for recovering (meth)acrolein or (meth)acrylic acid.

EFFECT: ensuring efficient recovering (meth)acrolein or (meth)acrylic acid from gas containing (meth)acrolein or (meth)acrylic acid, preventing polymerisation.

7 cl, 5 dwg, 4 ex

 

The technical field to which the invention relates

The present invention relates to a method of trapping (meth)acrolein or (meth)acrylic acid, more specifically to method of capture (meth)acrolein or (meth)acrylic acid using a solvent to capture (meth)acrolein or (meth)acrylic acid from the gas containing (meth)acrolein or (meth)acrylic acid obtained/s catalytic oxidation of propylene, propane or isobutylene in the vapor phase using molecular oxygen.

The level of technology

(Meth)acrolein or (meth)acrylic acid is usually produced novotrubnom reactor catalytic oxidation of propylene, propane or isobutylene in the vapor phase in the presence of a mixed oxide used as a catalyst using molecular oxygen or gas containing molecular oxygen. (Meth)acrolein or (meth)acrylic acid can be released from the resulting gaseous reaction mixture by the method of capture using solvent recovery.

An example of the standard method of capture (meth)acrolein or (meth)acrylic acid from the gas containing (meth)acrolein or (meth)acrylic acid, with a solvent includes a method of trapping with the use of water or aqueous solution as catching dissolve the self. An example of this method of trapping is a well-known method with the use of cooling a large volume of gas and the regulation of the composition of the aqueous solution used for capture, extraction thus (meth)acrolein or (meth)acrylic acid (see, for example, JP 09-157213 A).

The main disadvantage of the standard method of capture (meth)acrolein or (meth)acrylic acid from the gas containing (meth)acrolein or (meth)acrylic acid, with the use of an aqueous solution lay in the fact that the (meth)acrolein or (meth)acrylic acid partly does not fully capture the stated and unloaded/stayed together with the gaseous reaction mixture, since a very large volume of the gaseous reaction mixture is supplied to the installation of the trap.

Another example of the method of capture (Mat)acrolein or (meth)acrylic acid with the solvent includes a known method with the use of cooling a large volume of gas by changing the shape or location vnutrikorpusnykh device setup capture to extract thus (meth)acrolein or (meth)acrylic acid (see, for example, JP 2001-019655 A).

Method using high-performance nozzles for vnutrikorpusnykh device setup capture is unsatisfactory because when the setup capture ISOE is isoamsa machine tower (column), the deviation from the predetermined mode of operation with increasing distilled in the upper part of the column (meth)acrylic acid causes clogging due to polymerization of acrylic acid.

Description of the invention

The present invention was created in view of the foregoing problems, and an object of the present invention must provide a method and installation for efficient capture (meth)acrolein or (meth)acrylic acid from the gas containing (meth)acrolein or (meth)acrylic acid, with the use of this setup for preventing polymerization.

To solve these problems, the applicants of the present invention conducted serious studies in which it was found that the method of supplying gaseous reaction mixture in the installation trapping affects the efficiency of operation of the capture and prevent polymerization.

Thus, the present invention provides a method of trapping (meth)acrolein or (meth)acrylic acid, comprising a stage of contacting a gaseous reaction mixture containing (meth)acrolein or (meth)acrylic acid obtained/reduction reaction of catalytic oxidation in the vapor phase of one or both of the reactants selected from (A) propane, propylene or isobutylene and (B) (meth)acrolein, molecular color the house or gas, containing molecular oxygen, with the solvent in the setup capture to extract the (meth)acrolein or (meth)acrylic acid in a solvent, where the gaseous reaction mixture is fed into the plant capture from a variety of locations and subjected to collision in the setup capture.

The present invention provides installation recovery (meth)acrolein or (meth)acrylic acid by contacting a gaseous reaction mixture containing (meth)acrolein or (meth)acrylic acid obtained/reduction reaction of catalytic oxidation in the vapor phase of one or both of the reactants selected from (A) propane, propylene or isobutylene and (B) (meth)acrolein, molecular oxygen or gas containing molecular oxygen, with the solvent, and the specified installation capture includes an area of contact, in which the gaseous reaction mixture in contact with the solvent, a variety of devices supplying gaseous reaction mixture in the area of contact and the feeder of solvent to feed of solvent in the contact area, and specified the installation of multiple devices supplying gaseous reaction mixture serves gaseous reaction mixture in such a way that ensures its impact in the area of contact.

Brief description of drawings

Figure 1 is predstavljaet a flow chart of the case for the installation of capture according to the present invention.

Figure 2 is a longitudinal section of the lower shell columns capture 2, presented in figure 1.

Figure 3 presents the cross-section of the hull columns capture 2 along the line a-a'indicated in figure 2, which shows the lower part of the column and the method of connection to the frame of the nozzles 2C.

Figure 4 presents the cross-section of the hull columns capture 2 along the line a-a'indicated in figure 2, is another way of joining nozzles 2C.

Figure 5 presents the cross-section of the hull columns capture 2 along the line a-a'indicated in figure 2, which shows another way of attaching nozzles 2d, described in example 2.

The best option of carrying out the invention

The method of capture (meth)acrolein or (meth)acrylic acid of the present invention involves the step of contacting a gaseous reaction mixture containing (meth)acrolein or (meth)acrylic acid obtained/th reaction of catalytic oxidation in the vapor phase of one or both of the reactants selected from (A) propane, propylene or isobutylene and (B) (meth)acrolein, molecular oxygen or gas containing molecular oxygen, with the solvent in the setup capture to capture (meth)acrolein or (meth)acrylic acid with a solvent.

In the present invention, the term "(meth)is crolein" referred to acrolein or methacrolein, the term "(meth)acrylic acid" refers to acrylic acid or methacrylic acid. In industrial conditions referred to in the present invention a gaseous reaction mixture containing (meth)acrolein or (meth)acrylic acid is produced by oxidation of propane, propylene, isobutylene and/or (meth)acrolein in the presence of the solid catalyst using molecular oxygen, that is the way the so-called catalytic oxidation in the vapor phase.

Hereinafter in the description as a typical example will be used acrylic acid.

A common method of obtaining acrylic acid include: a process involving the interaction of propylene with a gas containing molecular oxygen, such as air, in the presence used as a catalyst of molybdenum oxide deposited on a solid basis, from obtaining acrylic acid (one-step way: see, for example, JP 07-053448 A); the method including the interaction of propylene with molecular oxygen in the presence used as a catalyst of molybdenum oxide deposited on a solid basis, in the first reaction zone to obtain acrolein and interaction of acrolein with molecular oxygen in the presence used as a catalyst of molybdenum oxide deposited on a solid basis, in the second reaction is the first area to obtain acrylic acid (two-stage method: see, for example, JP 47-010614 A and JP 63-093747 A). The gaseous product obtained by these methods can preferably be used as the gaseous reaction mixture in the present invention.

In the present invention a gaseous reaction mixture containing acrylic acid obtained as described above, is a gas containing acrylic acid. Thus, for separation of acrylic acid from a gaseous reaction mixture of acrylic acid is subjected to contacting with the solvent for recovery of acrylic acid, and acrylic acid is obtained in the form of a solution containing acrylic acid.

The gaseous reaction mixture contains acrylic acid obtained by catalytic oxidation in the vapor phase at high temperatures, usually from about 250 to 300°C., but preferably is cooled from 140 to 250°C., in particular from 170 to 220°C before it enters the column installation capture.

The solvent used in the method of recovery of the present invention (hereinafter indicated solvent may also be referred to as "safety solvent")is not specifically limited, but preferably is an aqueous solution containing 80% (wt.) or more water, more preferably an aqueous solution, containing 85% (wt.) or more of water. Components safety solvent in addition to the funds include formaldehyde, formic acid, acetic acid and acrylic acid. Such aqueous solutions can be used as catching solvents to improve the efficiency of capture of acrylic acid.

Install trap used in the method of trapping the present invention is not specifically limited if only it enables the contacting gas with liquid and to remove the fluid, but installing the capture of the tower type, containing a column for trapping is preferred. Column for trapping is not limited to a specific type, and examples of such columns include a column trapping with plates and column trapping with a nozzle.

Specific examples of dishes include nozzle plates, each of which has a drain pipe / tube sheet plates, valve plates, plates of superrally (SUPERFRAC trays, plates Maxi-cut (MAX-FRAC trays), and a plate with two fluid flows without drain pipes.

Examples of structured nozzles for use as attachments include: attachment SULZER PACKING, available from Sulzer Brothers Ltd.; the nozzle SUMITOMO SULZER PACKING, available from Sumitomo Heavy Industries, Ltd.; the nozzle MELLAPAK, available from Sumitomo Heavy Industries, Ltd.; the nozzle GEM-PAK, available from Koch-Glitsch, LP; nozzle MONTZ-PAK, available from Julius Montz GmbH; nozzle GOOD ROLL PACKING, available from Tokyo Tokushu Kanaami K.K.; nozzle HONEYCOMB PACK, availability is Yu from NGK Insulators, Ltd.; the nozzle IMPULSE PACKING, available from Nagaoka International Corporation; and the nozzle MC PACK, available from Mitsubishi Chemical Engineering Corporation.

Examples of disordered attachments include: attachment INTALOX SADDLES, available from Norton; nozzle TELLERETT available from Nittetsu Chemical Engineering Ltd.; the nozzle PALL RINGS, available from BASF Aktiengesellschaft; nozzle CASCADE MINI-RING available from Mass Transfer Ltd.; and the FLEXI nozzle RINGS, available from JGC Corporation.

The types of plates and nozzles is not limited in the present invention, and can be applied plates and nozzles of one or more types in combination as they are usually used.

In the present invention the gaseous reaction mixture is fed into the plant capture from a variety of locations and in such a way as to cause a collision in the setup capture.

The number of locations of the input gaseous reaction mixture is not specifically limited if the number is 2 or more. Preferably the number is in the range from 2 to 8, more preferably from the viewpoint of productivity, ease of maintenance, cost of equipment, etc. in the interval from 2 to 4.

The gaseous reaction mixture is fed into the plant capture from a variety of locations for a collision in the setup capture. Thus, the gaseous reaction mixture is dispersed in the setup capture more kontaktierung the m between the solvent and the gaseous reaction mixture without the use of a regulating element, such as plate collision or wall to regulate the flow of gas by contacting it with the gas. Further, the gaseous reaction mixture is dispersed without the use of a regulating element, which prevents the formation of a polymerized product to a regulatory element.

In the present invention all of the gaseous reaction mixture is supplied from a variety of locations, preferably collides in the setup capture. However, it is not necessary that all of the gaseous reaction mixture is supplied from a variety of locations, were subjected to collision, if it is sufficiently dispersed in the setup capture. In addition, in the present invention all of the gaseous reaction mixture is supplied from a variety of locations, preferably collides in one place. However, all of the gaseous reaction mixture is supplied from a variety of provisions that may collide in many locations in the installation of capture, if the gaseous reaction mixture is sufficiently dispersed in the setup capture.

The gaseous reaction mixture may collide in the installation catching by feeding a gaseous reaction mixture from a variety of locations in a direction to any place in the setup capture. The collision of gaseous reaction the th mixture in the installation of the trap can be caused by: exact setting of the feed direction of the gaseous reaction mixture and regulating the supply quantity in accordance with the direction of flow; exact definition of the supplied quantity of the gaseous reaction mixture and adjusting the direction of its filing in accordance with the submitted amount; or regulating the supply quantity or feed direction of the gaseous reaction mixture in accordance with the direction of flow or the supplied amount of the gaseous reaction mixture.

In the present invention, when set to a value (Q/N), where the entire quantity (Q) of the gaseous reaction mixture, is fed in recovery, divided by the number (N) of locations of the input gaseous reaction mixture in the reaction apparatus, the deviation of the flow rate of the gaseous reaction mixture in different locations, its input is preferably ±10% or less to improve the dispersive ability of the pigment gaseous reaction mixture in the setup capture. The flow rate can be controlled, for example, using a distribution device, such as the collector (distributor), or device flow control, such as a fan or valve; and the combined diameters of the individual nozzles for supplying gaseous reaction mixture in the installation of carbon capture and flow rate of the gaseous reaction mixture passing through each of the nozzles. This control flow is more efficient for the case when getoperationname mixture is subjected to a collision in a random place essentially equidistant from multiple locations in the setup capture.

In the present invention all of the gaseous reaction mixture, is fed in recovery from a variety of locations, preferably collides directly in one place to improve the dispersive ability of the pigment gaseous reaction mixture in the installation of the trap and prevent the formation of the cured product due to the contact between the element setup capture, such as control element, and gaseous reaction mixture.

In the present invention, when the cross section of the setup capture has a round shape, as mentioned above, the installation of the capture of the tower type, all gaseous reaction mixture, is fed in recovery from a variety of locations, collides directly in the center of the setup capture to improve the dispersive ability of the pigment gaseous reaction mixture in the setup capture, enhance contact between the gaseous reaction mixture and catching her by the solvent and prevent the above-mentioned formation of the cured product.

Install trap of the present invention is used to capture (meth)acrolein or (meth)acrylic acid collecting solvent by contacting razoobrazny the second reaction mixture with collecting solvent. Install trap includes an area of contact, where the gaseous reaction mixture in contact with the collecting solvent; many devices supplying gaseous reaction mixture in the zone of contact; and feeder solvent to feed safety solvent in the zone of contact.

The contact area is not specifically limited, unless specified area provides the opportunity to contact the gas with the liquid. An example of an area of the shielding device includes irrigation. However, in the present invention the cross-section area of the probe has a round shape to increase the dispersive ability of the pigment gaseous reaction mixture, and more preferably the use of plate columns or similar device, as described above.

Types of feeders gaseous reaction mixture is not specifically limited provided that the gaseous reaction mixture is fed into the zone of contact of each of the feed devices of the gaseous reaction mixture, is subjected to a collision in the area of contact. Each of the feed devices of the gaseous reaction mixture is not specifically limited provided that the gas is fed in a given direction. Each of the feed devices of the gaseous reaction mixture may be a device that can module shall synchronize the quantity of supplied gaseous reaction mixture, or device capable of changing a direction of flow of the gaseous reaction mixture. Examples of each of the devices supplying gaseous reaction mixture include the following devices: atomizer capable of changing a direction of the spray holes and reduce the diameter of the spray hole; and a nozzle fixed in the zone of contact.

The nozzle used in the present invention corresponds to the General definition. More precisely, the term "nozzle" means a nozzle connected with the main body of the equipment, and includes the outlet from the housing to the first flange. The nozzle is mounted by welding or fastening bolts. In the present invention each of the selected nozzles has a diameter suitable for the delivery of the gaseous reaction mixture in the zone of contact with a sufficient flow rate depending on the supply amount of the gaseous reaction mixture to ensure thus the collision gaseous reaction mixture in the zone of contact. The nozzles are installed in an arbitrary place in the zone of contact. The diameters of the nozzles may be the same or may differ from each other. An arbitrary position can be a single location or multiple locations.

In the present invention the device under the Chi gaseous reaction mixture is preferably installed in such a direction, that the gaseous reaction mixture is fed from each feeder gaseous reaction mixture, collides in one place in the zone of contact to improve the dispersive ability of the pigment gaseous reaction mixture in the zone of contact.

In the present invention are applied to the same feeder gaseous reaction mixture. Feeder gaseous reaction mixture are preferably in the same plane (at the same height) in the area of contact having a circular cross-section, the column trapping for supplying gaseous reaction mixture towards the center of the zone of contact to improve the dispersive ability of the pigment gaseous reaction mixture in the zone of contact.

In the present invention, the installation trapping preferably contains no such element as the partition or plate collision, to prevent direct collision with him gaseous reaction mixture is fed from the feeder gaseous reaction mixture, and the formation of the cured product, which ensures stable operation setup capture over a long period of time.

Feeder solvent is not specifically limited if only the solvent recovery can be fed into the zone of contact. Examples of condition the device for the supply of the solvent include known devices used to feed the solvent recovery in the installation of shielding gas with a liquid, such as the upper part of the column trapping, or irrigation device.

Materials for installation of capture, injectors and nozzles connected to the nozzles, are selected depending on the composition of the gaseous reaction mixture or safety solvent and temperature conditions and is not specifically limited. As these materials are often used stainless steel, but these materials of the present invention are not limited to stainless steels. Examples of such materials include steel grades SUS 304, SUS 304L, SUS 316, SUS 316L, SUS 317, SUS 317L, SUS 327 and corrosion-resistant alloys "hastelloys". The materials can be selected according to their physical properties for the fluid with regard to corrosion resistance.

Install trap of the present invention is used to capture (meth)acrolein or (meth)acrylic acid from a gaseous reaction mixture, but the substance that is extracted in the installation trapping the present invention is not limited to (meth)acrolein or (meth)acrylic acid. Installing the capture can be used to capture any component gas, which can be collected by contacting the gas with a liquid with the selection of a suitable solvent.

the alley will be described variant of implementation of the present invention with reference to the drawings, but the present invention is not limited to this option. Figure 1 is a flowsheet showing an example of setting the capture of acrylic acid as an option for implementation of the present invention.

As shown in figure 1, the installation of the trap is equipped with a housing 2 columns capture; line feed gaseous reaction mixture 1 in the column frame capture 2; line supply of solvent to feed of an aqueous solution of 3 as solvent trapping in the upper part of the body column capture 2; line bottom unloading liquid 4 from the column housing recovery, waste liquid is an aqueous solution 3 containing water-soluble component, such as acrylic acid, extracted from the gaseous reaction mixture 1; line discharge gas 5, warded off in the upper part of the pillar of capture, such as water vapor, obtained in the column frame capture 2; and a heat exchanger 6 for cooling the bottom part of the liquid 4, the return in the main body of the column trapping 2 line unloading bottom liquid. The input position of an aqueous solution of 3 in the column frame capture 2 on the supply line of the solvent is not specifically limited to the upper part of the pillar of capture and may be in a different location, such as the Central part of the pillar of capture, which can be in multiple locations, such as the upper part of the column of capture and the Central part of the pillar of capture.

As shown in figure 2, case 2 columns capture is a plate column trapping, equipped with plenty of plates dual segment with two fluid flows 2A. Two nozzles 2b as feeder gaseous reaction mixture, located in the lower part of the column trapping, connected to the supply line of the gaseous reaction mixture by means of flanges 2C. Nozzle 2b is located symmetrically relative to the center of the cross-section of the hull columns capture 2. As shown in figure 3, the nozzles 2b facing towards each other and are located in the direction of the longitudinal axis of the plates 2A, installed concentrically in the housing of the column trapping 2. 4 shows another method of installation of nozzles, wherein the nozzles 2b facing towards each other and are perpendicular to the longitudinal axis of the plate 2A.

In setting the trap the gaseous reaction mixture 1 containing acrylic acid obtained by catalytic oxidation in the vapor phase, is fed into the lower part of the body column capture 2 from the output device of the oxidation reactor (not shown). The gaseous reaction mixture 1 is cooled preferably to a temperature in the range from 140 to 250°C., particularly site is preferably in the range from 170 to 220°C using a heat exchanger (not shown), mounted on the output device of the oxidation reactor or line feed gaseous reaction mixture before introduction into the apparatus of capture of the tower type. If the gaseous reaction mixture is cooled to a temperature below 140°C., the acrylic acid is undesirable condenses in the pipe and cures that can lead to clogging of pipes, etc. Too high a temperature leads to an increase in gas volume and increase the amount of heat which must be dissipated in the column trapping, with the increase of the diameter of the column trapping. Thus, there is a trend of increasing hardware costs and reduce the efficiency of the capture.

When obtaining acrylic acid by catalytic oxidation of propylene in the vapor phase of the resulting gaseous reaction mixture usually contains acrylic acid, nitrogen, carbon dioxide, oxygen, carbon monoxide, non-condensable hydrocarbons, condensed organic compounds, water, etc. In the present invention, the term "condensation" refers to the compound, which in its pure form has a boiling point of 20°C or higher.

An aqueous solution of 3 as a safety solvent is fed into the upper part of the body column trapping. The flow temperature of the aqueous solution is preferably in the range from 20 to 50 is C. The volume of water in aqueous solution 3 to be input is from 0.5 to 2 volumes of water contained in the gaseous reaction mixture. The flow temperature of the aqueous solution is preferably low, but typically is in the range from 20 to 50°C. flow Temperature is below 20°C is not very economical because the refrigerator or other equipment can be costly. When the flow temperature is above 50°C the collection efficiency tends to decrease.

The exhaust heat preferably is controlled with a heat exchanger 6, is installed in the external device, the lower part of the column, to save the top temperature of the column trapping in a particular area, in particular within ±1°C temperature stable operation. Maintaining the temperature of the upper part of the column in a certain interval, it is possible to maintain a constant volume of water (steam)to be removed from the upper part of the column as a gas, warded off from the upper part of the column. In addition, can be maintained constant and the water content of the aqueous solution of acrylic acid in the lower part of the tower type apparatus, the concentration of acrylic acid in the bottom of the liquid 4.

The temperature of the bottom of the column is preferably equal to 86°C or lower, the temperature of the upper part of the column is preferably equal to 72°C or lower for p is edatrexate driving due to the polymerization of acrylic acid.

The temperature of the upper part of the column can be controlled using only peripheral heat exchanger bottom of the column, only the peripheral heat exchanger upper part of the column or by using two such heat exchangers.

In the present invention the location of the nozzles 2C are not specifically limited, if the nozzles are arranged so that they provide an impact of the gaseous reaction mixture 1 in the housing 2 columns capture. When the contact area is a plate column, as shown in figure 1, the nozzles preferably have a symmetrical, as shown in figure 3 and 4.

In the present invention, the diameter of each of the nozzles 2C are not specifically limited. The diameter of each of the nozzles 2C are usually determined by the gas flow in each of the nozzles 2C. Gas flow rate is changed depending on conditions such as the diameter or shape of the column 2, and the number of installed nozzles 3C, but is in the range from 3 to 80 m/sec, preferably in the range from 5 to 50 m/sec, more preferably in the range from 10 to 40 m/sec.

In the installation trapping gaseous reaction mixture 1 is essentially the same speed of flow of the two mounted opposite the nozzles 2C. The gaseous reaction mixture 1, are fed into the housing 2 columns olalia the Oia from each nozzle, is subjected to a collision in the Central part of the cross-section of the hull columns 2 and dispersed. In this case 2 columns specific anisotropy of the gaseous reaction mixture is reduced due to the collision of the moving gaseous reaction mixture 1. Therefore, the contact between the gaseous reaction mixture and the aqueous solution 3 is greatly increased in comparison with the variant in which there is no such collision. Thus, the gaseous reaction mixture 1 is effectively absorbed aqueous solution 3.

In the present invention the gaseous reaction mixture 1, which is blown in the setup capture through two or more nozzles 3C, subject to collision and dispersed, and therefore usually set partition is not needed.

Install trap that contains a single nozzle, which is applied the present invention, preferably equipped with a septum to improve the dispersive ability of the pigment of gas in the setup capture, but the partition is formed of the cured product. Disclaimer partitions leads to the fact that the gas collides with the wall surface opposite the nozzle and dispersed, but it is not preferable because the effect of dispersion is small.

Thus, the installation of two or more nozzles according to the present invention p is eduversum education polymerized product on the partition wall. Prevents deviation from the predetermined mode of operation, called therefore the cured product, which allows a stable operation mode setup capture over a long period of time.

The number of nozzles 2C is 2 or more, preferably from 2 to 8, more preferably from 2 to 4. The number is preferably large to demonstrate the effect of the present invention, but the maximum amount may be limited to technological and economic reasons.

Acrylic acid, caught in aqueous solution in the form of a bottom liquid 4, as described above, is subjected to the usual stages included in method of obtaining acrylic acid. That is, acrylic acid is subjected to solvent extraction for the extraction of an aqueous solution containing acrylic acid, a suitable extraction solvent, phase separation of the solvent, purification step or the like for obtaining purified acrylic acid.

Examples

Hereinafter the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the examples without extracting them from the zone of the present invention.

Example 1

Propylene is mixed with air and inert gas consisting of water, nitrogen and carbon dioxide. Propylene will overhaul interaction with molecular oxygen in the presence of a catalyst of molybdenum oxide, deposited on a solid carrier, in a first reaction zone with getting acrolein. Then acrolein is subjected to interaction with molecular oxygen in the presence of a catalyst of molybdenum oxide deposited on a solid carrier, a second reaction zone with obtaining, thus, the gaseous reaction mixture containing 3200 kg/h of acrylic acid.

1. The composition of the gaseous reaction mixture

The molar fraction
The nitrogen + carbon dioxide71,6%
Non-condensable components except the above (in particular, including unreacted propylene feedstock, oxygen and carbon monoxide)5,3%
Acrylic acid6,3%
Water16,4%
Condensed components except the above (specifically including acetic acid and maleic acid)0,4%
The mass fraction
The nitrogen + carbon dioxide68,2%
Non-condensable components except for the above5,8%
Acrylic acid15,2%
Water10,0%
Condensed components except for the above0,8%

Mass fraction of acrylic acid in the condensed components in the gaseous reaction mixture is 58.5 wt.%.

2. Installing capture

As you install the recovery using plate column presented in figure 2. As shown in figure 1, the column frame capture 2 is equipped with a circulation line for selection of a bottom liquid (aqueous solution containing acrylic acid, in the form of a bottom liquid 4 received in the lower part of the column) and for returning the liquid to the sixth column, counting from the bottom. The circulation was equipped with a heat exchanger 6 for cooling the circulating fluid.

The column frame capture 2 used in example 1, the height of 30000 mm and a diameter of 2100 mm, equipped with 36 dual plates, segment type with two flows of liquid and two nozzles for supplying gaseous reaction mixture, mounted in the lower part of the column, each having a diameter of 16 inches. As shown in figure 4, the nozzles is 2C are arranged symmetrically relative to the center of the cross-section of the hull columns capture 2.

The gaseous reaction mixture obtained as described above, cooled to 190°C. using a heat exchanger (not shown)installed on the discharge from the oxidation reactor, and served in the lower part of the housing 2 columns of nozzles 2C. Gas flow speed in the nozzle 2C is approximately 33 m/sec.

An aqueous solution of 3 at 40°C, containing 93 wt.% water and 6 wt.% acetic acid (remainder, equal to 1%, includes formaldehyde, formic acid and acrylic acid) as the absorbing solvent is served in the column frame capture 2 from the upper part of the column and feed safety solvent regulate in such a way that the pressure in the upper part of the column is 105 kPa. Collecting the solvent serves so that the amount of water in collecting the solvent is equal to the volume of water in the gaseous reaction mixture. The temperature of the upper housing 2 of the apparatus of capture of the tower type support at the level of 60°With the throttling of the heat exchanger 6, is installed in the circulation line.

After working for 3 months loss of acrylic acid with warded off from the upper part of the gas is 0.3%, and in case 2 columns capture not observed the formation of polymerized product.

Example 2

The mode of operation described in example 1, reproduce, with the difference that 4 injectors 2d, each of the I 12-inch-diameter set symmetrically in the same horizontal plane at the same distance from each other, as shown in figure 5; and gas flow rate in each nozzle is approximately 30 m/sec.

After working for 3 months loss of acrylic acid with warded off from the upper part of the gas is 0.3%, which corresponds to the result obtained in example 1. In the case of the column capture 2 is not observed the formation of a polymerized product.

Comparative example 1

Reproduce mode of operation described in example 1 with the difference that sets one nozzle with a diameter of 22 inches in one location, and velocity of gas flow in the nozzle is approximately 33 m/sec.

After working for 3 months loss of acrylic acid with warded off from the upper part of the gas is 1.5%, and in the case of the column capture 2 is not observed the formation of a polymerized product.

Comparative example 2

Reproduce mode of operation described in comparative example 1, with the difference that to improve the dispersion of the gas at the tip of the nozzle in the column frame capture 2 establish a vertical wall in the form of an inverted L.

The loss of acrylic acid with warded off from the upper part of the first gas is 0.4%, which is comparable with the result of example 1. However, in the bottom liquid is in the column frame capture 2 observed the formation of a polymerized product. After 2 months of work stop and examine the inside of the column trapping 2, on the wall see a large number of polymerized product.

Industrial applicability

According to the present invention the gaseous reaction mixture may be subjected to additional dispersion in the setup capture with increasing contact between the gaseous reaction mixture and the solvent without the application of currently used control device, such as a partition.

Thus, (meth)acrolein or (meth)acrylic acid can be effectively removed using a solvent while preventing polymerization.

1. The method of capture (meth)acrolein or (meth)acrylic acid, comprising the stage
cooling the gaseous reaction mixture containing (meth)acrolein or (meth)acrylic acid obtained/reduction reaction of catalytic oxidation in the vapor phase of one or both of the reactants selected from (A) propane, propylene or isobutylene and (B) (meth)acrolein, molecular oxygen or gas containing molecular oxygen, to a temperature of 140-250°C;
contact specified gaseous reaction mixture with a solvent at a temperature of between 20 and 50°C in installation recovery for ula is management (meth)acrolein or (meth)acrylic acid in a solvent, where
this facility trapping contains the contact area, where the gaseous reaction mixture in contact with the solvent, having a cross section of circular shape and a lot of devices supplying gaseous reaction mixture for supplying gaseous reaction mixture in the zone of contact,
feeder gaseous mixture is set in the area of contact at the same height in the direction towards the center of the zone of contact,
the gaseous reaction mixture is fed into the zone of contact of the input gas mixture is subjected to a collision directly at one point zone contact, and
setting the trap does not have a device which prevents direct impact of the gaseous mixture fed from the feeder gaseous reaction mixture.

2. The method of capture (meth)acrolein or (meth)acrylic acid according to claim 1, where the differences between the flow rates of the gaseous reaction mixture in many locations its input is ±10% or less.

3. The method of capture (meth)acrolein or (meth)acrylic acid according to claim 1, where all of the gaseous reaction mixture, is fed in recovery from a variety of locations, collides directly in the middle of the trap.

4. The method of capture (meth)acrolein or (meth)acrylic acid, n is 1, where the solvent is an aqueous solvent containing 80 wt.% or more of water.

5. The method of capture (meth)acrolein or (meth)acrylic acid according to claim 1, where the installation of a capture apparatus includes trapping tower containing the trapping column.

6. Setting trap for trapping (meth)acrolein or (meth)acrylic acid by contacting the gaseous reaction mixture is cooled to 140-250°C containing (meth)acrolein or (meth)acrylic acid obtained/reduction reaction of catalytic oxidation in the vapor phase of one or both of the reactants selected from (A) propane, propylene or isobutylene and (B) (meth)acrolein, molecular oxygen or gas containing molecular oxygen, with the solvent at a temperature of between 20 and 50°C, where the installation of a capture includes an area of contact, having a cross-section of the circular form, where the gaseous reaction mixture in contact with the solvent, a variety of devices supplying gaseous reaction mixture for supplying gaseous reaction mixture in the zone of contact and the feeder of solvent to feed of solvent in the contact area, where the feeder gaseous reaction mixture are at the same height in the zone of contact in the direction towards the center of the zone of contact so about the time, in order to cause a direct collision of the gaseous reaction mixture in the zone of contact in one place, and setting the trap does not have a device which prevents direct impact of the gaseous reaction mixture is fed from the feeder gaseous reaction mixture.

7. Install trap according to claim 6, where the area of contact includes a trapping column.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method of (meth)acrylic acid purification includes the stages as follows: distillations of the liquid containing raw (meth)acrylic acid being acrylic acid or methacrylic acid with one or more polymerisation inhibitors added as chosen from group consisting of phenol derivative, phenothiazine derivative, copper (meth)acrylate and copper dithiourethane, for the purpose to produce condensate of (meth)acrylic acid, containing (meth)acrylic acid of purity at least 90%; adding polymerisation inhibitor containing phenol derivative to condensate; and delivery of oxygen-containing gas that contains oxygen to condensate of (meth)acrylic acid in reflux tank wherein condensate of (meth)acrylic acid is collected, wherein oxygen-containing gas is delivered to condensate in reflux tank with using small-size bubble liquid injector, and pressure connection for oxygen-containing gas delivery to liquid injector whereat ratio (nm/tn) of oxygen delivery in oxygen-containing gas and condensate flow supplied to reflux tank at 0°C, 1 atm complies with ratio shown in equation 0.004≤A/B≤1.0, where A stands for O2 delivery (nm3/hour), B stands for condensate flow (tn/hour) of the condensate supplied to reflux tank, and symbol n in nm3/hour specifies the value under normal conditions (0°C, 1 atm: normal conditions).

EFFECT: effective method of high purity acid production wherein acid polymer formation in made condensate is prevented.

12 cl, 6 dwg, 7 ex

FIELD: chemistry.

SUBSTANCE: method of (meth)acrylic acid purification includes the stages as follows: distillations of the liquid containing raw (meth)acrylic acid being acrylic acid or methacrylic acid with one or more polymerisation inhibitors added as chosen from group consisting of phenol derivative, phenothiazine derivative, copper (meth)acrylate and copper dithiourethane, for the purpose to produce condensate of (meth)acrylic acid, containing (meth)acrylic acid of purity at least 90%; adding polymerisation inhibitor containing phenol derivative to condensate; and delivery of oxygen-containing gas that contains oxygen to condensate of (meth)acrylic acid in reflux tank wherein condensate of (meth)acrylic acid is collected, wherein oxygen-containing gas is delivered to condensate in reflux tank with using small-size bubble liquid injector, and pressure connection for oxygen-containing gas delivery to liquid injector whereat ratio (nm/tn) of oxygen delivery in oxygen-containing gas and condensate flow supplied to reflux tank at 0°C, 1 atm complies with ratio shown in equation 0.004≤A/B≤1.0, where A stands for O2 delivery (nm3/hour), B stands for condensate flow (tn/hour) of the condensate supplied to reflux tank, and symbol n in nm3/hour specifies the value under normal conditions (0°C, 1 atm: normal conditions).

EFFECT: effective method of high purity acid production wherein acid polymer formation in made condensate is prevented.

12 cl, 6 dwg, 7 ex

FIELD: chemistry.

SUBSTANCE: method of (meth)acrylic acid purification includes the stages as follows: distillations of the liquid containing raw (meth)acrylic acid being acrylic acid or methacrylic acid with one or more polymerisation inhibitors added as chosen from group consisting of phenol derivative, phenothiazine derivative, copper (meth)acrylate and copper dithiourethane, for the purpose to produce condensate of (meth)acrylic acid, containing (meth)acrylic acid of purity at least 90%; adding polymerisation inhibitor containing phenol derivative to condensate; and delivery of oxygen-containing gas that contains oxygen to condensate of (meth)acrylic acid in reflux tank wherein condensate of (meth)acrylic acid is collected, wherein oxygen-containing gas is delivered to condensate in reflux tank with using small-size bubble liquid injector, and pressure connection for oxygen-containing gas delivery to liquid injector whereat ratio (nm/tn) of oxygen delivery in oxygen-containing gas and condensate flow supplied to reflux tank at 0°C, 1 atm complies with ratio shown in equation 0.004≤A/B≤1.0, where A stands for O2 delivery (nm3/hour), B stands for condensate flow (tn/hour) of the condensate supplied to reflux tank, and symbol n in nm3/hour specifies the value under normal conditions (0°C, 1 atm: normal conditions).

EFFECT: effective method of high purity acid production wherein acid polymer formation in made condensate is prevented.

12 cl, 6 dwg, 7 ex

FIELD: chemistry.

SUBSTANCE: invention concerns improved method for obtaining (meth)acrylic acid involving steam phase catalytic oxidation of propylene, propane or isobutylene for production of reaction mix, absorption of oxidised reaction product in water to obtain water solution containing (meth)acrylic acid, concentration of water solution in the presence of azeotropic agent and distillation of obtained (meth)acrylic acid in distillation column to obtaining purified (meth)acrylic acid. During operation of distillation column, including operation interruption and resumption, the column is washed with water, and afterwards azeotropic distillation is performed in the presence of azeotropic agent.

EFFECT: efficient and fast cleaning of distillation column with extraction of valuable substance.

5 cl, 5 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining (meth)acrylic acid or (meth)acrolein, which includes process of catalytic gas-phase oxidation for obtaining (met)acrylic acid or (meth)acrolein by supplying propylene, propane or isobutylene and gas, containing molecular oxygen, into reactor, filled with catalyst, which contains composition of metal oxides, including Mo, where gas, containing molecular oxygen, is continuously supplied from outside on catalyst both during installation operation, and during stoppage of catalytic gas-phase oxidation process.

EFFECT: obtaining gaseous reaction product, which includes (meth)acrylic acid or (meth)acrolein, in which reduction of catalyst activity and selectivity of target product formation do not occur when installation operation is restarted after stoppage of catalytic gas-phase oxidation process.

2 cl, 2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: object of the present invention is to develop method for making catalyst to produce methacrylic acid by gaseous catalytic oxidation of metacrolein, isobutyl aldehyde or isobutyric acid. There is disclosed method for making catalyst to produce methacrylic acid by gaseous catalytic oxidation of metacrolein, isobutyl aldehyde or isobutyric acid, involving as follows: (a) the stage of mixing water and compounds, each containing any Mo, V, P, Cu, Cs or NH4, to prepare aqueous solution or dispersed compounds (further, both mentioned as a suspension); (b) the stage of drying suspension produced at the stage (a), to make dry suspension; (c) the stage of burning dry suspension produced at the stage (b), to make burnt substance; (d) the stage of filtrating mixed burnt substance produced at the stage (c) and water to separate aqueous solution and water-insoluble substance; and (e) the stage of drying water-insoluble substance produced at the stage (d) to make dry water-insoluble substance; and (f) the stage of coating the carrier with dry water-insoluble substance produced at the stage (e), with using a binding agent to make coated mould product, and (g) the stage of burning coated mould product produced at the stage (f) in inert gas atmosphere, in the air or with reducing agent added.

EFFECT: making catalyst with long life, high activity and selectivity.

8 cl, 9 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: present invention pertains to improvement of the method of producing (met)acrylic acid and complex (met)acrylic esters, involving the following stages: (A) reacting propane, propylene or isobutylene and/or (met)acrolein with molecular oxygen or with a gas, containing molecular oxygen through gas-phase catalytic oxidation, obtaining crude (met)acrylic acid; (B) purification of the obtained crude (met)acrylic acid, obtaining a (met)acrylic acid product; and (C) reacting raw (met)acrylic acid with alcohol, obtaining complex (met)acrylic esters, in the event that the installation used in any of the stages (B) and (C), taking place concurrently, stops. The obtained excess crude (met)acrylic acid is temporarily stored in a tank. After restoring operation of the stopped installation, the crude (met)acrylic acid, stored in the tank, is fed into the installation, used in stage (B), and/or into the installation used in stage (C). (Met)acrylic acid output of the installation used in stage (A) should be less than total consumption of (met)acrylic acid by installations used in stages (B) and (C).

EFFECT: the method allows for processing (met)acrylic acid, temporarily stored in a tank, when stage (B) or (C) stops, without considerable change in workload in stage (A).

2 ex

FIELD: chemistry.

SUBSTANCE: present invention pertains to improvement of the method of producing (met)acrylic acid or (met)acrolein using a multi-pipe reactor with a fixed bed. The reactor has several pipes, with at least one catalyst bed in the direction of the axis of the pipe. A heat carrier can regulate temperature outside the flow of the reaction pipe. In the reaction pipes, there is gas-phase catalytic oxidation of at least one type of oxidisable substance, propylene, propane, isobutylene and (met)acrolein by molecular oxygen or a gas, containing molecular oxygen. At the beginning of the process, the difference between the coolant temperature and the peak temperature of the catalyst is set in the interval 20-80°C, and during the process, peak temperature T(°C) of the catalyst in the direction of the axis of the pipe satisfies equation 1, given below: (equation 1), where L, T0, X and X0 stand for length of the reaction pipe, peak temperature of the catalyst in the direction of the axis of the pipe at the beginning of the process, the length up to the position which gives the peak temperature T at the input of the reaction pipe, and the length to the position which gives the peak temperature T0 at the input of the reaction pipe, respectively.

EFFECT: method allows for stable output of the target product, with high output for a long period of time, without reduction of catalyst activity.

3 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: present invention pertains to improvement of the method of producing (met)acrylic acid or (met)acrolein using a multi-pipe reactor with a fixed bed. The reactor has several pipes, with at least one catalyst bed in the direction of the axis of the pipe. A heat carrier can regulate temperature outside the flow of the reaction pipe. In the reaction pipes, there is gas-phase catalytic oxidation of at least one type of oxidisable substance, propylene, propane, isobutylene and (met)acrolein by molecular oxygen or a gas, containing molecular oxygen. At the beginning of the process, the difference between the coolant temperature and the peak temperature of the catalyst is set in the interval 20-80°C, and during the process, peak temperature T(°C) of the catalyst in the direction of the axis of the pipe satisfies equation 1, given below: (equation 1), where L, T0, X and X0 stand for length of the reaction pipe, peak temperature of the catalyst in the direction of the axis of the pipe at the beginning of the process, the length up to the position which gives the peak temperature T at the input of the reaction pipe, and the length to the position which gives the peak temperature T0 at the input of the reaction pipe, respectively.

EFFECT: method allows for stable output of the target product, with high output for a long period of time, without reduction of catalyst activity.

3 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: present invention pertains to perfection of the method of obtaining at least, one product of partial oxidation and/or ammoxidising of propylene, chosen from a group, comprising propylene oxide, acrolein, acrylic acid and acrylonitrile. The starting material is raw propane. a) At the first stage, raw propane, in the presence and/or absence of oxygen, is subjected to homogenous and/or heterogeneous catalysed dehydrogenation and/or oxydehydrogenation. Gas mixture 1, containing propane and propylene is obtained. b) If necessary, a certain quantity of the other components in gas mixture 1, obtained in the first stage, besides propane and propylene, such as hydrogen and carbon monoxide is separated and/or converted to other compounds, such as water and carbon dioxide. From gas mixture 1, gas mixture 1' is obtained, containing propane and propylene, as well as other compounds, besides oxygen, propane and propylene. c) At the third stage, gas mixture 1 and/or gas mixture 1' as a component, containing molecular oxygen, of gas mixture 2, is subjected to heterogeneous catalysed partial gas-phase oxidation and/or propylene, contained in gas mixture 1 and/or gas mixture 1', undergoes partial gas-phase ammoxidising. Content of butane-1 in gas mixture 2 is ≤1 vol.%. The method increases output of desired products and efficiency of the process.

EFFECT: increased output of desired products and efficiency of the process.

72 cl, 10 ex

FIELD: heating.

SUBSTANCE: invention concerns improved method of catalytic oxidation in vapour phase which supplies effective removing of reactionary heat, excludes hot spot formation, and supplies effective receipt of base product. Method of catalytic oxidation is disclosed in the vapour phase (a) of propylene, propane or isobutene by the instrumentality of molecular oxygen for receiving (meth)acrolein, and/or oxidation (b) of (meth)acrolein by molecular oxygen for receiving (meth)acryl acid, by the instrumentality of multiple-tubular reactor, contained: cylindrical reactor vessel, outfitted by initial material supply inlet hole and discharge hole for product, variety of reactor coolant pipes, located around the cylindrical reactor vessel and used for insertion the heat carrier into cylindrical reactor vessel or for removing the heat carrier from it, circulator for connection of variety loop pipeline to each other, variety of reaction tube, mounted by the instrumentality of tube reactor lattices, with catalyst. Also multiple-tubular reactor contains: variety of partitions, located lengthways of reaction tubes and used for changing heat carrier direction, inserted into reactor vessel. According to this heat carrier coolant flow is analysed and there are defined zones in reactor which have heat-transfer coefficient of heat carrier less than 1000 W/(m2·K); also reaction of catalytic oxidation is averted in the vapour phase in mentioned zones of reactor and reaction of catalytic oxidation is implemented in the vapour phase in reactor.

EFFECT: receiving of improved method catalytic oxidation in vapour phase which supplies effective removing of reactionary heat, excludes hot spot formation, and supplies effective receipt of base product.

3 cl, 6 dwg, 2 ex

FIELD: industrial organic synthesis.

SUBSTANCE: invention relates to improved process to produce acrylic acid via heterogeneously catalyzed gas-phase partial oxidation of propane wherein starting reactive gas mixture containing propane, molecular oxygen, and at least one gas diluent is passed at elevated temperature over a multimetal oxide bulk depicted by total stoichiometry as Mo1VbM1сM2вOn (I), in which M1 = Te and/or Sb and M2 is at least one element from group comprising Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, B, Ce, Zn, Si, and In; b = 0.01 to 1, c = >0 to 1, d = >0 to 1, and n = number, which is determined by valence and number of non-oxygen elements in (I). Propane is partially oxidized to produce acrylic acid in a process wherein composition of starting reaction mixture is at least two times varied in the course of process such that molar percentage of gas diluent (water steam) in starting reaction gas mixture decreases relative to molar percentage of propane contained in starting gas mixture.

EFFECT: reduced amount of water steam in gas mixture without loss in selectivity and activity of catalyst regarding target product.

5 cl, 1 dwg, 10 ex

FIELD: improved method for production of (meth)acrolein and (meth)acrylic acid.

SUBSTANCE: claimed method includes feeding of raw gas mixture through pipeline from raw material mixer into oxidation reactor and catalytic oxidation of raw mixture in vapor phase to produce (meth)acrolein or (meth)acrylic acid. Said pipeline is heated and/or maintained in heated state and temperature of gas mixture fed into oxidation reactor is by 5-250C higher then condensation temperature of raw gas mixture.

EFFECT: stable and effective method for production of (meth)acrolein and (meth)acrylic acid without alteration of raw mixture composition, abrupt temperature elevation and reducing of catalyst activity and durability.

5 cl, 1 dwg, 2 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing acrylic acid and selective oxidation of propylene to acrolein. Method involves carrying out reaction of propylene with oxygen in the first zone reaction with the first catalyst corresponding to the following formula: AaBbCcCadFeeBifMo12Ox wherein A means Li, Na, K, Rb and Cs and their mixtures also; B means Mg, Sr, Mn, Ni, Co and Zn and their mixtures also; C means Ce, Cr, Al, Sb, P, Ge, Sn, Cu, V and W and their mixtures also wherein a = 0.01-1.0; b and e = 1.0-10; c = 0-5.0 but preferably 0.05-5.0; d and f = 0.05-5.0; x represents a number determined by valence of other presenting elements. Reaction is carried out at enhanced temperature providing preparing acrylic acid and acrolein and the following addition of acrolein from the first reaction zone to the second reaction zone containing the second catalyst used for conversion of acrolein to acrylic acid. Method provides high conversion of propylene to acrylic acid and acrolein.

EFFECT: improved preparing method.

7 cl, 1 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: present invention pertains to extraction of a metallic catalyst from a mother solution, obtained during synthesis of carbonic acid, usually terephthalic acid. In the first version, the method of separating metallic catalyst from a stream of mother solution involves the following stages: (a) evaporation of the mother solution, containing carbonic acid, the metallic catalyst, impurities, water and a solvent, in the zone of the first evaporator, obtaining a vapour, containing water and solvent, and concentrated mother solution; (b) evaporation of the concentrated mother solution in the zone of the second evaporator, where evaporation in the zone of the second evaporator is carried out at 150-220°C temperature, forming a stream rich in solvent and a stream of super-concentrated mother solution in molten dispersion state, where a total of 95-99 wt % of solvent and water is removed from the mother solution during evaporation stages (a) and (b); (c) mixing the water-solvent solution in the mixing zone, with super-concentrated mother solution, forming an aqueous mixture; (d) separation of organic impurities in the aqueous mixture in the separation zone of solid substance/liquid phase, forming a pure aqueous mixture; (e) addition of extraction solvent to the aqueous mixture or pure aqueous mixture in the extraction zone, forming an extract or rafinate, containing the metallic catalyst; and (f) separation of the extract and the solvent rich stream in the separation zone, forming a stream of organic impurities with high boiling point and a stream of extraction solvent. The invention has three versions.

EFFECT: extraction of expensive metallic catalyst in active form, suitable for repeated use, and acetic acid, contained in the mother solution with removal of most impurities present in the extracted stream.

20 cl, 1 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to the removal of the metallic catalyst from stock solution, obtained during the synthesis of carboxylic acids, normally terephthalic acid. Method of removing the metallic catalyst from the stream of stock solution containing carboxyl acid includes the following stages: (a) graduating the stock solution, which contains the carboxyl acid, metallic catalyst, impurities, water and solvent, in the zone of the first evaporator obtaining a stream of water vapour and a stream of concentrated stock solution; (b) evaporating of the specified stream of concentrated stock solution to the zone of the second evaporator forming a stream rich in the solvent and a stream of super-concentrated stock solution; (c) removing organic impurities from super-concentrated stock solution with the help of water-solvent solution in the zone of the separating phase of solid substance/liquid forming a stream of water and a second stream of water; (d) mixing in the zone of mixing water and not necessarily the extraction solvent with the specified water stream and the specified second water stream forming and aqueous solution; (e) adding the extraction solvent to the specified water solution in the extraction zone forming a stream of extract and a stream of raffinate containing the specified metallic catalyst; and (f) separating the specified stream of extract in the separating zone forming a stream of organic impurities with a high boiling point and a stream of the removed extraction solvent. In a different version of the realisation of the method of removing the metallic catalyst from the stream of stock solution containing the carboxylic acid includes the following stages: (a) evaporating of the stock solution containing the carboxylic acid, metallic catalyst, impurities, water and solvent, in the zone of the first evaporator obtaining a stream of water and a stream of concentrated stock solution; (b) evaporating the specified stream of concentrated stock solution in the second evaporating zone obtaining a stream rich in the solvent and stream of super-concentrated stock solution, where about 85 to about 99% mass, of the solvent and water is removed from the specified stock solution at the stage (a) and stage (b) in combination; (c) removing of organic impurities from the specified super-concentrated stock solution with help of the water-solvent solution in the zone of the separating phase of solid substance/liquid forming a stream of water and a second stream of water; where the specified water-solvent solution is introduced to the specified zone of the separating phase of solid substance/liquid at a temperature interval from about 20°C to 70°C; (d) mixing in the zone for mixing water and not necessarily the extraction solvent with the specified stream of water and the specified second water stream forming a water mixture; (e) introducing the extraction solvent to the specified water solution to the extraction zone forming a stream of extract and a stream of raffinate; and (f) separating of the specified flow of extract in the zone of separation forming a flow of organic impurities with a high boiling point and a flow of the extraction solvent removed.

EFFECT: increase in the efficiency of the method of removing impurities and working capacity of the method in comparison to the existing methods.

17 cl, 1 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: method of obtaining product - purified carboxylic acid, includes: (a) oxidation of aromatic initial materials in primary oxidation zone with formation of raw carboxylic acid suspension; where raw carboxylic acid suspension contains terephthalic acid; where said oxidation is carried out at temperature within the range from 120°C to 200°C; (b) withdrawal of admixtures from raw suspension of carboxylic acid, removed at temperature from 140°C to 170°C from stage of oxidation of paraxylol in primary oxidation zone and containing terephthalic acid, catalyst, acetic acid and admixtures, realised in zone of solid products and liquid separation with formation of mother liquid flow and product in form of suspension; where part of said catalyst in said suspension of raw carboxylic acid is removed in said mother liquid flow; and where into said zone of solid products and liquid separation optionally additional solvent is added; (c) oxidation of said product in form of suspension in zone of further oxidation with formation of product of further oxidation; where said oxidation is carried out at temperature within the range from 190°C to 280°C; and where said oxidation takes place in said zone of further oxidation at temperature higher than in said primary oxidation zone; (d) crystallisation of said product of further oxidation in crystallisation zone with formation of crystallised product in form of suspension; (e) cooling of said crystallised product in form of suspension in cooling zone with formation of cooled suspension of purified carboxylic acid; and (i) filtration and optionally drying of said cooled suspension of purified carboxylic acid in filtration and drying zone in order to remove part of solvent from said cooled suspension of carboxylic acid with obtaining of said product - purified carboxylic acid.

EFFECT: purified carboxylic acid with nice colour and low level of admixtures, without using stages of purification like hydration.

8 cl, 1 tbl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention pertains to the perfection of the method of regulating quantities of dissolved iron in liquid streams during the process of obtaining aromatic carboxylic acids or in the process of cleaning technical aromatic carboxylic acids, characterised by that, to at least, part of the liquid stream for regulating the quantity of dissolved iron in it, at least one peroxide with formula R1-O-O-R2 is added. Here R1 and R2 can be the same or different. They represent hydrogen or a hydrocarbon group, in quantities sufficient for precipitation of the dissolved iron from the liquid. The invention also relates to the perfection of the method of obtaining an aromatic carboxylic acid, through the following stages: A) contacting the crude aromatic material which can be oxidised, with molecular oxygen in the presence of an oxidising catalyst, containing at least, one metal with atomic number from 21 to 82, and a solvent in the form of C2-C5 aliphatic carboxylic acid in a liquid phase reaction mixture in a reactor under conditions of oxidation with formation of a solid product. The product contains technical aromatic carboxylic acid, liquid, containing a solvent and water, and an off-gas, containing water vapour and vapour of the solvent; B) separation of the solid product, containing technical aromatic carboxylic acid from the liquid; C) distillation of at least part of the off gas in a distillation column, equipped with reflux, for separating vapour of the solvent from water vapour. A liquid then forms, containing the solvent, and in the upper distillation cut, containing water vapour; D) returning of at least, part of the liquid from stage B into the reactor; E) dissolution of at least, part of the separated solid product, containing technical aromatic carboxylic acid, in a solvent from the cleaning stage with obtaining of a liquid solution of the cleaning stage; F) contacting the solution from the cleaning stage with hydrogen in the presence of a hydrogenation catalyst and under hydrogenation conditions, sufficient for formation of a solution, containing cleaned aromatic carboxylic acid, and liquid, containing a cleaning solvent; G) separation of the cleaned aromatic carboxylic acid from the solution, containing the cleaning solvent, which is obtained from stage E, with obtaining of solid cleaned aromatic carboxylic acid and a stock solution from the cleaning stage; H) retuning of at least, part of the stock solution from the cleaning stage, to at least, one of the stages B and E; I) addition of at least, one peroxide with formula R1-O-O-R2, where R1 and R2 can be the same or different, and represent hydrogen or a hydrocarbon group, in a liquid from at least one of the other stages, or obtained as a result from at least one of these stages, to which the peroxide is added, in a quantity sufficient for precipitation of iron from the liquid.

EFFECT: controlled reduction of the formation of suspension of iron oxide during production of technical aromatic acid.

19 cl, 1 dwg, 6 ex, 4 tbl

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