Obtaining amides and/or acids from nitriles

 

The invention relates to the production of amides and/or NITRILES. The method is carried out by introducing into the treatment area of the nitrile as a first reagent and hydrating compounds. able to interact with the nitrile into amide by hydration of the nitrile and/or into the acid, as the second reagent. Nitrile is subjected to catalytic distillation in the treatment zone in the presence of hydrated compounds, with hydrating at least a portion of the nitrile into amide and/or formation of acid. Amide and/or acid is withdrawn from the treatment area. When the treatment area is located in the column or tower and includes at least one reaction zone and a distillation zone. In the reaction zone flows catalytic hydration reaction of the nitrile into amide and/or acid. The reaction zone contains a compacted layer of catalyst particles of hydration of copper or copper-based, located in the tower section. In the distillation zone below and/or above the catalyst layer, carry out the distillation of the products from the reaction zone and/or unreacted reagents. The technical result - the reduction of economic and energy costs. 13 C.p. f-crystals, 1 Il.

Brief description of the invention According to the present invention, provided is a method of obtaining amide and/or acid nitrile, which comprises the introduction into the treatment area nitrile, as the first reagent, and hydrating compounds, which are able to interact with the nitrile into the corresponding amide, as the second reagent, hydratherma while nitrile, and/or by conversion into its corresponding acid; the impact on the nitrile by catalytic distillation in the treatment zone, in the presence of hydrated compounds, hydrating, at least part of the nitrile to the corresponding amide and/or with the formation of the corresponding acid; and removing the amide and/or acid from the treatment area.

Catalytic distillation, thus, involves performing chemical interaction at the same time or in combination with distillation, in the same treatment area. The treatment area, thus, will include at least one reaction zone, in which the catalytic hydration reaction of the nitrile into amide and/or acid in the presence of a catalyst, and at least one distillation zone near the reaction zone in which the property

The reaction zone, thus, may include a dense layer of particles of a catalyst capable of catalyzing the conversion or hydrating the nitrile to its corresponding amide. Can be used with any suitable catalyst hydrating, as a rule, hydration catalyst for the hydration of copper or copper based, for example, hydration of copper-chromium catalyst hydrating or copper-oxide catalyst operations.

The first reagent may contain unsaturated or aromatic nitrile, such as Acrylonitrile, Methacrylonitrile, crotononitrile, allisland, or benzonitrile, which, thus, will hydrogenate itself to the corresponding unsaturated or aromatic amide and/or acid, it will not occur polymerization significantly. Instead, however, the first reagent may contain intense nitrite, such as acetonitrile, propionitrile, butyronitrile, or isobutyronitrile.

The treatment area, as a rule, be created in the column or tower, with a layer of catalyst is generated in the tower section. The distillation zone can thus be formed below and/or above the catalyst bed. Preferably, the distillation zone is created devices or equipment for distillation and then settle in the column below and/or above the catalyst layer, that is, in the zone (or zones) of distillation.

The method may include the boiling of the liquid component in the zone of boiling (reboiling), in working condition connected with the lower end of the treatment area, with the aim of creating a driving force for catalytic distillation. Part of the liquid component may then, if desired, be injected into the treatment area, for example, above or below the catalyst bed.

The liquid component may be such that he did not participate in the hydration reaction, that is, that it provides only the driving force for the catalytic distillation and, thus, contributed to the distillation of the reactants and products in the treatment area. In this case, the second reagent may be injected into the treatment zone at a point separated from the point of introduction of the first reagent or nitrile in the treatment area, for example, above the catalyst layer, if the nitrile is introduced into the treatment zone below the catalyst bed. The second reagent should, therefore, be capable of hydrate the nitrile under conditions prevailing in the treatment area, and in the presence of a catalyst. In particular, the second reagent may be water.

The liquid component may be an organic compound such as an alcohol, an aromatic compound or wax.

But the way Kim, to be, in particular, the same as the second reagent. In other words, part of the second reagent is then used for boiling, while part of it is introduced into the treatment area as described above.

One of the first and second reagents, which has a higher boiling point, may be injected into the treatment zone above the catalyst layer, while the reagent having a lower boiling temperature, is introduced above or below the catalyst bed. When the first reagent or the nitrile is a component with a higher boiling point, part of it will, therefore, be entered above the catalyst layer, while the remaining component will boil in the boiling zone to create a driving force for catalytic distillation.

The selection of the amide may be carried out as taken from the top of the component or the component of the distillate at the top of the treatment area or as a component of higher boiling point in the lower portion of the treatment area, for example, from the zone of boiling, depending on the relationship of the boiling points of the first and second reagents.

The column may be of any desired length and width, and, as a rule, a length in the range from 10 m to 60 m As a rule, it damyleny scale. The catalyst layer may also be of any desired length, for example 0.5 to 10 m Pressure in the column may vary within wide limits, for example from 10 kPa (wt.) up to 10,000 kPa (wt.), and can be adjusted by means of inert gas, such as nitrogen or argon. Pressure, and hence the reaction temperature in the column, will determine the resulting product. Thus, if the amide corresponding to the nitrile, which is introduced into the column is at a given pressure in the column and, consequently, at a given reaction temperature, the corresponding acid can be produced amide instead of or in addition to it by increasing the pressure in the column and, therefore, the reaction temperature, at which it interacts, so that is additional or excessive hydrolysis, which produces the corresponding acid.

The drawing is a simplified block diagram of the method according to the present invention.

Detailed description of the invention the Present invention will be hereinafter described in more detail with reference to the corresponding schematic drawing, which is a simplified block diagram of the method according to the present invention for production of amide and/or acid from n is, oznachaet the method according to the present invention for production of amide from a nitrile.

The method 10 includes a catalytic distillation column 12. The dimensions of the column 12 can vary widely, but typically they are about 10 m in length with an inner diameter of 25 mm

Inside the column 12 is created by the reaction zone 14 so that the above zone 14 creates a distillation zone 16, while another distillation zone 18 is created below the reaction zone 14. The reaction zone 14 includes a dense layer of catalyst particles of hydration of copper-based, such as applied copper-chromium catalyst deposited copper-oxide catalyst, or other equivalent catalyst operations. The distillation zone 16, 18 have a nozzle from Raschig rings (not shown).

The pipeline to enter the water 20 is included in column 12 above layer 14, while the pipeline to enter nitrile 22 included in column 12 directly below the layer 14. However, it should be noted that the pipeline to enter nitrile 22 may also include in column 12 above layer 14.

The reboiler 24 is located below the column 12. The output pipe 26 leads from the lower portion of the column 12 to the reboiler 24, while the outlet line 28 leads from reboiler 24.

When used in the reboiler 24 enter the amount of water sufficient to fill 30-80% of its capacity, and the water is heated. The pressure in the column 12 regulate in the range between 0.1 and 100 bar, if desired, by means of inert gas, such as nitrogen or argon. The water in the reboiler 24 boils in column 12 until, until it reaches the full delegacia. At this stage the input stream nitrile, such as Acrylonitrile, which has a lower boiling point than water, is introduced into the column 22 through inlet pipe 22, as a rule, with a speed of from 0.001 to 50 kg per hour, with subsequent introduction of water through the pipe 20 at a suitable speed, for example from 0.001 to 100 kg per hour. Typically, the nitrile used as source material prior to its introduction into the column stabilized against polymerization by using inhibitors radicals, such as hydroquinone or methylated hydroquinone. In the column support 12 conditions reflux distilled, and amide derived from nitrile, together with excess water, remove as flow from the bottom of the column through line 34 with a speed of from 0.002 kg to 150 kg per hour.

When modeling method 10 in the laboratory were performed following non-limiting when the Les in the wire bags stainless steel (22) is placed in a 5 m section of the catalytic distillation column 12, with dimensions of 10 m x 25 mm in diameter. One meter in the upper part of the column (zone 16) and 4 m in the lower part of the column (zone 18) fill the ring process. Demineralized water is introduced into the reboiler 24 to fill 30% of its capacity. In nitrogen atmosphere, the water boils in the column at atmospheric pressure (85 kPa) until then, until you reach delegacia (96oC). Acrylonitrile containing 35 million-1methylated hydroquinone (MeHQ), is entered at the insertion point (line 22) directly below the catalyst bed at a rate of 30 g/hour, and the water is introduced (line 20) above the zone of the catalyst with the speed of 84 g/hour. After the introduction of Acrylonitrile, the temperature inside the catalyst layer drops to the boiling point of the azeotropic mixture of Acrylonitrile-water (64oC). The resulting solution containing 35% of the mass of acrylamide (100% degree of conversion and 100% selectivity), remove from reboiler through the pipe 34 with the speed of 114 g/hour.

EXAMPLE 2 extrudates or pellets of catalyst based on copper oxide or copper-Hermitage catalyst in the reduced form (350 g), loaded wire mesh, stainless steel (10) and wrapped in humanomalies mesh, placed in the upper section of the glass which are filled with rings process or structured distillation packing. Deaerated demineralized water is introduced into the reboiler 30% fill its capacity. In nitrogen atmosphere, the water boils in the column at atmospheric pressure (85 kPa) until then, until you reach delegacia (96oC). Deaerated nitrile is introduced into the insertion point immediately below the catalyst bed with the speed of 10-25 g/hour, and water is injected into the column above the zone of the catalyst with the speed required to produce the product at a desired concentration. After the introduction of the nitrile temperature inside the catalyst layer drops to the boiling point of the azeotropic mixture of the nitrile-water. The resulting solution (25-130 g/h), containing up to 50% mass amide (>90% conversion and selectivity), remove from reboiler.

EXAMPLE 3 the extrudates of catalyst based on copper oxide in its restored form (900 g), loaded wire mesh stainless steel (22) and wrapped humanology grid, load 8.5 m section of the catalytic distillation column having dimensions of 10 m x 25 mm in diameter. The lower 1.5 m of the column fill 10 mm saddle-shaped nozzles, the Burleigh. Deaerated demineralized water is introduced into the reboiler 30% fill its capacity. In nitrogen atmosphere at a pressure offset (135oC). Deaerated Acrylonitrile (containing 35 million-1MeHQ) was injected at the insertion point immediately below the catalyst bed with the speed 48-152 g/hour, and water is injected into the column above the zone of the catalyst at such a speed as to produce a product at the required concentration. After the introduction of Acrylonitrile, the temperature inside the catalyst layer drops to the boiling point of the azeotropic mixture of Acrylonitrile-water (about 104oC). The resulting solution containing up to 50% of the mass of acrylamide (>98% degree of conversion and selectivity) are removed from reboiler with the speed of 200-500 g/hour.

EXAMPLE 4 IN this example, the design of the columns and the layer of the catalyst are the same as for example 3, but the nitrogen pressure inside the column is raised to a pressure higher than atmospheric pressure 400 kPa, resulting in the temperature in the reboiler is 158oC. When the above area of the catalyst is injected Acrylonitrile (180 g/h), the temperature in the zone of the catalyst is reduced to 135oC-145oWith, and obtain an aqueous solution of acrylic acid (about 75 g/h) and acrylamide (about 175 g/h).

EXAMPLE 5 the catalyst is a copper-oxide catalyst in its reduced form (13.5 kg) loaded in a wire mesh stainless steel is th size 10 m in height h mm in diameter. The lower 2 m of the column fill 10 mm saddle-shaped nozzles, the Burleigh. Deaerated demineralized water is introduced into the reboiler to 50% fill capacity. In nitrogen atmosphere under a pressure in excess of atmospheric pressure is 100 kPa, the water boils in the column until then, until you reach delegacia (121oC). Deaerated Acrylonitrile containing 35 million-1MeHQ, introducing the insertion point above the catalyst bed at a rate of 0.5-2.5 g/hour, and water is injected into the column above the zone of the catalyst at such a rate to produce the product at the required concentration. After the introduction of Acrylonitrile, the temperature inside the catalyst layer drops to the boiling point of the azeotropic mixture of Acrylonitrile-water (about 89oC). the pH of the resulting solution support between 5.0 and 6.0 by adding in the reboiler of 0.0125 M solution of sulfuric acid. The resulting solution containing up to 50% of the mass of acrylamide (>98% degree of conversion and selectivity), remove from reboiler with the speed of 5-30 kg/hour.

It is known the production of amides from NITRILES by hydration of NITRILES in the periodic reactors, reactors with fixed or weighted layer. There are three types of reactions, namely: (a) homogeneous catalyzed reaction, mainly with the basic metals, for example, copper oxide or chromium oxide as catalysts;
c) reaction in which the biocatalysts, such as enzymes, are used to facilitate hydration of NITRILES.

These reactions are used for the production of amides, for example for the production of acrylamide monomer nitrile such as Acrylonitrile. Such monomers, in turn, are used to produce water-soluble polymers and copolymers, which are used as flocculants in the mining industry, additives in the manufacture of paper, thickening agents, coatings for surfaces and products to increase oil production.

The applicant is aware that periodic processes catalyzed mainly sulfuric acid, strongly exothermic hydration reaction of NITRILES is complicated by the formation of the polymer, if the temperature of the reaction and attitude of the reagents is not carefully controlled. To complete the reaction, the acid is neutralized, and the resulting effluent containing mainly sulfates contaminated with acrylamide. This leads to the fact that it is necessary to crystallize from residual water and process in powder form highly toxic acrylamide.

The applicant also known C division, when technology is used with suspended layer, whereas when using separate reactors with a fixed layer, that is, when not using the sequence of reactors, acrylamide is produced only at low concentrations in water, about 7%. Stratification of the phases limits the amount of Acrylonitrile, which can be introduced into the reactor together with water. In this case, the catalyst, unreacted Acrylonitrile and water must be removed by filtration and/or distillation to achieve the desired concentration of approximately 50%. Besides the fact that they are uneconomical in relation to energy recovery (heat is removed at the stage of the reaction and re-added at the stage of distillation), these methods are very capital intensive, as for purification and concentration of the product requires multiple reactors and distillation towers. The service life of the catalyst is also limited, although the catalyst in some cases, it may be regenerated by oxidation and subsequent reduction with hydrogen.

The applicant has unexpectedly discovered that by applying the technology of catalytic distillation to hydration of amides can be eliminated many of the disadvantages of the known methods.the Omiya train station capital investment (usually one reaction capacity against five reaction vessels in the known methods) for small production effluent or in its absence. Another advantage is that the heat from the reaction is partly used to heat the reactants, which leads to less energy consumption. Because the catalytic distillation is substantially distillation process, controlling the reaction temperature and, thus, prevention or inhibition of unwanted polymerization, is not difficult. In addition, the required concentration of the product (50%) can be achieved without additional separation processes, and the service life of the catalyst increases. There is only a small undesirable polymerization or her absence, because the product is continuously removed from the heat source. Thus, an aqueous solution of the product at the desired concentration (1%-60%) can be obtained directly from the reactor without the need for additional purification or concentration, while the energy consumption is minimized. In the case of olefinic NITRILES, oligomerization/polymerization is not an issue, if the pH is maintained between 3 and 8, since the product n-3 butanamide, obtained using the method according to the present invention, can be used as monomers in polymerization reactions. For example, using the method according to the present invention from acrylamido received non-ionic and anionic polyacrylamides. It is assumed that by means of the method according to the present invention will also be possible to produce acrylamide, suitable for the production of cationic polyacrylamides.


Claims

1. Method for producing amide and/or acid nitrile, comprising the introduction into the treatment area nitrile as the first reagent, and hydrating compounds, which are able to interact with the nitrile into the corresponding amide by hydration of the nitrile and/or its conversion to the corresponding acid, as the second reagent; the impact on the nitrile by catalytic distillation in the treatment zone, in the presence of hydrated compounds, with hydrating at least a portion of the nitrile to the corresponding amide and/or with the formation of the corresponding acid; and selection of amide and/or acid from the treatment area, wherein the treatment area is located in the column or purpose nitrile into amide and/or acid in the presence of a catalyst, and at least one distillation zone near the reaction zone in which is a distillation of the product (s) of the reaction from the reaction zone and/or unreacted reactants; the reaction zone contains a compacted layer of catalyst particles of hydration of copper or copper-based and specified area that contains the specified layer of the catalyst is located in the tower section, and the distillation zone is located below and/or above the catalyst bed.

2. The method according to p. 1, where the first reagent contains unsaturated or aromatic nitrile, which thus hydrated to the corresponding unsaturated or aromatic amide and/or acid.

3. The method according to p. 1 or 2, where the distillation zone is located below and above the catalyst bed.

4. The method according to p. 1 or 2, which includes boiling of the liquid component in the zone of boiling, which is operable connected to the lower part of the treatment area to provide the driving force for catalytic distillation, whereby part of the liquid component is not necessarily introduced into the treatment zone above or below the catalyst bed.

5. The method according to p. 4, where the liquid component is such that he did not participate in the hydration reaction, and provided the only movement is e processing, the second reagent is introduced into the treatment zone at a point separated from the point of introduction into the treatment area of the first reagent.

6. The method according to p. 5, where the second reactant is water and where the liquid component is an organic compound.

7. The method according to p. 4, where the liquid component and the second reactant is water, so that the liquid component is involved in the hydration reaction.

8. The method according to p. 1 or 2, where the reagent from the first and second reagents with a higher boiling point, is injected into the treatment zone above the catalyst layer, and the compound having a lower boiling temperature, is injected below the catalyst bed.

9. The method according to p. 3, which includes boiling of the liquid component in the zone of boiling connected in working condition with the bottom part of the treatment area to provide the driving force for catalytic distillation, and part of the liquid component is not necessarily injected into the treatment area above or below the catalyst bed.

10. The method according to p. 3, which has a higher boiling point of the reagent from among the first and second reagents is introduced into the treatment zone above the catalyst layer, and the compound having a lower boiling temperature, is injected below the catalyst bed.

11. The method according to the processing above the catalyst layer, and the compound having a lower boiling temperature, is injected below the catalyst bed.

12. The method according to p. 5, which has a higher boiling point of the reagent from among the first and second reagents is introduced into the treatment zone above the catalyst layer, and the compound having a lower boiling temperature, is injected below the catalyst bed.

13. The method according to p. 6, which has a higher boiling point of the reagent from among the first and second reagents is introduced into the treatment zone above the catalyst layer, and the compound having a lower boiling temperature, is injected below the catalyst bed.

14. The method according to p. 7, which has a higher boiling point of the reagent from among the first and second reagents is introduced into the treatment zone above the catalyst layer, and the compound having a lower boiling temperature, is injected below the catalyst bed.

 

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15 cl, 1 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to method of reverse splitting of Michael adducts, contained in fluid F with weight part ≥ 10 wt %, counted per liquid F weight, which were formed in the process of obtaining acrylic acid or its esters, in installation of reverse splitting, which includes, at least, one pump P, separation column C, which from bottom to top consists of bottom part, separating part, which is adjacent to bottom part and contains internal devices with separating effect, and head part, which follows it, in which pressure in gaseous phase decreases from bottom to top, as well as indirect heat exchanger with circulation of heat carrier UW, which has, at least, one secondary volume and, at least, one primary volume, separated from said, at least, one secondary volume by means of real separating wall D, in which fluid F with supply temperature TZ is continuously introduced into separation column C in point of supply I, which is located in said separation column C above the lowest internal device with separating effect; expenditure flow M˙ of fluid F with temperature TSU, flowing into bottom part through internal devices with separating effect, containing Michael adducts, is continuously taken away in located at the lowest level of bottom part of column C by means of pump P, in such a way that in bottom part as bottom fluid set is level S of fluid, flowing into it, which constitutes less than half of distance A, measured from point of separating column C, located at the lowest level, to lower surface of the lowest internal device with separating effect in separation column C, while in the remaining volume of bottom part, located above said level of fluid, pressure of gas GD exists, as well as, at least, one partial flow I from expenditure flow M˙* is passed through, at least, one secondary volume of indirect heat exchanger with circulation of heat carrier UW, and by indirect heat exchange with liquid heat carrier, passed simultaneously through, at least, one primary volume of said indirect heat exchanger with circulation of heat carrier UW, is heated to temperature of reverse splitting TRS, which is above temperature TSU; and from removed from, at least, one secondary volume of indirect heat exchanger with circulation of heat carrier UW with temperature TRS flow of substance M˙ in point of supply II, which is below the lowest internal element with separating effect of separation column C and above level S of bottom fluid, at least, one partial flow II is supplied back into bottom part of separation column C in such a way that said, at least, one partial flow II in bottom part of separation column C is not directed on bottom fluid, and, at least, from one of two flows M˙, M˙* discharged is partial flow as residual flow on condition that temperature of reverse splitting TRS is set in such a way that, on one hand, in the process of passage of, at least, one secondary volume of indirect heat exchanger with circulation of heat carrier UW, at least, part of Michael adducts, contained in, at least, one partial flow I, are split with formation of respective to them products of reverse splitting, as well as, on the other hand, at least, one partial flow II, supplied back into separation column C, under existing in bottom part in point of supply II gas pressure GD, is boiling, and gaseous phase, which is formed in the process of boiling, containing, at least, partial amount of product of reverse splitting, is supplied into head part of column C as gas flow G, containing product of reverse splitting, following decreasing towards head part of column C gas pressure, and said gas flow G by direct and/or indirect cooling is partially condensed still in head part of separation column C and/or being discharged from head part of separation column C, condensate, formed in this process is, at least, partially returned to separation column C as reflux fluid, and gas flow, remaining in the process of partial condensation, is discharged, with pump P representing radial centrifugal pump with semi-open radial working wheel. Coefficient of efficiency Q of claimed method constitutes at least 20%.

EFFECT: improvement of method.

14 cl, 9 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining terephthalic acid, including a) interaction of 2,5-furanedicarboxylic acid, 2,5-furane dicarboxilate or their mixture with ethylene in presence of solvent with formation of bicyclic ether at temperature in the interval from 100°C to 250°C and pressure in the interval from approximately 10 lb/sq.inch (about 68.95 kPa) to 2000 lb/sq.inch (about 13.79 MPa) and b) dehydration of bicyclic ether.

EFFECT: method ensures effective obtaining terephthalic acid with reduced amount of admixtures, coloured admixtures and carbon oxides, which are formed in industry in case of liquid-phase oxidation of methyl-substituted benzoles, or without said admixtures at all.

16 cl, 1 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to method of producing α, β ethylenically unsaturated carboxylic acid or its ester, such as methacrylic acid or its alkyl ethers, for example, methyl methacrylate. Method involves stages of interaction of formaldehyde or suitable source thereof with carboxylic acid or its ester, for example, propionic acid or its alkyl ethers, in presence of catalyst and optionally in presence of alcohol, selected from C1-C30 alkanol, including aryl-alcohols. Catalyst contains group II metal phosphate crystals, having rod- or needle-like morphology. Phosphate can be hydroxyapatite, pyrophosphate, hydroxyphosphate, PO42- phosphate or their mixture. Metal of group II can be selected from Ca, Sr, Ba or mixtures thereof, for example hydroxyapatite strontium and calcium hydroxyapatite. Invention also relates to catalyst system containing crystalline metal phosphate catalyst and catalyst carrier. Metal phosphate has rod- or needle-like morphology.

EFFECT: technical result is high selectivity of product.

19 cl, 10 tbl, 24 ex

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing acrylic acid, acrylic acid derivatives or mixtures thereof, where, in particular, method includes a step of bringing into contact a flow containing hydroxypropionic acid, hydroxypropionic acid derivatives or mixture thereof, with catalyst containing (a) at least one anion of condensed phosphate, which is selected from a group consisting of formulae (I), (II) and (III), where n is equal to at least 2 and m is at least 1; and (b) at least two different cations, wherein said cations include: (i) at least one univalent cation and (ii) at least one polyvalent cation; catalyst is substantially neutrally charged; additionally molar ratio of phosphorus and said at least two different cations is 0.7-1.7, to obtain acrylic acid, acrylic acid derivatives or mixtures thereof as a result of contact with said catalyst.

EFFECT: methods for catalytic dehydration of hydroxypropionic acid, hydroxypropionic acid derivatives or mixtures thereof into acrylic acid, acrylic acid derivatives or mixture thereof are carried out with high output and selectivity and without significant conversion into undesirable by-products, such as acetaldehyde, propionic acid and acetic acid.

35 cl, 4 tbl, 15 ex

FIELD: chemistry.

SUBSTANCE: there are presented catalysts for dehydration of 3-hydroxypropionic acid, derivatives 3-hydroxypropionic acid or mixtures thereof into acrylic acid, acrylic acid derivatives or their mixture with high output and selectivity, short time of stay, and without significant conversion in undesirable by-products, such as, for example, acetaldehyde, propionic acid and acetic acid. Catalyst contains mono-phosphate salt described by formula (III): and mono-phosphate salt described by formula (IV): where MI represents univalent cation and MII is divalent cation, wherein catalyst, in fact, is neutral charged and molar ratio of said MIIHPO4 and said MIH2PO4 in above catalyst is from 0.2 to 5. Method of producing said catalyst includes step where mixed compounds containing phosphor, wherein above compounds contain compound of formula (VI), wherein mentioned a is equal to 1, and compound of formula (VII), where specified a equal to 2:

where MI represents univalent cation, where MII is divalent cation. Another method of producing catalyst includes step on which are BaHPO4 and KH2PO4 are combined in molar ratio of 3:2 to 2:3 to form solid mixture and ground said solid mixture to produce said catalyst.

EFFECT: dehydration 3-hydroxypropionic acid, derivatives 3-hydroxypropionic acid or mixtures thereof into acrylic acid, acrylic acid derivatives or their mixture with high output and selectivity.

12 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing acrylic acid, derivatives of acrylic acid or mixtures thereof, where the method, in particular, includes a step at which there is brought into contact a flow containing hydroxypropionic acid, hydroxypropionic acid derivatives or mixtures thereof, with a catalyst containing: a. anion monohydromonophosphate, which is described by formula (I): [HPO4]2- (I), b. and anions dihydromonophosphate, described by formula (II): [H2PO4]- (II), and c. at least two different cations, while the catalyst is neutrally charged; additionally, the molar ratio of the said anion of monohydromonophosphate and the said anion of dihydromonophosphate in the specified catalyst is from 0.1 to 10.

EFFECT: methods for catalytic dehydration of hydroxypropionic acid, hydroxypropionic acid derivatives or mixtures thereof into acrylic acid, acrylic acid derivatives or mixture thereof are carried out with high output and selectivity and without significant conversion into undesirable by-products, such as acetaldehyde, propionic acid and acetic acid.

40 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: catalysts are mixed condensed phosphates, containing (a) at least one anion condensed phosphate of formula (I) [PnO3n+1](n+2)- (I), where n is equal to at least 2, and (b) at least two different cation. Catalyst, in fact, neutral charge, and molar ratio of phosphorus and said at least two different cations is from 0.7 to 1.7. Cations include: (i) at least one univalent cation; and (ii) at least one polyvalent cation, and the multivalent cation is selected from the group consisting of Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Sn2+, Pb2+, Ti3+, Cr3+, Mn3+, Al3+, Ga3+, Y3+, In3+, Sb3+, Bi3+, Si4+, Ti4+, V4+, Ge4+, Mo4+, Pt4+, V5+, Nb5+, Sb5+ and mixtures thereof. Invention also discloses methods of producing catalysts. First method comprises steps of mixed and heated at least two different compounds containing phosphor, each said compound is described by one of the formulae (IV) and (XV), or any of hydrated forms said formulae MIy(H3-yPO4) (IV); MIIvH(4-2v)P2O7 (XV), where MI represents a univalent cation; where MII is a divalent cation; where y denotes 0, 1, 2 or 3; where v is 0, 1 or 2. Second method comprises steps of mixed and heated (a) at least one compound containing phosphorus, at that each said compound is described by one of the formulae (IV)-(VI) and (XV), or any of hydrated forms said formulae MIy(H3-yPO4) (IV); MIIy(H3-yPO4)2 (V); MIIIy(H3-yPO4)3 (VI); MIIvH(4-2v)P2O7 (XV), where MI represents a univalent cation; where MII is a divalent cation; where MIII is a trivalent cation; where y denotes 0, 1, 2 or 3; where v is 0, 1 or 2; and (b) at least one compound does not contain phosphorus, selected from a group consisting of nitrate salts, at that each said compound is described by one of formulas (XXVI)-(XXVII), or any of hydrated forms said formulae MINO3 (XXVI); MII(NO3)2 (XXVII). Third method comprises steps of (a) Ca2P2O7 and KH2PO4 in molar ratio 3:1 to form a solid mixture, and (b) calcined said solid mixture of stepwise at 50 °C, 80 °C, 120 °C and at from 450 °C to 550 °C, to obtain said catalyst.

EFFECT: there are presented catalysts for dehydration of hydroxipropionic acid derivatives hydroxipropionic acid or mixtures thereof into acrylic acid, acrylic acid derivatives or their mixture with high output and selectivity, short-term stay and without significant conversion in undesirable by-products, such as, for example, acetaldehyde, propionic acid and acetic acid.

24 cl, 2 tbl, 13 ex

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