The method of selection of technical sodium formate

 

(57) Abstract:

The invention relates to a technology for technical formate sodium from aqueous solution technical Chlorella, which is a waste product of chloroform. The process is carried out by decomposing technical Chlorella sodium hydroxide. Specified aqueous solution is evaporated to a residual moisture content 16,8 - to 29.7 wt.%, preferably at atmospheric pressure and a temperature of 125 - 132°C. one stripped off the pulp is passed on crystallization by cooling, then dried, evaporated residual moisture of the pulp in a stream of air. The result is improved efficiency of the process by eliminating the split operation salts. 2 C.p. f-crystals, 1 table.

The invention relates to chemical technology and is intended for technical formate sodium allocated from the aqueous solution from the production of chloroform, and used as a preservative roughage (silage, wet hay) in agriculture.

There is a method of allocation of technical sodium formate aqueous solution of sodium formiate, obtained by splitting technical Chlorella aqueous sodium hydroxide solution, by evaporation on a water bath (100oC) technology and can be used only in laboratory and pilot conditions.

There is a method of allocating formate, alkali metal, in particular sodium formate, from mother solutions for the production of pentaerythritol by evaporation in vacuum at a temperature of 60 - 70oC to beats. weight of 1.15-1.4 g/cm3followed by treatment with alcohol, having a boiling point of not higher than 100oC. the resulting mass is crystallized and separated by filtration. The precipitate is dried to obtain a marketable product, and the filtrate is subjected to regeneration before reuse in the process (ed. St. USSR N 396995, class C 07 C 53/06, 51/48, publ. 15.01.76). The disadvantage of this method involves the use of an organic solvent and the necessity of regeneration. The use of alcohol with a boiling point not higher than 100oC makes the process of excretion of sodium formiate flammable and explosive.

One of the disadvantages of the known method is eliminated in the method of separation of anhydrous sodium formate from the aqueous solution after extraction of polyols obtained by the condensation of aldehydes with formaldehyde, by removing water by azeotropic distillation using benzene, toluene or xylene as azeotroping agent. The aqueous layer azeotropic mixture is directed to the main stage polucheniya formate sodium dried from an organic solvent (patent RF N 2090550, class. C 07 C 53/06, 31/24, B 01 D 3/40, publ. 20.09.97). In connection with the use of organic solvents, the process of separating the sodium formate is flammable and explosive.

The closest to the essential features to the present invention is a method of separation of sodium formiate, including the evaporation of the mother liquor obtained after separation of pentaerythritol from the reaction mass condensation of formaldehyde with acetaldehyde in the presence of sodium hydroxide, crystallization by cooling, filtering in the centrifuge and drying technical formate sodium Aeropostale the dryer. In this method, the crystallization of lead under vacuum at a residual pressure of 2 to 6 kPa while evaporating and removing part of the water in the amount of 10 - 20% by weight of the solution and cooling it to a temperature of 55 - 75oC with a speed of 1.5 to 3 deg/min (RF patent N 2078758, class C 07 C 53/06, 31/24, B 01 D 9/02, publ. 10.05.97). In connection with the exception of the use of organic solvents is reduced fire and explosion hazards in the process. The technological regime to the maximum extent takes into account the established differences in the crystallization of sodium formate and pentaerythritol.

However, the technological transfer installed REGO splitting technical Chlorella aqueous solution of sodium hydroxide, leads to the precipitation of sodium chloride that is present as an impurity in the original solution, and the sodium formate remains in solution. The separation of sodium chloride and sodium formate in the process of selection of technical sodium formate is not economically justified, because as sodium chloride and sodium formate are preservatives roughage (silage, wet hay) in agriculture.

The technical task of the present invention is the elimination of salt fractionation in the process of selection of technical sodium formate and adequate improvement of the economy of the process.

The problem is solved in that in the method of selection of technical sodium formiate, including the evaporation of an aqueous solution, which is the waste of organic production, crystallization by cooling and drying, as the aqueous solution using waste production of chloroform by the method of splitting technical Chlorella sodium hydroxide, evaporating the aqueous solution is conducted to a residual moisture content 16,8-to 29.7 wt.% in one stripped off the pulp, which is passed to the crystallization by cooling and drying.

Another difference is that the evaporation is carried out at atmospheric dispareunia one stripped off residual moisture of the pulp in a stream of air.

The method was verified in the laboratory.

Example 1. In a round bottom flask with a capacity of 1 l, equipped with a mechanical stirrer and a thermometer, was loaded 772,8 g of an aqueous solution of sodium formiate, obtained after separation of the chloroform from the reaction mass splitting technical Chlorella sodium hydroxide content of 63.2 wt.% water. Evaporation of an aqueous solution was carried out at atmospheric pressure until a temperature one stripped off the pulp 125oC. Obtained 368,5 g of water condensate and 404,3 g one stripped off the pulp with a moisture content

< / BR>
Part one stripped off the pulp in the amount of 120 g was subjected to crystallization by cooling and drying in a laboratory model of runners in air flow. Received of 85.7 g technical formate sodium with a water content of 2.0 wt.%.

Example 2. The process is similar to that described in example 1. Was evaporated 764,4 g of an aqueous solution of sodium formate containing 63,2 wt.% water until a temperature perivenous mass 127oC. Obtained 378,2 g of water condensate and 385,2 g one stripped off the pulp with a moisture content

< / BR>
During crystallization and drying of 120 g one stripped off the pulp obtained 89,0 g technical formate sodium with a water content of 1.8 wt.%.

Example 3. Was evaporated 884,829oC. Obtained to 473.6 g of water condensate and 411,2 g one stripped off the pulp with a moisture content

< / BR>
During crystallization and drying of 120 g one stripped off the pulp obtained 97,0 g technical formate sodium with a water content of 2.1 wt.%.

Example 4. Was evaporated 784,5 g of an aqueous solution of sodium formate containing 60,0 wt.% water until a temperature perivenous mass 129oC. Obtained 403,5 g of water condensate and 381 g one stripped off the pulp with a moisture content

< / BR>
During crystallization and drying of 120 g one stripped off the pulp obtained 100 grams of technical sodium formate with a moisture content of 1.5 wt.%.

Example 5. Was evaporated 881,3 g of an aqueous solution of sodium formate containing 60,0 wt.% water until a temperature perivenous mass 131oC. Obtained 451,3 g of water condensate and 430 g one stripped off the pulp with a moisture content

< / BR>
During crystallization and drying of 120 g one stripped off the pulp obtained 99,6 g technical formate sodium with a water content of 1.2 wt.%.

Example 6. Was evaporated 898 g of an aqueous solution of sodium formate containing 60,0 wt.% water until a temperature perivenous mass 132oC. Obtained 466,5 g of water condensate and 431,5 g one stripped off the pulp with a moisture content

< / BR>
When Chris is AC.%.

Conditions and results of experiments for clarity in the table.

These examples show industrial acceptability and effectiveness of the proposed method.

Evaporation of an aqueous solution obtained after separation of the chloroform from the reaction mass splitting technical Chlorella sodium hydroxide, to a residual moisture content in perivenous the pulp below to 16.8 wt.% it is impractical because of the increased viscosity perivenous pulp and deterioration of its transportation. Evaporation of the specified solution to a residual moisture content above to 29.7 wt. % in one stripped off the pulp is also impractical due to the deterioration of crystallization and drying of technical sodium formate.

The most preferred conditions of parki solution should be considered final temperature privelage solution 129 - 131oC. In this case, the residual moisture is removed by evaporation by the heat of crystallization of sodium formiate and cooling in air flow.

1. The method of selection of technical sodium formiate, including the evaporation of an aqueous solution, which is the waste of organic production, crystallization by cooling and drying, characterized in that as odnm sodium, evaporation of an aqueous solution is conducted to a residual moisture content 16,8 - to 29.7 wt.% in one stripped off the pulp, which is passed to the crystallization by cooling and drying.

2. The method according to p. 1, wherein the evaporation is carried out at atmospheric pressure and a temperature of 125 - 132oC.

3. The method according to p. 1 or 2, characterized in that the crystallization by cooling and drying is carried out by evaporation of residual moisture one stripped off the pulp in a stream of air.

 

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FIELD: crystal growing.

SUBSTANCE: invention relates to adipic acid crystals and treatment thereof to achieve minimum crystal caking. Crystals are prepared by crystallization of adipic acid from aqueous medium or between treating it with aqueous solution. Crystals are then subjected to ripening stage, that is crystals are held at temperature between 10 and 80°C until content of exchangeable water in crystals falls below 100 ppm, while using an appropriate means to maintain ambient absolute humidity at a level of 20 g/m3. Renewal of ambient medium is accomplished by flushing crystal mass with dry air flow having required absolute humidity. Means to maintain or to lower absolute humidity contains moisture-absorption device placed in a chamber. Content of exchangeable water in crystals is measured for 300 g of adipic acid crystals, which are enclosed in tightly sealed container preliminarily flushed with dry air and containing 2 g of moisture absorbing substance. In chamber, temperature between 5 and 25°C is maintained for 24 h. Content of water will be the same as amount of water absorbed by absorbing substance per 1 g crystals. Total content of water exceeds content of exchangeable water by at least 20 ppm.

EFFECT: minimized caking of crystals and improved flowability.

13 cl, 5 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for isolating crystalline terephthalic acid comprising less 150 mas. p. p. per million (ppm) of p-toluic acid with respect to weight of terephthalic acid. Method involves the following steps: (1) preparing a solution containing from 10 to 35 wt.-% of dissolved terephthalic acid wherein from 150 to 1100 ppm of p-toluic acid is dissolved with respect to mass of terephthalic acid at temperature from 260°C to 320°C and under pressure providing maintaining the solution in liquid phase; (2) charge of solution from step (1) to crystallization zone comprising multitude amount of associated crystallizers wherein the solution is subjected for cooling at evaporation at the controlled rate by the moderate pressure and temperature reducing resulting to crystallization of terephthalic acid and wherein the solution pressure at the end of crystallization zone is equal to atmosphere pressure or lower; (3) condensation of solvent evaporated from crystallizers and recovering the condensed solution to the crystallization zone to place of descending flow from crystallizer wherein solvent is removed by evaporation, and (4) isolation of solid crystalline terephthalic acid comprising less 150 ppm of p-toluic acid with respect to the terephthalic acid mass by separation of the phase liquid-solid substance under atmosphere pressure. The advantage of method is preparing the end product in improved crystalline form and carrying out the process under atmosphere pressure or pressure near to atmosphere pressure.

EFFECT: improved method of crystallization.

3 cl, 1 dwg, 1 tbl, 2 ex

FIELD: chemical industry; methods of production of the purified crystalline terephthalic acid.

SUBSTANCE: the invention is pertaining to the improved method of production and separation of the crystalline terephthalic acid containing less than 150 mass ppm of the p-toluene acid in terms of the mass of the terephthalic acid. The method provides for the following stages: (1) loading of (i) para- xylene, (ii) the water reactionary acetic-acidic medium containing the resolved in it components of the oxidation catalyst, and (iii) the gas containing oxygen fed under pressure in the first zone of oxidation, in which the liquid-phase exothermal oxidization of the para-xylene takes place, in which the temperature and the pressure inside the first being under pressure reactor of the oxidization are maintained at from 150°С up to 180°С and from 3.5 up to 13 absolute bars; (2) removal from the reactor upper part of the steam containing the evaporated reactionary acetic-acidic medium and the gas depleted by the oxygen including carbon dioxide, the inertial components and less than 9 volumetric percents of oxygen in terms of the non-condensable components of the steam; (3) removal from the lower part of the first reactor of the oxidized product including (i) the solid and dissolved terephthalic acid and (ii) the products of the non-complete oxidation and (ii) the water reactionary acetic-acidic medium containing the dissolved oxidation catalyst; (4) loading of (i) the oxidized product from the stage (3) and (ii) the gas containing oxygen, into the second being under pressure zone of the oxidation in which the liquid-phase exothermal oxidization of the products of the non-complete oxidization takes place; at that the temperature and the pressure in the second being under pressure reactor of the oxidization are maintained from 185°С up to 230°С and from 4.5 up to 18.3 absolute bar; (5) removal from the upper part of the second steam reactor containing the evaporated water reactionary acetic-acidic medium and gas depleted by the oxygen, including carbon dioxide, the inertial components and less, than 5 volumetric percents of oxygen in terms of the non-condensable components of the steam; (6) removal from the lower part of the second reactor of the second oxidized product including (i) the solid and dissolved terephthalic acid and the products of the non-complete oxidation and (ii) the water reactionary acetic-acidic medium containing the dissolved oxidation catalyst; (7) separation of the terephthalic acid from (ii) the water reactionary acetic-acidic medium of the stage (6) for production the terephthalic acid containing less than 900 mass ppm of 4- carboxybenzaldehyde and the p-toluene acid; (8) dissolution of the terephthalic acid gained at the stage (7) in the water for formation of the solution containing from 10 up to 35 mass % of the dissolved terephthalic acid containing less than 900 mass ppm of the 4- carboxybenzaldehyde and the p-toluene acid in respect to the mass of the present terephthalic acid at the temperature from 260°С up to 320°С and the pressure sufficient for maintaining the solution in the liquid phase and introduction of the solution in contact with hydrogen at presence of the catalytic agent of hydrogenation with production of the solution of the hydrogenated product; (9) loading of the solution of the stage (8) into the crystallization zone including the set of the connected in series crystallizers, in which the solution is subjected to the evaporating cooling with the controlled velocity using the significant drop of the temperature and the pressure for initiation of the crystallization process of the terephthalic acid, at the pressure of the solution in the end of the zone of the crystallization is atmospheric or below; (10) conduct condensation of the dissolvent evaporated from the crystallizers and guide the condensed dissolvent back into the zone of the crystallization by feeding the part of the condensed dissolvent in the line of removal of the product of the crystallizer, from which the dissolvent is removed in the form of the vapor; and (11) conduct separation of the solid crystalline terephthalic acid containing less than 150 mass ppm of the p-toluene acid in terms of the mass of the terephthalic acid by separation of the solid material from the liquid under the atmospheric pressure. The method allows to obtain the target product in the improved crystalline form.

EFFECT: the invention ensures production of the target product in the improved crystalline form.

8 cl, 3 tbl, 2 dwg, 3 ex

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

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: method of separating multi-atom alcohols, for instance, neopentylglycol and sodium formiate, includes evaporation and cooling of reaction mixture, addition of organic solvent, crystallisation of sodium formiate, separation of sodium formiate from saturated solution of multi-atom alcohol, for instance, by filtration, and crystallisation of multi-atom alcohol. Reaction mixture is evaporated until two liquid layers are formed, which are separated into light phase - water-multi-atom alcohol and heavy phase -water-salt, separated water-salt fraction of solution is cooled until sodium formiate contained in it in form of cryslallohydrate is crystallised, sodium formiate crystals are separated, and remaining mother-solution is returned to process head, to evaporation stage, then separated light phase - water-multi-atom alcohol is additionally evaporated until 70% of contained in it sodium formiate is crystallised, then cooled to 25-30°C and subjected to processing with organic solvent from line of single-atom saturated alcohols, for instance, methane, for removal of remaining admixtures, with further crystallisation of multi-atom alcohol from remaining mother-solution.

EFFECT: reduction of amount of used organic solvent, elimination of high-temperature stage of extraction, preservation of yield of pure target products.

2 cl, 2 dwg, 1 ex

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: proposal is given of a method of removing impurities from a water mixture or purified water mixture through extraction of the water mixture or purified water mixture using an extractive solvent in the extraction zone with formation of a stream of extract and a stream of raffinate and, optionally, separation of the extract stream and the solvent rich stream in the separation zone with formation of a stream of organic impurities with high boiling point and a stream of extractive solvent.

EFFECT: provision for extracting metallic catalyst in active form, reusable at the paraxylene recycling stage.

29 cl, 2 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a thermal separation method using fractional condensation of a product-gas mixture, obtained through heterogeneous catalysed partial oxidation of propene and/or propane in gaseous phase to acrylic acid, for separating at least one mass flow, concentrated with acrylic acid, from a product-gas mixture containing acrylic acid, which involves continuous static operation of at least one device for thermal separation, containing at least one effective separation chamber with a fractionation column which has mass-transfer trays as built-in separating elements, in which the product-gas mixture is loaded, containing acrylic acid as at least one mass flow, and from which at least one mass flow containing acrylic acid is unloaded under the condition that, the overall mass flow loaded into the effective separation chamber and obtained from combining separate mass flows loaded into the separating chamber, contains X wt % components distinct from acrylic acid, the mass flow which is unloaded from the effective separation chamber with the largest content of acrylic acid, contains Y wt % components distinct from acrylic acid, ratio X:Y is ≥5, effective separation chamber, except the loading and unloading place, is bordered by a solid phase and contains, besides the mass-exchange trays as built-in separating elements in the fractionation column, at least one circulating heat exchanger, and total volume of the chamber, filled with liquid phase, is ≥1 m3, wherein temperature of the liquid phase is at least partially ≥80°C, when the effective separation chamber is divided into n separate volume elements, wherein the highest and lowest temperature of liquid phase in a separate volume element differ by not more than 2°C, and the volume element in the effective separation chamber is solid, total dwell time ttotal.

≤20 h, where A = (Ti-To)/10°C, To= 100°C, Ti = arithmetic mean value of the highest and lowest temperature of the ith volume element in the liquid phase in °C, msi = total mass of acrylic acid in the volume of the liquid phase of the ith volume element, mi = total liquid phase mass unloaded from the ith volume element, and is the sum of all volume elements i, under the condition that, volume elements i with liquid phase mass mi and as volume elements with a dead zone are also not included in the sum of all volume elements i, as well as volume elements i, which do not contain liquid phase, and total amount of liquid phase contained in volume elements with a dead zone is not more than 5 wt % of the total amount of liquid phase contained in the effective separation chamber.

EFFECT: separation of mass flow concentrated with acrylic acid.

10 cl, 12 dwg, 2 ex, 2 tbl

FIELD: chemistry.

SUBSTANCE: sodium hydroxide solution is added to a technical mixture of benzoic and cinnamylic acid, obtaining a precipitate. Water is added to obtain a homogeneous solution. The obtained technical mixture of sodium salts of benzoic and cinnamylic acid with composition ranging from 2:1 to 1:2 and overall concentration ranging from 3 to 5 M is then mixed with sulphuric acid with concentration ranging from 3 to 5 M. Addition of sulphuric acid is stopped at pH of the medium between 8 and 9, and the precipitated complex of cinnamylic acid with its sodium salt is filtered from the reaction mixture, dissolved in excess amount of water to dissolve sodium salt of cinnamylic acid. Cinnamylic acid precipitates, and is further treated with sulphuric acid with concentration ranging from 3 to 5 M to pH between 1 and 2. The precipitated crystals of cinnamylic acid are separated; the reaction mixture remaining after separation of the complex is mixed with a solution of sulphuric acid with concentration ranging from 3 to 5 M until pH between 1 and 2. As a result, crystalline benzoic acid forms.

EFFECT: formation of complexes of carboxylic acids with their sodium salts for separating components of a mixture of carboxylic acids with similar chemical and physico-chemical properties.

2 ex

FIELD: anti-conglomeration agents.

SUBSTANCE: invention relates to loose product based on potassium formate, which contains 0.1 to 1% water and 0.5-5% water-soluble conglomeration-preventing agent, such as potassium carbonate or potassium hydroxide, which possesses affinity for water and corresponds to equilibrium humidity below equilibrium 15% relative humidity (22°C) for potassium formate.

EFFECT: provided modifying and conglomeration preventing agents for potassium formate to allow it to achieve looseness under practical storage and processing conditions.

3 cl, 4 tbl, 4 ex

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