EP2588440A1 - Procédé de production d'acide formique - Google Patents

Procédé de production d'acide formique

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Publication number
EP2588440A1
EP2588440A1 EP11728826.6A EP11728826A EP2588440A1 EP 2588440 A1 EP2588440 A1 EP 2588440A1 EP 11728826 A EP11728826 A EP 11728826A EP 2588440 A1 EP2588440 A1 EP 2588440A1
Authority
EP
European Patent Office
Prior art keywords
formic acid
stream
tertiary amine
distillation apparatus
amine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11728826.6A
Other languages
German (de)
English (en)
Inventor
Daniel Schneider
Klaus-Dieter Mohl
Martin Schäfer
Karin Pickenäcker
Stefan Rittinger
Thomas Schaub
Joaquim Henrique Teles
Rocco Paciello
Gerd Kaibel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Priority to EP11728826.6A priority Critical patent/EP2588440A1/fr
Publication of EP2588440A1 publication Critical patent/EP2588440A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
    • C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/09—Preparation of carboxylic acids or their salts, halides or anhydrides from carboxylic acid esters or lactones
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/50—Use of additives, e.g. for stabilisation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C53/00—Saturated compounds having only one carboxyl group bound to an acyclic carbon atom or hydrogen
    • C07C53/02—Formic acid

Definitions

  • the present invention relates to a process for the production of formic acid by thermal separation of a stream containing formic acid and a tertiary amine (I) which comprises combining a tertiary amine (I) and a formic acid source with a liquid stream containing formic acid and a tertiary amine (I. ) in a molar ratio of 0.5 to 5, 10 to 100 wt .-% of the minor components contained therein, and from the obtained liquid stream in a distillation apparatus at a bottom temperature of 100 to 300 ° C and a pressure of 30 to 3000 hPa abs of formic acid removed by distillation.
  • Formic acid is an important and versatile product. It is used, for example, for acidification in the production of animal feed, as a preservative, as a disinfectant, as an adjuvant in the textile and leather industry, as a mixture with their salts for de-icing of airplanes and runways and as a synthesis component in the chemical industry.
  • the currently most common process for the production of formic acid is the hydrolysis of methyl formate, which can be obtained for example from methanol and carbon monoxide.
  • the aqueous formic acid obtained by hydrolysis is then subsequently concentrated, for example using an extraction aid such as a dialkyl formamide (DE 25 45 658 A1).
  • the recovery of formic acid is also known by thermal cleavage of compounds of formic acid and a tertiary nitrogen base.
  • These compounds are generally acidic ammonium formates of tertiary nitrogen bases, in which formic acid has reacted with the tertiary nitrogen bases beyond the classical salt formation step to form stable, hydrogen-bonded bridged addition compounds.
  • the addition compounds of formic acid and tertiary nitrogen bases can be formed by combining the tertiary nitrogen base and a formic acid source.
  • WO 2006/021, 41 1 discloses the preparation of such addition compounds in general (i) by direct reaction of the tertiary nitrogen base with formic acid, (ii) by transition metal-catalyzed hydrogenation of carbon dioxide to formic acid in the presence of the tertiary nitrogen base, (iii) by reaction of methyl formate with water and subsequent extraction of the formic acid formed with the tertiary nitrogen base, and (iv) by reaction of methyl formate with water in the presence of the tertiary nitrogen base.
  • addition compounds of formic acid and tertiary nitrogen bases for the production of formic acid bind strong enough first to the formic acid as free formic acid from the medium, for example the reaction medium in which the formic acid is formed only by chemical synthesis, or to extract, for example, from a dilute formic acid solution and thereby easier to separate the formic acid in the form of their addition compounds, but on the other hand, are weak enough to subsequently dissolve the formic acid from the addition compounds by thermal cleavage again to concentrate and purify them in free form.
  • EP 0 001 432 A discloses a process for recovering formic acid by hydrolysis of methyl formate in the presence of a tertiary amine, especially an alkylimidazole, to form addition compounds of formic acid and the tertiary amine.
  • the resulting hydrolysis mixture which contains unreacted methyl formate, water, methanol, addition compounds and tertiary amine, is freed from the low-boiling components methyl formate and methanol in a first distillation column. In a second column, the remaining bottoms product is dewatered.
  • the dewatered bottoms product of the second column which still contains addition compounds and tertiary amine, is then fed to a third column and therein the addition compounds are thermally split into formic acid and tertiary amine.
  • the released formic acid is removed as an overhead product.
  • the tertiary amine accumulates in the bottom and is recycled to the hydrolysis.
  • DE 34 28 319 A discloses a process for the recovery of formic acid by hydrolysis of methyl formate.
  • the resulting hydrolysis mixture containing unreacted methyl formate, water, methanol and formic acid is freed from the low-boiling components methyl formate and methanol in a first distillation column.
  • the aqueous formic acid obtained in the bottom is then extracted with a higher-boiling amine, in particular a longer-chain, hydrophobic C 6 -C to trialkylamine, in the presence of an additional hydrophobic solvent, in particular an aliphatic, cycloaliphatic or aromatic hydrocarbon, and thereby to a reacted aqueous addition compound of formic acid and the amine.
  • This is dehydrated in a second distillation column.
  • the dewatered addition compound arising in the sump will now be described according to the teaching of
  • EP 0 181 078 A and EP 0 126 524 A describe processes for obtaining formic acid by hydrogenating carbon dioxide in the presence of a transition metal catalyst and a tertiary amine such as a d- to do-trialkylamine to form an addition compound of formic acid and the tertiary amine, working up the hydrogenation with separation of the catalyst and the low boilers, replacement of the adduct by a weaker, higher boiling tertiary amine, in particular by an alkylimidazole, with separation of the first tertiary amine and subsequent thermal cleavage of the newly formed addition compound in a distillation column.
  • a transition metal catalyst and a tertiary amine such as a d- to do-trialkylamine
  • the stream containing formic acid and amine is fed into the central region of the column "30".
  • the formic acid released during the thermal decomposition is removed as top product.
  • the weaker, higher-boiling tertiary amine accumulates in the sump and is recycled to the stage of base exchange.
  • WO 2008/1 16,799 discloses a process for recovering formic acid by hydrogenating carbon dioxide in the presence of a transition metal catalyst, a high boiling polar solvent such as an alcohol, ether, sulfolane, dimethyl sulfoxide or amide, and a polar amine bearing at least one hydroxyl group to form an addition compound of formic acid and the amine. According to the doctrine of
  • the hydrogenation effluent for thermal cleavage of the addition compound can be fed directly to a distillation apparatus.
  • a distillation apparatus This may include a distillation column and, if short residence times are desired, also a thin film or falling film evaporator.
  • the released formic acid is removed as an overhead product.
  • the polar amine and the polar solvent and, if appropriate, not separated catalyst collect in the bottom and can be recycled to the hydrogenation stage.
  • WO 2006/021, 41 1 describes a process for the recovery of formic acid by thermal cleavage of an addition compound of formic acid and a tertiary amine (quaternary ammonium formate), in which the tertiary amine has a boiling point of 105 to 175 ° C.
  • Preferred tertiary amines are alkylpyridines.
  • the special boiling range of the tertiary amines increases the color stability of the formic acid obtained.
  • the addition compound to be used can generally be obtained from the tertiary amine and from an acid source.
  • the discharge from the adduct synthesis is first freed from volatile components and then fed to the thermal cleavage.
  • the thermal cleavage is carried out as usual in a distillation column, wherein the formic acid and amine-containing stream according to FIG. 1 in the central region of the column (C) is supplied.
  • the released formic acid is removed as an overhead product.
  • the tertiary amine which may optionally still contain residues of formic acid, collects in the bottom and can be recycled to the formic acid source.
  • EP 0 563 831 A discloses an improved process for the thermal cleavage of an addition compound of formic acid and a tertiary amine (quaternary ammonium formate) with the obtainment of formic acid.
  • the addition compound to be used can generally be obtained from the tertiary amine and a formic acid source.
  • the discharge from the synthesis is first freed from volatile components and then fed to the thermal cleavage in the middle of a distillation column.
  • the improvement is essentially to carry out the thermal cleavage of the addition compound in the presence of a secondary formamide, which increases the color stability of the formic acid obtained.
  • the released formic acid is removed as an overhead product.
  • the tertiary amine and the secondary formamide accumulate in the bottom and can be recycled to the formic acid source.
  • the object of the present invention was to find a process for the production of formic acid by thermal separation of a stream containing formic acid and a tertiary amine, which has advantages over the prior art and which is able to obtain formic acid in high yield, high concentration and high purity , Furthermore, the process should also be able to be carried out as energy-favorably as possible and in particular have economic advantages over the methylformamide hydrolysis currently used industrially. The focus is also on a low color number and high color stability. Furthermore, the method should of course be easy to perform and be reliable.
  • step (b) separating from the liquid stream obtained from step (a) from 10 to 100% by weight of the minor components contained therein;
  • step (c) removed by distillation from the liquid stream obtained from step (b) in a distillation apparatus at a bottom temperature of 100 to 300 ° C and a pressure of 30 to 3000 hPa abs of formic acid; and which is characterized in that the tertiary amine (I) employed is an amine which has a boiling point higher than that of formic acid by at least 5 ° C. at a pressure of 1013 hPa abs, in addition, the tertiary amine (I) to be used in step (a) and the separation rate in step
  • step (c) selects distillation apparatus such that two liquid phases form in the bottom discharge of the distillation apparatus mentioned in step (c) under the conditions present in step (d),
  • step (d) separating the bottoms discharge from the distillation apparatus mentioned in step (c) into two liquid phases, wherein the upper liquid phase has a molar ratio of formic acid to tertiary amine (I) of 0 to 0.5 and the lower liquid phase a molar ratio of formic acid to tertiary Amine (I) of 0.5 to 5;
  • step (f) recycling the lower liquid phase of the phase separation from step (d) to step (b) and / or (c).
  • Under formic acid source is to be understood as a stream which contains formic acid in dilute, contaminated and / or chemically bound form, or which contains a precursor, is generated by the formic acid by chemical reaction.
  • dilute and / or contaminated formic acid can come from a variety of production processes or applications. For example, it can be diluted with water or organic solvents and contaminated with various other accompanying substances. Examples which may be mentioned as dilute, contaminated formic acid from the fermentation of renewable raw materials and aqueous formic acid from the methyl formate hydrolysis after the separation of methanol and residual methyl formate.
  • the addition in chemically bound form can be carried out, for example, in the form of a complex, a salt or an addition compound between the formic acid and an amine other than the tertiary amine (I).
  • all chemical reactions in which formic acid is produced can be considered as chemical reactions.
  • the production of formic acid by hydrolysis of methyl formate and the production of formic acid by transition metal-catalyzed hydrogenation of carbon dioxide are of particular industrial significance. Both of these synthesis options are well known in the art and described in various variants and embodiments.
  • Another technically relevant possibility for the production of formic acid by chemical reaction is, for example, the direct reaction of carbon monoxide with water.
  • methyl formate, water and tertiary amine (I) are usually added to the hydrolysis reactor together or sequentially to trap the formic acid formed by the hydrolysis with the tertiary amine (I) in the form of an addition compound to remove the hydrolysis balance , As a result, a high conversion of methyl formate can be achieved and a particularly advantageous separation of the unreacted water by a subsequent distillation possible.
  • the tertiary amine (I) is generally added to the hydrogenation reactor to form a stream containing formic acid and a tertiary amine (I) already in the hydrogenation.
  • step (a) Preference is given in step (a) to the generation of the stream comprising formic acid and tertiary amine (I) by hydrolysis of methyl formate in the presence of water and tertiary amine (I). Further preferred in step (a) is the generation of the stream comprising formic acid and tertiary amine (I) from dilute formic acid by concentration in the presence of tertiary amine (I). However, particularly preferred in step (a) is the generation of the stream comprising formic acid and tertiary amine (I) by hydrolysis of methyl formate in the presence of water and tertiary amine (I).
  • the liquid stream produced in contacting tertiary amine (I) and a formic acid source in step (a) has a formic acid to tertiary amine (I) molar ratio of 0.5 to 5.
  • the molar ratio is preferably> 1 and preferably ⁇ 4 and more preferably ⁇ 3.
  • the said molar ratio refers to the total liquid flow, regardless of whether it is mono- or polyphase.
  • the liquid stream comprising formic acid and a tertiary amine (I) produced in step (a) generally has a concentration of formic acid plus tertiary amine (I) of from 1 to 99% by weight, based on the total amount of the stream.
  • said stream has a concentration of formic acid plus tertiary amine (I) of> 5% by weight and more preferably of> 15% by weight and preferably of ⁇ 95% by weight and more preferably of ⁇ 90% by weight. % on.
  • I formic acid plus tertiary amine
  • step (a) From the liquid stream obtained from step (a) 10 to 100 wt .-% of the minor components contained therein are separated.
  • the stated range of values is based on the concentration of secondary components that the liquid stream generated in step (a) has. In the following, this concentration is called “C-component (stream from step (a))".
  • the secondary component-depleted liquid stream corresponds to the stream fed to the distillation apparatus in step (c). Its concentration will be referred to below as "CNobenkom nenten (feed stream to step (c))".
  • the above separation of minor components refers to the quotient
  • step (b) Preferably, in step (b)> 20 wt .-% and particularly preferably> 30 wt .-% and preferably ⁇ 99.99 wt .-% and particularly preferably ⁇ 99.9 wt .-% of the secondary components are separated.
  • the term secondary components are all components contained in the liquid stream obtained in step (a), which are neither formic acid nor tertiary amine (I).
  • Examples include water, methanol (in particular in the hydrolysis of methyl formate), dissolved non-hydrolyzed methyl formate (in particular in the hydrolysis of methyl formate), possible degradation products of the tertiary amine (I), dissolved inert gases, homogeneous catalyst (in particular in the Hydrogenation of carbon dioxide), dissolved carbon dioxide or dissolved hydrogen (especially in the hydrogenation of carbon dioxide), solvents, other components.
  • the manner in which the secondary components are separated is irrelevant to the process according to the invention.
  • the customary and known methods for the separation of liquid mixtures can be used.
  • distillative separation is mentioned here. In this, the liquid mixture is separated in a distillation apparatus.
  • low-boiling secondary components such as methanol, methyl formate or water can be separated overhead or as a side draw.
  • high-boiling secondary components via bottoms and the formic acid and tertiary amine (I) -containing mixture as side stream or overhead product.
  • membrane, absorption, adsorption, crystallization, filtration, sedimentation or extraction methods are also possible. Extraction methods are preferred in the concentration of dilute aqueous formic acid and the use of tertiary amines (I), which are not or only partially miscible with water.
  • steps (a) and (c) are carried out in the method according to the invention in addition to step (b).
  • Formic acid is removed by distillation from the liquid stream obtained from step (b) in a distillation apparatus at a bottom temperature of 100 to 300 ° C. and a pressure of 30 to 3000 hPa.
  • the distillation apparatus comprises in addition to the actual column body with internals, among other things, a top condenser and a bottom evaporator.
  • this may optionally also include other peripheral devices or internals, such as a flash tank in the inlet (for example, for separation of gas and liquid in the inlet to the column body), an intermediate evaporator (for example, for improved heat integration of the method) or internals for avoidance or reduction aerosol formation (such as tempered soils, demisters, coalescers or deep bed diffusion filters).
  • the column body can be equipped, for example, with packings, fillers or trays.
  • the number of required separation stages is particularly depending on the nature of the tertiary amine (I), the concentration of formic acid and tertiary amine (I) in the feed of the distillation apparatus in step (c) and the desired concentration or the desired purity of formic acid, and can be determined by the skilled person in a conventional manner.
  • the number of required separation stages is> 3, preferably> 6, and more preferably> 7.
  • the stream comprising formic acid and a tertiary amine (I) from step (b) can be fed to the column body in the distillation apparatus, for example as a side stream.
  • the addition may be preceded by, for example, a flash evaporator.
  • a flash evaporator In order to minimize the thermal load on the supplied stream in the distillation apparatus, it is generally advantageous to supply it to the lower portion of the distillation apparatus.
  • step (c) it is preferred in step (c) to supply the stream comprising formic acid and a tertiary amine (I) in the region of the lower quarter, preferably in the region of the lower fifth and particularly preferably in the region of the lower sixth of the present separation steps, whereby of course also a direct feed into the swamp is included.
  • step (c) it is also preferred in step (c) to feed the said stream from step (b) containing formic acid and a tertiary amine (I) to the bottom evaporator of the distillation apparatus.
  • the distillation apparatus is at a bottom temperature of 100 to 300 ° C and a
  • the distillation apparatus is preferably operated at a bottom temperature of> 120 ° C., more preferably of> 140 ° C. and preferably of ⁇ 220 ° C. and particularly preferably of ⁇ 200 ° C.
  • the pressure is preferably> 30 hPa abs, particularly preferably> 60 hPa abs, and preferably ⁇ 1500 hPa abs and particularly preferably ⁇ 500 hPa abs.
  • formic acid can be obtained as top and / or side product from the distillation apparatus.
  • the feed contains boiling components easier than formic acid, it may be advantageous to separate them by distillation as the top product and the formic acid in the side draw.
  • gases possibly dissolved in the feed such as, for example, carbon monoxide or carbon dioxide
  • Contains the feed higher than formic acid boiling ingredients, formic acid is preferably removed by distillation as a top product, but optionally instead or additionally in the form of a second stream in the side take.
  • the higher than formic acid boiling components are then preferably removed in this case via an additional side stream.
  • the side If necessary, it is possible to reduce the residual current with secondary components to separate the secondary components to step (b).
  • Formic acid with a content of up to 100% by weight can be obtained in this way.
  • formic acid contents of 75 to 99.995 wt .-% are easily achievable.
  • the residual content which is missing at 100% by weight is mainly water, and according to the substances introduced into the distillation apparatus in addition to formic acid and the tertiary amine (I), of course other components such as solvents or also possible decomposition products are conceivable.
  • water may already be present in the feed of the distillation apparatus but may also be formed by decomposition of formic acid itself during the thermal separation in small amounts.
  • water is discharged with a part of the eliminated formic acid in a side stream.
  • the formic acid content of this side stream is typically 75 to 95% by weight.
  • the formic acid content of the product thus obtained is then usually at 85 to 95 wt .-%.
  • the aqueous formic acid from the side stream may optionally be recycled to step (b) to separate the water.
  • oxidative degradation of the tertiary amines (I) can occur by the presence of oxygen and it is therefore particularly advantageous, especially when operating the distillation apparatus at pressures below 0.1 MPa abs, to allow the penetration of oxygen through
  • particularly dense flange connections such as those with grooved gaskets or weld lip seals
  • nitrogen-covered flange connections A suitable flange connection is for example in
  • the formic acid obtainable by the process according to the invention has a low color number and a high color number stability.
  • the content of such secondary components is in the available Formic acid at ⁇ 100 ppm by weight, preferably at ⁇ 50 ppm by weight and most preferably at ⁇ 25 ppm by weight.
  • step (c) it may also be advantageous to use a plurality of distillation apparatuses in step (c), especially if in addition to the free formic acid and the amine (I) -containing
  • distillation apparatus for separating the formic acid can also be configured as thermally coupled distillation columns or as a dividing wall column.
  • the tertiary amine (I) to be used in the process according to the invention has a boiling point at least 5 ° C. higher than formic acid at a pressure of 1013 hPa abs.
  • the tertiary amine (I) to be used preferably has a boiling point higher than at least 10 ° C., more preferably at least 50 ° C. and very particularly preferably at least 100 ° C., than formic acid.
  • a restriction with respect to an upper limit for the boiling point is not necessary since for the process according to the invention the lowest possible vapor pressure of the tertiary amine (I) is fundamentally advantageous.
  • the boiling point of the tertiary amine (I) in a optionally by known methods from vacuum to 1013 hPa abs projected pressure, below 500 ° C.
  • the tertiary amine (I) to be used in step (a) and the separation rate in the distillation apparatus mentioned in step (c) should be selected such that in the bottom effluent the distillation apparatus mentioned in step (c) is less than that in step (d) Conditions form two liquid phases.
  • the formation of two liquid phases is mainly determined by the chemical and physical properties of the two phases. These in turn can be influenced just by the choice of the tertiary amine (I), by the separation rate in the distillation apparatus, but also by the presence of any additional components such as solvents and their concentrations.
  • I tertiary amine
  • the separation rate is the quotient (feed stream to step (c)) [g I h] - m formic acid (bottoms discharge) [g I h] _
  • the separation rate can be easily influenced by the temperature and pressure conditions in the distillation apparatus and by the residence time in the distillation apparatus. It can be determined by simple experiments, if appropriate, also during operation of the method according to the invention.
  • step (d) the bottoms discharge from the distillation apparatus mentioned in step (c) is separated into two liquid phases, the upper liquid phase having a molar ratio of formic acid to tertiary amine (I) of from 0 to 0.5 and the lower liquid phase a molar ratio of Formic acid to tertiary amine (I) of 0.5 to 5 has.
  • the phase separation can be carried out, for example, in a separate phase separator, which is connected downstream of the distillation apparatus.
  • phase separator in the bottom region of the distillation apparatus, in the region of the bottom evaporator or else in the region of the bottom evaporator circulation.
  • the use of a centrifugal separator is possible or possibly even advantageous.
  • the bottoms discharge is usually cooled in an intermediate heat exchanger to a temperature in the range of 30 to 180 ° C.
  • the phase separation preferably takes place at a temperature of> 50 ° C. or at a temperature of ⁇ 160 ° C.
  • the upper liquid phase in step (d) has a molar ratio of formic acid to tertiary amine (I) of preferably> 0.005 and particularly preferably> 0.015, and preferably ⁇ 0.25 and particularly preferably ⁇ 0.125.
  • the lower liquid phase in step (d) has a molar ratio of formic acid to tertiary amine (I) of preferably> 0.75 and particularly preferably> 1, and preferably ⁇ 3.5 and particularly preferably ⁇ 3.
  • the separation rate in the distillation apparatus mentioned in step (c) is selected such that the molar ratio of formic acid to tertiary amine (I) in the bottom effluent is from 0.1 to 2.0.
  • Bottom discharge is the entirety of the liquid bottoms condensates which leave the distillation apparatus and are separated into two liquid phases according to step (d). It is irrelevant whether the bottoms condensates, for example, directly from the bottom of the distillation apparatus itself, the bottom of the marsh evaporator, or from both.
  • the separation rate in the distillation apparatus mentioned in step (c) is preferably selected such that the molar ratio of formic acid to tertiary amine (I) in the bottom effluent is preferably ⁇ 1.5.
  • the top liquid phase of the phase separation from step (d) is returned to step (a) according to step (e).
  • the tertiary amine (I) contained in the upper liquid phase can be used by combining with the formic acid source to further generate a stream containing formic acid and tertiary amine (I).
  • from 10 to 100%, preferably from 50 to 100%, particularly preferably from 80 to 100%, very particularly preferably from 90 to 100% and in particular from 95 to 100%, of the upper liquid phase is returned to step (a).
  • the upper liquid phase is preferably recycled directly to the hydrolysis stage.
  • step (f) the lower liquid phase of the phase separation from step (d) is returned to step (b) and / or (c).
  • the formic acid present in the lower liquid phase can likewise be used for the production of formic acid by distillative removal.
  • the lower liquid phase can thus be (i) split back to step (b), (ii) to step (b) and (c) or (iii) to step (c).
  • step (c) the return to step (c) is preferred since this usually places the loading of the lower liquid phase containing formic acid and tertiary amine (I) at a minimum and the material flow in step (b) is not increased quantitatively, which would otherwise be correspondingly greater
  • step (b) and / or (c) from 10 to 100%, preferably from 50 to 100%, particularly preferably from 80 to 100%, very particularly preferably from 90 to 100% and in particular from 95 to 100%, of the lower liquid phase is returned to step (b) and / or (c) .
  • step (a) it is also possible, in addition to the said recycling of the lower liquid phase to step (b) and / or (c), also to recycle a further part to step (a).
  • step (a) for example, in the case of the production of formic acid by over- transition-metal-catalyzed hydrogenation of carbon dioxide advantageous, since this is usually carried out in the presence of a polar solvent, which also accumulates in the lower liquid phase and thus can be recycled back to step (a).
  • step (d) it has been recognized that the detached metals and metal compounds accumulate in polar liquid phases, in particular in the lower liquid phase formed in step (d). Furthermore, it has been found that it is advantageous to discharge the metals and metal compounds from the lower liquid phase formed according to step (d).
  • the upper phase formed in step (d), which is recycled after step (a), is virtually free of metals and metal compounds. This avoids that the dissolved metals and metal compounds are distributed over recycled process streams throughout the system and cause the problems described above.
  • the way of removing the metals and metal compounds is basically not limited. It is advisable, for example, to discharge them via a so-called "purge stream".
  • the simplest separation is the enrichment of the metal compounds over the solubility limit and the discharge as a solid, for example from the phase separation vessel in step (d).
  • the discharged "purge stream" it may be advantageous to use the discharged "purge stream". to evaporate, preferably in vacuo.
  • Formic acid and tertiary amine (I) would evaporate and could then be recovered by condensation.
  • the metals and metal compounds would remain as evaporation residue. It would also be conceivable to partially evaporate, for example, formic acid to lower the solubility and then to filter off the precipitated metals and metal compounds.
  • removing the metals and metal compounds from the lower liquid phase are to remove them from the discharged "purge stream", for example by washing with a lye, by adsorption on suitable adsorbents or by treatment with an ion exchanger.
  • suitable adsorbents are commercially available activated carbons, silica gels, zeolites, molecular sieves, aluminum oxides and ion exchange resins having various functional groups, such as -SO 3 H, -CO 2 H, -NR 1 R 2 (R 1 , R 2 being, for example, H, alkyl, -CH 2 CO 2 H, Called -CH2PO3H2, -C (SH) NH), -PO3H2, -SH).
  • R 1 , R 2 being, for example, H, alkyl, -CH 2 CO 2 H, Called -CH2PO3H2, -C (SH) NH), -PO3H2, -SH).
  • the measures mentioned can, of course, be
  • the tertiary amine (I) which is preferably used in the process according to the invention has the general formula (Ia)
  • radicals R 1 to R 3 are identical or different and independently of one another represent an unbranched or branched, acyclic or cyclic, aliphatic, araliphatic or aromatic radical having in each case 1 to 16 carbon atoms, preferably 1 to 12 carbon atoms, wherein individual Carbon atoms independently of one another may also be substituted by a hetero group selected from the group -O- and> N-, and two or all three radicals may also be linked together to form a chain comprising at least four atoms each.
  • Suitable amines are:
  • Dimethyl-decylamine, dimethyl-dodecylamine, dimethyl-tetradecylamine, ethyl-di- (2-propyl) -amine (Sdpioi3 hPa 127 ° C), dioctyl-methylamine, dihexyl-methylamine.
  • Tricyclopentylamine tricyclohexylamine, tricycloheptylamine, tricyclooctylamine and theirs
  • Methyl-2-propyl groups substituted derivatives. Dimethylcyclohexylamine, methyldicyclohexylamine, diethylcyclohexylamine, ethyldicyclohexylamine, dimethylcyclopentylamine, methyldicyclopentylamine.
  • Triphenylamine methyldiphenylamine, ethyldiphenylamine, propyldiphenylamine, butyldiphenylamine, 2-ethylhexyldiphenylamine, dimethylphenylamine, diethylphenylamine, dipropylphenylamine, dibutylphenylamine, bis (2-ethyl -hexyl) -phenylamine, tribenzylamine, methyldibenzylamine, ethyl-dibenzylamine and their by one or more methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl or 2-methyl -2-propyl groups substituted derivatives.
  • N-Ci-bis-Ci2-alkyl-piperidines N, N-di-Ci-bis-Ci 2- alkyl-piperazines, N-Ci-bis-Ci 2 -alkylpyrrolidines, N-Ci-bis-Ci2 Alkyl imidazoles and their by one or more methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl or 2-methyl-2-propyl groups substituted derivatives.
  • tertiary amines (I) used are of course at a pressure of 1013 hPa abs a boiling point higher by at least 5 ° C than formic acid.
  • the radicals R 1 to R 3 are the same or different and independently of one another a straight or branched, acyclic or cyclic, aliphatic, araliphatic or aromatic radical each with 1 to 16 carbon atoms, preferably 1 to 12 carbon atoms, wherein individual carbon atoms can be substituted independently of one another by a hetero group selected from the group -O- and> N- and two or all three radicals to form a least four atoms at least , saturated chain can also be interconnected.
  • At least one of the radicals on the alpha carbon atom preferably carries two hydrogen atoms.
  • tertiary amine (I) an amine of the general formula (Ia) in which the radicals R 1 to R 3 are independently selected from the group C 1 to C 12 alkyl, C to Cs Cycloalkyl, benzyl and phenyl.
  • tertiary amine (I) a saturated amine of the general formula (Ia).
  • tertiary amine (I) an amine of the general formula (Ia) in which the radicals R 1 to R 3 are independently selected from the group C 5 to C 1 -alkyl, in particular tri n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, dimethylcyclohexylamine, methyldicyclohexylamine, dioctylmethylamine and dimethyl-decylamine.
  • R 1 to R 3 are independently selected from the group C 5 to C 1 -alkyl, in particular tri n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, dimethylcyclohexylamine, methyldicyclohexylamine, dioctylmethylamine and dimethyl-decylamine.
  • the type and amount of the individual forms may, depending on the present conditions, such as the relative proportions of formic acid to tertiary amine (I), the presence of other components (for example, water, solvents, by-products, impurities) and thus ultimately also the concentration of formic acid and tertiary amine (I), the temperature and the pressure be different.
  • Ammonium formate (molar ratio of formic acid to tertiary amine (I) of 1) or formic acid-rich adduct with the tertiary amine (I) (molar ratio of formic acid to tertiary amine (I) of> 1).
  • the type and quantity of the individual forms is irrelevant.
  • step (c) to be supplied liquid stream from step (b) in addition to formic acid and tertiary amine (I) also contain other components, such as minor components that were not or not completely separated in step (b).
  • the concentration of possible further components besides formic acid and tertiary amine (I) in the liquid stream to be supplied to step (c) or the content of formic acid and tertiary amine (I) present in this stream is generally fundamental to carrying out the process according to the invention irrelevant.
  • step (b) it is therefore advisable to supply a stream of at least 10% by weight, preferably at least 50% by weight and particularly preferably at least 80% by weight, of total content of formic acid and tertiary amine (I).
  • the liquid stream from step (b) to be fed to step (c) may optionally also contain so-called solvents.
  • an electrostatic factor also abbreviated EF, of preferably> 200 ⁇ 10 -30 cm has emerged as a measure.
  • the electrostatic factor EF is defined as the product of the relative dielectric constant s r and the dipole moment ⁇ of the solvent (see, for example, C. Richardt, "Solvents and Solvent Effects in Organic Chemistry", 3rd edition, Wiley-VCH Verlag
  • step (d) ensures that the optional solvent has a certain minimum polarity and is miscible with the lower liquid phase in step (d).
  • solvents depending on the particular system (for example, type of tertiary amine (I), concentrations, temperature, pressure and the like), for example, improve the separation of the two liquid phases.
  • classes of substances which are particularly suitable as an optional solvent in particular diols and their formic acid esters, polyols and their formic acid esters, sulfones, sulfoxides, open-chain or cyclic amides and mixtures of the substance classes mentioned in question.
  • Diols and polyols can be esterified due to their OH groups in the presence of formic acid. This is done in the inventive method, especially in step (c) in the thermal separation of the formic acid and tertiary amine (I) containing stream in said distillation apparatus.
  • Non-polar solvents may optionally reduce the concentration of formic acid in the upper liquid phase.
  • the process according to the invention is preferably carried out without addition of a solvent.
  • Fig. 1a shows a simplified block diagram of a general embodiment of the method according to the invention.
  • the individual letters have the following meaning:
  • a formic acid source is fed via stream (1) and tertiary amine (I) via stream (8) to device A to produce a stream containing formic acid and tertiary amine (I).
  • the formic acid source to be supplied may, for example, already contain formic acid in dilute, contaminated and / or chemically bound form, or contain a precursor which produces formic acid by chemical reaction.
  • Stream (2) containing formic acid and tertiary amine (I) is withdrawn from device A and fed to device B for separation of secondary components. This may, for example, be a distillation apparatus in which low-boiling secondary components can be removed by distillation. The separated secondary components are removed via stream (3).
  • the concentrated formic acid and tertiary amine (I) stream of the distillation apparatus C is supplied. This is the distillative removal of formic acid as stream (5).
  • the bottom of the distillation apparatus C is fed to the phase separation vessel D as stream (6) for phase separation.
  • the upper liquid phase is recycled as stream (8) to the device A.
  • the lower liquid phase is recycled as stream (7) to the distillation apparatus C.
  • Fig. 1b shows a further simplified block diagram of a general embodiment of the method according to the invention. In this, the individual letters have the following meaning:
  • A apparatus for producing a formic acid and tertiary amine (I)
  • FIG. 1 b distillation apparatus with integrated phase separation
  • the process according to FIG. 1 b essentially corresponds to the process according to FIG. 1 a, but with the difference that the phase separation is integrated into the distillation apparatus C.
  • Formic acid is also separated from the distillation apparatus C as stream (5).
  • the upper liquid phase is recycled as stream (8) to the device A.
  • the lower liquid phase is recycled as stream (7) to the distillation apparatus C.
  • FIG. 2 shows a simplified block diagram of a preferred embodiment of the process according to the invention in the region of the distillation apparatus C and the phase separation D.
  • the individual letters have the following meaning:
  • Stream (4) containing formic acid and tertiary amine (I) is fed to the column body C1.
  • the formic acid is removed by distillation via stream (5) as overhead product, via stream (5a) as side product and / or via stream (5b) as side product
  • stream (5) the formic acid is removed by distillation via stream (5) as overhead product
  • stream (5a) the side product
  • 5b the three following variants are followed.
  • the first variant plays a role if, in the feed to the distillation apparatus C, secondary components are also contained which boil more easily than formic acid. These are then separated as stream (5).
  • the separation of formic acid (for example with a formic acid content of up to 100 wt .-%) is then carried out via stream (5a).
  • water-containing formic acid (for example having a formic acid content of 75 to 95% by weight) is then generally removed. If desired, the aqueous formic acid in stream (5b) can be recycled to step (b) to separate the water.
  • the second variant usually plays a role when in the feed to the distillation apparatus C no or the desired formic acid quality non-interfering secondary components are contained which boil easier than formic acid.
  • the formic acid (for example with a formic acid content of up to 100% by weight) is then separated off via stream (5).
  • Hydrogenated formic acid (for example having a formic acid content of 75 to 95% by weight) is then generally removed via stream (5a).
  • the aqueous formic acid in Stream (5a) may optionally be recycled to step (b) to separate the water. Therefore, in this case, current (5b) can usually be omitted.
  • the third variant usually plays a role when the desired formic acid quality is already achievable by electricity (5). This is the case, for example, if the content of water and secondary components which have a lower boiling point than formic acid in the feed to the distillation apparatus C is so low that their content must be reconciled with the desired quality requirements of formic acid. This variant may therefore have particular significance for the recovery of formic acid with a content of 75 to 95 wt .-%.
  • the feed stream (4) is generally between the side of the streams (5a) / (5b) and the bottom of the column body C1 or in a further preferred embodiment in the lower fourth of the present separation stages.
  • the bottom product of the column body C1 is withdrawn as stream (6).
  • Stream (6a) is added to the bottom evaporator C2 for heating.
  • Via stream (6x) is recycled formic acid-containing vapor and optionally liquid stream containing tertiary amine (I) and / or formic acid to the column body C1.
  • a partial stream (6b) of the bottom discharge is fed to the phase separation vessel D via an optional heat exchanger H, in which the stream is cooled.
  • the upper liquid phase is recycled as stream (8) to the device A.
  • the lower liquid phase is recycled as stream (7) to the distillation apparatus C.
  • stream (7) can also be completely or partially recycled to the bottom of the column body C1.
  • 3 shows a simplified block diagram of another embodiment which is preferred in the process according to the invention in the region of the distillation apparatus C and the phase separation D.
  • the individual letters have the following meaning:
  • Stream (4) containing formic acid and tertiary amine (I) is fed to the column body C1.
  • the formic acid is removed by distillation via stream (5) as overhead product, via stream (5a) as side product and / or via stream (5b) as side product , wherein in particular the two variants mentioned in the description of FIG. 2 are followed.
  • the feed stream (4) to the column body C1 is generally located between the side of the stream (5a) and the bottom of the column body C1 or in a further preferred embodiment in the lower fourth of the present separation stages.
  • the bottom product of the column body C1 is discharged as stream (6).
  • the lower liquid phase is added as stream (6a) for heating to the bottom evaporator C2.
  • Via stream (6x) is recycled formic acid-containing vapor and optionally liquid stream containing tertiary amine (I) and / or formic acid to the column body C1.
  • the upper liquid phase of the phase separation vessel in the evaporator circulation D1 is supplied as stream (6b) to the phase separation vessel D2 via an optional heat exchanger H, in which the stream is cooled.
  • the upper liquid phase is recycled as stream (8) to the device A.
  • the lower liquid phase is recycled as stream (7) to the distillation apparatus C.
  • phase separation vessel D2 and possibly also the heat exchanger H can be omitted and the upper liquid phase removed from the phase separation vessel in the evaporator circulation D1 as stream (6b) and recycled as stream (8) to the device A.
  • stream (7) and / or stream (6a) can also be completely or partially recirculated to the bottom of the column body C1.
  • FIG. 4 shows a simplified block diagram of a further embodiment which is preferred in the process according to the invention in the region of the distillation apparatus C and the phase separation D.
  • the individual letters have the same meaning as in FIG. 2.
  • the variant from FIG. 4 differs from FIG from Fig. 2 in that the feed of the phase separation vessel D, which optionally takes place via the heat exchanger H, does not originate from the bottom of the column body C1, but from the bottom of the bottom evaporator C2. Also in this variant, instead of returning the stream (7) to the bottom evaporator C2, stream (7) can also be completely or partially recycled to the bottom of the column body C1.
  • FIG. 5 shows a simplified block diagram of a further embodiment preferred in the process according to the invention in the area of the distillation apparatus C and the phase separation D.
  • the individual letters have the same meaning as in FIG. 2.
  • the variant from FIG. 5 differs from FIG from Fig. 2 in that the formic acid and tertiary amine (I) containing stream (4) is not supplied to the column body C1, but the bottom evaporator C2.
  • stream (7) instead of recirculating stream (7) to the bottom evaporator C2, stream (7) can also be completely or partially recycled to the bottom of the column body C1.
  • FIG. 6 shows a simplified block diagram of a further embodiment preferred in the method according to the invention in the region of the distillation apparatus C and the phase separation D.
  • the individual letters have the same meaning as in FIG. 3.
  • the variant of FIG. 6 differs from FIG from Fig. 3 in that the formic acid and tertiary amine (I) containing stream (4) is not supplied to the column body C1, but the bottom evaporator C2. Also in this variant, instead of the return of electricity (7) and / or stream (6a) to the bottom evaporator C2 stream (7) and / or stream (6a) are also completely or partially recycled to the bottom of the column body C1.
  • FIG. 7 shows a simplified block diagram of a further embodiment which is preferred in the process according to the invention in the region of the distillation apparatus C and the phase separation D.
  • the individual letters have the same meaning as in FIG. 2.
  • the variant from FIG. 7 differs from FIG from FIG. 5 in that the feed of the phase separation vessel D, which optionally takes place via the heat exchanger H, does not originate from the bottom of the column body C1 but from the bottom of the bottom evaporator C2. Also in this variant, instead of returning the stream (7) to the bottom evaporator C2, stream (7) can also be completely or partially recycled to the bottom of the column body C1.
  • a general embodiment for concentrating or purifying dilute and / or contaminated formic acid is based on the process described under FIGS. 1 a and 1 b.
  • the formic acid source via stream (1) is the diluted and / or contaminated formic acid.
  • apparatus A which may be for example a static mixer, a mixing nozzle, a stirred tank, a reaction column (eg for low boiling impurities) or an extraction column (for example for aqueous formic acid), stream (1) and the tertiary amine (I) are streamed (8) to form a stream (2) containing formic acid, tertiary amine (I) and diluting solvent (such as water) and / or contaminating minor components (impurities).
  • solvent such as water
  • the current then enters device B, in which the secondary components are partially or completely separated.
  • the secondary components are partially or completely separated.
  • these can be separated, for example, even in apparatus A by the use of a so-called reaction column.
  • the mixture of the formic acid source with the tertiary amine (I) would be carried out, for example, in a reaction column or a reactor with attached distillation column, in which the low-boiling secondary components can be removed by distillation.
  • device B If it concerns the concentration of aqueous diluted formic acid, in device B the majority of the water is separated. If the aqueous dilute formic acid used is so strongly diluted that stream (2) can be separated into two phases, preference is given to using as device B a phase separation vessel. The water phase settles as the lower phase and can be removed. The upper phase contains formic acid and tertiary amine (I) and is fed via stream (4) to the distillation apparatus C.
  • the devices A and B can in this case be combined in an apparatus, for example an extraction column. in which aqueous formic acid in the upper part of the column, the amine (I) in the lower part of the column is supplied.
  • the formic acid and amine (I) containing phase In the bottom of the column then de-acidified water would be withdrawn, at the top of the column, the formic acid and amine (I) containing phase, which may optionally contain small amounts of water.
  • adjuvants may be added, such as, for example, nonpolar hydrocarbons, such as octane or decane.
  • the configuration in the region of the distillation apparatus C and the phase separation D can be carried out, for example, as described in FIGS. 2 to 7.
  • Secondary components which boil between formic acid and the tertiary amine (I) can, for example, also be taken off in the distillation apparatus C as side stream. If appropriate, it is appropriate to choose the tertiary amine (I) in terms of its boiling point so that a side offtake of the secondary components is possible. Possibly remaining in the bottom secondary components can be removed depending on the amount, for example in a branched stream from the lower or upper liquid phase by suitable methods, such as evaporation, distillation or adsorption on activated carbon.
  • aqueous formic acid can be concentrated to up to 100% by weight.
  • FIG. 8 A preferred embodiment for the recovery of formic acid by hydrolysis of methyl formate is shown in Fig. 8 by a simplified block diagram. In it, the individual letters have the following meaning:
  • A apparatus for the hydrolysis of methyl formate and production of a formic acid and tertiary amine (I) containing stream
  • Methyl formate (streams (1 a) and (3b)), water (streams (1 b) and (3c)) and tertiary amine (I) (stream (8)) are fed to the device A.
  • device A in principle all devices can be used in which a weakly exothermic conversion of fluid streams is possible. Examples which may be mentioned are stirred tanks, tube reactors or tube bundle reactors, in each case without internals or with internals (such as, for example, beds, random packings, perforated sheets and the like).
  • Device A is preferably operated adiabatically or under cooling.
  • Hydrolysis of methyl formate thus gives a formic acid, tertiary amine (I), Stream containing methanol, water and methyl formate, which is taken as stream (2) from the device A and the device B is supplied.
  • the methyl formate conversion and thus the composition of the stream (2) depends primarily on the relative feed amounts of the three feed streams methyl formate, water and tertiary amine (I) to the apparatus A, the type of tertiary amine (I) used, the residence time and the reaction temperature.
  • the conditions which are meaningful for the respective reaction system can easily be determined by the person skilled in the art, for example by preliminary experiments. Usually, the reaction takes place in a temperature range of 80 to 150 ° C and a pressure range of 0.4 to 25 MPa abs.
  • the molar ratio of formic acid to tertiary amine (I) is usually 0.5 to 3, although of course deviations from this range are possible.
  • the molar ratio of formic acid to tertiary amine (I) is not or only insignificantly changed by the distillation apparatus B, so that this also in stream (4) is usually 0.5 to 3, whereby of course deviations from this range are possible.
  • Stream (4) is fed to the distillation apparatus C.
  • the formic acid is removed by distillation via stream (5) as overhead product, via stream (5a) as side product and / or via stream (5b) as side product.
  • the explanation of Fig. 2 regarding the separation of the formic acid via the streams (5), (5a) and / or (5b) also applies to the present embodiment.
  • formic acid can be used as stream (5) overhead or as
  • Stream (5a) can be obtained as a side product. Water-containing formic acid is then taken off as side product via stream (5a) or (5b). In individual cases, it may even be sufficient to remove formic acid or hydrous formic acid only via stream (5) as the top product. Depending on the specific embodiment, the side stream (5b) or even both side streams (5a) and (5b) can thus be dispensed with.
  • this can be carried out as described in FIG. 1 b, also with an integrated phase separator.
  • the embodiments of Figs. 2 to 7 are preferred.
  • the bottom product of the distillation apparatus C is fed as stream (6) to the phase separation vessel D.
  • this can of course also be integrated in the distillation apparatus C according to FIG. 1 b.
  • the phase separation vessel D the bottom product is separated into two liquid phases.
  • a heat exchanger can optionally be interposed between the distillation apparatus C and the phase separation vessel D for cooling the withdrawn bottom stream.
  • a lower phase separation temperature generally leads to a somewhat better separation in terms of the formic acid content, but causes due to the use of a heat exchanger additional effort and energy consumption. Advantages and disadvantages should therefore be weighed in each case.
  • the upper liquid phase from the phase separation vessel D is recycled via stream (8) to the device A.
  • the lower liquid phase is recycled via stream (7) to the distillation apparatus C.
  • minor components can be removed depending on the amount, for example, in a branched stream from the lower or upper liquid phase by suitable methods, such as evaporation, distillation or adsorption on activated carbon.
  • the methyl formate stream (1a) is introduced into the distillation apparatus B as shown in FIG. This embodiment is generally advantageous when the available as stream (1 a) methyl formate is still contaminated with residual amounts of methanol, for example by a preceding methyl formate synthesis step with methanol partial conversion and incomplete workup of the methyl formate.
  • both the methyl formate stream (1a) and the water stream (1b) are fed to the distillation apparatus B, as shown in FIG.
  • this embodiment is generally advantageous when hot condensate or steam is available as a water source, as this can be used in the distillation device B, the thermal energy stored therein.
  • a further embodiment it is of course also possible to add the methyl formate stream (1a) into the device A, but the water stream (1b) into the distillation device B. Dies
  • Fig. 11a shows an embodiment with a distillation column.
  • FIGS. 11b to 11e show different embodiments with two distillation columns.
  • FIGS. 12a to 12c show various embodiments with three distillation columns.
  • Preferred for the embodiment of the distillation apparatus B are the variants with one or two distillation columns.
  • these can also be configured as a thermally coupled or dividing wall column.
  • the process of the invention enables the recovery of formic acid in high yield and high purity by thermal separation of a stream containing formic acid and a tertiary amine.
  • the process is simple and reliable feasible.
  • the formic acid to be obtained has a low color number and a high color stability.
  • the process according to the invention also ensures that only extremely small amounts of formic acid or virtually no formic acid are transported back in the amine-containing recycle stream from the process step of the distillative removal of formic acid to the formic acid source. Larger amounts of formic acid in the recycle stream would lead to increased process streams and thus both higher investment costs and higher energy consumption can result. This has an especially pronounced effect on the hydrolysis of methyl formate, in which recycled formic acid would lead to a decrease in the conversion of methyl formate. Thus, in processes without phase separation, it is therefore necessary to work permanently with high separation rates in the distillative removal of formic acid in order to achieve a low formic acid concentration in the recirculated amine stream.
  • the corrosion rate in the distillation apparatus is lower than in the methods of the prior art, in which a much lower content of formic acid in the swamp is sought.
  • a decrease in the corrosion rate by a factor of 2 to 3 is to be expected with a temperature lower by 10 ° C.
  • this has a positive effect on the durability of the column material, on the other hand, on the content of undesired traces of foreign metals in the sump, which is lower in the inventive method than in a corresponding method according to the prior art.
  • the traces of foreign metals there is another advantage in addition to the lower concentration.
  • the corrosion metals are almost exclusively in the polar, lower liquid phase and therefore the upper liquid phase containing predominantly the tertiary amine (I) is in principle free of foreign metals.
  • the dissolved foreign metals can optionally be selectively discharged via a purge stream or are at least localized via the recycle stream in step (f). Therefore, the foreign metals are not or only to the slightest extent returned to the formic acid source (ie the process step (a)) and thus they can develop there and in the subsequent process steps thus no adverse effects.
  • the method according to the invention also has the advantage, due to the milder conditions in the thermal separation, that the distillation apparatus can be operated at a lower temperature.
  • the distillation apparatus can be operated at a lower temperature.
  • the process according to the invention can also be used in particular in conjunction with the hydrolysis of methyl formate as the formic acid source and has technical and economic advantages over the currently industrially practiced operating processes of methyl formate hydrolysis with subsequent dewatering by means of an extraction aid or a two-pressure distillation.
  • Examples 1 to 14 were carried out analogously to Example 3, but with the difference that the added amount of formic acid (expressed as molar ratio of formic acid / amine in total) was varied. The results can be seen in Table 2. These show that, for example, the two-phase nature of a system can also depend on the molar ratio of formic acid / amine.
  • Comparative Example 15 and Examples 16 to 17 In Comparative Example 15, one mole of methyl-di-cyclohexylamine was placed in a glass flask stirred by means of a magnetic stirrer, and 0.21 mol of formic acid (98-100% by weight) were added dropwise at room temperature. After the end of the addition, the solution was stirred for 30 minutes. The product obtained was solid (see Table 3). In Examples 16 to 17, a mol of methyl-di-cyclohexylamine was likewise introduced into a glass flask which had been stirred by means of a magnetic stirrer and 0.21 mol of formic acid (98-100% by weight) were added dropwise at room temperature.
  • the examples show that, for example, in the absence of a phase decay (as in Comparative Example 15) can be induced by the addition of a suitable polar solvent, a decomposition into two liquid phases wherein the formic acid is enriched together with the polar solvent in the lower phase.
  • C1 column body (internal diameter 32 mm) with 18 bubble cap trays and condenser and adjustable reflux divider at the top of the column
  • C2 bottom evaporator (oil-heated thin-film evaporator with a surface of
  • the apparatuses of the laboratory system 1 consisted of glass and the connection lines of Teflon. Laboratory system 1 was operated continuously under reduced pressure.
  • Laboratory plant 1 relates to the essential process parts of the distillative separation of formic acid and the phase separation to allow the separate recycling of the upper and lower liquid phase and is modeled inter alia for the concentration and purification of formic acid, which, for example, previously obtained by the hydrolysis of methyl formate ,
  • Example 25 was carried out in the laboratory 1.
  • the distillation apparatus was operated at a head pressure in the column body C1 of 0.01 MPa abs and set a reflux ratio of reflux to distillate of 4.
  • the temperature at the lower end of the thin film evaporator was 143 ° C.
  • the gaseous discharge of the evaporator was fed as stream (6x) to the column body C1.
  • the liquid effluent of the column body was fed as stream (6a) at the top of the thin film evaporator C2.
  • the top product of the column body C1 was obtained as stream (5) 45.5 g / h of 99 wt .-% formic acid.
  • This formic acid contained only 13 ppm by weight of organic impurities and had an APHA color number of 1, which remained unchanged even after 9 days storage at room temperature.
  • the liquid discharge of the thin film evaporator was passed as stream (6b) to the phase separation vessel D. This was operated at a temperature of 30 ° C.
  • the upper liquid phase was withdrawn continuously as stream (8) at 367 g / h).
  • Stream (8) contained 98.5% by weight of tri- n-octylamine and only 1.4% by weight of formic acid, which corresponds to a molar ratio of formic acid: amine of 0.1.
  • the loss of formic acid by decomposition was determined by measuring the amount of exhaust gas and the exhaust gas composition by means of the gas chromatographically determined fractions of the decomposition products hydrogen, carbon dioxide and carbon monoxide. Only 0.3% of formic acid, based on the formic acid recovered as distillate, was decomposed.
  • Example 25 shows the recovery according to the invention of very pure and color-stable ant formic acid while simultaneously obtaining two liquid phases from the bottom effluent of the distillation apparatus, the upper liquid phase consisting almost entirely of tri-n-octylamine and thus very well suited for recycle to step (a) and the lower liquid phase with 14% by weight of formic acid and 86% by weight of tri-n-octylamine is very well suited for recycling to step (b) and / or (c).
  • Example 26 was carried out as Example 25 but using instead of a synthetic mixture of tri-n-octylamine and formic acid as stream (4) the stream (7) collected from Example 25.
  • the product obtained as the top product of the column body C2 as stream (5) contained 22 ppm by weight of organic by-products and had an APHA color number of 2.
  • the loss of formic acid by decomposition also remained very low at 0.3%, based on the distillate of the formic acid recovered.
  • Example 26 confirms that the lower liquid phase from step (d) via stream (7) can be easily recycled to step (c) without any apparent loss in the quality of the formic acid to be recovered.
  • Example 27 confirms that the lower liquid phase from step (d) via stream (7) can be easily recycled to step (c) without any apparent loss in the quality of the formic acid to be recovered.
  • Example 27 was also carried out in the laboratory 1.
  • the distillation apparatus was operated at a head pressure in the column body C1 of 0.015 MPa abs and set a reflux ratio of reflux to distillate of 4.
  • About stream (4) 533 g / h of a mixture of tri-n-hexylamine and formic acid (molar ratio of formic acid: amine 1, 5) fed into the top of the thin film evaporator C2.
  • the temperature at the lower outlet of the thin-film evaporator was 158 ° C.
  • the gaseous discharge of the evaporator was fed as stream (6x) to the column body C1.
  • the liquid effluent of the column body was fed as stream (6a) at the top of the thin film evaporator C2.
  • the top product of the column body C1 was obtained as stream (5) 78 g / h of 99 wt .-% formic acid.
  • This formic acid contained only 25 ppm by weight of organic impurities and had an APHA color number of 5, which remained unchanged even after 49 days of storage at room temperature.
  • the liquid discharge of the thin film evaporator was passed as stream (6b) to the phase separation vessel D. This was operated at a temperature of 80 ° C.
  • the upper liquid phase was withdrawn continuously as stream (8) at 364 g / h.
  • Stream (8) contained 99.0 wt .-% of tri-n-hexylamine and only 1, 0 wt .-% formic acid, which corresponds to a molar ratio of formic acid: amine of 0.06.
  • the lower liquid phase was withdrawn continuously as stream (7) at 73 g / h.
  • the loss of formic acid by decomposition was determined by measuring the amount of exhaust gas and the exhaust gas composition by means of the gas chromatographically determined fractions of the decomposition products hydrogen, carbon dioxide and carbon monoxide. Only 0.2% of formic acid, based on the formic acid recovered as distillate, was decomposed.
  • Example 27 shows that even with a variation of the process conditions and especially when using a different tertiary amine than in Example 25 by the inventive method, a very pure and color-stable formic acid can be obtained. Also in this case, two liquid phases were obtained from the bottom effluent of the distillation apparatus, wherein the upper liquid phase consisted almost completely of tri-n-hexylamine and thus is very well suited for recycling to step (a) and the lower liquid phase with 20 wt. % Formic acid and 78% by weight of tri-n-hexylamine is very well suited for recycle to step (b) and / or (c).
  • Example 28 was carried out essentially as Example 27, but using instead of a synthetic mixture of tri-n-hexylamine and formic acid as stream (4) the stream (7) collected from Example 27. Over stream (4), 518 g / h of this mixture were added at the top of the thin film evaporator C2 fed. The temperature at the lower end of the thin film evaporator was 160 ° C. The top product of the column body C1 was obtained as stream (5) 76 g / h of 99 wt .-% formic acid. This formic acid contained only
  • the liquid discharge of the thin film evaporator was passed as stream (6b) to the phase separation vessel D. This was operated at a temperature of 80 ° C.
  • the upper liquid phase was withdrawn continuously as stream (8) at 407 g / h.
  • Stream (8) contained 98.0% by weight of tri-n-hexylamine and only 1.4% by weight of formic acid, which corresponds to a molar ratio of formic acid: amine of 0.08.
  • the lower liquid phase was withdrawn continuously as stream (7) at 7 g / h.
  • Stream (7) contained 79% by weight of tri-n-hexylamine and 19% by weight of formic acid, which corresponds to a molar ratio of formic acid: amine of 1.4.
  • In total, in the stream (6b) there was a ratio of formic acid: amine 0.1.
  • the loss of formic acid by decomposition was 0.7%, based on the distillate of the formic acid recovered.
  • Example 28 confirms that even when using a tertiary amine other than in Example 26, the lower liquid phase from step (d) via stream (7) without any loss of quality of the formic acid to be recovered can be easily recycled to step (c). Comparative Example 29
  • Comparative Example 29 was also carried out in the laboratory 1.
  • the distillation apparatus was operated at a top pressure in the column body C1 of 0.015 MPa abs and set a reflux ratio of reflux to distillate of 4.
  • About stream (4) 492 g / h of a mixture of tri-n-hexylamine and formic acid (molar ratio of formic acid: amine 1, 5) fed to the top of the thin film evaporator C2.
  • the temperature at the lower end of the thin-film evaporator was 171 ° C.
  • the gaseous discharge of the evaporator was fed as stream (6x) to the column body C1.
  • the liquid effluent of the column body was fed as stream (6a) at the top of the thin film evaporator C2.
  • the top product of the column body C1 was obtained as stream (5) 72 g / h of 99 wt .-% formic acid.
  • This formic acid had an APHA color number of 10 but increased to 20 after only 7 days
  • the liquid discharge of the thin film evaporator was passed as stream (6b) to the phase separation vessel D, which was operated at a temperature of 80 ° C. However, only a single-phase liquid discharge was obtained. This contained 99.2 wt .-% of tri-n-hexylamine and
  • Example 30 the laboratory system 1 was operated as in Example 27, but with the difference that in the bottom of the column body C1 and in the bottom of the thin film evaporator C2 each have a stainless steel plate (20 mm ⁇ 50 mm ⁇ 3 mm) of the material with the Material numbers 1 .4406, 1.4462 and 1 .4439 were attached. The plant was then operated continuously for 15 days, being further differentiated from Example 27, the two liquid streams stream (7) and (8) and mixed with fresh, anhydrous formic acid, so that a constant ratio of formic acid: tri-n -hexylamine of 1, 5 adjusted. This mixture was used as feed stream (4).
  • the content of the corrosion metals Cr, Fe, Mo and Ni in the streams (7) and (8) was quantitatively determined by ICP-MS (Inductively Coupled Plasma Mass Spectrometry).
  • the upper liquid phase (stream (8)) contained 32 ppm by weight Cr, 42 ppm by weight Fe, 7 ppm by weight Mo and 2 ppm by weight Ni.
  • Example 30 shows that the so-called corrosion metals are specifically located in the lower liquid phase and thus can be removed by suitable measures and targeted from this.
  • the upper liquid phase to be recycled to step (a) is in fact free of corrosion metals.
  • Laboratory system 2 Laboratory system 2
  • Laboratory plant 2 was used to investigate step (b) of the process according to the invention or specifically for the investigation of the dehydration of a formic acid, tertiary amine (I) and water-containing mixture.
  • Example 31 was carried out in the laboratory plant 2. 230 g / h of a mixture containing 8.0% by weight of water, 30.5% by weight of formic acid and 61.5% by weight of tri-n-hexylamine were added to the column, which resulted in a molar ratio of formic acid : Amine of 2.9 and a mass ratio of formic acid: water of 79:21 corresponds. In the stationary state a sump temperature of 155 ° C. The distillate essentially contained water with only 0.16% by weight of formic acid.
  • the bottom product contained 32.7 wt .-% formic acid, 65.8 wt .-% tri-n-hexylamine and only 1, 5 wt .-% water, corresponding to a molar ratio of formic acid: amine of 2.9 and a mass ratio Formic acid: water of 96: 4. Thus, 81% of the minor component water was separated.
  • Example 32 was carried out in the same way as Example 31, but with the difference that 262 g / h of a mixture containing 8.2% by weight of water, 40.6% by weight of formic acid and 51.3% by weight were introduced into the column. % Tri-n-hexylamine were added, which corresponds to a molar ratio of formic acid: amine of 4.6 and a mass ratio of formic acid: water of 83:17. In the stationary state, a bottom temperature of 137 ° C was established. The distillate essentially contained water with only 0.05% by weight of formic acid. The bottom product contained
  • Examples 31 and 32 show that from an aqueous mixture of formic acid and tri-n-hexylamine it is already possible to easily separate off about 80% of the water present by means of a relatively simple distillation.
  • Laboratory plant 3 was used to investigate steps (a) and (b) of the process according to the invention or specifically for the investigation of the hydrolysis of methyl formate and the subsequent distillative removal of unreacted methyl formate, formed methanol and water.
  • the simplified block diagram of laboratory system 3 is shown in FIG. 14. In it, the individual letters have the following meaning:
  • A1 stirred tank (volume 3.5 L, electrically heated)
  • A2 tubular reactor (inner diameter 80 mm, length 1200 mm, filled with 2 mm glass balls, electrically heated)
  • B1 Distillation apparatus with column body (inside diameter 55 mm, equipped with tissue packs each with 1, 3 m packing height and a specific surface area of 750 m 2 / m 3 , wherein the feed is between the two packing beds) and oil-heated falling film evaporator (surface 0.45 m 2 )
  • B2 Distillation apparatus with column body (inside diameter 55 mm, equipped with tissue packs each with 1, 3 m packing height and a specific surface area of 750 m 2 / m 3 , wherein the feed is between the two packing beds) and oil-heated falling film evaporator (surface 0.15 m 2 )
  • the equipment and lines of the laboratory equipment 3 consisted of a nickel-based alloy with the material number 2.4610. Coriolis flowmeters were used to measure the mass flows. Laboratory plant 3 was operated continuously.
  • Example 33 was carried out in the laboratory plant 3. Via stream (1 a), 853 g / h of methyl formate were metered in via metering pumps, 256 g / h of water via stream (1b) and 1535 g / h of tri-n-hexylamine via stream (8) into the reactor A1. Reactor A1 was operated at 130 ° C and 1, 2 MPa gauge. The effluent of reactor A1 was passed into the after-reactor A2, which was also operated at 130 ° C and 1, 2 MPa gauge.
  • Stream (2) was a product mixture containing 58.1% by weight of tri-n-hexylamine, 15.0% by weight of formic acid, 10.4% by weight of methanol, 3.8% by weight of water and 12 , 7 wt .-% of methyl formate, which corresponds to a molar ratio of formic acid: amine of 1, 51.
  • Stream (2) was depressurized and passed into the column body of the distillation apparatus B1. At a top pressure of 0.18 MPa abs and a reflux ratio of 1.7, the top product taken off as stream (3b) was a mixture containing essentially formed methanol and unreacted methyl formate.
  • the bottom product used as stream (3d) was 1990 g / h of a mixture of 74.9% by weight of tri-n-hexylamine, 5.3% by weight of water, 19.8% by weight of formic acid and 0.1% by weight .-% methanol.
  • the bottom temperature in the column body was 133.degree.
  • Stream (3d) was decompressed and sent to the column body of the distiller B2.
  • 69 g / h aqueous formic acid (formic acid content 82.5% by weight) were fed to the column body via stream (5a) in order to simulate recirculation of aqueous formic acid, as described in the description of FIG. 2 as a side draw of the distillation apparatus in step (c) and can be returned to step (b).
  • the top product of the distillation apparatus B2 was stripped off at a top pressure of 0.1 1 MPa abs and a reflux ratio of 1.7 g / h, which contained essentially water and 0.1% by weight formic acid.
  • About stream (4) 1949 g / h of a mixture of 76.9 wt .-% of tri-n-hexylamine, 21, 2 wt .-% formic acid and 1, 9 were obtained as the bottom product at a bottom temperature in the column body of 160 ° C. .-% of water.
  • the molar ratio of formic acid: amine in stream (4) was 1.61.
  • Example 33 shows that the process according to the invention can also be obtained in the hydrolysis of methyl formate and its subsequent work-up by separation of secondary components, in particular residual methyl formate, formed methanol and water, a stream strongly enriched in formic acid and tri-n-hexylamine. This can then, as the examples 27 to 28 show indirectly, are used for the distillative removal of very pure formic acid.
  • Table 1

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Abstract

L'invention concerne un procédé d'obtention d'acide formique par séparation thermique d'un courant contenant de l'acide formique et une amine tertiaire (I. Dans le cadre dudit procédé, en mettant en contact une amine tertiaire (I) et une source d'acide formique, on obtient un courant liquide contenant de l'acide formique et une amine tertiaire (I) selon un ratio molaire se situant dans la plage allant de 0,5 à 5, on sépare 10 à 100 % en poids des composants secondaires qu'il contient et, à partir du courant liquide obtenu, on enlève l'acide formique par distillation dans un dispositif de distillation à une température de bas de colonne se situant dans la plage allant de 100 à 300°C et sous une pression allant de 30 à 3000 hPa abs. Puis on sépare le produit de queue du dispositif de distillation en deux phases liquides et on renvoie la phase liquide supérieure dans la source d'acide formique et la phase liquide inférieure vers la séparation des composants secondaires et/ou dans le dispositif de distillation.
EP11728826.6A 2010-06-29 2011-06-28 Procédé de production d'acide formique Withdrawn EP2588440A1 (fr)

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EP10167679 2010-06-29
EP10187280 2010-10-12
EP11728826.6A EP2588440A1 (fr) 2010-06-29 2011-06-28 Procédé de production d'acide formique
PCT/EP2011/060770 WO2012000964A1 (fr) 2010-06-29 2011-06-28 Procédé de production d'acide formique

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US8877965B2 (en) 2010-06-29 2014-11-04 Basf Se Process for preparing formic acid by reaction of carbon dioxide with hydrogen
PL2655310T3 (pl) * 2010-12-21 2015-05-29 Basf Se Sposób wytwarzania kwasu mrówkowego drogą reakcji ditlenku węgla z wodorem
US8742171B2 (en) 2011-06-09 2014-06-03 Basf Se Process for preparing formic acid
US8993819B2 (en) 2011-07-12 2015-03-31 Basf Se Process for preparing cycloheptene
US8703994B2 (en) 2011-07-27 2014-04-22 Basf Se Process for preparing formamides and formic esters
US8946462B2 (en) 2011-11-10 2015-02-03 Basf Se Process for preparing formic acid by reaction of carbon dioxide with hydrogen
WO2013092403A1 (fr) * 2011-12-20 2013-06-27 Basf Se Procédé de préparation d'acide formique
US8835683B2 (en) 2011-12-20 2014-09-16 Basf Se Process for preparing formic acid
US8889905B2 (en) 2011-12-20 2014-11-18 Basf Se Process for preparing formic acid
CN104812731A (zh) * 2012-11-27 2015-07-29 巴斯夫欧洲公司 生产甲酸的方法
US9428438B2 (en) 2012-11-27 2016-08-30 Basf Se Process for preparing formic acid
CN110980763B (zh) * 2019-12-24 2022-10-18 福州大学 一种分子筛的改性方法和用途

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DE2545658C2 (de) 1975-10-11 1985-12-19 Basf Ag, 6700 Ludwigshafen Verfahren zur Gewinnung von Carbonsäuren aus ihren wäßrigen Lösungen
DE2744313A1 (de) 1977-10-01 1979-04-12 Basf Ag Verfahren zur herstellung von ameisensaeure
GB8307611D0 (en) 1983-03-18 1983-04-27 Bp Chem Int Ltd Formic acid
DE3428319A1 (de) 1984-08-01 1986-02-13 Hüls AG, 4370 Marl Verfahren zur gewinnung wasserfreier bzw. weitgehendwasserfreier ameisensaeure
GB8424672D0 (en) * 1984-09-29 1984-11-07 Bp Chem Int Ltd Production of formic acid
DE4211141A1 (de) 1992-04-03 1993-10-07 Basf Ag Verfahren zur Herstellung von Ameisensäure durch thermische Spaltung von quartären Ammoniumformiaten
DE102004040789A1 (de) * 2004-08-23 2006-03-02 Basf Ag Verfahren zur Herstellung von Ameisensäure
KR20090123972A (ko) 2007-03-23 2009-12-02 바스프 에스이 포름산의 제조 방법
DE102009046310B4 (de) 2008-11-24 2018-10-25 Basf Se Verfahren zur destillativen Gewinnung von Rein-1,3-Butadien aus Roh-1,3-Butadien

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* Cited by examiner, † Cited by third party
Title
None *
See also references of WO2012000964A1 *

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RU2013103601A (ru) 2014-08-10
SG186264A1 (en) 2013-01-30
CA2801580A1 (fr) 2012-01-05
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KR20130088838A (ko) 2013-08-08

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