RU2783708C2 - Method for production of ethylenamine compounds - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for production of polyethylenamine compounds selected from a group of polyethylenamines and hydroxyethylethylenamines, including stages, at which: at an attachment stage, adduct of CO₂ with an initial compound including a fragment -NH-CH₂-CH₂-NH-, or a fragment -NH-CH₂-CH₂-OH or HO-CH₂-CH₂-OH is provided, at a reaction stage, a reaction of a hydroxy-functional compound selected from a group of ethanolamines and dihydroxyethane with an amino-functional compound is conducted, while at least part of the total amount of hydroxy-functional compounds and amino-functional compounds is provided in the form of adduct with CO₂ to form adduct of CO₂ with the polyethylenamine compound, at a removal stage, adduct CO₂ with the polyethylenamine compound is converted into a corresponding resulting polyethylenamine compound, while a fraction containing a recirculated compound including the fragment -NH-CH₂-CH₂-NH-, or the fragment -NH-CH₂-CH₂-OH or HO-CH₂-CH₂-OH, or its adduct with CO₂ is supplied at the end of the reaction stage or the removal stage to the attachment stage or the reaction stage, while the recirculated compound contains, per one molecule, in average smaller total amount of fragments -NH-CH₂-CH₂-NH- and fragments -NH-CH₂-CH₂-OH than the resulting polyethylenamine compound.

EFFECT: provision of a selective method for the production of polyethylenamine compounds in a way acceptable on an industrial scale.

20 cl, 18 dwg

Description

The present invention relates to a process for the production of ethyleneamine compounds, in particular polyethyleneamines and hydroxyethylethyleneamines. In particular, the invention relates to an integrated process for the preparation of these compounds.

Ethyleneamines are composed of two or more nitrogen atoms linked by ethylene units. Ethyleneamines can be presented in the form of linear chains H2N(-CH2-CH2-NH)p-H.

For p=1, 2, 3, 4, ... this gives, respectively, ethylenediamine (EDA), diethylenetriamine (DETA), linear triethylenetetramine (L-TETA) and linear tetraethylenepentamine (L-TEPA). It is clear that this series can be continued. With three or more ethylene units, branched ethyleneamines such as N(CH2-CH2-NH2)3, trisaminoethylamine (TAEA) can also be prepared. Two neighboring nitrogen atoms can be connected by two ethylene units to give the piperazine ring -N(-)2-N-. Piperazine rings may be present in longer chains to form the corresponding cyclic ethyleneamines.

Ethyleneamines, in particular diethylenetriamine (DETA) and higher ethyleneamines, are commercially attractive products. The term "higher ethyleneamines" means ethyleneamines containing three or more ethylene units. In particular, interest in higher ethyleneamines is growing because these compounds have many commercial applications, for example, as a raw material for production or for use in asphalt additives, corrosion inhibitors, epoxy curing agents, fabric softeners, fuel additives. , for hydrocarbon refining, in ion exchange resins, lubricating oil additives, paper wet strength resins, oilfield chemicals, solvents, synthetic resins such as polyamide resins, mineral processing processing aids, and surfactants.

Hydroxyethylethyleneamines are used in chemical processes as solvents or reagents. For example, aminoethylethanolamine, or AEEA, of the formula H2N-CH2-CH2-NH-CH2-CH2-OH is an organic base used in the industrial production of fuels or oil additives, chelating agents and surfactants. Long chain ethanolamines, such as monoethanolamine compounds of the formula H2N-(CH2-CH2-NH)q-CH2-CH2-OH, where q is 2 or more, are of interest as intermediates in various types of organic synthesis, for example in the production of esters from carboxylic acids. They can also be used, for example, as surfactants in the production of synthetic resins, in the production of emulsifiers, in fabric softeners and as curing agents for epoxy resins.

The production of ethyleneamines is currently dominated by two methods, namely the reductive amination of monoethanolamine (MEA) and the ethylene dichloride (EDC) method.

The reductive amination of MEA occurs in the presence of a hydrogenation/dehydrogenation catalyst in excess ammonia. After reductive amination of MEA to produce EDA, side reactions, including transamination, produce a mixture of large amounts of ethylene and ethanolamines. The output is mainly mono- and diethylene products (EDA, DETA, piperazine (PIP) and AEEA). Higher ethylene and ethanolamines are also formed, but the mixture is so complex that it is not efficient to produce the most important higher ethyleneamines TETA and TERA in high yield.

Several transamination attempts have been reported to produce ethyleneamines with two or more ethylene units, however, they seem to be limited mainly to the diethylene compound (DETA).

The EDC process consists in a displacement reaction between EDC (ethylene dichloride) and ammonia and/or other ethyleneamine at elevated temperature and pressure to form hydrochlorides, to which sodium hydroxide is then added to form mixtures of ethyleneamines and NaCl. Currently, the EDC-based process is the main method for the production of higher polyethylene polyamines. The EDC method is entirely dependent on the use of ethylene dichloride, which is costly, difficult to process, and is associated with certain safety and environmental conditions. In addition, the EDC process produces a blend of many different polyethylene polyamines, such as in commercial blends such as TETA. In addition, the EDC process generates a significant amount of undesirable NaCl, which can cause corrosion and the formation of colored products.

Various processes have been described for the production of hydrocyethylethyleneamines.

For example, SU 3383417 describes the production of aminoethylethanolamine by reacting monoethanolamine with itself in the presence of a catalyst containing nickel, copper and a small amount of chromium oxide, manganese oxide, molybdenum oxide and thorium oxide.

SU 7700806 describes a process for the preparation of ethyleneamines and ethanolamines by hydrogenation amination of monoethylene glycol and ammonia in the presence of a catalyst. This method includes two stages, at the same time, in the first stage, the amination is carried out over a hydroamination catalyst with a degree of conversion of monoethylene glycol not more than 40%, in the second stage, the reaction is carried out over a catalyst supported on a substrate, including ruthenium and cobalt and having a certain particle shape.

SU 4387249 describes the reaction of ethylenediamine (EDA), ethanolamine (MEA) and urea to form aminoethylethylene urea (UDETA) and ethylene urea (EU), which after hydrolysis with NaOH (aq.) gives diethylenetriamine (DETA) and ethylenediamine (EDA).

SU 4503250 describes a process for the preparation of linear polyalkylene polyamines, which involves reacting ammonia or an alkyleneamine compound with two primary amino groups, or mixtures thereof, with an alcohol or an alkanolamine compound containing a primary amino group and a primary or secondary hydroxy group, or mixtures thereof, in the presence of a carbonic acid derivative at a temperature , at which this reaction will proceed at a pressure sufficient to keep the reaction mixture essentially in the liquid phase. This method leads to the formation of urea adducts with polyalkylene polyamines. The urea adducts are converted to polyethylenepolyamines by reaction with 50% aqueous KOH at reflux overnight. 8 moles of KOH are used per mole of carbon dioxide.

There is currently a high demand for higher ethyleneamine compounds. Therefore, there is a need for a process for the selective production of such higher compounds in an efficient and commercially acceptable manner. Such a method is provided by the present invention.

The invention relates to an integrated method for the production of polyethyleneamine compounds selected from the group of polyethyleneamines and hydroxyethylethyleneamines, comprising the steps in which:

- at the stage of addition, an adduct of CO ₂ is provided with the initial compound, including a fragment -NH-CH ₂ -CH ₂ -NH- or a fragment -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH,

- at the reaction stage, a hydroxy functional compound selected from the group of ethanolamines and dihydroxyethane is reacted with an amino functional compound, while at least part of the total amount of hydroxy functional compounds and amino functional compounds is provided in the form of a CO ₂ adduct, with the formation of a CO ₂ adduct with a polyethyleneamine compound ,

- the removal step converts the CO2 adduct with the polyethyleneamine compound to the corresponding resulting polyethyleneamine compound,

at the same time, the fraction containing the recycled compound, including the -NH-CH2-CH2-NH- fragment or the -NH-CH2-CH2-OH or HO-CH2-CH2-OH fragment, or the CO2 adduct with it, is fed at the end of the reaction stage or a removal step to an addition step or a reaction step,

at the same time, the recycled compound per molecule contains, on average, a lower total number of -NH-CH2-CH2-NH- fragments and -NH-CH2-CH2-OH fragments than the resulting polyethyleneamine compound.

Thanks to the present invention, efficient and commercially acceptable production of ethyleneamine compounds is possible. Although the product of this process is referred to as the resulting polyethyleneamine, it should be understood throughout this document that multi-component products or even multiple products are possible within the resulting polyethyleneamine. In addition, as is clear from the embodiments of the invention, the resulting polyethyleneamine may contain hydroxyl groups. Other advantages of the present invention and specific embodiments of its implementation will become apparent from the following description.

In its simplest form, the general reaction underlying the method of the invention can be exemplified as the reaction of ethylenediamine (EDA) with monoethanolamine (MEA) to form diethylenetriamine (DETA) and water:

H2N-CH2-CH2-NH2+HO-CH2-CH2-NH2 → H2N-CH2-CH2-NH-CH2-CH2-NH2+H2O

However, ethylenediamine and monoethanolamine do not react directly. They become reactive after the transformation of one of them into an adduct with CO2 with the release of water. Although many CO2 adducts are cyclic ureas or cyclic carbamates, the CO2 adduct moiety in many embodiments of the invention typically interacts with a moiety in which two nitrogen atoms, or a nitrogen atom and an oxygen atom or two oxygen atoms, are connected by a -C(O )-. Therefore, they can also be linear with a connection between the nitrogen and/or oxygen atoms of two different molecules. In addition, CO2 can also form an adduct with an amine or alcohol at the terminal one-sided group connected to only one nitrogen or oxygen atom. One of the adducts of CO2 with ethylenediamine is ethylene urea. One of the CO2 adducts with monoethanolamine is 2-oxazolidone, also referred to herein as CMEA. Here is an example of the addition step of the method according to the invention.

(EU)

(СМЕА)

(EU)

(CMEA)

A reaction can then be carried out between ethylenediamine and CMEA to form the adduct of CO2 with DETA, also referred to herein as UDETA, and water. The same product can be obtained from the reaction between EU and MEA.

(UDETA)

(UDETA)

Then, in a removal step, the CO2 adduct with UDETA can be converted to DETA. This can be done, for example, by reaction with water, with the concomitant formation of CO2.

As will be appreciated by those skilled in the art, the process can similarly be carried out using ethyleneamine compounds and/or hydroxy functional compounds longer than EDA and/or CMEA as starting materials. The use of hydroxy functional compounds with one hydroxyl group will lead to the formation of ethyleneamine compounds. The use of hydroxy functional compounds with two hydroxyl groups, such as monoethylene glycol/dihydroxyethane (HO-CH2-CH2-OH) or diethanolamine (HO-CH2-CH2-NH-CH2-CH2-NH2) will lead to the formation of hydroxyethylethyleneamines, which in turn , can be converted to polyethyleneamines.

The method described above looks deceptively simple. It has been found that it is difficult to efficiently implement such a process on a commercial scale. The present invention enables the effective implementation of this method.

The first step of the process of the present invention is an addition step that produces a CO2 adduct with a parent compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety. The attachment step can be carried out in various ways.

In one of the embodiments of the invention, the addition step includes the step of reacting gaseous CO2 with a parent compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety, resulting in the formation corresponding adducts with CO2. This step is also referred to herein as the absorption step.

In another embodiment of the addition step, the CO2 adduct is prepared by reacting a starting compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety with a non-CO2 compound , which can transfer a carbonyl group to the starting compounds with the formation of their adduct with CO2. Such compounds may be referred to as CO2 supply compounds.

CO2-feeding compounds other than CO2 in the context of the present invention include organic compounds in which the carbonyl moiety is suitable for the transfer described above. Organic compounds with a suitable carbonyl moiety include urea and its derivatives; linear and cyclic alkylene ureas, especially cyclic ethylene urea, mono- or disubstituted alkylene ureas, alkyl and dialkyl ureas, linear and cyclic carbamates, organic carbonates, their derivatives and precursors. Such derivatives or precursors may include, for example, ionic compounds such as carbonate or bicarbonate salts, carbamic acids and corresponding salts, which, in some embodiments, can be converted in situ to linear and cyclic carbamates or urea compounds. When such ionic compounds are used in the context of the present invention, they are organic, hydrocarbon-based carbonate, bicarbonate or carbamate salts. Preferably the CO2 supply compound is CO2 or an organic compound suitable for use as the carbon dioxide supply compound wherein the alkylene is ethylene or urea or ethylene carbonate, more preferably the carbon dioxide supply compound is added at least in part in the form of carbon dioxide or urea. The carbon dioxide supply compound can be present in the process in the same molecule as the amine or ethanolamine compound by using the above urea or carbamate compound.

Examples of carbon dioxide supply compounds are

На этом изображении САЕЕА означает аминоэтилэтаноламин карбамат, UDETA означает диэтилентриаминмочевину, DAEU означает диаминоэтилмочевину, АЕ АЕ карбамат означает аминоэтиламиноэтанол карбамат, CHE-DETA означает гидроксиэтилдиэтилентриамин карбамат, U1TETA означает триэтилентетраминмочевину в концевом положении, DUTETA означает триэтилентетрамин 1,3-димочевину.

In this image CAEEA means aminoethylethanolamine carbamate, UDETA means diethylenetriamineurea, DAEU means diaminoethylurea, AE AE carbamate means aminoethylaminoethanol carbamate, CHE-DETA means hydroxyethyldiethylenetriamine carbamate, U1TETA means triethylenetetramineurea at the end position, DUTETA means triethylenetetramine 1,3-diurea.

The carbon dioxide supply compound is reacted, most preferably in the form of carbon dioxide, urea, an ethanolamine compound and a carbamate or an amine compound and urea, or a combination thereof.

An embodiment of the addition step in which the CO2 adduct is produced by a reaction between a starting compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety and a compound not being CO2 that can transfer a carbonyl group by the parent compound can also be called a CO2 transfer step.

In the reaction step of the process according to the invention, a hydroxy-functional compound selected from the group of ethanolamines and dihydroxyethane is reacted with an amino-functional compound, whereby at least a part of the total amount of hydroxy-functional compounds and amino-functional compounds is provided in the form of an adduct with CO2, forming a CO2 adduct with polyethyleneamine compound.

In the removal step of the process according to the invention, the CO2 adduct with the polyethyleneamine compound is converted to the corresponding resulting polyethyleneamine compound. This step is called the removal step because the carbonyl group is removed from the molecule.

There are various ways to carry out the removal step.

In one embodiment, the removal step includes the step of reacting the CO2 adduct with the polyethyleneamine compound and water to form CO2 and the corresponding ethyleneamine compound. This embodiment is also referred to herein as the desorption step.

In another embodiment of the invention, the removal step is performed by reacting the CO2 adduct with the polyethyleneamine compound and an inorganic base, resulting in the formation of the polyethyleneamine compound and a carbonate. This step is also referred to herein as the alkali treatment step. In the context of the present invention, an inorganic base is a Lewis or Bronsted base that does not contain carbon-carbon bonds. In many embodiments, the inorganic base contains a metal, alkali metal, or alkaline earth metal cation and, in many embodiments, is a Brønsted base. Preferably, the inorganic base is a strong inorganic base free of carbon-carbon bonds and having a pKb of less than 1.

In another embodiment of the invention, the removal step is carried out by transferring a carbonyl group from a CO2 adduct with a polyethyleneamine compound to a compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety. . This stage is also called the CO2 transfer stage.

In the present description, the addition step is shown as the step in which a CO2 adduct is formed with the parent compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety, while the reaction step is shown as a step in which a reaction is carried out between a hydroxy functional compound and an amino functional compound, wherein at least a part of the total amount of hydroxy functional compounds and amino functional compounds is provided in the form of an adduct with CO2, to form a CO2 adduct with a polyethyleneamine compound, and the step of removing is the step in which the CO2 adduct with the polyethyleneamine compound is converted to the corresponding product, the resulting polyethyleneamine compound. As will be appreciated by those skilled in the art, depending on the reaction conditions, some reaction may also take place in the addition step, the removal step may also take place during the reaction step. In particular, during the reaction step, carbonyl groups can be transferred from a CO2 adduct with a polyethyleneamine compound to a compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety.

A distinctive feature of the present invention is that the fraction containing the recycled compound, including the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, or CO2 adducts with them, is fed at the end of the reaction step or the removal step or the separation step into the addition step or the reaction step, wherein the recycled compound per molecule contains, on average, a lower total amount of -NH-CH2-CH2-NH- fragments and -NH fragments -CH2-CH2-OH than the resulting polyethyleneamine compound.

In one of the embodiments of the invention, the recycled compound is a parent compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety or a CO2 adduct with it. In another embodiment of the invention, the recycled compound is an intermediate. Of course, the recycled portion may contain both starting compounds and intermediate compounds.

It should be noted that the present application describes a plurality of streams directed from one stage to another stage. Except where expressly stated otherwise, it is possible to supply the flow from one stage to another in full or in part. If a compound is indicated to be fed from one stage to another, other compounds may also be present in the stream fed from one stage to another.

The invention is further explained with reference to the figures. Figures 1-12 show various embodiments of the method according to the invention.

Regarding the figures, the following is noted:

The figures are intended to illustrate the invention. The invention is not limited to them.

Embodiments of the invention shown in different figures may be combined unless they are mutually exclusive.

The figures are flow charts illustrating the process according to the invention. The figures do not show the reactor plant. For example, an absorption step, a reaction step, and a desorption step, indicated in the figures as three different steps, may be carried out sequentially in one tank. In addition, the different lines show how the components pass from one reaction step to another. They do not reflect actual designs.

The figures do not always show all the elements of the method according to the invention.

The figures do not show all purge streams or make-up streams that may occur in the practice of the process according to the invention; those skilled in the art will appreciate that, in practice, purge streams and make-up streams may be necessary to maintain stable operation.

As will be appreciated by those skilled in the art, the three steps of the process according to the invention are also not completely separate in the sense that some reactions may occur during the addition step and the removal step depending on the prevailing process conditions and medium composition. This does not detract from the description of the individual stages presented in this document.

In FIG. 1 shows an example of a basic method according to the invention. The starting compound, including the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, is fed through line 1 to stage 2 of the accession, where it is combined with CO2 or other supply carbon dioxide by the compound supplied via line 3 to form a CO2 adduct with the parent compound. The stream containing the CO2 adduct is sent via line 4 to reaction stage 5, where a reaction is carried out between it and another reactant (already present, supplied through an inlet not shown, or supplied from addition stage 2), while the reagents in the reaction stage are hydroxy-functional a compound selected from the group of ethanolamines and monoethylene glycol, and an amino compound, wherein at least part of the total amount of hydroxy functional compounds and amino functional compounds are provided in the form of an adduct with CO2 supplied from stage 2. In stage 5 of the reaction, an adduct of CO2 with a polyethyleneamine compound is formed, which line 6 serves on stage 7 removal. The fraction containing the recycled compound, including the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, or its adduct with CO2, is fed through line 61, in this case , at the end of the reaction step, in this case, the addition step. In the removal step 7, the CO2 adduct with the polyethyleneamine compound is converted to the corresponding ethyleneamine compound, which is withdrawn via line 9. The compound containing the carbonyl group removed from the CO2 adduct with the polyethyleneamine compound is withdrawn via line 10. Lines 63 and 64 are optional and allow for withdrawal and dose the compounds before, after or during the reaction. Compounds which can then be diverted or dosed include CO ₂ , H ₂ O, amino compounds and/or their derivatives with urea.

In one of the preferred embodiments of the present invention, the addition step is an absorption step in which CO2 is absorbed by a reaction medium containing a parent compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH moiety or HO -CH2-CH2-OH to form a CO2 adduct with said compound, and the removal step is a desorption step in which the CO2 adduct with the polyethyleneamine compound reacts with water to form the corresponding ethyleneamine compound and CO2. This embodiment of the invention is shown in FIG. 1a. In FIG. 1a, the starting compound, comprising the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, is fed through line 1 to absorption stage 2, where it is combined with CO2 supplied along line 3, and the reaction is carried out with the formation of a CO2 adduct with the starting compound. The CO2 adduct is fed through line 4 to reaction stage 5, where a reaction is carried out with another reagent, while the reagents in the reaction stage are a hydroxyfunctional compound selected from the group of ethanolamines and dihydroxyethane, and an amino compound, while at least part of the total amount hydroxy functional compounds and amino functional compounds are provided in the form of an adduct with CO2 supplied from stage 2. In stage 5 of the reaction, an adduct of CO2 with polyethyleneamine compound is formed, which is fed via line 6 to stage 7 of desorption. The stripping gas can be fed to stage 7 through line 8, the stripping gas containing CO2 is removed through line 10. The resulting polyethyleneamine compound is removed through line 9, then it can be subjected to the necessary processing. The fraction containing the recycled compound, including the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, or its adduct with CO2, is fed through line 61, in this case , at the end of the reaction step, in this case, the addition step.

The stripping gas used in the process according to the invention may have any desired composition. It may contain inert gases such as nitrogen or noble gases to provide volume and stripping. The presence of water can be adjusted as steam is advantageous in terms of blowing and heat input. On the other hand, since water is consumed in the desorption step and produced in the reaction step and addition step, adjusting the water content in the gas streams of the process according to the invention makes it possible to control the reaction steps. The presence of compounds that interfere with the reaction, or the presence of which may cause undesirable side effects, is preferably limited. For example, it is preferable to limit the presence of oxygen in this process, since it can lead to coloring. Therefore, gases and liquids, such as water, used in the process according to the invention, if desired, can be subjected to an oxygen removal step.

In one embodiment of the present invention, the CO2 formed in the desorption step is fed at least in part to the absorption step.

One embodiment of this possibility is shown in Fig. 2, where the CO2 supplied via line 3 to the absorption stage 2 comes from the desorption stage via line 10. Since it may be desirable not to recycle all of the CO2, a separate line 11 branches off from line 10. Line 62 is optional. It allows you to add CO2 to compensate for losses.

In another embodiment of the present invention, the stripping gas withdrawn from the stripping stage is subjected to a CO2 removal stage and recycled, at least in part, to the stripping stage.

One embodiment of this possibility is shown in Fig. 3, where the stripping gas containing CO2 is supplied via line 10 to the stage 12 of removing CO2. Stripping gas is withdrawn via line 8 and recycled to the stripping stage 7 . CO2 is withdrawn through line 13. Line 27 is optional. It allows you to add N ₂ to compensate for losses.

Another embodiment of this capability is shown in FIG. 4 where an absorption step is used to remove CO2 from the stripping gas. In FIG. 4, as in FIG. 2, stripping gas containing CO2 is withdrawn from the desorption stage 7 via line 10 and fed to the absorption stage via line 3. Line 62 is optional. It allows you to add CO2 to compensate for losses. In the CO2 absorption step 2, CO2 is absorbed from the CO2-containing stripping gas. Stripping gas, from which CO2 has been removed, is withdrawn from the absorption stage and fed through line 8 to the desorption stage 7. Line 27 is optional. It allows the addition of stripping gas to compensate for losses.

In FIG. 5 shows another embodiment of the present invention in which a separation step 14 is carried out after the removal step. The separation step 14 results in the separation of recycled compounds, eg starting materials and/or intermediates, which are withdrawn via line 16 and, in the embodiment shown, fed to the addition step 2. They can also be fed to the reaction step (not shown in the figure). At separation stage 14, a product fraction is also obtained - higher ethyleneamine compounds, which is withdrawn through line 15.

Another embodiment of this possibility is shown in FIG. 6. In this embodiment, the separation step 17 is carried out after the reaction step and before the removal step. In this separation step, recycled compounds, for example starting materials or their CO2 adducts or intermediates or their CO2 adducts, are separated from the CO2 adduct with polyethyleneamine compounds and fed via line 18, in this case, to addition stage 2. They can also be fed to reaction step 5 (not shown). The CO2 adduct with the polyethyleneamine compound is fed via line 19 to the removal stage 7 .

In one embodiment of the present invention, the removal step comprises a first removal step and an additional removal step, wherein the first removal step and the additional removal step are independently selected from the group consisting of

- a stripping step in which a reaction is carried out between the adduct of CO2 with a polyethyleneamine compound and water to form CO2 and the corresponding polyethyleneamine compound,

- an alkali treatment step in which a reaction is carried out between a CO2 adduct with a polyethyleneamine compound and an inorganic base, resulting in the formation of a polyethyleneamine compound and a carbonate salt, and

- a CO2 transfer step in which a carbonyl group is transferred from a CO2 adduct with a polyethyleneamine compound to a compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety,

at the same time, in the first stage of removal, a part of the adduct of CO2 with a polyethyleneamine compound present in the stream entering this stage is converted into polyethyleneamine compounds, while a part of the adduct of CO2 with a polyethyleneamine compound present in the stream entering the first stage of removal is not converted during the first removal stage and enters the second removal stage. Of course, it is also possible to provide for other removal steps.

It may be preferable that the first removal step is a desorption step or a CO2 transfer step and the additional removal step is a stripping step or an alkali treatment step, which steps are different from each other. Examples of possible combinations are desorption followed by alkaline treatment and desorption combined with recirculation, optionally with alkaline treatment of the individual fractions.

In one embodiment of the invention, the removal step includes a desorption step in which not all of the CO2 adducts are converted to polyethyleneamine compounds. Thus, the product fed from the desorption step 7 to the separation step may still contain CO2 adducts with polyethyleneamine compounds. If so, it has been found that CO2 adducts tend to be CO2 adducts with higher polyethyleneamine compounds rather than CO2 adducts with lower boiling starting materials. In this case, the separation step 14 leads to the separation of recycled compounds, in particular the starting materials which are withdrawn via line 16, the higher polyethyleneamine product fraction which is withdrawn via line 15 and the fraction containing CO2 adducts with higher polyethyleneamine compounds. This last fraction is withdrawn from separation stage 14 via line 20. It can be processed in various ways, as shown in FIG. 7a, 7b, 7c and 7d.

In FIG. 7a, the CO2 adduct with higher polyethyleneamine compounds removed via line 20 is not subjected to an additional removal step, but is used as such in the process. It may also be subjected to additional purification or separation steps (not shown).

In FIG. 7b, the CO2 adduct with higher polyethyleneamine compounds withdrawn via line 20 is recycled to the desorption stage 7.

In FIG. 7c, the CO2 adduct with higher polyethyleneamine compounds withdrawn via line 20 is fed to an additional removal stage 21. In the additional removal stage 21, more stringent conditions are created than in the desorption stage 7. The desorption step 7 is carried out using water and CO2 evolution, while the additional removal step 21 can be carried out differently, for example using a (strong) inorganic base. In an additional removal step 21, a fraction of the resulting polyethyleneamine compounds is withdrawn via line 22 and a residual fraction is withdrawn via line 23. If the removal step 21 is a treatment with a (strong) base, the residual fraction is a salt fraction.

In FIG. 7d, the CO2 adduct with higher polyethyleneamines or hydroxyethylethyleneamines withdrawn via line 20 is fed back, at least partially, to reaction stage 5.

It is noted that in Fig. 7a, 7b and 7c show the process of the present invention incompletely.

In general, the residual fractions formed in the process according to the invention, whether water, salt or organic fractions, can be subjected to the necessary treatment. In one of the embodiments of the invention, they are combined with the residual fractions of other enterprises and treated in one installation, for example, in a wastewater treatment plant. In another embodiment of the invention, the bottom product, for example the heavy organic fraction, is fed to a purification plant where it is separated into other products. It can also be fed as a feed to other reactors where, if desired, it can be combined with other feeds. Purification of the target product can be carried out in specialized modes. It is also possible to combine the product obtained by the method according to the invention with the product obtained in other processes or in other modes of the method according to the invention and subject the combined product to a purification step.

The usual purification steps for product fractions or residual fractions may be applied as required. These include the removal of impurities, for example, in one or more stages of absorption, selective extraction, distillation, filtration and other stages known to those skilled in the art.

As will become apparent to those skilled in the art, and as is common in the chemical industry, the heat generated in one stage can be used as an energy source in other stages. The same applies to water and steam (as described elsewhere in this document).

In the reaction step of the process according to the invention, a hydroxy functional compound selected from the group of ethanolamines and dihydroxyethane is reacted with an amino functional compound, wherein at least a part of the total amount of hydroxy functional compounds and amino functional compounds is provided in the form of an adduct with CO2. Thus, in one embodiment of the invention, the amino compound is wholly or partly provided in the form of an adduct with CO2. In this case, the amino compound is fed wholly or partly to the addition step, where it is converted to an adduct with CO2, which is then fed to the reaction step together with the hydroxy functional compound also fed to the reaction step. This embodiment of the invention is shown in FIG. 8a, where the amino compound is fed to the addition step via line 101, the hydroxy functional compound is fed to the reaction step via line 102. In FIG. 8b shows the reverse possibility where the hydroxy functional compound is fed to the coupling step via line 102 and the amino compound is fed to the reaction step via line 101. The most effective option may be when both the amino compound and the hydroxy functional compound are fed to the coupling step 2. This embodiment of the invention is shown in FIG. 8s. In this figure, the connections are supplied on separate lines 101 and 102. Obviously, these connections can be combined and served on one line. It is noted that in Fig. 8a, 8b and 8c, the method of the present invention is not fully shown.

Water is formed in the reaction step. If desired, water from the reaction step may be directed to a removal step, in particular when the removal step is a desorption step or an alkali treatment step, which is usually carried out in the presence of water.

In the addition step, the starting compound, including the -NH-CH2-CH2-NH- fragment or the -NH-CH2-CH2-OH or HO-CH2-CH2-OH fragment, is converted into a CO2 adduct with the indicated starting compound. If the addition step is an absorption step, this step consumes CO2 and produces water. Conversely, at the stage of desorption, the CO2 adduct with the amine is converted into an amine in the presence of water. This reaction consumes water and produces CO2. In one embodiment of the present invention, a CO2 containing stream is withdrawn from the desorption stage and sent to the absorption stage, and a water containing stream is withdrawn from the absorption stage and sent to the desorption stage. Water is also formed during the reaction step. Therefore, in one embodiment of the invention, a stream containing water is withdrawn from the reaction stage and fed to the desorption stage. In FIG. 9 shows these stages. In FIG. 9, line 10 denotes the stripping gas stream containing CO2, which is fed to the absorption stage 2. Line 62 is optional. It allows you to add CO2 to compensate for losses. Line 8 denotes a purge gas stream containing water (eg steam) withdrawn from the absorption stage 2 and fed to the desorption stage 7. Line 27 is optional and allows the addition of stripping gas to compensate for losses. Line 24 denotes the flow of water coming from reaction stage 5, which is fed at least partially to desorption stage 7 via line 26. Line 25 is a purge for the case where not all of the water is to be recycled.

If desired, the separation step may be carried out between the reaction step and the removal step and after the removal step. In one embodiment of the invention, the removal step is a desorption step. One embodiment of this capability is shown in FIG. ten.

As shown in FIG. 10, the separation step 17 is carried out after the reaction step and before the desorption step. In this separation step, the recycled compounds or their CO2 adducts, e.g. the starting materials or their CO2 adducts, are separated from the CO2 adduct with the polyethyleneamine compound and removed via line 18. They are fed at least partially to the absorption stage 2 or the 5 reactions (not shown). The CO2 adduct with the polyethyleneamine compound is fed via line 19 to the desorption stage 7. An additional separation step 14 is carried out after the desorption step 7. In this case, separation step 14 results in the separation of a product fraction, higher ethyleneamine compounds, which is withdrawn via line 15, and a fraction containing CO2 adducts with higher polyethyleneamine compound, which is withdrawn via line 20. This fraction can be subjected to the necessary processing, for example, as described above in the context of FIG. 7. Lighter compounds such as starting materials and intermediates, if present and desired, can be diverted via line 16 and recycled to addition step 2 or reaction step 5 (recycle not shown).

As noted above, the embodiments shown in the various figures may be combined unless they are mutually exclusive. Some preferred combinations are shown in the following figures.

In FIG. 11 shows a preferred embodiment of the present invention, which is a combination of the embodiments shown in FIG. 4, 5 and 7b.

As shown in FIG. 11, the starting compound, comprising the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, is fed via line 1 to absorption stage 2, where it is combined with CO2, fed through line 3, and carry out the reaction between them with the formation of an adduct with CO2. Line 62 is optional, it allows you to add CO2 to compensate for losses. The CO2 adduct is fed through line 4 to reaction stage 5, where it reacts with another reagent, while the reactants in the reaction stage are a hydroxyfunctional compound selected from the group of ethanolamines and dihydroxyethane, and an amino compound, while at least part of the total the amounts of hydroxy functional compounds and amino functional compounds are provided in the form of an adduct with CO2 coming from stage 2. In reaction stage 5, an adduct of CO2 with polyethyleneamine compound is formed, which is fed via line 6 to stage 7 of desorption. In the desorption stage 7, the stripping gas is fed through line 8, the stripping gas containing CO2 is withdrawn through line 10 and fed to the absorption stage 2. In absorption stage 2, CO2 is absorbed from the stripping gas containing CO2. Stripping gas, from which CO2 has been removed, is withdrawn from the absorption stage and fed through line 8 to the desorption stage 7. Through line 27, if necessary, additional stripping gas can be supplied.

The resulting polyethyleneamine compound is withdrawn via line 9 and fed to separation stage 14. The separation step 14 results in the separation of the feedstocks, which are withdrawn via line 16 and fed to the absorption step 2. They can also be fed to the reaction step (not shown in this figure). In the separation step 14, a product fraction is also formed - higher polyethyleneamine compounds, which is withdrawn via line 15, and a fraction containing CO 2 adducts with higher polyethyleneamine compounds. This last fraction is withdrawn from separation stage 14 via line 20 and recycled to the desorption stage.

In FIG. 12 shows another preferred embodiment of the present invention. In accordance with FIG. 12, the starting compound, comprising the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, is fed through line 1 to absorption stage 2, where it is combined with CO2, supplied through line 3, and carry out the reaction with the formation of an adduct with CO2. Line 62 is optional. It allows you to add CO2 to compensate for losses. The CO2 adduct is fed through line 4 to reaction stage 5, where it reacts with another reagent, while the reactants in the reaction stage are a hydroxyfunctional compound selected from the group of ethanolamines and dihydroxyethane, and an amino compound, while at least part of the total the quantities of hydroxy functional compounds and amino functional compounds are provided in the form of an adduct with CO2 coming from stage 2. In reaction stage 5, an adduct of CO2 with a polyethyleneamine compound is formed, which is fed via line 6 to separation stage 17. In this separation step, the starting materials or their adducts with CO2 are separated from the CO2 adduct with the polyethyleneamine compound and are fed via line 18, in this case, to absorption stage 2. They can also be directed to step 5 of the reaction. The CO2 adduct with the polyethyleneamine compound is fed via line 19 to the desorption stage 7. In the desorption stage 7, the stripping gas is fed through line 8, the stripping gas containing CO2 is withdrawn through line 10 and fed to the absorption stage 2. In absorption stage 2, CO2 is absorbed from the stripping gas containing CO2. Stripping gas, from which CO2 has been removed, is withdrawn from the absorption stage and fed through line 8 to the desorption stage 7. The polyethyleneamine compounds obtained are withdrawn via line 9 and sent to separation stage 14. In separation step 14, a product fraction of higher polyethyleneamine compounds is obtained, which is withdrawn via line 15, and a fraction containing CO2 adducts with polyethyleneamine compounds. This last fraction is withdrawn from separation stage 14 via line 20 and recycled to the desorption stage. Lighter compounds such as starting materials and intermediates, if formed and if desired, can be diverted via line 16 and recycled to the addition step 2 or reaction step 5 (recycle not shown). Through line 27, if necessary, additional stripping gas can be supplied.

The various steps are described in more detail below.

Starting compounds and reaction products

The invention is directed to a method for the production of ethyleneamine compounds selected from polyethyleneamine compounds and hydroxyethylethylene compounds. They are obtained by reaction between a hydroxy functional compound selected from the group of ethanolamines and dihydroxyethane and amino compounds.

Preferred amino compounds are ethylenediamine (EDA), n-methylethylenediamine (MeEDA), diethylenetriamine (DETA), piperazine (PIP), c-aminoethylpiperazine (AEP), triethylenetetramine (TETA), n,n'-diaminoethylpiperazine (DAEP), tetraethylenepentamine (TEPA) ) and pentaethylenehexamine (PEHA).

Preferred hydroxy functional compounds are ethanolamine (MEA), aminoethylethanolamine (AEEA), hydroxyethyldiethylenetriamine (HE-DETA), hydroxyethyltriethylenetetramine (HE-TETA) and diethanolamine.

Some structures of amino functional compounds and hydroxy functional compounds are given below.

Preferred examples of polyethyleneamine compound products are triethylenetetramine (TETA), n,n'-diaminoethylpiperazine (DAEP), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), n-[(2-aminoethyl)-2-aminoethyl]piperazine) (PEEDA) and 1-[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]piperazine) (PEDETA).

In one embodiment of the invention, aminoethylethanolamine (AEEA) and ethylenediamine (EDA) are reacted to form higher ethylenepolyamines, mainly triethylenetetramine (TETA) and tetraethylenepentamine (TEPA).

In another embodiment of the invention, a reaction is carried out between MEA (monoethanolamine) and DETA (diethylenetriamine) with the formation of higher ethylenepolyamines, mainly triethylenetetramine (TETA) and tetraethylenepentamine (TEPA).

Accession stage

As indicated above, the attachment step may be an absorption step or a CO2 transfer step, or a combination of these embodiments. Of course, the CO2 adduct as such can also be supplied from other sources. The absorption step and the CO2 transfer step are explained below.

absorption stage

In the absorption step of the process according to the invention, CO2 is absorbed by a reaction medium containing a starting compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety to form an adduct CO2 with the indicated parent compound. Thus, CO2 adducts with these compounds include compounds in which the -NH-CH2-CH2-NH- fragment is converted to a urea fragment, where two nitrogen atoms are connected by a carbonyl fragment and an ethylene fragment in accordance with the following structural formula:

CO2 adducts also include carbamates in which the -NH-CH2-CH2-OH fragment is converted to a carbamate fragment, where the oxygen atom and nitrogen atom of the -NH-CH2-CH2-OH fragment are connected by a carbonyl fragment and an ethylene fragment.

CO2 adducts also include compounds in which HO-CH2-CH2-OH is converted to an ethylene carbonic acid molecule, where two oxygen atoms of HO-CH2-CH2-OH are connected by a carbonyl moiety and an ethylene moiety.

As stated above, CO2 adducts are present in the form of adducts formed as a result of the reaction in one molecule. Of course, CO2 adducts can also be formed as a result of the reaction of reactive groups of different molecules. In the context of the present application, a CO2 adduct moiety in many embodiments of the invention is a moiety in which two nitrogen atoms or a nitrogen atom and an oxygen atom or two oxygen atoms are connected via a -C(O)- moiety. In addition, adducts with CO2 can also be formed with an amine or alcohol in the terminal one-sided group, i.e., they can be adducts connected to only one nitrogen or oxygen atom.

The absorption step is carried out by bringing CO2 into contact with the reaction medium containing the starting compound, including the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, with the formation of an adduct with CO2. The contacting step should be carried out under conditions that absorb CO2 and form a CO2 adduct.

The reaction conditions include the reaction temperature, which, in General, is at least 120°C. Below 120° C., the reaction rate is generally too low for significant conversion in a reasonable time. It may be preferable that the reaction temperature is at least 140°C, in particular at least 150°C, more specifically at least. 170°C. In general, the reaction is carried out at a temperature of at most 400°C. Thus, the temperature can be at most 300°C, in particular at most 250°C, or even at most 220°C. Preferred is a temperature in the range of 170-220°C.

The pressure during the reaction is determined, for the most part, by the supply of CO2 to the reaction medium, while the total pressure in the system decreases during the reaction due to the consumption of CO2. In general, the total pressure in the system is at most 75 bar abs. In general, the total pressure is at least 2 bar abs., in particular at least 5 bar abs., more specifically at least 10 bar abs.

The amount of CO2 supplied to the reaction stage is not critical. The minimum amount is determined by the amount needed to convert the starting amino compound into the corresponding adduct with CO2. Therefore, the molar ratio between CO2 and -NH-CH2-CH2-NH- moieties or -NH-CH2-CH2-OH or HO-CH2-CH2-OH moieties is generally at least 0.1:1. A ratio of at least 0.2:1, in particular at least 0.5:1 may be more adequate when more urea adduct is to be produced. A large excess of CO2 is not detrimental to the process, but is generally undesirable for economic reasons. Therefore, a value of 500:1 can be named as the overall maximum. The amount of CO2 supplied will depend on the amount of urea adduct required in the final product.

In one of the embodiments of the invention, the absorption step is carried out by carrying out a reaction between a compound selected from the group of initial amino functional compounds and hydroxy functional compounds, including at least one moiety -NH-CH2-CH2-NH- and at least two ethylene fragment, with CO2 in the presence of an auxiliary compound selected from ethylenediamine (EDA), monoethanolamine (MEA) and mixtures thereof, wherein the molar ratio of the auxiliary compound to the amino compound is at least 0.02:1. This process is described in the unpublished European patent application 17172487.5, the disclosure of which is incorporated herein by reference, the PCT and other applications claiming priority thereof, which are also incorporated by reference.

For the processes of this embodiment, it is preferred that the ethyleneamine compound be selected from diethylenetriamine (DETA), triethylenetetramine (L-TETA), aminoethylethanolamine (AEEA), and hydroxyethyldiethylenetriamine (HE-DETA). It is preferred that the molar ratio of auxiliary compound to amino compound is at least 0.05:1, in particular at least 0.1:1 and/or at most 10:1. It is preferred that the reaction be carried out at a temperature of at least 120°C, preferably at least 140°C, in particular at least 150°C, more in particular at least 170°C and /or at most 400°C, in particular at most 350°C, more specifically at most 300°C, more specifically at most 250°C or even at most 220°C, for example , at a temperature in the range of 170-250°C or 170-220°C. It is preferred that the molar ratio between CO2 and the -NH-CH2-CH2-NH-amino compound moieties is at least 0.5:1 and/or at most 500:1. It is preferred that the reaction time is at most 10 hours, in particular at most 6 hours, more specifically at most 3 hours and/or at least 5 minutes, in particular from 0.5 to 2 hours.

In one of the embodiments of the invention, the absorption stage is carried out as a two-stage process, while,

- in the absorption step, a liquid medium containing an ethyleneamine compound comprising a linear group -NH-CH2-CH2-NH- is brought into contact with a flow of CO2-containing gas at a pressure of at most 20 bar abs. with the formation of a liquid medium in which CO2 is absorbed,

- in this liquid medium, conditions are created for the formation of an adduct with CO2, and at the stage of formation of the adduct, an adduct of CO2 with an ethyleneamine compound is obtained, while the conditions for the formation of an adduct with CO2 include a temperature of at least 120 ° C, while the total pressure at the end the CO2 adduct stage is at most 20 bar abs., wherein the temperature in the absorption stage is lower than that in the CO2 adduct stage.

This process is described in the unpublished European patent application 17185947.3, the disclosure of which is incorporated herein by reference, the PCT and other applications claiming priority thereof, which are also incorporated by reference.

By separating the CO2 absorption step from the urea formation step in this embodiment, the CO2 absorption step can be carried out at relatively low temperature and pressure. And since CO2 is already present in the system at the beginning of the urea formation stage. In the absorption step, CO2 is absorbed into the liquid reaction medium. At the reaction stage, the absorbed CO2 reacts with the ethyleneamine compound to form an adduct, cyclic urea. This means that no additional supply of CO2 is required in the urea formation step, and that the absorption step is carried out until such an amount of CO2 is absorbed into the liquid medium, which is sufficient to achieve the desired conversion of the ethyleneamine compound to cyclic urea in the urea formation stage. As stated above, an additional supply of CO2 to the reaction medium in the urea formation stage (in addition to the CO2 supplied in the absorption stage) is not required and generally not advisable, since this will cause an increase in pressure in the urea formation stage. If necessary for any reason, at most 20% of the total amount of CO2 required to achieve the desired urea conversion is added in the urea formation step, in particular at most 10%. In one of the embodiments of this option, the flow containing CO2 gas includes at least 95% vol. CO2. In another embodiment of this option, the stream containing CO2 gas includes at most 70% vol. CO2, in particular, at most 60% vol. CO2 and more than 0.01% vol., in particular, from 4 to 60% vol. It may be preferable that the step of bringing the liquid medium into contact with the CO2-containing gas stream in the absorption step is carried out at a temperature of from 0°C to 200°C, in particular at a temperature of at most 190°C, more specifically at most , 150°C or at most 130°C, more specifically at most 110°C, preferably at a value of at least 20°C, in particular at least 40°C. It may be preferable that the maximum total pressure in the absorption step is from 1 to 15 bar abs., more specifically from 1 to 10 bar abs., even more specifically from 1 to 3 bar abs. It may be preferred that the temperature in the urea formation step is at least 140°C, in particular at least 150°C, in particular at least 170°C, preferably at most 400°C. , in particular at most 300°C, in particular at most 250°C, or even at most 220°C. The urea formation step is preferably carried out in a closed vessel. It may be preferable that the urea formation step is carried out in a tank where the volume of the liquid medium is up to at least 50% of the total volume of the tank (including headspace), in particular at least 70%, more specifically, at least 85%. It may be preferred that the pressure at the end of the cyclic urea formation step be less than 15 bar abs., in particular less than 10 bar abs., in some embodiments less than 5 bar abs. or even less than 3 bar abs.

CO2 transfer stage

In one embodiment of the invention, the attachment step includes a CO2 transfer step. At the stage of CO2 transfer, the carbonyl group is transferred from the source of CO to the initial compound, which includes the fragment -NH-CH2-CH2-NH- or the fragment -NH-CH2-CH2-OH or HO-CH2-CH2-OH, with the formation of the CO2 adduct with the initial a material comprising a moiety -NH-CH2-CH2-NH- or a moiety -NH-CH2-CH2-OH or HO-CH2-CH2-OH. Sources of CO are described above.

The reaction conditions include the reaction temperature, which, in General, is at least 100°C. Below 100° C., the reaction rate is generally too slow for significant conversion in a reasonable time. It may be preferable that the reaction temperature is at least 125°C, in particular at least 150°C, more specifically at least. 170°C. In general, the reaction is carried out at a temperature of at most 400°C. Thus, the temperature can be at most 300°C, in particular at most 250°C, or even at most 220°C. Preferred is a temperature in the range of 170-220°C.

In general, the total pressure in the system is at most 75 bar abs. In general, the total pressure is at least 2 bar abs., in particular at least 5 bar abs., more specifically at least 10 bar abs.

The amount of CO fragments supplied to the reaction stage is not critical. The minimum amount is determined by the amount needed to convert the starting amino compound into the corresponding adduct with CO2. Therefore, the molar ratio between CO moieties and, independently, -NH-CH2-CH2-NH- moieties, -NH-CH2-CH2-OH moieties, or HO-CH2-CH2-OH moieties, is generally at least 0, 1:1. A ratio of at least 0.2:1, in particular at least 0.5:1 may be more adequate when more urea adduct is to be produced. A large excess of CO fragments is not detrimental to the process, but is generally undesirable for economic reasons. Therefore, a value of 500:1 can be named as the overall maximum. The number of CO fragments will depend on the given amount of adduct - urea in the final product.

Reaction step

In the reaction step of the process according to the invention, a hydroxy-functional compound selected from the group of ethanolamines and dihydroxyethane is reacted with an amino-functional compound, whereby at least a part of the total amount of hydroxy-functional compounds and amino-functional compounds is provided in the form of an adduct with CO2, forming a CO2 adduct with a polyethyleneamine compound.

This process is preferably carried out at a temperature of at least 100°C. Preferably, the temperature should be less than 400°C. A more preferred temperature is from 200 to 360°C. Even more preferably, the temperature is from 230 to 340°C. Most preferably, the temperature is from 250 to 310°C. In those embodiments of the invention, where the ethanolamine compound is monoethanolamine, the most preferred temperature range is from 230 to 290°C.

The reaction time during this process in one of the embodiments is from 5 minutes to 15 hours, preferably from 0.5 to 10 hours, more preferably from 1 to 6 hours.

Those skilled in the art will recognize that too long a reaction time is undesirable, not only for reasons of process economics, but also because it can lead to the formation of undesirable high boiling by-products. In extreme cases, too long a reaction time can lead to undesirable decomposition and coloration.

, реакцию проводят, предпочтительно, в жидкости, при этом, жидкость содержит воду, так как в этом случае может быть увеличен и выход, и селективность. Если одно или более из гидроксифункционального соединения, аминосоединения или подводящего диоксид углерода соединения в условиях реакции являются жидкостью, они не рассматриваются как часть указанной жидкости, в которой осуществляют способ настоящего изобретения.If any of the parent compounds include piperazine units

, the reaction is carried out preferably in a liquid, the liquid containing water, since in this case both the yield and the selectivity can be increased. If one or more of the hydroxy functional compound, the amine compound, or the carbon dioxide supply compound is a liquid under the reaction conditions, they are not considered to be part of said liquid in which the method of the present invention is carried out.

In one of the preferred embodiments of the invention, when compounds with piperazine units are involved in the method of the present invention, the liquid contains at least 50% by weight. water and up to 100% wt. water, while, more preferably, the remaining 50 wt%. constitutes a polar liquid, homogeneously miscible with water under the conditions of the method of the present invention. More preferably, the liquid contains at least 75 wt%. water, even more preferably at least 90% wt., most preferably at least 95% wt. relative to the total weight of the liquid.

The reactor used may be any suitable reactor, including a continuously stirred reactor, a flow reactor, a tubular or multitube reactor. The reactor may be adiabatic or may be provided with external or internal heating devices. The raw material may be supplied at one point or at a plurality of points. It may consist of a plurality of stages with heat exchange between the stages.

Those skilled in the art will recognize that the devices used in the reaction step, as well as in other steps of the process according to the invention, must be specialized. That is, they must withstand prolonged exposure to reactants and products under reaction conditions, including, as described herein, significant temperatures and pressures. In addition to the fact that the reactor and other devices must withstand the reaction conditions, it is also important that they do not release material that could impair the quality of the product being produced. For example, since metal ions can lead to coloration of the product, the material of construction of the various devices must be chosen so that metal ions are not released to an unacceptable degree. Suitable materials include, but are not limited to, high quality steels such as austenitic stainless steels, super austenitic stainless steels, ferritic stainless steels, martensitic stainless steels, precipitation hardening martensitic stainless steels, and duplex stainless steels. The choice of proper construction materials is within the skill of the art.

The process may be carried out in one or more batch reactors, optionally in fed batch mode and/or in a continuously operating system in a single reactor or continuous flow reactor cascade, optionally with multiple feed points.

It has been found that by adding at least 0.6 mole equivalent of carbon dioxide supplying compound per mole of amine compound, the yield of ethyleneamines is significantly increased and also the amount of by-products is reduced.

Therefore, a molar ratio of CO2 and/or carbon dioxide supply compound to amino compound of at least 0.6 to 1 is preferred.

Preferably, the molar ratio of CO2 and/or carbon dioxide supply compound to amino compound is from 0.7 to 20 molar equivalents of carbon dioxide supply compound per mole of amino compound, more preferably from 0.7 to 6:1, even more preferably from 0. 8:1 to 3:1.

In another high yield embodiment, the molar ratio of hydroxy functional compound to amino compound is at least 0.7:1, the molar ratio of carbon dioxide supply compound to amino compound is at least 0.05:1. In such embodiments, the yield of ethyleneamines is also high.

Even more preferably, the molar ratio of hydroxy functional compound to amino compound is from 1:1 to 2:1, the molar ratio of carbon dioxide supply compound to amino compound is from 0.7:1 to 3:1.

In order to achieve high selectivity of ethyleneamine with respect to the starting materials, especially with respect to the hydroxy functional compound, the molar ratio of the hydroxy functional compound to the amino compound is from 0.05:1 to 0.7:1, the molar ratio of CO2 and/or carbon dioxide supplying compound to the amino compound is higher than the molar ratio of ratio of hydroxy functional compound to amino compound.

More preferably, the mole ratio of CO2 and/or carbon dioxide supply compound to amino compound is at least 10% higher than the mole ratio of hydroxy functional compound to amino compound. In another more preferred embodiment of the invention, the molar ratio of hydroxy functional compound to amino compound is from 0.1 to 0.5.

It should be noted that there are carbon dioxide supply compounds that include more than one carbonyl group, which can be separated from the molecule to transfer to a hydroxy compound, for example, DU-TETA. When determining the molar ratio of such compounds, one should take into account the molar amount of carbon monoxide that they can release to transfer to the hydroxy compound. Therefore, 1 mole of DU-TETA should be considered as 2 moles of a carbon dioxide supply compound.

The molar ratio between the compounds described above is determined by the reagents involved in the process, and does not depend on the dosing regimen of these reagents.

In some embodiments, it is advantageous to combine, at least in part, the reaction step with a separation and/or removal step by performing a reactive separation step, such as reactive distillation. In the reactive distillation step, the reaction step described above occurs under conditions chosen such that the CO2 adduct with the starting compounds reacts to form the CO2 adduct with polyethyleneamine, and in the same reactive separation step, the formed CO2 adduct with polyethyleneamine is either separated from the other components, or transfers the CO fragment to another component in the reactor, which may be either the remaining starting compounds or by-products. This stage is also referred to as the CO2 transfer stage. This process is described in the unpublished European patent application 17185943.2, the disclosure of which is incorporated herein by reference, the PCT and other applications claiming priority thereof, which are also incorporated by reference.

In one embodiment, the cyclic alkylene ureas are converted to the corresponding alkylene amines by reaction with an amino functional compound selected from the group of primary amines or secondary amines that have a higher boiling point than the alkylene amines formed in the process, wherein the process is a reactive separation, and the reaction mixture contains less than 10% wt. water relative to the total weight of the reaction mixture. It may be preferable to carry out the reaction at less than 7% wt. water relative to the entire reaction mixture. It may be preferred that the pressure be less than 25 bar abs., in particular less than 500 mbar abs. In general, the reaction proceeds at a temperature of at least 150°C.

Removal stage

As indicated above, the removal step may include a stripping step, a CO transfer step, a (strong) inorganic base treatment step, or a combination of several of these steps. These stages are explained below.

In the removal step, CO2 adducts with polyethyleneamine compounds are converted to CO2 and polyethyleneamine compounds. It is preferred that at least 10 mol%. CO2 adducts present in the system were converted into the corresponding polyethyleneamines. The maximum depends on the following desorption and recycling steps.

Desorption stage

In the desorption step, CO2 adducts with polyethyleneamine compounds are converted into polyethyleneamine compounds by reaction with water to remove CO2. The reaction takes place in the liquid phase.

The reaction with water, as a rule, takes place at a temperature of at least 150°C. If the reaction temperature is below 150°C, CO2 adducts with ethyleneamine compounds do not react to a significant extent. It is preferred that the reaction be carried out at a temperature of at least 180°C, in particular at least 200°C, more specifically at least 230°C or even at least 250°C. Preferably, the temperature in this step does not exceed 400°C, in particular at most 350°C, more specifically at most 320°C. Pressure is not critical to this process, provided that the reaction medium remains liquid. As a general range, values from 0.5 to 100 bar abs. depending on the set temperature. It is preferred that the CO2 removal step be carried out at a pressure of at least 5 bar, in particular at least 10 bar, in order to maintain a sufficient amount of amine and water in the medium. In view of the high costs associated with high pressure devices, it may be preferable that the pressure is at most 50 bar, in particular at most 40 bar.

The amount of water depends on the desired degree of conversion and on the process conditions. In general, the amount of water is at least 0.1 mol of water per mol of CO2 adduct in the feed. Large amounts are often used, for example at least 0.2 moles per mole of CO2 adduct, in particular at least 0.5 moles of water per mole of CO2 adduct. The maximum is not critical for the method according to the invention, however, too much water will require the use of unnecessarily large equipment. An amount of at most 500 moles of water per mole of cyclic ethylene adduct with CO2, in particular, at most 300 moles, more specifically, at most 200 moles, in some embodiments of the invention, at most, 100 moles or at most 50 moles.

Depending on the reaction temperature and the desired degree of conversion, the reaction time can vary over a wide range, for example at least one minute, in particular at least 5 minutes, more specifically from 15 minutes to 24 hours. In one of the embodiments of the invention, the reaction time may be at least 30 minutes or at least 1 hour. It may be preferred that the reaction time ranges from 1 hour to 12 hours, in particular from 1 hour to 6 hours. If low temperatures are used, a longer reaction time may be required to achieve a given conversion.

In one of the embodiments of the present invention, the desorption step is carried out by reacting CO2 adducts with ethyleneamine compounds in liquid phase with water in an amount of 0.1-20 moles of water per mole of CO2 adduct at a temperature of at least 230° C. to remove CO2 . It has been found that the use of a small amount of water, combined with a relatively high temperature and removal of CO2, provides an efficient process with a sufficient degree of conversion and the formation of a small amount of by-products. It has been found that in this embodiment of the process according to the invention it is possible to obtain a sufficient degree of conversion with a relatively limited amount of water, at most 20 moles of water per mole of CO2 adduct. It has been found that it is possible to carry out the process even with less water, for example at most 15 moles of water per mole of CO2 adduct, more specifically at most 10 moles of water per mole of CO2 adduct, or even at most 5 moles of water per mole of adduct with CO2.

The range of 0.1-20 moles of water per mole of adduct with CO2 refers to the total amount of water added during the process, based on the amount of urea fragments in the feed at the beginning of the reaction. To achieve complete conversion of 1 mole of the adduct with CO2, 1 mole of water is needed. Since complete conversion is not always necessary, it is possible to use less water. Therefore, water is used in an amount of at least 0.1 mol per mol of CO2 adduct. Often a larger amount is used, for example at least 0.2 moles per mole of CO2 adduct, in particular at least 0.5 moles per mole of CO2 adduct.

Water can be added at the beginning of the desorption step in one portion. However, it is preferable to add water during the process in several portions or continuously. In continuous operation, multiple feed points can be used. By achieving a match between the amount of water added and the amount of water consumed during the reaction, the excess of water in the reaction mixture can be limited. It has been found that the formation of by-products is thus reduced.

The molar ratio of water to urea fragments is calculated relative to the water present in the liquid reaction medium. If water is added in the form of vapor, which may be an advantageous embodiment of the invention, combining the addition of water with the supply of heat to the reaction mixture, most of the vaporous water will not be absorbed into the liquid reaction medium. It is within the skill of those skilled in the art to select the conditions for the process of adding water in the form of steam so that a predetermined amount of water is absorbed into the reaction medium. Water may also be present in the feedstock at the start of the reaction, for example, as a result of the process by which the feedstock is produced. Water can also be added in liquid form.

In one embodiment, the desorption step removes CO2. The removal of CO2 can be carried out when the conversion of alkylene urea to ethyleneamine compounds has already been completed. However, it is preferable to remove CO2 during the reaction. The removal of CO2 can be carried out in a manner known in the art. The easiest way to do this is to purge the reaction vessel. A stripping fluid, in particular a stripping gas, can be used to accelerate the removal of CO2. Other measures to enhance the removal of CO2 are obvious to those skilled in the art and include measures such as agitation of the reaction medium, sparging of stripping gas, thin film evaporation, use of packing or trays, and so on.

If stripping gas is used, its flow rate is usually at least 1 m ³ per 1 m ³ reactor volume per hour (at reaction temperature and pressure), at most 100 m ³ per 1 m ³ reactor volume per hour (at temperature and reaction pressure). This amount of stripping gas can be obtained by evaporating the liquid inside the reaction vessel, resulting in the formation of stripping gas in situ. The above ranges also apply to this embodiment. Of course, it is also possible to combine the addition of stripping gas with the formation of stripping gas in situ.

The CO2-containing stripping fluid withdrawn from the CO2 removal stage may contain, for example, from 1 to 99 mol%. CO2. In other embodiments of the invention, the stripping fluid may contain 1-80 mol%. CO2 or 1-60% mol. CO2. In some embodiments, the effluent from the CO2 removal step may contain 1-40 mol %. CO2 or 1-20% mol. CO2. A lower CO2 content results in a more efficient stripping, but also leads to the use of more stripping gas. It is within the competence of specialists to establish an appropriate balance between these parameters.

If desired, the desorption step may be carried out using water in the presence of an amine compound selected from the group of primary amines, cyclic secondary amines and bicyclic tertiary amines. This embodiment of the invention is a variant of the process described in previously unpublished PCT Application No. PCT/EP2017/052944, which is incorporated herein by reference also to indicate priority.

Primary amines are amino compounds in which the amino group has the formula R4-NH ₂ where R4 may be an organic group, preferably an aliphatic hydrocarbon with optional heteroatoms such as oxygen and/or nitrogen. Secondary cyclic amines are amines of the formula R5-NH-R6 where R5 and R6 together form a hydrocarbon ring, optionally with heteroatoms such as oxygen and/or nitrogen, preferably a piperazine ring. Tertiary bicyclic amines are amines of the formula R7-N(-R9)-R8, where R7 and R8 together form a hydrocarbon ring, optionally with heteroatoms such as oxygen and/or nitrogen, and R7 and R9 together form another hydrocarbon ring, optionally, with heteroatoms such as oxygen and/or nitrogen. All of these groups R4 - R9 may have substituents such as alkyl or hydroxyalkyl groups. Primary amines, cyclic secondary amines and bicyclic tertiary amines include a sterically relatively unhindered amino group. In the present context, a compound is defined as a primary amine or a secondary cyclic amine or a tertiary bicyclic amine if one of the amino groups in the compound is a primary amino group or a secondary cyclic amino group or a tertiary bicyclic amino group, regardless of whether the compound includes other amino groups that may be different in its nature. The compound may also include two or more different amino groups, for example, a primary amino group and a secondary cyclic amino group, or a primary amino group, a secondary cyclic amino group and a tertiary bicyclic amino group.

Preferred examples of primary amines are alkylamines, linear ethyleneamines and alkanolamines. Preferred examples of cyclic secondary amines are amines containing a terminal piperazine ring. Preferred examples of bicyclic tertiary amines are 1,4-diazobicyclo[2.2.2]octane (DABCO), 1,4-diazobicyclo[2.2.2]octan-2-yl)methanol and 1-azobicyclo[2.2.2]octane (quinucedine ).

The amine compound is preferably a compound having more than one amino group, wherein at least one of the amino groups is a primary amine, more preferably an amine in which two amino groups are a primary amine.

Preferred amino compounds are ethylenediamine (EDA), n-methylethylenediamine (MeEDA), diethylenetriamine (DETA), ethanolamine (MEA), aminoethylethanolamine (AEEA), piperazine (PIP), n-aminoethylpiperazine (AEP), 1,4-diazobicyclo[2.2. 2]octane (DABCO), 1,4-diazobicyclo[2.2.2]octan-2-yl)methanol, triethylenetetramine (TETA), n-diethyldiamine-2-imidazolidinone (U1TETA), n,n'-diaminoethylpiperazine (DAEP) , n, n'-diaminoethyl-2-imidazolidinone (U2TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and monocyclic ureas with TEPA and PEHA (i.e., U1TEPA, U2TEPA, U1PEHA, U2PEHA, U3PEHA) and bicyclic ureas isomers of PEHA (i.e., DUPEHA), polyethyleneimine (PEI) or alkyleneimine on a solid support.

The amino compound is preferably present in a molar amount of 0.001 to 100 equivalents per mole of CO2 adduct, more preferably 0.01 to 50 equivalents, even more preferably 0.05 to 30 equivalents, even more preferably 0.15 up to 25 equivalents, most preferably 0.20 to 20 equivalents.

In the desorption step, CO2 adducts with ethyleneamine compounds are converted into CO2 and ethyleneamine compounds. It is preferred that at least 10 mol%. CO2 adducts in the system were converted into the corresponding ethyleneamines. The maximum will depend on the subsequent desorption and recycling steps.

Treatment with a (strong) inorganic base

In one embodiment of the invention, the removal step is carried out using a (strong) inorganic base. In the context of the present invention, a strong inorganic base is one that does not contain carbon-carbon bonds and has a pKb of less than 1.

In one embodiment, the strong inorganic base is selected from the group of metal hydroxides, in particular from the group of alkali and alkaline earth metal hydroxides, in particular sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide and barium hydroxide. In one embodiment of the invention, the strong inorganic base is selected from the group of metal oxides, in particular from the group of alkali and alkaline earth metal oxides, in particular from calcium oxide, magnesium oxide and barium oxide. The choice of a strong inorganic base from the group of sodium hydroxide, potassium hydroxide, magnesium hydroxide (oxide) and calcium hydroxide (oxide) may be preferred. The use of sodium hydroxide and potassium hydroxide may be considered particularly preferred. Other strong inorganic bases such as ammonium hydroxide can also be used. As will be appreciated by those skilled in the art, mixtures of various inorganic bases may be used. Can also be used compounds that include a base in addition to other components, as well as compounds that can be converted to inorganic bases in the reaction medium.

The lower limit of the molar ratio of the inorganic base to the adduct with CO2 is not critical. A value of at least 0.2:1 may be mentioned. If complete conversion of the CO2 adduct to the corresponding ethyleneamine compound is to be achieved, it may be preferable to use a larger amount, for example in a molar ratio of at least 0.5:1, in particular at least 1:1. It may be preferable to use a larger amount to increase the reaction rate, for example a molar ratio of inorganic base to CO2 adduct of at least 1.5:1, in particular at least 2:1.

Even more base does not contribute to greater conversion, but is associated with additional costs, therefore it is preferable that the molar ratio of inorganic base to the molar amount of adduct with CO 2 in the product fed to the treatment with inorganic base is at most 20:1, in particular , at most, 15:1, more specifically, at most, 10:1. It has been found that even a smaller amount of inorganic base may be sufficient, contrary to the teachings of the prior art. More specifically, it has been found that good results can be obtained with a molar ratio of inorganic base to CO2 adduct of at most 7.5:1, in particular at most 6.5:1, more particularly at most 5 .5:1. It has been found that using a molar ratio of at most 5.5:1 results in complete conversion of the CO2 adduct and high yields of the resulting ethyleneamine compounds. It may be preferable to use even less inorganic base per mole of CO2 adduct, eg in a molar ratio of at most 5:1, in particular at most 4:1, more particularly at most 3:1. The molar ratio is calculated relative to the molar amount of the adduct with CO2 in the feedstock fed to the alkali treatment stage.

Treatment with an inorganic base can be carried out, for example, by bringing the material to be treated into contact with a concentrated aqueous solution of an inorganic base. Depending on the nature of the base and the further composition of the reaction medium, it may also be possible to add the base in solid form and dissolve it in the reaction medium. As will be appreciated by those skilled in the art, the goal is to bring the base into solution so that the hydroxyl groups can react with the CO2 adduct without over diluting the reaction medium.

The reaction can be carried out at a temperature ranging from room temperature to 400°C. The temperature and pressure should be chosen so that the reaction mixture is present in the liquid phase. Higher temperatures are advantageous because they lead to a reduction in the reaction time. It may be preferable to carry out the reaction at a temperature of at least 100°C, in particular at least 140°C, in particular at least 170°C. On the other hand, higher temperatures may cause undesirable formation of by-products. Therefore, it may be preferable to carry out the reaction at a temperature of at most 350°C, in particular at most 280°C.

Depending on the reaction temperature, the reaction time can vary over a wide range, for example from 15 minutes to 24 hours. It may be preferred that the reaction time is from 1 hour to 12 hours, in particular from 1 hour to 6 hours. If less base is used, a longer reaction time may be required to achieve a given conversion.

Upon completion of the reaction, a reaction mixture containing ethyleneamine compounds and a carbonate salt of an inorganic base will be obtained. The salt can be removed by methods known in the art, for example by filtration when the salt is present in solid form.

The process according to the invention can be carried out in a batch mode, in a batch mode with water or in a continuous mode, for example, in a cascade of continuous flow reactors. Depending on the scale of production, continuous operation may be preferred.

Combination of removal steps

A particular combination of removal steps includes a stripping step followed by treatment with a strong inorganic base, optionally after a separation step that separates the desired compounds. Reference is made to the unpublished European patent application 17185950.7, the disclosure of which is incorporated herein by reference, and the PCT and other applications claiming priority thereof, which are also incorporated by reference.

In one embodiment, the combination comprises the conversion of cyclic alkylene ureas to the corresponding alkylene amines by a process comprising:

- at the first stage, the conversion of the cyclic alkylene urea to the corresponding alkylene amines by carrying out the reaction of the cyclic alkylene urea in the liquid phase with water with the removal of CO2 at a conversion of 5% mol. up to 95% mol. alkylene urea raw materials into the corresponding amines and

- in the second stage, adding an inorganic base and carrying out the reaction of the cyclic alkylene urea remaining after the first stage with an inorganic base with its complete or partial conversion to the corresponding alkyleneamines.

Another particular combination of removal steps includes a combination of one or more desorption steps with one or more reactive separation steps. The reactive separation encompasses the transfer of CO2, wherein the carbonyl group of the CO2 adduct with the polyethyleneamine compound is transferred to a compound comprising a -NH-CH2-CH2-NH- moiety or a -NH-CH2-CH2-OH or HO-CH2-CH2-OH moiety. Reference is made to the previously unpublished European Patent Application 17185945.7, the disclosure of which is incorporated herein by reference.

In one embodiment, the combination encompasses the conversion of a cyclic alkylene urea containing feedstock to the corresponding alkylene amines by a process comprising:

- a desorption step in which the cyclic alkylene urea is converted to the corresponding alkylene amines by reacting the cyclic alkylene urea with water in the liquid phase to remove CO2,

a reactive separation step in which the cyclic alkylene urea is converted to the corresponding alkylene amines by reaction with an amino functional compound selected from the group of primary amines or secondary amines with a higher boiling point than the alkylene amines formed in the process.

The reactive separation step may preferably be carried out as a reactive distillation step. This embodiment is also described above in the context of the reaction step. In one embodiment, the desorption step precedes the reactive separation step. In another embodiment of the invention, the reactive separation step precedes the desorption step. It is also possible to carry out at least two desorption stages with one or more reactive separation stages between them, or at least two reactive separation stages with one or more desorption stages between them.

The reactive separation step may be carried out at any appropriate pressure. During the reaction, the pressure in the reaction separation system is preferably at most 127 bar abs., more preferably at most 50 bar abs., even more preferably at most 25 bar abs. Depending on the composition of the reaction medium, lower pressures may be applied, for example less than 15 bar or less than 5 bar. The process can also be carried out at subatmospheric pressure, for example less than 700 mbar abs., more preferably less than 100 mbar abs., even more preferably less than 25 mbar abs., most preferably less than 5 mbar abs. In general, the pressure is at least 0.1 mbar abs.

The reactive separation step is preferably carried out at a temperature of at least 150°C, in particular at least 180°C, in some embodiments at least 200°C or at least 230°C , sometimes at least 250°C. Preferably, during the process the temperature does not exceed 400°C, more preferably 350°C. In one embodiment of the invention, the reactive separation step of the amine removal step is carried out at a temperature in the range of 180-300° C. and a pressure of at most 2000 mbar abs., in particular at most 1000 mbar abs., more specifically, at most 500 mbar abs., more specifically at most 200 mbar abs. It may be preferable to carry out the reactive separation step at a temperature of 200-260° C. and a pressure of at most 50 mbar abs. In general, the reactive separation step is carried out for 1 minute to 12 hours. Preferably, the reaction separation step lasts less than 10 hours, more preferably less than 8 hours, most preferably less than 5 hours.

Separation stage

Separation steps can be carried out at various points in the process according to the invention. They can be carried out by methods known in the art, as will be appreciated by those skilled in the art.

For example, as noted above, the product of the reaction step may be subjected to a separation step to separate the starting compounds from the (CO2 adducts with the product) resulting polyethyleneamine compound. The separation step can be carried out, for example, by distillation, since the starting compounds have a lower boiling point than the resulting polyethyleneamine compounds or their adducts with CO2.

The desorption step is accompanied by the formation of CO2, which is removed from the reaction mixture after or during the desorption step. So this is also a separation stage. Those skilled in the art will appreciate how this step can be carried out. Reference is also made to what is described above.

At various points in the process according to the invention, additional separation steps may be carried out in which the resulting polyethyleneamine compounds are separated from the starting compounds, intermediates and/or CO2 adducts with polyethyleneamine compounds. Likewise, this process can be appropriately carried out by distillation. Other suitable methods will be apparent to those skilled in the art.

Those skilled in the art will appreciate that in a multi-step process according to the invention, it is possible to combine products from multiple runs of the same step and then process the combined product in other steps. If desired, product from other processes may be added. Conversely, it is also possible to separate product fractions from one stage and feed them to different plants.

Claims (47)

1. An integrated method for the production of polyethyleneamine compounds selected from the group of polyethyleneamines and hydroxyethylethyleneamines, which includes stages in which: at the stage of accession, an adduct of CO ₂ is provided with the initial compound, including a fragment -NH-CH ₂ -CH ₂ -NH- or a fragment -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, at the reaction stage, a hydroxy functional compound selected from the group of ethanolamines and dihydroxyethane is reacted with an amino functional compound, while at least a part of the total amount of hydroxy functional compounds and amino functional compounds is provided in the form of an adduct with CO ₂ , with the formation of an adduct of CO ₂ with a polyethyleneamine compound , the removal step converts the CO ₂ adduct with the polyethyleneamine compound to the corresponding resulting polyethyleneamine compound, at the same time, a fraction containing a recycled compound, including a fragment -NH-CH ₂ -CH ₂ -NH- or a fragment -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, or its adduct with CO ₂ is fed at the end of the reaction step or the removal step to the addition step or the reaction step, at the same time, the recycled compound, per molecule, contains on average a lower total number of -NH-CH ₂ -CH ₂ -NH- fragments and -NH-CH ₂ -CH ₂ -OH fragments than the resulting polyethyleneamine compound. 2. The method according to p. 1, in which the stage of accession includes the stage of absorption, which is the reaction of gaseous CO ₂ with the original connection, including a fragment -NH-CH ₂ -CH ₂ -NH- or a fragment -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, with the formation of the corresponding adduct with CO ₂ . 3. The method according to claim 1 or 2, in which the addition step includes the step of reacting a starting compound comprising a -NH-CH ₂ -CH ₂ -NH- moiety or a -NH-CH ₂ -CH ₂ -OH or HO-CH moiety ₂ -CH ₂ -OH, with a carbon dioxide supply compound capable of transferring a carbonyl group to the parent compounds, with the formation of their adduct with CO ₂ . 4. The method according to any one of the preceding claims, wherein the removal step comprises a stripping step in which the CO ₂ adduct with the polyethyleneamine compound reacts with water to form CO ₂ and the corresponding resulting polyethyleneamine compound. 5. The method according to any one of the preceding claims, wherein the removal step comprises an alkali treatment step in which the CO ₂ adduct with the polyethyleneamine compound is reacted with an inorganic base to form the resultant polyethyleneamine compound and a carbonate salt. 6. The method according to any one of the preceding claims, wherein the removal step comprises a CO ₂ transfer step in which a carbonyl group is transferred from a CO ₂ adduct with a polyethyleneamine compound to a compound comprising a -NH-CH ₂ -CH ₂ -NH- moiety or a - NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH. 7. A method according to any one of the preceding claims, wherein the addition step includes an absorption step and the removal step includes a stripping step, wherein the CO ₂ formed in the stripping step is fed at least partially to the absorption step. 8. A method according to any one of the preceding claims, wherein the addition step includes an absorption step and the removal step includes a stripping step, wherein the stripping gas from the stripping step is subjected to a CO ₂ removal step and recycled at least partially , to the desorption stage. 9. The method according to claim 8, in which the stripping gas containing CO ₂ is withdrawn from the desorption stage and fed to the absorption stage, where CO ₂ is absorbed from the stripping gas containing CO ₂ and the stripping gas from which CO ₂ is removed is removed from absorption stage and fed to the desorption stage. 10. The method according to any of the preceding claims, wherein the separation step is carried out after the removal step, wherein the separation step produces a fraction containing a recycled compound comprising a -NH-CH ₂ -CH ₂ -NH- moiety or a -NH-CH moiety ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, or CO ₂ adduct with it, which is fully or partially fed to the addition stage or reaction stage, while the recycled compound, per molecule, contains on average less the total number of -NH-CH ₂ -CH ₂ -NH- fragments and -NH-CH ₂ -CH ₂ -OH fragments than the resulting polyethyleneamine compound, the recycled compound includes starting compounds and optionally intermediate compounds, a fraction is additionally obtained in the separation step the resulting polyethyleneamine compounds. 11. The method according to any one of the preceding claims, wherein the separation step is carried out after the reaction step and before the removal step, wherein the separation step produces a fraction containing a recycled compound comprising a moiety -NH-CH ₂ -CH ₂ -NH- or a moiety -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, or an adduct of CO ₂ with it, which is completely or partially fed to the addition stage or the reaction stage, while at the separation stage a fraction is additionally obtained, containing an adduct of CO ₂ with a polyethyleneamine compound, which is fed to the removal stage. 12. A method according to any one of the preceding claims, wherein the removal step comprises a first removal step and one or more additional removal steps, wherein the removal steps are independently selected from the group consisting of: a desorption step in which the CO ₂ adduct with the polyethyleneamine compound is reacted with water to form CO ₂ and the corresponding resulting polyethyleneamine compound, an alkaline treatment step in which a CO ₂ adduct with a polyethyleneamine compound and an inorganic base are reacted to form the resultant polyethyleneamine compound and a carbonate salt, and a CO ₂ transfer step in which a carbonyl group is transferred from a CO ₂ adduct with a polyethyleneamine compound to a compound containing a -NH-CH ₂ -CH ₂ -NH- moiety or a -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ moiety -CH ₂ -OH, at the same time, at the first stage of removal, a part of the CO ₂ adduct with a polyethyleneamine compound present in the stream entering this stage is converted into polyethyleneamine compounds, while a part of the CO ₂ adduct with a polyethyleneamine compound present in the stream entering the first stage of removal is not converted into during the first removal stage and enters the additional removal stage. 13. The method of claim 12, wherein the first removal step is a desorption step or a CO ₂ transfer step and the additional removal step is a stripping step or an alkali treatment step, which steps are different from each other. 14. Process according to any one of the preceding claims, wherein a product containing polyethyleneamine compounds and CO ₂ adducts with polyethyleneamine compounds is obtained at the removal stage, and this product is fed to a separation stage, where a fraction containing CO ₂ adducts with polyethyleneamine compounds is separated from the polyethyleneamine compounds , and subject it to processing in one or more of the following ways: subjected, at least in part, to purification and processing in additional separation steps, are recycled, at least in part, to the removal stage, fed at least in part to an additional removal stage, which is carried out under more stringent conditions than the first removal stage, and which includes, in particular, treatment with an inorganic base, is fed at least partially to the reaction step. 15. The method according to any one of the preceding claims, wherein the starting materials are supplied to the reaction step in one of the following ways: the amino-functional compound is fully or partially fed to the addition step, where it is converted into an adduct with CO ₂ , which is then fed to the reaction step, while the hydroxy-functional compound is fed to the reaction step, the hydroxy-functional compound is fed wholly or partly to the addition step, where it is converted into an adduct with CO ₂ , which is then fed to the reaction step, while the amino-functional compound is fed to the reaction step, both the hydroxy functional compound and the amino functional compound are fed to the addition step, where they are fully or partially converted to CO ₂ adducts, which are then fed to the reaction step. 16. A method according to any one of the preceding claims, wherein the addition step includes an absorption step, the removal step includes a desorption step, and wherein the CO ₂ containing stream is removed from the stripping stage and fed to the absorption stage, and the water containing stream is removed from absorption stage and fed to the desorption stage. 17. A process according to any one of the preceding claims, wherein the water-containing stream is withdrawn from the reaction stage and fed to the removal stage. 18. The method according to any one of the preceding claims, wherein the separation step is carried out after the reaction step and before the removal step, and an additional separation step is carried out after the removal step. 19. The method according to any one of the preceding paragraphs, including the stages at which: the starting compound, including the fragment -NH-CH ₂ -CH ₂ -NH- or the fragment -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, is fed to the absorption stage, where it is combined with CO ₂ and carry out the reaction with the formation of CO ₂ adduct, the CO ₂ adduct is fed to the reaction stage, where it reacts with another reagent, while the reagents at the reaction stage are a hydroxy functional compound selected from the group of ethanolamines and dihydroxy ethane, and an amino compound, while at least a part of the total number of hydroxy functional compounds and amino functional compounds are provided in the form of an adduct with CO ₂ , with the formation of a product containing an adduct of CO ₂ with a polyethyleneamine compound, the product containing the adduct of CO ₂ with the polyethyleneamine compound is fed to the desorption stage, where it comes into contact with the stripping gas, and the stripping gas containing CO ₂ is removed from the desorption stage and fed to the absorption stage, stripping gas, from which CO ₂ is absorbed, is withdrawn from the absorption stage and fed to the desorption stage, the product of the desorption stage is fed to the separation stage, where a fraction of the starting material is obtained, which is fed to the absorption stage or the reaction stage, a fraction of the resulting polyethyleneamine compounds, which is removed from the separation stage, and a fraction containing CO ₂ adducts with polyethyleneamine compounds, which is fed to the desorption stage or reaction step. 20. A method according to any one of the preceding claims, comprising the steps of: the starting compound, including the fragment -NH-CH ₂ -CH ₂ -NH- or the fragment -NH-CH ₂ -CH ₂ -OH or HO-CH ₂ -CH ₂ -OH, is fed to the absorption stage, where it is combined with CO ₂ and carry out the reaction with the formation of an adduct with CO ₂ , the CO ₂ adduct is fed to the reaction stage, where it reacts with another reagent, while the reagents at the reaction stage are a hydroxy functional compound selected from the group of ethanolamines and dihydroxy ethane, and an amino compound, while at least a part of the total number of hydroxy functional compounds and amino functional compounds are provided in the form of an adduct with CO ₂ , with the formation of a product containing an adduct of CO ₂ with a polyethyleneamine compound, the product containing the CO ₂ adduct with the polyethyleneamine compound is fed to the separation stage, in which a fraction of the starting material is obtained, which is fed to the absorption stage or the reaction stage, while the rest is fed to the desorption stage, in the desorption stage, the residue of the separation stage is brought into contact with the stripping gas, and the stripping gas containing CO ₂ is withdrawn from the desorption stage and fed to the absorption stage, stripping gas, from which CO ₂ is absorbed, is withdrawn from the absorption stage and fed to the desorption stage, the product of the desorption stage is fed to an additional separation stage, where a fraction of the resulting polyethyleneamine compounds is obtained, which is withdrawn from the separation stage, and a fraction containing CO ₂ adducts with polyethyleneamine compounds, which is fed to the desorption stage or the reaction stage.

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