Mutual citations and related applications
[2]
This application claims the benefit of priority based on the date of Korea Patent Application No. 10-2017-0114623 07 years 09 January 2017, and all information disclosed in the literature of the Korea patent application are included as part of the specification.
[3]
[4]
Art
[5]
The present invention is one in the esterification reaction using a gas-liquid separation system according to the manufacturing method of the ester compositions containing them and method of removing the alcohol.
[6]
BACKGROUND
[7]
Phthalate plasticizer accounts for 92% of global plasticizer market (Mustafizur Rahman and Christopher S.Brazel "The plasticizer market: an assessment of traditional plasticizers and research trends to meet new challenges" Progress in Polymer Science 2004, 29, 1223-1248 reference), mainly poly is given to the vinyl chloride (hereinafter, such as PVC & quot;) in flexibility, durability, cold resistance, and introduced into a variety of content in an additive, PVC is used in order to improve the lowering workability viscosity upon melting, such as a solid pipe grow well, yet soft and hard products, from food packaging and blood bags, have a close relationship with the real world than any other material from the flexible product that can be used such as flooring have had direct contact with the human body as the inevitable widely used applications.
[8]
However phthalate PVC and compatibility and excellent plasticizer Despite the soft grant, and during recent phthalate plasticizer is used real-life of the contained PVC product is gradually seeps out products of endocrine disorders (environmental hormones) estimating materials and heavy metal levels there are hazards controversy that may act as a carcinogen is raised (NR Janjua et al. "Systemic Uptake of Diethyl Phthalate, Dibutyl Phthalate, and Butyl Paraben Following Whole-body Topical Application and Reproductive and Thyroid Hormone Levels in Humans" Environmental Science and Technology 2008, page 42, 7522-7527). In particular, for environmental hormones since the introduction of the report that the phthalate-based plasticizers of the amount is the number of di-ethylhexyl phthalate (di- (2-ethylhexyl) phthalate, DEHP) is discharged to the outside of PVC in the United States in the 1960s, 1990s deohaejyeo interest in the study of the human body, including various hazards of phthalate plasticizers were starting to global environmental regulations are made.
[9]
In many researchers phthalate and to cope with environmental hormone problem, and environmental regulations due to plasticizer outlet, developing a phthalate-based plasticizer prepared when using the anhydride is a new non-phthalate alternative plasticizers excluded that or suppress the outflow of the phthalate-based plasticizer body to develop a spill suppression technology that can meet even significantly reduce the risks as well as environmental standards has proceeded out the research.
[10]
On the other hand, the non-phthalate as plasticizers, terephthalate-based plasticizers include phthalate as well as the same level in of plasticizer properties side, and the spotlight as a free substance from the environmental problems, a variety of terephthalate-based plasticizer, a situation which is being developed the physical properties are excellent terephthalate-based research to develop a plasticizer, as well as also has been actively carried out research on the plant for the production of such terephthalate-based plasticizer, more efficient and economical in terms of process design design of a simple process that is required.
[11]
[12]
Prior Art Document
[13]
Patent Documents
[14]
Patent Document 1: Republic of Korea Patent No. 10-1354141 No.
[15]
[16]
Non-Patent Document
[17]
(비특허문헌 1) Mustafizur Rahman and Christopher S. Brazel "The plasticizer market: an assessment of traditional plasticizers and research trends to meet new challenges" Progress in Polymer Science 2004, 29, 1223-1248
[18]
(비특허문헌 2) N. R. Janjua et al. "Systemic Uptake of Diethyl Phthalate, Dibutyl Phthalate, and Butyl Paraben Following Whole-body Topical Application and Reproductive and Thyroid Hormone Levels in Humans" Environmental Science and Technology 2008, 42, 7522-7527
[19]
Detailed Description of the Invention
SUMMARY
[20]
The present invention provides a monovalent way removal of the alcohol in a removal method which can effectively remove the unreacted alcohol in the reactor, provided that the time the esterification process to remove the unreacted alcohol in the esterification reactor with a high efficiency in the it would.
[21]
Problem solving means
[22]
In accordance with one embodiment of the present invention for solving the above problems, the present invention is reacted with a liquid compartment and a gas phase compartment space, vapor outlet line and the reaction chamber associated with the gas phase compartment in the position at the upper end of said reaction space, the reactor It is located at the side portion in the esterification reactor containing a liquid outlet line connected to the reactor in the liquid phase section of the carboxyl group, which ester group and a carbonyl nilgye compound and a monovalent alcohol having at least one functional group selected from the group consisting anhydride reaction step; Including; and a liquid stream, the first containing the alcohol from the gaseous stream and the liquid phase outlet line to the one containing the alcohol from the vapor outlet line is gas-liquid separated in the gas-liquid separation column step in which the monovalent alcohol is removed and flowing the liquid stream to the vapor-liquid separating column 1 in the esterification reaction will be started from the moment of total a 10% to 70% of the time required for the gas-liquid separation is provided a method of removing the alcohol.
[23]
[24]
In accordance with one embodiment of the present invention for solving the above problems, the present invention is the esterification 1 in the reaction is included in the method for removing the alcohol, the esterification reaction described above is a direct esterification reaction, wherein the first after the step that the alcohol is removed, by adding an alcohol for trans reaction in the esterification reactor performing a trans-esterification reaction; and further comprising a said carbonyl nilgye compound group is a carboxyl group, an ester group or an acid anhydride 2 this manufacturing method is provided of more than one of ester-linked composition.
[25]
Effects of the Invention
[26]
According to the invention, provided that the time can remove the unreacted alcohol from the esterification reactor to a desired level in, so that when applied to the removal direct esterification reaction according to the invention, directly after the esterification reaction the same reactor even if performing the trans-esterification reaction it is possible to ensure good conversion rates, it is possible to directly integrate the result esterification reaction step, and the trans esterification reaction step, it is possible to obtain due to the process equipment, such as to reduce economic efficiency.
[27]
Brief Description of the Drawings
[28]
1 is a process flow diagram showing an example of a step of the first one is removed, the alcohol according to the method of removing the alcohol in the esterification reaction of the present invention.
[29]
Mode for the Invention
[30]
Hereinafter, the present invention will be described in more detail to aid the understanding of the present invention.
[31]
The terms or words used in the description and claims of the present invention is general and not be construed as limited to the dictionary meanings are not, the inventor accordingly the concept of a term to describe his own invention in the best way on the basis of the principle that can be defined, which must be interpreted based on the meanings and concepts corresponding to technical aspects of the present invention.
[32]
[33]
According to the invention, it is located at the upper end of the liquid compartment and a reaction chamber having a vapor compartment and the reaction space is located at the side of the rising section and the connected vapor outlet line and the reaction chamber in the reactor liquid outlet line connected to the reactor in the liquid compartment the method comprising the carbonyl compound and nilgye monovalent alcohol having from esterification reactor, a carboxyl group, an ester group and at least one functional group selected from the group consisting of a reaction containing an acid anhydride; Including; and a liquid stream, the first containing the alcohol from the gaseous stream and the liquid phase outlet line to the one containing the alcohol from the vapor outlet line is gas-liquid separated in the gas-liquid separation column step in which the monovalent alcohol is removed and flowing the liquid stream to the vapor-liquid separating column 1 in the esterification reaction will be started from the moment of total a 10% to 70% of the time required for the gas-liquid separation is provided a method of removing the alcohol.
[34]
Esterification reactor containing the reaction space, vapor outlet line and a product line which is the one that the gas-liquid separation system used in the method of removing the alcohol, the reaction is carried out; And gas-liquid separation space and the lower return line and the gas-liquid separator having a top outlet line column; wherein a, may comprise a liquid outlet line connected to the side surface of the gas-liquid separation column from the liquid compartment of the esterification reactor.
[35]
Specifically, the esterification reactor, ester reaction is carried out is located at the upper end of the reaction chamber and the reaction chamber having a liquid compartment and a gas phase compartment located at the lower end of the vapor outlet line to the gas phase compartment in the reactor, the reaction space is may include a product line to the reactor in the liquid compartment.
[36]
The vapor-liquid separating column esterification the vapor stream containing the low boiling point mixture in the reaction product and the vapor evaporated from the reactor flows through the vapor outlet line of the reactor, the gas-liquid separation space, which gas-liquid separation is performed, the liquid reaction product to esterification reactor It is a low boiling point mixture in a lower return line and the gas phase is recovered by removal may be provided with an upper outlet line flowing.
[37]
In addition, the liquid phase outlet line above esterification is located at the side of the reactor is connected to the liquid compartment to be a liquid phase in the reactor outlet stream 1/2 of the column height direction so as to be supplied to the gas-liquid side separation column It can be connected.
[38]
On the other hand, in the case of esterification process, in particular, in the process for preparing an esterification composition with trans-esterification reaction of the ester compound, it is generally performed in the direct esterification reaction step and esterification reaction step, trans separation. In order to direct the esterification reaction step and the trans esterification reaction step is combined into one step to be the integration of the reactor preceding.
[39]
However, when the direct esterification reaction and trans-esterification reaction is carried out in a single reactor, using the product of ester compounds of the reaction after the direct esterification reaction it has been performed there is a trans-esterification reaction proceeds, the direct esterification When the low boiling point mixture containing the unreacted alcohol from the reaction allows a predetermined amount or more remains, trans-esterification is the forward problem does not proceed smoothly in the reaction, and problems that can become the conversion rate of the trans-esterification reaction significantly inferior accordingly a.
[40]
Accordingly, the reaction will be to integrate the first unreacted after direct esterification reaction it is essential to remove low boiling point mixture containing the alcohol in a certain amount or less.
[41]
In this regard, by sending a conventional esterification process, the esterification vapor phase material of the gas-liquid separating column in the reactor 1 of the unreacted through the reduced pressure to remove the low boiling point mixture containing the alcohol perform the gas-liquid separating unreacted 1 It is to remove the low boiling point mixture such as alcohol. However, the gas-liquid separation through the same pressure may mothayeo poor efficiency due to the narrowness of the mass transfer area will not reduce the unreacted alcohol content in the desired level of the reactor, even if it possible to reduce the speed is too slow, then the whole procedure, there is a problem in that delay.
[42]
However, if there is a 1 in accordance with the present invention applied to a method for removing the alcohol, the liquid outlet lines is provided, whereby separating the inside in addition to the stream flowing into the gas-liquid separating column as a vapor stream through a pressure-reactor, the liquid self-liquid in the esterification reactor column because they enter with the liquid stream to the liquid phase outlet line, to maximize the efficiency of gas-liquid separation can be the unreacted 1 significantly reduced the rate at which alcohol is removed, accordingly, and is within the remaining unreacted first reactor alcohol flowing into it is possible to reduce the amount to a very small amount, this one may become possible to process integration with trans-esterification reaction, as is described above, if the removal of the alcohol that is applied to the direct esterification reaction and trans-esterification product of a reaction high it can be a way to get a high yield.
[43]
[44]
According to the invention, the method of removing the monohydric alcohol in the esterification reaction may greatly esterification reaction step to the first can be separated by a removal stage of the alcohol, the esterification reaction step is carboxylated in the esterification reactor described above group, will for the carbonyl nilgye compound and a monovalent alcohol having at least one functional group selected from the group consisting an ester group and an acid anhydride reaction, the stripping step of the monovalent alcohol is vapor stream from the esterification reactor in the above-described gas-liquid separating column and as the liquid stream is introduced to perform the gas-liquid separation would be monovalent alcohol is removed.
[45]
In the step in which the esterification reaction is carried out can be performed is a typical esterification reaction, the conditions of the esterification reactions may be subject to a well-known reaction conditions.
[46]
In addition, steps 1, the alcohol is removed, the liquid phase of the liquid stream through the exit line enters the gas-liquid separating column monovalent alcohol in the gas-liquid separation column of the vapor stream, and esterification reactor via a vapor outlet line of the esterification reactor there can be removed, and the 1 can be included in the alcohol is vaporized from the reaction vapor stream, as it may be included in the liquid stream as a liquid. That is, contain a monohydric alcohol in both the liquid stream and the vapor stream may be flowing into the gas-liquid separating column, the conditions applicable to the gas-liquid separation are conditions that are typically used as they can be applied to both.
[47]
However, the one that according to the method of removing the alcohol, it is necessary to control the time of sending the liquid stream across the separation process in the gas-liquid separation column. That is, about 10% of the total time required for the gas-liquid separation step to 70%, preferably from 30% to 70%, 35% to 65%, more preferably 40% to 60%, optimally from 45% to 58% after this time has passed through the liquid phase outlet line it may be required to control inflow of a liquid stream into a vapor-liquid separation column. If the gas-liquid separator is sent to a liquid stream from the time of the prior 10% of the time from time or total travel being started while a gas-liquid separation column, but can be a monovalent alcohol is removed to a certain amount, the improvement of the removal rate there may occur a problem that there is no significant difference in not introducing the liquid outlet line.
[48]
That is, in the case of controlling the time for passing the liquid stream into a vapor-liquid separation column in the reactor may be a gas-liquid separation efficiency maximized, that point may be a time point at which about 10 to 70% of the elapsed time against the overall separation process .
[49]
In general, the gas-liquid separation process, i.e. the time that one is required for the removal of alcohol is usually, but can of about 80 min to 140 min, the time required can vary depending on the separation capacity of the volume and the gas-liquid separation column of the reactor, this additional separation process due to the presence, etc. since time required for full separation process can be reduced, but not the total time required for the separation process to be particularly limited.
[50]
Further, the flow rate of the liquid stream that is in a liquid outlet line, and the more the separation efficiency can be increased, it may be advantageous to not less than about 25% from the total amount of the reaction product of the liquid phase at least within the reactor. However, as the flow rate of the liquid stream increases the increase in gas-liquid separation efficiency is not increased in proportion to, the growth rate can be significantly greater than the increase in flow rate.
[51]
Components contained in the low boiling point mixture with the unreacted alcohol, but there may be more water, may be an important factor in the removal of water also esterification reaction, the removal of moisture is an important role than in the middle of the esterification reaction Therefore, in the reaction step of removing the monohydric alcohol after one it can not generally be removed together when the alcohol is removed.
[52]
The gas-liquid separation space of the gas-liquid separation column is a tray type (tray type), filling-type (packed type) or may be a hybrid of the two, and thus may be called as tray columns, packed columns or tray / filling mixed columns, gas-liquid separating column in the gas-liquid separation system according to the invention can be properly adjusted according to the ingredient and the content contained in the low boiling point mixture to be removed.
[53]
In the esterification reaction raw material, a monovalent alcohol can be an alkyl group of 2 to 20 carbon atoms. Further, carbonyl nilgye compounds it may be applied to both an ester group, a carboxyl group or an acid anhydride as a functional group a compound having one or more, for example, acetic acid and its ester or anhydride, phthalic acid and its ester or anhydride, isophthalic acid this and its ester or anhydride, terephthalic acid and its ester or anhydride, citric acid and its ester or anhydride, succinic acid and its esters or anhydride, trimellitic acid and its esters or anhydride, benzoic acid and its esters or anhydride, etc. It may be applied, and the like in addition to the acetic acid, butyric acid, pentane or acid may be applied, may be applied such as the ester thereof derived from a natural oil or an epoxidized oil. In other words the process is the reaction between the compound with the esterification reaction can take place performed, it can be applied without removal of monovalent alcohols according to the method of the present invention limits.
[54]
[55]
According to the invention, there is provided a method of manufacturing a polyester composition which comprises the above-mentioned first method the removal of the alcohol.
[56]
More specifically, the method comprising the carbonyl compound and the monovalent alcohol nilgye reaction having at least one functional group selected from the esterification reactor, a carboxyl group, an ester group, and the group consisting anhydride; A step in which the first vapor stream and a liquid stream comprising an alcohol is introduced into the gas-liquid separation column from the esterification reactor 1, the alcohol is removed; It includes; and performing a trans esterification reaction to the esterification reactor is the first input to a different carbon number alcohol and the alcohol.
[57]
As described above, there is a 1 in accordance with the present invention can proceed even include trans-esterification reaction in the same reactor if the removal of alcohol applied to the direct esterification reaction, to achieve the integration of the reaction equipment through it, and this economic according can benefit from various aspects such as fairness.
[58]
[59]
Not more than 1 with reference to the accompanying drawings in accordance with the present invention will be described in detail one example of a gas-liquid separation system used in removal of the alcohol.
[60]
1 is a process flow diagram illustrating an example of the gas-liquid separation system. 1, is provided with an internal space in which the esterification reaction carried out direct esterification reactor 11 having a liquid compartment and a gas phase compartment is located at the upper end of the reaction space is connected to the vapor compartment vapor is the vapor stream outlet It located at the lower end of the outlet line 111 and the reaction space is provided with a product that is associated with a liquid product compartment the outlet line (112).
[61]
Vapor stream flowing out through the vapor outlet line 111 can be connected with the bottom of the gas-liquid separation column 12, the gas-liquid separation column 12 has a gas-liquid separation space, which gas-liquid separation is carried out of the inlet vapor stream , to the upper part to the upper outlet line (122) to be removed are low boiling compounds including the unreacted alcohol, the bottom may be provided with a back that is liquefied reaction products are collected lower return line 121 through a gas-liquid separation.
[62]
Further, the gas-liquid separation from the liquid phase section of the esterification reactor 11. esterification reactor 11 to be connected with a liquid compartment can be a liquid stream outlet and the outlet liquid stream may be introduced into the gas-liquid separation column 12 of the the column may be provided with a liquid outlet line 113 is connected to the side portion of (12).
[63]
The liquid phase outlet line 113 may be located at the lower end of the esterification reactor 11. esterification reactor 11 can be located on the side to be with product line 112 of, as shown in Fig. That is, the position of the liquid outlet line 113 is connected, as long as the liquid phase within the reactor compartment (11) but is not the location is not particularly limited. The partial flowing into the gas-liquid separation column 12 can also be preferably located on the side of the gas-liquid separation column 12, but can be preferably introduced into the at least 1/2 of the height direction of the column, among the side, but it may also be designed for a liquid outlet line 113 to be introduced into the upper end of the gas-liquid separation column 12.
[64]
In the case of the gas phase stream that flows through the vapor outlet line 111 there may be caused to flow through the pressure of the esterification reactor 11, in the case of the liquid stream, the liquid stream over a certain height of the gas-liquid separation column 12, there is a power source, such as a liquid phase outlet line 113, a pump (not shown) to be provided to send.
[65]
[66]
Example
[67]
And to more specifically explain the present invention by the following examples. However, the Examples are not limited the scope of the invention to these are for illustrating the invention.
[68]
[69]
The following Examples and Comparative Examples of the commercial process was simulated program by using the ASPEN PLUS simulate the removal of the monohydric alcohol in the esterification reaction in the present invention, the conditions of the gas-liquid separation under reduced pressure from the normal pressure for 120 minutes to 80 torr It was conducted while.
[70]
[71]
Example 1
[72]
As a reaction raw material, terephthalic acid 5.5T / hr, 2- ethyl hexanol by introducing 13.5T / hr to the esterification reactor 11, and proceeds directly to the ester The reaction, after the reaction was complete, about 45% of the total separation process Duration the total flow rate of the liquid stream is a liquid stream through the liquid outlet line from the elapsed since the separation point, starting 54 minutes, the time and introduced into the gas-liquid separation column, with the liquid phase outlet line is 100% of the reaction product the total amount of in the liquid phase reactor the gas-liquid separation was carried out for a total of 120 minutes to control.
[73]
[74]
Example 2
[75]
Except that after the cost of about 58% of the total separation process time is elapsed time separation begins after 70 minutes the liquid stream through the liquid phase outlet line enters the gas-liquid separating column was carried out in the same manner gas-liquid separating both as described in Example 1.
[76]
[77]
Example 3
[78]
Except that a liquid phase stream and then in an about 12.5% ​​of the total separation process time is elapsed time of separation 15 minutes after via the liquid phase outlet line enters the gas-liquid separating column was carried out in the same manner gas-liquid separating both as described in Example 1.
[79]
[80]
Example 4
[81]
Except by controlling the total flow rate of the liquid stream to 25% by weight of the total amount of the reaction product in the liquid phase reactor to the gas-liquid separation was performed for a total of 120 minutes so as to perform gas-liquid separation in the same manner as in Example 1 both.
[82]
[83]
Example 5
[84]
Except that a liquid phase stream and then in the 45% of the total separation process time is elapsed time of separation 54 minutes after via the liquid phase outlet line enters the gas-liquid separating column was carried out the same gas-liquid separation both in the Example 4.
[85]
[86]
Example 6
[87]
Except that a liquid phase stream and then in an about 12.5% ​​of the total separation process time is elapsed time of separation 15 minutes after via the liquid phase outlet line enters the gas-liquid separating column was carried out the same gas-liquid separation both in the Example 4.
[88]
[89]
Comparative Example 1
[90]
A gas-liquid separation was carried out without applying the liquid outlet line, the conditions of the esterification reaction and vapor-liquid separation was applied in the same manner as in Example 1.
[91]
[92]
Comparative Example 2
[93]
Separated from starting point to which the liquid stream through the liquid phase outlet line enters the gas-liquid separating column was carried out except for the same gas-liquid separation, and both the first embodiment.
[94]
[95]
Comparative Example 3
[96]
Separated from starting point to which the liquid stream through the liquid phase outlet line enters the gas-liquid separating column was carried out except for the same gas-liquid separation both in the Example 4.
[97]
[98]
Experimental Example 1
[99]
Example 1 to 6 and Comparative Examples 1 to 3 according to the gas-liquid separation, to calculate the time and the amount of time it takes until the shortening rate of the 2-ethylhexanol content in the esterification reactor will be not more than 2% by weight of the the results are shown in tables 1 and 2.
[100]
TABLE 1
　 Rate of the liquid stream 1) Disconnect the starting point Time Duration reduced rate
(weight%) (minute) (%)
Example 1 100 54 minutes, 45% 90.0 25.0
Example 2 100 70 minutes, 58% 99.6 17.0
Example 3 100 15 min, 12.5% 105.6 12.0
Comparative Example 1 0 - 120.0 0.0
Comparative Example 2 100 Immediately 112.8 6.0

[101]
TABLE 2
　 Rate of the liquid stream 1) Disconnect the starting point Time Duration reduced rate
(weight%) (minute) (%)
Example 4 25 54 minutes, 45% 105.0 12.5
Example 5 25 70 minutes, 58% 110.4 8.0
Example 6 25 15 min, 12.5% 112.8 6.0
Comparative Example 1 0 - 120.0 0.0
Comparative Example 3 25 Immediately 115.2 4.0

[102]
1) a relative amount based on the total amount of the reaction product of the liquid phase within the reactor,
[103]
Referring to Tables 1 and 2, in the case of Comparative Example 1, the liquid stream is not utilized as compared to Examples 1 to 6 used in the gas-liquid separator through the liquid phase outlet line time to reach the target amount of 2-ethylhexanol this can be concluded that it takes quite a lot.
[104]
In the case of the from the gas-liquid separation start timing without adjusting the release point, comparison From flowing a liquid stream into a vapor-liquid separation column Examples 2 and 3, the separation time shortened enough to did almost not see the effect of increasing the gas-liquid separation efficiency due to the liquid stream We can see almost none. Through this, the increased efficiency of the separation process by the liquid stream can be confirmed that a liquid phase stream that is important, the regulation of the time for flowing the gas-liquid separation column.
[105]
Furthermore, Examples 4 to 6 In spite of not only 1/4 compared with the use of a liquid stream through the liquid outlet lines in Comparative Example 2, and was further reduced the time to reach the target amount of 2-ethylhexanol, in a short time it is also confirmed that to reduce the 2-ethylhexanol as a low content.
[106]
[107]
Reference Numerals
[108]
11: esterification reactor 12: gas-liquid separating column
[109]
111: vapor exit line 112: product line
[110]
113: liquid outlet line
[111]
121: lower recovery line 122: top outlet line

WE Claims

[Claim 1]
Esterification which is located at the upper end of the reaction chamber, said reaction chamber having a liquid compartment and a gas phase compartment is located at the side of the vapor compartment and connected vapor outlet line and the reaction chamber in the reactor contains a liquid outlet line connected to the reactor, within the liquid compartment in the reactor, a carboxyl group, the method comprising the carbonyl compound and nilgye monovalent alcohol having an ester group and at least one functional group selected from the group consisting anhydride reaction; Including; and a liquid stream, the first containing the alcohol from the gaseous stream and the liquid phase outlet line to the one containing the alcohol from the vapor outlet line is gas-liquid separated in the gas-liquid separation column step in which the monovalent alcohol is removed and flowing the liquid stream to the vapor-liquid separating column the esterification reaction is one method of removing the alcohol in that, starting from the moment of total a 10% to 70% of the time required for the gas-liquid separation.
[Claim 2]
The method of claim 1 wherein the flowing of the liquid stream to the gas-liquid separation column is the method of removing the monohydric alcohol will be started from the time of 35% to 65% of the total time required for the gas-liquid separation.
[Claim 3]
The method of claim 1 wherein the flowing of the liquid stream to the gas-liquid separation column is the method of removing the monohydric alcohol will be started from the time of the total travel of 45% to 58% of the time required for the gas-liquid separation.
[Claim 4]
The method of claim 1, wherein the removal of the monohydric alcohol in the gaseous stream that is flowing out of the vapor outlet line by the pressure of the esterification reactor.
[Claim 5]
The method of claim 1, wherein the gas-liquid separating column is a tray type (tray type), filling-type (packed type) or a method of removing the monohydric alcohol is one of those mixed.
[Claim 6]
Article comprising a monovalent way removal of the alcohol in the first term esterification reaction, wherein an esterification reaction is a direct esterification reaction, after the step in which the monohydric alcohol is removed, the alcohol transformer responsive to the esterification reactor the method of producing a polyester composition further comprising a, and the carbonyl compound is nilgye carboxyl group, an ester group or acid anhydride group bonded to at least 2; additional input by trans esterification step to carry out the reaction.
[Claim 7]
7. The method of claim 6 wherein the trans-alcohol reaction is a process for producing a polyester composition having an alkyl group different from the group of monovalent alcohol is applied to the direct esterification reaction.