ZA200304431B - Method and device for separating a substance mixture into the component parts thereof by means of extractive distillation in a separating wall column - Google Patents
Method and device for separating a substance mixture into the component parts thereof by means of extractive distillation in a separating wall column Download PDFInfo
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- ZA200304431B ZA200304431B ZA2003/04431A ZA200304431A ZA200304431B ZA 200304431 B ZA200304431 B ZA 200304431B ZA 2003/04431 A ZA2003/04431 A ZA 2003/04431A ZA 200304431 A ZA200304431 A ZA 200304431A ZA 200304431 B ZA200304431 B ZA 200304431B
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- Prior art keywords
- dividing
- constituents
- wall column
- solvent
- take
- Prior art date
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- 238000000895 extractive distillation Methods 0.000 title claims abstract description 47
- 239000000203 mixture Substances 0.000 title claims abstract description 38
- 239000000126 substance Substances 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000004821 distillation Methods 0.000 claims abstract description 30
- 239000000470 constituent Substances 0.000 claims description 102
- 239000002904 solvent Substances 0.000 claims description 70
- 230000008929 regeneration Effects 0.000 claims description 30
- 238000011069 regeneration method Methods 0.000 claims description 30
- 238000004891 communication Methods 0.000 claims description 14
- 238000011001 backwashing Methods 0.000 claims description 13
- 238000010992 reflux Methods 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 4
- 239000002798 polar solvent Substances 0.000 claims description 4
- 230000000630 rising effect Effects 0.000 claims description 3
- 238000009835 boiling Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- -1 alpha-olefins) Chemical class 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 101100195396 Human cytomegalovirus (strain Merlin) RL11 gene Proteins 0.000 description 1
- 108700012361 REG2 Proteins 0.000 description 1
- 101150108637 REG2 gene Proteins 0.000 description 1
- 101100120298 Rattus norvegicus Flot1 gene Proteins 0.000 description 1
- 101100412403 Rattus norvegicus Reg3b gene Proteins 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000010779 crude oil Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 150000001993 dienes Chemical class 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000013557 residual solvent Substances 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000004711 α-olefin Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/141—Fractional distillation or use of a fractionation or rectification column where at least one distillation column contains at least one dividing wall
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/34—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping with one or more auxiliary substances
- B01D3/40—Extractive distillation
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a method and a device for separating a substance mixture into three component parts thereof by extractive distillation. In order to reduce the amount of energy and investment required, the extractive distillation is carried out introduced into a distillation column embodied in the form of a separating wall column (K1). As a result it is possible to obtain three products (P1, P2, P3) with a high degree of purity in a single distillation step even when the substance mixtures are close-boiled.
Description
to
P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner - 1 -
Process and apparatus for separating a mixture of substances into its constituents by extractive distillation in a dividing-wall column
The invention relates to a process for separating a mixture of substances into three constituents by extractive distillation, and to an apparatus for carrying out the process.
In many processes used in the processing of crude oil and natural gas and both the chemical and petrochemical industries, the problem arises of separating mixtures of substances into their constituents. A standard method consists in distillation of the mixture of : substances, making use of the different boiling points of the individual constituents of the mixture of substances: However, mixtures which boil in a narrow i. range can no longer be separated at an economically viable level of outlay using standard distillation.
What is known as “extractive distillation” is often used for mixtures of this type. This process involves the use of a solvent which influences the relative volatilities of the constituents which are to be separated. The addition of the solvent significantly increases the differences in the relative volatilities of the individual constituents, so that they can be separated by distillation.
Extractive distillation is recommended in particular for mixtures which boil within a narrow range and the individual constituents of which have sufficiently different polarities. The presence of a polar solvent causes the relative volatilities to shift. Nonpolar constituents and constituents with a low polarity become more volatile relative to constituents with a a AMENDED SHEET
LA 'P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner
Ix - 2 - medium level of polarity, and highly polar constituents become less volatile relative to constituents with only a medium level of polarity. If it is desired to obtain more than just two fractions from a narrow-boiling mixture of this type, a correspondingly increased number of individual extractive distillation steps are required, corresponding to the number of n-1 distillation steps as required in standard distillation to obtain n fractions. To separate a constituent of a medium polarity level from relatively nonpolar constituents, on the one hand, and from more polar constituents, on the other hand, therefore, it is necessary to connect two extractive distillations in series.
However, the previous methods used for extractive distillation are very energy-intensive and moreover require high investment costs, in particular if a plurality of stages are required.
Therefore, the present invention is based on the object a need exists of configuring a process of the type described in the introduction and an apparatus for carrying out the process in such a way that the energy consumption and the investment costs are reduced.
According to the invention, in terms of the process this object is achieved need is fulfilled by the fact that the extractive distillation is carried out in the presence of a solvent in a distillation column which is designed as a dividing-wall column and in a central section is divided into a feed side and a removal side by a vertical dividing wall, a further distillation zone being located both above and below the dividing wall, so that there is a connection between the feed side and the removal side at those locations, that the mixture of substances is added to the dividing-wall a P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner : column on the feed side, and the extractive distillation is carried out in such a manner that the separated constituents are in each case obtained in the top and bottom region of the dividing-wall column and in the region of a centre take-off provided on the removal side, and the constituents obtained in this way are taken off from the dividing-wall column.
The invention is based on the consideration of separating even mixtures of substances which boil : within a narrow range into three constituents in just one stage. While the prior art requires two stages connected in series to do this, with the invention it is possible to carry out the extractive distillation in a single distillation column. This significantly reduces the energy and investment costs. Even if the dividing-wall column has to be made larger than each of
Co the two individual columns of ‘the prior art, .the overall investment costs required for this single column are significantly lower than those required for the two-column system. The thermal coupling which is realized in a dividing-wall column means that columns of this type operate under more favourable thermodynamic conditions than the traditional two-column arrangement.
The invention is particularly suitable for separating substance-mixture streams into three part-streams which differ through different polarities of their constituents. In this case, the substance-mixture stream is fed into a distillation column which is designed as a dividing-wall column and in a central section is divided into a feed side and a removal side by a vertical dividing wall, a further distillation zone being located both above and below the dividing- wall column, so that there is a connection between the feed side and the removal side at those locations. The
=“ P00240-DEa/AVA=EN-AVA 2398 18.01.2001 - Lehner dividing-wall column is operated in the presence of a polar solvent in the dividing-wall column in such a : manner that on the feed side, the nonpolar constituents and/or the constituents with a low polarity are driven into the top region of the dividing-wall column, while the constituents with a high polarity are washed back into the bot tom region of the dividing-wall column. The constituents with a medium polarity level pass to the removal side both via the bottom end of the dividing wall and via its top end. On the ‘removal side, the nonpolar constituents and the constituents with a low : polarity are forced out of reflux liquid in a zone above a centre take-off, and the constituents with a higher polarity are washed back out of the rising gas : in a zone below the centre take-off, so that the purity of the constituents with a medium level of polarity can be maintained. As a result, the constituents with a medium level of polarity can be obtained in the region
Co of the centre take-off, while the monpolar constituents and/or the constituents with a low polarity can be obtained at the top of the dividing-wall column and the constituents with a high polarity can be obtained at the bottom of the dividing-wall column. Finally, a product stream which includes the constituents with a medium polarity level 1s discharged via the centre take-off, while a product stream, which includes the : nonpolar constituents and/or constituents with a low polarity, is discharged via a top take-off provided in the upper region of the dividing-wall column. The solvent, which contains the constituents with a high polarity, is discharged via a bottom take-off provided in the lower region of the dividing-wall column. ‘It is expedient for a high-boiling, polar solvent to be used. This may either be a pure solvent or a mixture with water or other solvents. All solvents used for standard extractive distillation can be used. The
AMENDED SHEET v S P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner fo - 5 _ . apparatus has a distillation column which is designed as a dividing-wall column and in a central section is divided into a feed side and a removal side by a vertical dividing wall, a further distillation zone being located both above and below the dividing wall, so that there is a connection between the feed side and the removal side, a feed for the mixture of substances being arranged on the feed side and a centre take-off for a constituent obtained by extractive distillation being arranged on the removal side, while a top take- off in the top region of the dividing-wall column and a bottom take-off in the bottom region of the dividing- wall column are provided for the other two constituents obtained by extractive distillation, and the dividing- wall column has a solvent feed.
It is preferable for the bottom take-off to be in communication with a regeneration device, in which the constituents obtained in the bottom region of the dividing-wall column by extractive distillation are separated from the solvent. A product take-off, via which the constituents which have been separated from the solvent are discharged as products, is connected to this regeneration device. Furthermore, a return line, which is in communication with the top region of the dividing-wall column, is connected to the regeneration device. The regenerated solvent is fed back to the dividing-wall column via this return line.
Moreover, it is advantageous for the top take-off; centre take-off and bottom take-off each to be in communication with a backwashing device in which the solvent is washed back out of the product streams in question by returned product. In this case, the backwashing device which is in communication with the centre take-off preferably has a return line for backwashed solvent, which is connected to the
: P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner apparatus has a distillation column’ which is designed as a dividing-wall column and in a central section is : divided into a feed side and a removal side by a vertical: dividing wall, a further distillation zone being located both above and below the dividing wall, so that there is a connection between the feed side and : the feed-in side [sic], a feed for the mixture of : substances being arranged on the feed side and a centre take-off for a constituent obtained by extractive distillation being arranged on the removal side, while a top take-off in the top region of the dividing-wall column and a bottom take-off in the bottom region of the dividing-wall column are provided for the other two constituents obtained by extractive distillation, and the dividing-wall column has a solvent feed.
It is preferable for the bottom take-off to be in : communication with a regeneration device, in which the constituents obtained in ‘the bottom region of the dividing-wall column by extractive distillation are separated from the solvent. A product take-off, via which the constituents which have been separated from the solvent are discharged as products, 1s connected to this regeneration device. Furthermore, a return line, which is in communication with the top region of the dividing-wall column, is connected to the regeneration device. The regenerated solvent is fed back to the dividing-wall column via this return line.
Moreover, it is advantageous for the top take-off, centre take-off and bottom take-off each to be in communication with a backwashing device in which the solvent 1s washed back out of the product streams in question by returned product. In this case, the backwashing device which is in communication with the centre take-off preferably has a return line for backwashed solvent, which is connected to the
’ P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner dividing-wall column in the region of the centre take-off, so that the solvent which has been washed back can be fed back into the dividing-wall column in this region.
According to a particularly preferred embodiment of the apparatus according to the invention, the regeneration device is integrated in the lower region of the dividing-wall column. In this case, a side take-off which is in communication with a backwashing device for backwashing the solvent is arranged above the regeneration device.
Under certain circumstances, for design reasons it may ! 15 be necessary to split the distillation column into two or more sections. In this case, the individual : part-columns are connected to one another via lines in such a manner that .the method of operation corresponds to that of an unsplit distillation column. The present invention also relates to split dividing-wall columns of this type.
A range of advantages are associated with the invention. For example, the invention has for the first time made it possible to separate even mixtures of substances which boil within a narrow range into three constituents by extractive distillation in a single distillation step. The fact that both a light end and a heavy end of the mixture of substances are removed in a single apparatus means that it is possible to eliminate an entire distillation column and its accessories (boilers, condenser, reflux vessels, solvent feeds, solvent discharges and pumps) . The invention significantly reduces the total investment costs, even if the dividing-wall column has to be of larger dimensions than each of the two individual columns. The thermal coupling which is brought about in the
° P00240-DEa/AVA=EM-AVA 2398 : 18.01.2001 - Lehner dividing-wall column means that the column operates more favourably in thermodynamic terms than the : traditional two-column arrangement. A further advantage is that ‘when thermally sensitive substances are being processed, these substances have to be boiled less frequently. The overall result is a well-designed technical solution enabling even mixtures of substances : which boil within a narrow range to be separated by extractive distillation with a low level of outlay on apparatus. :
The invention can be used wherever more than only two fractions are to be obtained by extractive distillation from a mixture of substances which boils within a narrow range. In particular, the invention can advantageously be employed to obtain aromatics (e.g. benzene), olefins (e.g. alpha-olefins), dienes (e.g. butadiene) and . oxygen-containing compounds (e.g. - alcohols, ketones, esters, etc.). :
In the text which follows, the invention is explained in more detail on the basis of exemplary embodiments which are diagrammatically depicted in the figures, the previous solutions from the prior art also being illustrated in figures for comparison purposes. In the drawing:
Figure 1 shows an outline circuit diagram of a two-stage extractive distillation of the most simple type in accordance with the prior art;
Figure 2 shows an outline circuit diagram of a two-stage extractive distillation with common solvent regeneration in accordance with the prior art; :
‘ P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner - 9 =
Figure 3 shows an outline «circuit diagram of a two-stage extractive distillation in a dividing-wall column with separate solvent regeneration in accordance with the invention;
Figure 4 shows an outline circuit diagram of a fully integrated two-stage extractive distillation in accordance with the invention.
The basic principle of an arrangement for separating mixtures of substances which boil within a narrow range into their three constituents by extractive distillation in accordance with the prior art is illustrated in Figure 1. As in the remaining Figures 2, 3 and 4, all the steps used for thermal integration and heat recovery have been omitted in this highly : simplified circuit diagram. The distillation zones ~~ = which are present in each of the distillation columns So have been indicated by X sections in Figures 1-4. In a first extractive distillation ED], all nonpolar constituents and also all the constituents with only a low polarity are separated out of the narrow-boiling substance-mixture charge E and obtained via the top as first product Pl. For this purpose, the reflux quantity
RL11, the solvent quantity L1 and the bottom heating 011 are set in such a way that above the point at which the substance-mixture charge E is fed in, all the constituents with a polarity higher than a certain limit polarity (and therefore with a lower relative volatility) are washed back out of the rising vapour.
Below the feed-in point, the nonpolar constituents and the constituents with a polarity lower than the said limit polarity are stripped out of the liquid running down. The solvent extracted via the bottom is therefore laden only with the constituents whose polarity exceeds the limit value in question. These are expelled from
; P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner the . solvent in the regeneration column REG1l, and the regenerated solvent taken off via the bottom is reused in the first extractive distillation ED1. The top product of the regeneration column REG1l, which contains all the constituents with a polarity higher than the said limit polarity, is then fed to a second extractive distillation ED2, the operating conditions of which are set in such a way that the constituents with a medium , polarity level form the top product P2, while all the highly polar constituents remain in the solvent and are taken off with the latter via the bottom. During the regeneration of the solvent in the regeneration column
REG2, the highly polar components are formed as top product P3. The regenerated solvent L2 itself is fed back into the second extractive distillation ED2.
Figure 2 shows a further, somewhat sleeker outline circuit diagram of. a‘ conventional arrangement for. } : separating constituents with a medium level of polarity out of a mixture of substances which boils within a narrow range. In this case, the second extractive distillation and a partial regeneration of the solvent from the first regeneration stage of Figure 1 are combined in a single column. In this highly simplified circuit diagram too, all the steps required for thermal integration and heat recovery have been omitted. The corresponding installation parts and corresponding process steps are denoted by the same reference symbols as in Figure 1. In the first extractive distillation
ED1, once again all the nonpolar constituents and also all the constituents with only a low polarity are separated out of the narrow-boiling substance-mixture charge E and obtained via the top as first product Pl.
The solvent taken off via the bottom is once again laden only with those constituents whose polarity exceeds the said limit value. The laden solvent is fed into a second extractive distillation ED2, the top
. P00240-DEa/AVAZEM-AVA 2398 18.01.2001 - Lehner product P2 of which contains all the components with a medium polarity level. The lower part of this column can also be considered a partial regeneration of the solvent L1 from the first extractive distillation ED1, since in this section all the constituents with a medium polarity level are forced out of the solvent.
The solvent taken off from the second extractive distillation ED2 via the bottom is then laden only with the constituents with the highest polarity. These are forced out of the solvent in the third column, the regeneration REG, and are obtained as third product P3 via the top. The solvent, which has now been fully regenerated, is taken off from the bottom of the regeneration column REG and distributed between the two extractive distillation columns ED1 and ED2.
Figure 3 illustrates a two-stage extractive distillation in a dividing-wall column with separate . solvent recovery "in accordance with the invention. A: substance-mixture stream E comprising «constituents which boil within a narrow range and have different polarities is fed to the dividing-wall column Kl. The dividing-wall column Kl is divided into a feed side, which is illustrated on the left in the figure, and a removal side, which is illustrated on the right in the figure, by a vertical dividing wall T. By regulating the reflux quantity RL1, the solvent quantity L and the bottom heating 01, the dividing-wall column K1 is operated in such a way that on the feed side the nonpolar constituents of the narrow-boiling charge-substance mixture E and/or those constituents with a low polarity are forced into the top region of the dividing-wall column, while the constituents with a high polarity are washed back into the bottom region of the dividing-wall column. By contrast, the constituents with a medium level of polarity pass to the removal side of the dividing-wall column K1 both via the lower
> P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner end of the dividing wall T and via the upper end of the dividing wall T. On the removal side, the nonpolar constituents and/or the constituents with a low polarity are forced out of reflux liquid in a zone above the centre take-off M. On the other hand, the constituents with a high polarity are washed back in a : zone below the centre take-off M. In this way, the purity of the middle fraction can be maintained.
Therefore, in the dividing-wall column Kl, the charge- substance mixture E is divided into three different products of the desired purity, which each can respectively be taken off from the dividing-wall column
Kl as part-streams from the top region, the bottom region and via the centre take-off M. The part-stream
S1 which has been taken off from the top region of the dividing-wall column Kl contains the nonpolar constituents and/or the constituents with only a low ~.. wpelarity. In the top section of the dividing-wall" column (between the addition of the solvent L and the Co addition of the reflux RL1l), the solvent vapours are washed back, so that this product stream does not contain any solvent. It can be obtained directly as product Pl. The gaseous part-stream S2, which contains : the constituents with a medium level of polarity, is taken off via the centre take-off M. Since the part- stream S2 also carries with it solvent vapours, the solvent has to be recovered in a column K2. In the column K2, the constituents with a medium level of polarity are purified by the removal of the residual solvent vapours. Finally, the solvent is returned to the dividing-wall column K1 in the region of the centre take-off M via the stream S3. The constituents with a medium level of polarity from which the solvent residues have been removed in column K2 are finally obtained as product P2. A part-stream S4 which contains solvent laden with the constituents with a high polarity is discharged from the bottom region of the s P00240-DEa/AVA=EM-AVA 2398 18.01.2001 - Lehner dividing-wall column Kl. The part-stream S4 is fed to a regeneration stage REG which is designed as a distillation column. In the regeneration stage REG, the constituents with a high polarity are forced out of the solvent and can be obtained as product P3, the solvent vapours being washed back in the upper section of the regeneration column REG. Finally, the solvent is returned to the upper region of the dividing-wall column Kl via the stream L. In this way, it is possible to obtain three products Pl, P2 and P3 with a high level of purity from a narrow-boiling substance-mixture stream E using a single dividing-wall column Kl.
Figure 4 shows a variant of the extractive distillation in a dividing-wall column illustrated in Figure 3. This variant of the invention differs from the arrangement shown in Figure 3 through the fact that the lower part ~~ - ..0f the regeneration stage REG has been integrated:intoc oo ~~ the dividing-wall column Kl1 and the upper (backwashing) part has been replaced by a smaller side column K3, the solvent recovered in this column K3 being returned direct to the dividing-wall column Kl. This results in a fully integrated two-stage extractive distillation which comprises a single dividing-wall column Kl and two small side columns K2 and K3. This arrangement achieves a particularly economical process by reducing the energy consumption and the investment costs to the maximum possible extent.
Claims (12)
1. Process for separating a mixture of substances into three constituents by extractive distillation, characterized in that the extractive distillation is carried out in the presence of a solvent in a distillation column which is designed as a dividing- wall column and in a central section is divided into a feed side and a removal side by a vertical dividing wall, a further distillation zone being located both above and below the dividing wall, so that there is a connection between the feed side and the feed-in side [sic] at those locations, in that the mixture of substances is added to the dividing-wall column on the feed side, and the extractive distillation is carried out in such a manner that the separated constituents Coe are in each case obtained in the top and bottom region FE of the dividing-wall column and in the region of a centre take-off provided on the removal side, and the constituents obtained in this way are taken off from the dividing-wall column. ]
2. Process for separating a substance-mixture stream into three part-streams which differ through different polarities of their constituents, characterized in that a) the substance-mixture stream is fed into a distillation column which is designed as a dividing-wall column and in a central section is | divided into a feed side and a removal side by a vertical dividing wall, a further distillation zone being located both above and below the dividing wall, so that there is a connection between the feed side and the feed-in side {[sic] at those locations,
° P00240-Dia/AVA=EM-AVA 2398
18.01.2001 - Lehner b) the dividing-wall column is operated in the presence of a polar solvent in the dividing-wall column in such a manner that c) on the feed side, the nonpolar constituents and/or the constituents with a low polarity are driven into the top region of the dividing-wall column, while the constituents with a high polarity are washed back into the bottom region of the dividing-wall column, and the constituents with a medium polarity level pass to the removal side both via the bottom end of the dividing wall and via its top end, d) on the removal side, the nonpolar constituents and/or the constituents with a low polarity are driven out of reflux liquid in a zone above a : centre take-off, and the constituents with a high SL polarity are washed back out of the rising gas in a zone below the centre take-off, so that the constituents with a medium polarity level are obtained in the region of the centre take-off while the nonpolar constituents and/or the constituents with a low polarity are obtained at the top of the dividing-wall column and the constituents with a high polarity are obtained at the bottom of the dividing-wall column, and e) a product stream which includes the constituents with a medium polarity level is discharged via the : centre take-off, while a product stream, which includes the nonpolar constituents and/or constituents with a low polarity, is taken off via a top take-off provided in the upper region of the dividing-wall column, and the solvent, which contains the constituents with a high polarity, is
® P00240-DEa/AVA=EM-AVA 2398
18.01.2001 - Lehner
. discharged via a bottom take-off provided in the lower region of the dividing-wall column. :
3. Process according to Claim 2, characterized in that the solvent which is extracted from the bottom region of the dividing-wall column and contains the constituents with a high polarity is fed to a regeneration zone, in which the constituents with a high polarity are separated from the solvent and obtained as further product, while ‘the solvent which has been regenerated in this way 1s returned to the top region of the dividing-wall column.
4. Process according to Claim 2 or 3, characterized in that the solvent is washed back out of the corresponding product streams by returned product. } ‘
5. Process according to Claim 4, characterized in So that the solvent which has been washed back out of the product stream of the centre take-off is returned again to the dividing-wall column in the region of the centre take-off.
6. Process according to one of Claims 3 to 5, characterized in that the regeneration zone is integrated in the lower region of the dividing-wall column, and in that the constituents with a high polarity are removed from the dividing-wall column via a side take-off, which is arranged above the regeneration zone, and are fed to the backwashing of the solvent.
7. Process according to Claim 5 or 6, characterized ‘in that the centre take-off and/or the side take-off from the lower region are extracted from the dividing-wall column as gas and are fed to the corresponding backwashing of the solvent.
- P00240-DEa/AVA=EM-AVA 2398
18.01.2001 - Lehner
8. Apparatus for separating a mixture of substances into three constituents by extractive distillation, characterized in that the apparatus has a distillation column which is designed as a dividing-wall column and in a central section is divided into a feed side and a removal side by a dividing wall, a further distillation zone being located both above and below the dividing wall, so that there is a connection between the feed side and the feed-in side [sic], a feed for the mixture of substances being arranged on the feed side and a centre take-off for a constituent obtained by extractive distillation being arranged on the removal side, while a top take-off in the top region of the dividing-wall column and a bottom take-off in the bottom region of the dividing-wall column are provided for the other two constituents obtained by extractive Lo distillation, and the dividing-wall column has a solvent feed. Co
9. Apparatus according to Claim 8, characterized in that the bot tom take-off is in communication with a regeneration device, in which constituents obtained in the bottom region of the dividing-wall column by extractive distillation are separated from the solvent, a product take-off for the constituents which have been separated from the solvent and a return line for the regenerated solvent being connected to the regeneration device, and the return line being in communication with the top region of the dividing-wall column.
10. Apparatus according to Claim 8 or 9, characterized in that top take-off, centre take-off and bottom take-off are each in communication with a backwashing device in which the solvent is washed back out of the product streams in question by returned product.
- P00240-DEa/AVA=EM_AVA 2398
18.01.2001 - Lehner
11. , Apparatus according to Claim 10, characterized in that the backwashing device which is in communication with the ‘centre take-off has a return line for backwashed solvent which is connected to the dividing-wall column in the region of the centre take-off.
12. Apparatus according to one of Claims 8 to 11, characterized in that the regeneration device is integrated in the lower region of the dividing-wall column, a side take-off, which is in communication with a backwashing device for backwashing the solvent, being arranged above the regeneration device.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10061220 | 2000-12-08 | ||
| DE10102168A DE10102168A1 (en) | 2000-12-08 | 2001-01-18 | Method and device for separating a mixture of substances into its components by extractive distillation in a dividing wall column |
| PCT/EP2001/012059 WO2002045811A1 (en) | 2000-12-08 | 2001-10-18 | Method and device for separating a substance mixture into the component parts thereof by means of extractive distillation in a separating wall column |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| ZA200304431B true ZA200304431B (en) | 2005-01-26 |
Family
ID=26007916
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| ZA2003/04431A ZA200304431B (en) | 2000-12-08 | 2003-06-06 | Method and device for separating a substance mixture into the component parts thereof by means of extractive distillation in a separating wall column |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP1339469B1 (en) |
| AT (1) | ATE340617T1 (en) |
| AU (1) | AU2002223625A1 (en) |
| DE (2) | DE10102168A1 (en) |
| NO (1) | NO20032575L (en) |
| WO (1) | WO2002045811A1 (en) |
| ZA (1) | ZA200304431B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10233388A1 (en) * | 2002-07-23 | 2004-02-12 | Basf Ag | Process for continuously operating pure distillation of the solvent methanol used in the coupling product-free propylene oxide synthesis with simultaneous removal of the methoxypropanols and the high boilers |
| DE10322655A1 (en) * | 2003-05-20 | 2004-12-09 | Basf Ag | Process for the recovery of crude 1,3-butadiene from a C4 cut |
| DE10341614A1 (en) | 2003-09-10 | 2005-04-28 | Basf Ag | Process for the preparation of xylylenediamine (XDA) |
| SE541051C2 (en) * | 2016-09-28 | 2019-03-19 | Perstorp Ab | The processing of a product stream resulting from a caprolactone production |
| CN113072425A (en) * | 2021-04-20 | 2021-07-06 | 青岛科技大学 | Method for separating ethanol, cyclohexanol and water by extractive distillation-pressure swing distillation of dividing wall tower |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19849651C2 (en) * | 1998-10-29 | 2003-01-16 | Krupp Uhde Gmbh | Rectifying column for the extractive distillation of closely or azeotropically boiling mixtures |
| DE19958464C2 (en) * | 1999-12-03 | 2002-02-28 | Krupp Uhde Gmbh | Extractive distillation process and column for carrying out the process |
| DE10019196C1 (en) * | 2000-04-17 | 2001-09-27 | Krupp Uhde Gmbh | Recovery of pure benzene, toluene or toluene and xylene from aromatic fraction containing non-aromatics uses on column with main zone of 2 parallel chambers for extractive distillation and extractant recovery |
| DE10022465A1 (en) * | 2000-05-09 | 2001-11-15 | Basf Ag | Processing a four carbon cut from the fractionation of crude oil, useful for the recovery of 1,4-butadiene, comprises extractive distillation, selective hydrogenation and distillation |
-
2001
- 2001-01-18 DE DE10102168A patent/DE10102168A1/en not_active Withdrawn
- 2001-10-18 AU AU2002223625A patent/AU2002223625A1/en not_active Abandoned
- 2001-10-18 DE DE50111115T patent/DE50111115D1/en not_active Expired - Lifetime
- 2001-10-18 AT AT01999409T patent/ATE340617T1/en not_active IP Right Cessation
- 2001-10-18 WO PCT/EP2001/012059 patent/WO2002045811A1/en active IP Right Grant
- 2001-10-18 EP EP01999409A patent/EP1339469B1/en not_active Expired - Lifetime
-
2003
- 2003-06-06 NO NO20032575A patent/NO20032575L/en unknown
- 2003-06-06 ZA ZA2003/04431A patent/ZA200304431B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE10102168A1 (en) | 2002-06-20 |
| EP1339469B1 (en) | 2006-09-27 |
| NO20032575L (en) | 2003-08-07 |
| DE50111115D1 (en) | 2006-11-09 |
| ATE340617T1 (en) | 2006-10-15 |
| EP1339469A1 (en) | 2003-09-03 |
| WO2002045811A1 (en) | 2002-06-13 |
| NO20032575D0 (en) | 2003-06-06 |
| AU2002223625A1 (en) | 2002-06-18 |
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