JP2002143603A - Simulation method of distillation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the convergent property of a simulation work at the time of simulating in a distillation apparatus provided with a combined distillation tower. SOLUTION: In the distillation apparatus provided with the combined distillation tower, the simulation is to be performed by using a simulation program of a distillation apparatus provided with a multiple tower. The distribution ratio of the combined distillation tower is inputted as a liquid distribution ratio set to distribute the liquid descending from the top of a main tower to a descending liquid in the feed side and a liquid descending in a side cut side, the initial value of the flow rate of steam supplied to the side cut side from the feed side is inputted and the pressure difference of the steam between the pressure of the main tower and the pressure of a side tower is calculated based on the initial value of flow rate of the steam to change the flow rate of the steam by corresponding to the calculated pressure difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for simulating a distillation apparatus.

[0002]

2. Description of the Related Art Conventionally, there has been provided a distillation apparatus provided with a composite column in which a plurality of distillation columns are combined in order to obtain products by separating each component from a stock solution containing a plurality of components by distillation. However, in the distillation apparatus, if each distillation column is separately constructed, the area occupied by the distillation apparatus increases. Further, in the side column type distillation apparatus, since it is necessary to control the distribution of steam between the respective distillation columns in order to adjust the pressure in each of the distillation columns, the respective distillation columns cannot be operated stably. .

[0003] Therefore, there has been provided a distillation apparatus provided with a Petlique-type distillation column in which an inner cylinder is disposed in an outer cylinder, and a stock solution is supplied into the inner cylinder to perform distillation. However, in this case, it is necessary to support the inner cylinder with respect to the outer cylinder, arrange a line through the outer cylinder, and attach a feed nozzle to the inner cylinder, which complicates the structure of the distillation column. And the cost of the distillation apparatus increases. In addition, since the space between the line and the outer cylinder and the space between the feed nozzle and the inner cylinder cannot be sufficiently sealed, the efficiency of distillation is reduced. Since the inner cylinder and the outer cylinder are arranged concentrically, and the collecting section and the concentrating section have a ring-shaped structure, it is difficult to arrange the filling material, and the collecting section and the concentrating section are concentrated. The structure of the tray provided in the section becomes complicated.

[0004] Therefore, there has been provided a distillation apparatus provided with one combined distillation column whose interior is partitioned by a flat partition. The combined distillation column is provided with a feed nozzle for supplying an undiluted solution to the column side, and includes a concentrating unit formed above the feed nozzle, and a collecting unit formed below the feed nozzle. A first distillation section,
A concentrating section connected to the upper end of the first distillation section, formed above the upper end, and formed below the upper end, and adjacent to the concentrating section of the first distillation section via a partition; A second distillation section having a recovery section, and a lower end of the first distillation section, which is connected to a lower end of the first distillation section, is formed above the lower end, and is connected to a recovery section of the first distillation section and an intermediate partition. It has an adjacent concentrating section and a third distillation section provided with a collecting section formed below the lower end. Then, in the distillation apparatus, the undiluted solution is supplied to the column side via the feed nozzle, the distillate at the top of the combined distillation column, the bottoms at the bottom, and the side cut liquid at the column side. Can be obtained.

In this case, the area occupied by the distillation apparatus can be reduced, the distillation column can be operated stably, the cost of the distillation apparatus can be reduced, and the packing or tray can be easily arranged. And the efficiency of distillation can be increased.

By the way, in manufacturing a distillation apparatus,
It is desirable to perform a simulation and evaluate the simulation result, but a simulation program for a distillation apparatus having a combined distillation column is not provided. Therefore, a commercially available simulation program incorporating a general distillation calculation method (for example, Simulat)
ion Sciences Inc. "PRO / I"
I "simulation program" Distilla
Tion Column Unit Operation
n "," Side Columns ", etc.). The simulation program is created by appropriately combining a single distillation calculation model, and by inputting various data relating to the main tower and the side tower, and converging the simulation work,
In order to be able to obtain, as a simulation result, the flow rate balance of the distillate obtained at the top of the main tower, the bottoms obtained at the bottom of the main tower, and the side cut liquid obtained at the tower side of the side tower. Has become.

[0007]

However, since the conventional simulation program has not been developed for a distillation apparatus having a combined distillation column, a simulation is performed by setting a model of the combined distillation column. Is possible, but the convergence of the simulation work is extremely low.

[0008] The present invention solves the problems of the conventional simulation program and improves the convergence of the simulation work when performing a simulation on a distillation apparatus having a combined distillation column. An object of the present invention is to provide a simulation method.

[0009]

For this purpose, in the method for simulating a distillation apparatus according to the present invention, the inside of the tower body is divided into a first chamber and a second chamber by a partition, and a stock solution is supplied to the side of the tower. A distillate is discharged at the top of the tower,
With respect to a distillation apparatus provided with a combined distillation column in which bottom liquid is discharged at the bottom and a side cut liquid is discharged at the side of the column, the first position set above the main column and the top of the side column Are connected by the first liquid flow path and the first vapor flow path, and the second position set below the main tower and the bottom of the side tower are connected by the second liquid flow path and the second vapor flow The simulation is performed by using a simulation program of a distillation apparatus having a composite column connected by a channel.

The distribution ratio for distributing the liquid descending from the top of the combined distillation column to the first chamber and the second chamber is determined by adjusting the liquid descending from the top of the main tower to the inside of the main tower. The flow rate of each liquid set to be distributed to the liquid descending on the feed side and the liquid sent to the side tower through the first liquid flow path and descending on the side cut side in the side tower. And the initial value of the flow rate of steam supplied from the feed side to the side cut side. Further, based on the initial value of the flow rate of the steam, the pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower is calculated, and the pressure difference is calculated according to the calculated pressure difference. Change the steam flow.

In another method for simulating a distillation apparatus according to the present invention, the inside of the tower body is divided into a first chamber and a second chamber by a partition, and a stock solution is supplied to the tower side, and a distillate is collected at the top of the tower. Discharged, bottom product is discharged at the bottom of the column, and the first position set above the main column and the side column of the distillation apparatus having the combined distillation column in which the side cut liquid is discharged at the side of the column. The top is connected to the first liquid flow path and the first vapor flow path, and the second position set below the main tower and the bottom of the side tower are connected to the second liquid flow path and the second liquid flow path. The simulation is performed using a simulation program of a distillation apparatus having a composite column connected by the vapor flow path.

The distribution ratio for distributing the liquid descending from the top of the combined distillation column to the first chamber and the second chamber is determined by adjusting the liquid descending from the top of the main tower to the inside of the main tower. The flow rate of each liquid set to be distributed to the liquid descending on the feed side and the liquid sent to the side tower through the first liquid flow path and descending on the side cut side in the side tower. And the initial value of the heating calorie in the evaporator connected to the main tower. Further, a reflux ratio of the distillate is calculated based on the initial value of the heating heat amount, and the heating heat amount is changed in accordance with the calculated reflux ratio.

[0013] In still another method for simulating a distillation apparatus according to the present invention, the inside of the tower main body is partitioned by a first partition.
Compartment and a second compartment, and the undiluted solution is supplied to the tower side,
A distillate is discharged at the top of the column, a bottoms is discharged at the bottom of the column, and a distillation apparatus having a combined distillation column in which a side cut liquid is discharged at the side of the column. The first position and the top of the side tower are connected by the first liquid flow path and the first vapor flow path, and the second position set below the main tower and the bottom of the side tower are connected to the second position. The simulation is performed using a simulation program of a distillation apparatus having a composite column connected by a liquid flow path and a second vapor flow path.

The distribution ratio for distributing the liquid descending from the top of the combined distillation column to the first chamber and the second chamber is determined by determining the liquid descending from the top of the main tower in the main tower. The flow rate of each liquid set to be distributed to the liquid descending on the feed side and the liquid sent to the side tower through the first liquid flow path and descending on the side cut side in the side tower. , The initial value of the flow rate of steam supplied from the feed side to the side cut side, and the initial value of the amount of heating heat in the evaporator connected to the main tower. Further, based on the initial value of the flow rate of the steam, the pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower is calculated, and the pressure difference is calculated according to the calculated pressure difference. The flow rate of steam is changed, the reflux ratio of the distillate is calculated based on the initial value of the heating heat amount, and the heating heat amount is changed in accordance with the calculated reflux ratio.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a conceptual diagram of a combined distillation column according to an embodiment of the present invention, and FIG. 3 is a conceptual diagram of a distillation apparatus according to an embodiment of the present invention.

In the figure, 10 is a combined distillation column,
The combined distillation column 10 includes a first section 11, a second section 12, a third section
Section 13, fourth section 14, fifth section 15, sixth section 16, seventh section 17, eighth
It comprises a section 18 and a ninth section 19.

In the fourth section 14 to the sixth section 16, the column body of the combined distillation column 10 has first chambers 14A to 16A and second chambers 14B to 14C by plate-shaped partitions 22 to 24, respectively. 16B, and the first chambers 14A to 16A and the second chambers 14B to 16B are adjacent to each other. In addition, the first chambers 14A to 16A
A causes the first distillation section 25 to
1, second section 12, third section 13 and second section
The second distillation section 26 is formed by the chamber 14B by the second chamber 15.
B, 16B, 7th section 17, 8th section 18
And the ninth section 19 form a third distillation section 27.

The partitions 22 to 24 can be made of a heat insulating material, or the insides of the partitions 22 to 24 can be made to have a heat insulating structure by evacuating the inside of the partitions 22 to 24. In that case, between the first chamber 14A and the second chamber 14B, between the first chamber 15A and the second chamber 15B, and in the first chamber 1
Since heat transfer between 6A and the second chamber 16B can be reduced, the efficiency of distillation can be increased.

A feed nozzle 41 is formed substantially at the center of the column side of the combined distillation column 10 in communication with the first chamber 15A, and a side cut nozzle 42 is formed in communication with the second chamber 15B. Also, the combined distillation column 1
The first section 11 is disposed at the top of the
Section 11 has a steam outlet 4 connected to a condenser 81
3 and a reflux liquid inlet 44 are respectively formed. further,
A ninth section 19 is provided at the bottom of the combined distillation column 10, and a bottoms outlet 45 and a vapor inlet 46 are formed in the ninth section 19 by being connected to an evaporator 82. A distillation apparatus is constituted by the combined distillation column 10, the condenser 81, the evaporator 82 and the like.

In the first distillation section 25,
First chamber 1 disposed above feed nozzle 41
The enrichment section AR1 is formed by 4A, and the collection section AR2 is formed by the first chamber 16A disposed below the feed nozzle 41. In the second distillation section 26, the enrichment section AR3 is formed by the second section 12 disposed above the upper end of the first distillation section 25, and the recovery section AR4 is formed by the second chamber 14B. You. Further, in the third distillation section 27, the enrichment section AR5 is formed by the second chamber 16B by the first distillation section 25.
The collecting sections AR6 are respectively formed by the eighth sections 18 disposed below the lower ends of the sections.

In this manner, the upper end of the first distillation section 25 is connected to substantially the center of the second distillation section 26, and the lower end of the first distillation section 25 is connected to substantially the center of the third distillation section 27. You.

In the combined distillation column 10 configured as described above, the stock solution M containing the components A to C is supplied through the feed nozzle 41. Component A has a lower boiling point than component B, and component B has a lower boiling point than component C. Then, the collection unit AR2
In, the stock solution M supplied via the feed nozzle 41 descends, generates vapors rich in the components A and B upward, and generates liquids rich in the components B and C as it goes downward. From the lower end of the section 25 to the third distillation section 27
Is supplied with a liquid rich in components B and C.

The liquids rich in the components B and C are heated in the third distillation section 27 to become vapors rich in the components B and C, and while rising in the recovery section AR2, the undiluted solution M
To generate a vapor rich in components A and B from the stock solution M.

Subsequently, the vapors rich in components A and B are:
The liquid rising in the enrichment section AR1 is supplied from the upper end of the first distillation section 25 to the second distillation section 26, cooled and condensed in the second distillation section 26, and is rich in components A and B. become. Then, a part of the liquid rich in the components A and B is refluxed to the concentration section AR1, and is brought into contact with the vapor rich in the components A and B rising in the concentration section AR1. In this way, vapors rich in components A and B are supplied from the upper end of the first distillation section 25 to the second distillation section 26.

In the recovery section AR6, the liquid rich in the components B and C descends, and generates vapor rich in the component B at the upper portion and generates liquid rich in the component C at the lower portion. Therefore, the liquid rich in the component C is discharged from the bottom outlet 45 as bottoms.

A part of the bottom liquid discharged from the bottom liquid outlet 45 is sent to the evaporator 82 and is heated by the evaporator 82 to become a vapor rich in the component C. The steam rich in the component C is supplied from the steam inlet 46 to the ninth section 19, and the inside of the ninth section 19 and the recovery section AR
As it rises in 6, it comes into contact with the liquids rich in components B and C, generating vapors rich in component B from the liquids rich in components B and C.

Subsequently, a part of the vapor rich in the component B is
The liquid rises in the enrichment section AR5 and comes into contact with the liquid rich in the component B from the second distillation section 26 at the upper end of the third distillation section 27 to become a liquid rich in the component B. In this way, the liquid rich in component B obtained at the upper end of the third distillation section 27 is converted into a side cut liquid by the side cut nozzle 4.
Exhausted from 2.

On the other hand, the recovery section AR of the second distillation section 26
At 4, the liquids rich in components A and B descend, producing vapors rich in component A above and liquids rich in component B downward. The liquid rich in component B obtained at the lower end of the second distillation section 26 is discharged from the side cut nozzle 42 as a side cut liquid. Then, the vapor rich in the component A rises in the enrichment part AR3, and the vapor outlet 43
And is sent to the condenser 81 and the condenser 81
To form a liquid rich in component A, and the liquid rich in component A is discharged as a distillate.

Thus, the vapor rich in components A and B is separated into the vapor rich in component A and the liquid rich in component B in the second distillation section 26, and The vapor is discharged at the top into a liquid rich in component A, which is discharged as a distillate. On the other hand, the liquid rich in the component B is discharged from the side cut nozzle 42 as a side cut liquid. The liquid rich in components B and C is separated into a liquid rich in component B and a liquid rich in component C in the third distillation section 27, and the liquid rich in component B is used as a side cut liquid. The liquid rich in the component C discharged from the side cut nozzle 42 is discharged as bottom liquid at the bottom of the column.

Then, in order to increase the efficiency of distillation of the component A, a part of the distillate discharged from the condenser 81 is refluxed from the reflux liquid inlet 44 to the first section 11 as a reflux liquid, and is concentrated. It is brought into contact with the vapor rich in component A rising in the section AR3.

In this embodiment, each of the enrichment sections AR1, AR3, AR5 and each of the recovery sections AR2, AR
4. AR6 is formed by a packing consisting of one node, but depending on the relative volatility between the components to be distilled, the packing used to secure the number of theoretical plates required for distillation is It can also be formed by a filling consisting of a plurality of nodes depending on the properties. In addition, a distributor can be provided between nodes. Further, the feed nozzle 41 and the side cut nozzle 42 do not always need to be arranged at the same height.

In this way, the stock solution M can be separated into the components A to C without using a composite column.
Further, since it is not necessary to repeat heating and cooling in the composite tower, it is not necessary to arrange a large number of instrumentation components such as a condenser, an evaporator, and a pump. Therefore, not only the occupied area can be reduced, but also the usage amount and energy consumption of the utility can be reduced, and the cost of the distillation apparatus can be reduced.

The combined distillation column 10 has about 30 to 100 theoretical plates as a whole, and the fourth section 14 and the sixth section 16 each have about 5 to 30 plates. preferable.

A collector 54 and a channel-type distributor 61 are provided in the third section 13. The liquid collected by the collector 54 is distributed by the distributor 61 to the first section at a predetermined distribution ratio.
Different amounts are distributed to the chamber 14A and the second chamber 14B.

A collector 62 is disposed immediately above the feed nozzle 41 in the first chamber 15A, and a tubular distributor 63 is disposed immediately below the feed nozzle 41.
The liquid collected by the distributor 6 together with the stock solution M supplied through the feed nozzle 41
3 to the first chamber 16A.

On the other hand, a chimney hat type collector 65 is provided immediately above the side cut nozzle 42 in the second chamber 15B.
However, a tubular type distributor 66 is disposed immediately below, and a part of the liquid collected by the collector 65 is used as a side cut liquid by the side cut nozzle 4.
2 and the remainder is supplied by the distributor 66 to the second chamber 16B.

Further, a collector 67 and a tubular distributor 68 are provided in the seventh section 17, and the liquid descending from the sixth section 16 is:
After being collected by the collector 67, it is supplied to the eighth section 18 by a distributor 68.

By the way, in the present embodiment, the second
The liquid descending from the section 12 to the third section 13 is distributed by the distributor 61 to the first chamber 14A and the second chamber 14B. It is set in advance based on the distillation conditions such as the composition, the number of theoretical plates of the combined distillation column 10, and the purity (quality) required for the product.

For this purpose, the distributor 61
Comprises a distributor (not shown) for distributing liquid in a direction perpendicular to the partition 22, and the first
The amount of the liquid supplied to the chamber 14A is made different from the amount of the liquid supplied to the second chamber 14B.
Since the side cut liquid is discharged from the side cut nozzle 42, the amount of the liquid supplied to the second chamber 14B is larger than the amount of the liquid supplied to the first chamber 14A.

When it is necessary to change the distillation conditions in order to obtain two or more types of products in the distillation apparatus, it is necessary to change the distribution ratio in accordance with the distillation conditions. Therefore, a plurality of the distribution units are provided, and the distribution ratio is made different for each distribution unit. Therefore, the liquid descending from the second section 12 is
It is collected by the collector 54 and is selectively supplied to the distributor 61 via the switching valves 83 and 84.

As described above, since the liquid can be distributed at the optimum distribution ratio only by disposing the distribution unit, a large number of analyzers, a flow controller, a flow control valve, a level sensor, and the like for distributing the liquid can be provided. Not only is there no need to dispose instrumentation components, but there is no need to operate each instrumentation component to perform complicated control. Therefore, not only the size of the distillation apparatus can be reduced, but also the cost of the distillation apparatus can be reduced.

By the way, in manufacturing the distillation apparatus,
It is desirable to perform a simulation and evaluate the simulation result, but a simulation program for a distillation apparatus including the combined distillation column 10 is not provided. Therefore, a simulation program (Simulation Sciences In) which is created by combining a single distillation calculation model and is intended for a distillation apparatus having a combined column including a main tower and a side tower.
c. "PRO / II" simulation program "Distillation Column Unit"
Operation "," Side Column "
s ").

FIG. 4 is a diagram showing a distillation apparatus assumed in the simulation program according to the embodiment of the present invention.

In the figure, 31 is the main tower, 32 is the side tower, 3
Reference numeral 3 denotes the main body of the main tower 31, 34 denotes the main body of the side tower, 35 denotes a condenser, 36 denotes an evaporator, and 70 denotes a liquid reservoir. The main tower 31 has 42 theoretical plates, and the condenser 35 has a plate #
1, stage # 2 to stage # 41 are set in the tower main body 33, and stage # 42 is set in the evaporator 36. The side tower 32 has 20 theoretical plates, and the columns D1 to D20 (in the figure, for convenience, columns D1, D3, D5, D7, D9, D
Only 11, D13, D15, D17, D19, D20 are represented. ) Is set. The main tower 31, the side tower 3
2. A distillation apparatus is constituted by the condenser 35, the evaporator 36, and the like.

On the tower side of the main tower 31, the feed nozzle 71 communicates with the stage # 22 and the liquid outlet 91 and the vapor inlet 94 communicate with the stage # 12 as the first position. A vapor outlet 95 and a liquid inlet 98 are respectively formed in communication with the stage # 32 as a position. At the top of the main tower 31, a vapor outlet 73 and a reflux liquid inlet 74 are formed in communication with the stage # 2. At the bottom of the main tower 31, the bottom outlet of the main tower 31 is communicated with the stage # 41. A steam inlet 76 is formed.

On the side of the side tower 32, a side cut nozzle 72 is formed in communication with the stage D10. At the top of the side tower 32, a liquid inlet 92 and a vapor outlet 93 are formed in communication with the stage D1. At the bottom of the side tower 32, a vapor inlet 96 and a liquid outlet 97 are formed in communication with the stage D20.

In the distillation apparatus, the enrichment section BED1 is performed by the stages # 2 to # 11, the enrichment section / recovery section BED2 is performed by the stages # 12 to # 31, the recovery section BED3 is performed by the stages # 32 to # 41, and the stage D1 is performed. Collection unit BE by ~ D10
D4 forms the concentration section BED5 by the steps D11 to D20.

Therefore, when the stock solution M is supplied to the tower side of the main tower 31 via the stock solution flow path L11 and the feed nozzle 71, steam rich in the component A is discharged from the steam outlet 73, and The rich vapor is sent to the condenser 35 and condensed into a liquid rich in the component A. The liquid rich in the component A is discharged from the condenser 35 as a distillate, and is stored in the liquid reservoir 70. ) A part of the distillate discharged from the reservoir 70 is refluxed as reflux liquid from the reflux liquid inlet 74 to the stage # 2, and the remainder of the distillate is returned to the distillate flow path L12.
To a distillate storage unit (not shown). Also,
A liquid rich in the component C is discharged from the bottom outlet 75 as a bottom liquid, and a part of the bottom liquid is sent to the evaporator 36 and evaporated to be a vapor rich in the component C. The vapor rich in the component C is sent to the vapor inlet 76, and is supplied to the stage # 41 from the vapor inlet 76, and the remainder of the bottoms is returned to the bottoms storage section (not shown) via the bottoms flow path L13. Sent to
Then, the liquids rich in the components A and B are discharged from the liquid outlet 91, supplied to the stage D1 from the liquid inlet 92 via the first liquid flow path L1, and the vapor rich in the components A is discharged from the vapor outlet 93. Then, the steam is supplied from the steam inlet 94 to the stage # 12 via the first steam flow path L2. Further, steam rich in the components B and C is discharged from the steam outlet 95, and is supplied from the steam inlet 96 to the stage D20 through the second steam flow path L4,
A liquid rich in the component C is discharged from the liquid outlet 97, and the second
Is supplied from the liquid inlet 98 to the stage # 32 via the liquid flow path L3. Further, the component B from the side cut nozzle 72
Is discharged and sent to a side cut liquid storage section (not shown) via the side cut liquid flow path L14.

S1 is the flow rate of the undiluted solution M flowing in the undiluted liquid flow path L11, S2 is the flow rate of the distillate flowing in the distillate flow path L12, S3 is the flow rate of the distillate flowing in the distillate flow path L13, S
4 is the flow rate of the liquid flowing through the first liquid flow path L1, S5 is the flow rate of the vapor flowing through the second vapor flow path L4, S6 is the flow rate of the vapor flowing through the first vapor flow path L2, and S7 is the second liquid Channel L
3, the flow rate of the liquid flowing through the side cut liquid flow path S8
4 is the flow rate of the side cut liquid flowing through the liquid.

Next, using a simulation program assuming a distillation apparatus provided with a combined column comprising the main tower 31 and the side tower 32 having the above-described configuration, a distillation apparatus provided with the combined distillation column 10 shown in FIG. A simulation method for performing a simulation will be described.

FIG. 1 is a flowchart showing the operation of the simulation method according to the embodiment of the present invention, and FIG. 5 is a block diagram of a simulation apparatus according to the embodiment of the present invention.

In FIG. 5, 101 is a control unit, 102 is an operation panel as input means, 103 is a display as first output means, and 104 is a printer as second output means. The operator operates the display 103
When the operation panel 102 is operated on the basis of instructions, messages, and the like displayed on the screen of FIG. 1 to input predetermined items, the control unit 101 performs a simulation operation, performs a technical calculation, and displays the calculation result of the technical calculation. It is displayed on the screen of the display 103 or printed by the printer 104.

In this case, benzene (B) is used as the component A.
A simulation method for simulating a distillation apparatus for distilling a stock solution M containing toluene (T) as component B and xylene (X) as component C will be described. Then, a commercially available simulation program incorporating a general distillation calculation method is used. The simulation program is created by appropriately combining a single distillation calculation model, and is intended for a distillation apparatus having a combined column including a main column 31 (FIG. 4) and a side column 32.

First, the operator operates the operation panel 102 to control the flow rate of the stock solution M as a raw material supplied to the combined distillation column 10 through the feed nozzle 41 (FIG. 2), that is, the feed flow rate and the stock solution M. , The composition of the components A to C, ie, the raw material composition, the composition of the component B in the side cut liquid as a product, ie, the product composition, the main tower 3
The calculation conditions for the pressure in the first and side columns 32, that is, the operating pressure, the number of theoretical plates of the combined distillation column 10, that is, the number of theoretical plates, and the like are set as follows.

[0056] Next, the operator operates the operation panel 102 to input simulation conditions in order to set performance specifications of the distillation apparatus, and records the simulation conditions in an input holder (not shown) as recording means.

That is, the operator first inputs the flow rate (the amount of distillate withdrawn at the tower top) S2 [kg / hr] based on the target material balance, and then inputs the target material balance. Based on this, a flow rate (amount of withdrawn liquid at the bottom of the column) S3 [kg / hr] is input as follows.

Flow rate S2: 50 [kg / hr] Flow rate S3: 50 [kg / hr] Next, the operator inputs a liquid distribution ratio η. In this case, in the simulation program, the flow rate of the liquid descending on the feed side (stage # 12 in the tower main body 33) among the liquid descending from the top of the tower main body 33 to Sm
[Kg / hr]. Then, the flow rate S4 [kg / h
r] is sent from the main tower 31 to the side tower 32 (stage D1 in the tower body 34) via the first liquid flow path L1.
The liquid distribution ratio η for distributing the liquid to the feed side and the side cut side is represented by η = Sm / S4.

Then, the operator operates the combined distillation column 10.
In, is distributed by the distributor 61,
The distribution ratio of the liquid supplied to the first chamber 14A and the second chamber 14B is input as the liquid distribution ratio η. Then, the most standard distribution ratio of each of the flow rates Sm and S4 is set so that the value of the distribution ratio is 10 in total, for example, Sm: S4 = 3: 7. In this case, the liquid distribution ratio η is η = 0.42857.

The distribution ratio and the liquid distribution ratio η of each of the flow rates Sm and S4 can be arbitrarily set.

As described above, the distribution ratio of the liquid in the combined distillation column 10 depends on the feed side and the side column 3 in the main column 31.
2 is converted into the liquid distribution ratio η on the side cut side, so that the convergence of a simulation operation described later can be improved.

Next, the operator sets the flow rate S5 [kg / h
r], that is, the provisional flow rate is set to the initial value dS
Set as 5 and enter as follows:

DS5: 1579 [kg / hr] By using the controller function CN1 incorporated in the simulation program in advance, the flow rate S5 is converged according to a predetermined convergence condition and becomes a normal value.

Subsequently, the operator sets a default value of the heating heat amount Qr [kcal / hr] in the evaporator 36, that is, a provisional heating heat amount as an initial value dQr, and inputs as follows.

DQr = 0.27981 × 10 ⁶ [kcal / hr] Note that by using the controller function CN2 previously incorporated in the simulation program, the heating heat amount Qr is converged according to a predetermined convergence condition, and Value.

When the simulation conditions are input as described above, the operator operates the operation panel 102 to input the connection stream of the main tower 31. That is, the operator sets the raw liquid flow path L11 and the distillate flow path L1.
2, bottom liquid flow path L13, first liquid flow path L1, second vapor flow path L4, first vapor flow path L2, and second liquid flow path L
# 3, stages # 22, # 1, # 42, # 1
2, # 32, # 12, and # 32 are input, and the distillate flow path L12, the bottom liquid flow path L13, and the first liquid flow path L1
For the distillate, bottoms, liquid and vapor flowing through the second vapor flow path L4, the flow rates S2 to S5 and the phase (liquid phase or gas phase) are input as follows.

Flow rate S2: 50 [kg / hr] Distillate phase: liquid phase Flow rate S3: 50 [kg / hr] Boiler phase: liquid phase Flow rate S4: 1000 [kg / hr] Liquid phase: Liquid phase Flow rate S5: 1000 [kg / hr] Vapor phase: Gas phase Next, the operator operates the operation panel 102 to determine the packing data and the column diameter in the combined distillation column 10 and the main column 31 and the side. Input is made in correspondence with the packing data and the column diameter in the column 32. In this case, the enrichment section AR1 and the recovery section AR2 in the combined distillation tower 10 are respectively provided in the main tower 31.
The enrichment section AR3 in the combined distillation column 10 is made to correspond to the enrichment section BED1 in the main tower 31, and the collection section AR4 and the enrichment section AR5 in the combined distillation tower 10 are Each of them corresponds to the recovery section BED4 and the enrichment section BED5 in the side tower 32, and is connected to the recovery section AR6 in the combined distillation tower 10.
Is made to correspond to the recovery section BED3 in the main tower 31.

The packing data is stored in the enrichment section BED1, enrichment section / collection section BED2, collection section BED3, and collection section BED.
4 and the type of each packing in the concentration section BED5, and each packing height. In this case, as the type of each of the fillers, a regular filler (“MELL” manufactured by Sumitomo Heavy Industries, Ltd.)
APAK250Y ”,“ MELLAPAK250X ”
4500 [mm] are input as the filling heights.

Further, regarding the column diameter, the combined distillation column 10
The first chambers 14A to 16A and the second chambers 14B to 16 in
B, ie, the equivalent diameters δ1 and δ2 are calculated, and the equivalent diameters δ1 and δ2 are calculated as the main tower 31 and the side tower 3 respectively.
Input as the tower diameter of 2.

When the diameter of the column body of the combined distillation column 10 is d, the sectional area of the first chambers 14A to 16A is Q1, and the sectional area of the second chambers 14B to 16B is Q2, the sectional area is Q1, if Q2 are equal, becomes ^{Q1 = Q2 = (πd 2/} 4) / 2 = πδ1 2/4 = πδ2 2/4. Therefore, the equivalent diameters δ1 and δ2 are as follows: δ1 = δ2 = d / √ (2)

In this case, the equivalent diameters δ1 and δ2 are 100
0 [mm] is input.

When the flow rate S8 is smaller than the flow rates S2 and S3, the present invention can also be applied to an eccentric combined distillation column having an eccentric middle partition in the tower body. In this case, the equivalent diameter does not become d / √ (2), but the actual cross-sectional area of the first chambers 14A to 16A and the second chambers 14B to 16B.
It is calculated based on the cross-sectional area of B.

Next, the operator operates the operation panel 102 to input the connection stream of the side tower 32. That is, the operator operates each stage D1 to which the first liquid flow path L1, the second vapor flow path L4, the first vapor flow path L2, the second liquid flow path L3, and the side cut liquid flow path L14 are connected. , D
20, D1, D20, D10, and the first
For the steam, liquid and side cut liquid flowing through the vapor flow path L2, the second liquid flow path L3 and the side cut liquid flow path L14, the flow rates S6 to S8 and the phase (whether liquid phase or gas phase) are as follows. Enter

Flow rate S6: 1000 [kg / hr] Vapor phase: gas phase Flow rate S7: 1000 [kg / hr] Liquid phase: liquid phase Flow rate S8: 900 [kg / hr] Side cut liquid phase: liquid phase Subsequently, the operator operates the operation panel 102 to
By inputting the pressure Pa [mmHg] at the top of the side tower 32, preparations are made for a first convergence process described later. Note that the pressure Pa is the same as the pressure in the stage # 12 of the main tower 31.
Is equal to the pressure at

Next, when the operator operates the operation panel 102 to give an instruction to start the simulation work,
The control unit 101 starts a simulation operation.

Accordingly, when the operator operates the operation panel 102 to specify the controller function CN1 incorporated in the simulation program in advance, the first convergence processing means (not shown) of the control unit 101 1 is performed. In the first convergence process, the pressure loss in the first chambers 14A to 16A is defined as the pressure loss DPM in stages # 12 to # 31 in the main tower 31, and the pressure loss in the second chambers 14B to 16B is determined as the side tower 32.
When the pressure loss DPS at the stages D1 to D20 is set, the repetitive calculation for reducing the pressure loss difference ΔDP is performed.

In this case, as described above, the pressure P
a [mmHg] and the pressure in the stage # 12 of the main tower 31 are made equal, so that the steam rich in the components B and C flows from the steam outlet 95 to the steam inlet 96 through the second steam in order to reduce the pressure loss difference ΔDP. The pressure difference is reduced by the balance of the flow rate sent through the steam flow path L4.

That is, when the pressure in the stage D20 of the side tower 32 is P1 [mmHg] and the pressure in the stage # 32 of the main tower 31 is P2 [mmHg], the pressures P1, P2
Iterative calculation is performed so that the pressure difference ΔP becomes 0 (zero).
Therefore, the target value of the pressure difference ΔP is a predetermined value close to 0,
In this embodiment, the pressure difference is set to 0.0001 [mmHg], the flow rate S5 is set as a variable, and the pressure difference ΔP is set to 0.0
The flow rate S5 is changed by iterative calculation so as to converge to 001 [mmHg], and is converged. In the present embodiment, the initial value dS5 is 1579 [kg / h
r], and the flow rate S5 is finally converged to 158
0.7095 [kg / hr].

In the repetitive calculation, first, the initial value d
The pressure difference ΔP is calculated based on S5, the flow rate S5 is changed at a predetermined rate of change corresponding to the calculated pressure difference ΔP, and the calculation of the pressure difference ΔP and the change of the flow rate S5 are performed when the pressure difference ΔP becomes 0. .0001 [mmHg] or less.

As described above, since the repetitive calculation is automatically performed by the controller function CN1, the operation of converging the pressure difference ΔP and the flow rate S5 can be simplified.
Therefore, the convergence of the simulation work can be improved.

The feed side (stage # 3 in the tower body 33)
Since the convergence of the steam distribution ratio for distributing the steam to 2) and the side cut side (stage D20 in the tower main body 34) can be improved, the convergence of the simulation operation can be improved. Then, the flow rate of the steam rising on the feed side and the flow rate of the steam rising on the side cut side can be easily set.

When the operator operates the operation panel 102 and designates the controller function CN2 previously incorporated in the simulation program,
A second convergence processing unit (not shown) of the control unit 101 performs a second convergence process. In the second convergence process, an appropriate heating heat amount Qr corresponding to the distillate reflux ratio RR
Is repeatedly calculated so that is obtained.

In this case, the reflux ratio RR is equal to the flow rate Sr [mo of the liquid refluxed to the stage # 2 via the reflux liquid inlet 74.
1 / hr] and the flow rate S2 [mol / hr], and is represented by RR = Sr / S2.

Then, the reflux ratio RR is set to 60,
The calorific value Qr is used as a variable, and the reflux ratio RR converges to 60.
Thus, the heating heat amount Qr is changed by the repetitive calculation,
Be bundled. In the present embodiment, the initial value d
Qr is 0.27981 × 10 ⁶[Kcal / hr]
The heating heat amount Qr is finally converged to 0.280
32 × 10⁶[Kcal / hr].

In the repetitive calculation, first, the initial value d
The recirculation ratio RR is calculated based on Qr, and the heating heat amount Qr is changed at a predetermined rate of change in accordance with the calculated recirculation ratio RR. The process is repeated until the reflux ratio RR reaches 60 at 0.001. The convergence accuracy is selected depending on the rigor of the process of the distillation apparatus.

As described above, the repetitive calculation is automatically performed by the controller function CN2, so that the operation of converging the reflux ratio RR and the heating heat amount Qr can be simplified. Therefore, the convergence of the simulation work can be improved. In addition, an appropriate amount of heating heat Qr corresponding to the reflux ratio RR can be easily obtained.

When the simulation operation is completed, the distillate obtained at the top of the main tower 31, the main tower 31
Can be obtained as simulation results of the bottom flow obtained at the bottom of the column and the flow balance of the side cut liquid obtained at the column side of the side column 32.

Next, the flowchart will be described. Step ST1 Calculation conditions are set. Step ST2 Distillate flow rate S2 and bottoms flow rate S
Enter 3. Step ST3 The liquid distribution ratio η is input. Step ST4 The initial value dS5 of the steam flow rate S5 is input. Step ST5 An initial value dQr of the heating heat amount Qr is input. Step ST6 The connection stream of the main tower 31 is input. Step ST7 The packing data and the column diameter are input. Step ST8 The connection stream of the side tower 32 is input. Step ST9 A first convergence process is performed. Step ST10 A second convergence process is performed, and the process ends.

The present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0090]

As described above in detail, according to the present invention, in the method for simulating a distillation apparatus, the inside of the tower body is divided into the first chamber and the second chamber by a partition, and the undiluted solution is placed on the side of the tower. Is supplied, a distillate is discharged at the top of the column, a bottoms is discharged at the bottom of the column, and a distillation apparatus equipped with a combined distillation column from which side cut liquid is discharged at the side of the column. The set first position and the top of the side tower are connected by the first liquid flow path and the first vapor flow path, and the second position set below the main tower and the bottom of the side tower Are simulated using a simulation program of a distillation apparatus having a composite column connected by a second liquid flow path and a second vapor flow path.

The distribution ratio for distributing the liquid descending from the top of the combined distillation column to the first chamber and the second chamber is determined by adjusting the liquid descending from the top of the main tower to the inside of the main tower. The flow rate of each liquid set to be distributed to the liquid descending on the feed side and the liquid sent to the side tower through the first liquid flow path and descending on the side cut side in the side tower. And the initial value of the flow rate of the steam supplied from the feed side to the side cut side. Further, based on the initial value of the flow rate of the steam, the pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower is calculated, and the pressure difference is calculated according to the calculated pressure difference. Change the steam flow.

In this case, the distribution ratio of the combined distillation column is converted into the liquid distribution ratio of the main column and the side column, and the initial value of the flow rate of the steam supplied from the feed side to the side cut side is inputted. Based on the initial value of the flow rate of the steam, a pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower is calculated, and the pressure difference of the steam corresponding to the calculated pressure difference is calculated. Since the flow rate is changed, the convergence of the simulation work can be improved.

In another method for simulating a distillation apparatus according to the present invention, the inside of the tower body is divided into a first chamber and a second chamber by a partition, and a stock solution is supplied to the side of the tower, and a distillate is collected at the top of the tower. Discharged, bottom product is discharged at the bottom of the column, and the first position set above the main column and the side column of the distillation apparatus having the combined distillation column in which the side cut liquid is discharged at the side of the column. The top is connected to the first liquid flow path and the first vapor flow path, and the second position set below the main tower and the bottom of the side tower are connected to the second liquid flow path and the second liquid flow path. The simulation is performed using a simulation program of a distillation apparatus provided with a composite column connected by the vapor flow path.

The distribution ratio for distributing the liquid descending from the top of the combined distillation column to the first chamber and the second chamber is determined by changing the liquid descending from the top of the main tower to the inside of the main tower. The flow rate of each liquid set to be distributed to the liquid descending on the feed side and the liquid sent to the side tower through the first liquid flow path and descending on the side cut side in the side tower. , And the initial value of the heating heat amount in the evaporator connected to the main tower. Further, a reflux ratio of the distillate is calculated based on the initial value of the heating heat amount, and the heating heat amount is changed in accordance with the calculated reflux ratio.

In this case, the distribution ratio of the combined distillation column is converted into the liquid distribution ratio of the main column and the side column, and the initial value of the amount of heating heat in the evaporator connected to the main column is inputted. The reflux ratio of the distillate is calculated based on the initial value of the heat amount, and the heating heat amount is changed in accordance with the calculated reflux ratio, so that the convergence of the simulation operation can be improved.

[0096] In still another method for simulating a distillation apparatus according to the present invention, the inside of the tower main body is partitioned by a first partition.
Compartment and a second compartment, and the undiluted solution is supplied to the tower side,
A distillate is discharged at the top of the column, a bottoms is discharged at the bottom of the column, and a distillation apparatus having a combined distillation column in which a side cut liquid is discharged at the side of the column. The first position and the top of the side tower are connected by the first liquid flow path and the first vapor flow path, and the second position set below the main tower and the bottom of the side tower are connected to the second position. The simulation is performed using a simulation program of a distillation apparatus having a composite column connected by a liquid flow path and a second vapor flow path.

The distribution ratio for distributing the liquid descending from the top of the combined distillation column to the first chamber and the second chamber is determined by changing the liquid descending from the top of the main tower to the inside of the main tower. The flow rate of each liquid set to be distributed to the liquid descending on the feed side and the liquid sent to the side tower through the first liquid flow path and descending on the side cut side in the side tower. , The initial value of the flow rate of steam supplied from the feed side to the side cut side, and the initial value of the amount of heating heat in the evaporator connected to the main tower. Further, based on the initial value of the flow rate of the steam, the pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower is calculated, and the pressure difference is calculated according to the calculated pressure difference. The flow rate of steam is changed, the reflux ratio of the distillate is calculated based on the initial value of the heating heat amount, and the heating heat amount is changed in accordance with the calculated reflux ratio.

In this case, the distribution ratio of the combined distillation column is converted into the liquid distribution ratio of the main column and the side column, and the initial value of the flow rate of the steam supplied from the feed side to the side cut side is inputted. Based on the initial value of the flow rate of the steam, a pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower is calculated, and the pressure difference of the steam corresponding to the calculated pressure difference is calculated. While the flow rate is changed, the initial value of the heating heat in the evaporator connected to the main tower is input, and the reflux ratio of the distillate is calculated based on the initial value of the heating heat, and the calculated reflux is calculated. Since the amount of heating heat is changed according to the ratio, the convergence of the simulation work can be improved.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an operation of a simulation method according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a combined distillation column according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram of a distillation apparatus according to an embodiment of the present invention.

FIG. 4 is a diagram showing a distillation apparatus assumed in a simulation program according to the embodiment of the present invention.

FIG. 5 is a block diagram of a simulation device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Combined distillation tower 14A-16A 1st chamber 14B-16B 2nd chamber 22-24 Partition 31 Main tower 32 Side tower 35, 81 Condenser 36, 82 Evaporator L1, L3 1st, 2nd liquid flow path L2, L4 First and second steam channels # 12, # 32 stages

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 13, 2000 (200.11.
13)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Continued on the front page (72) Inventor Yuji Suzuki 2-1-1 Tanidocho, Tanashi-shi, Tokyo Sumitomo Heavy Industries, Ltd. Tanashi Factory F-term (reference) 4D076 AA13 AA22 AA23 AA24 BB04 BB25 BB27 CA11 CC24 DA25 EA03Y EA05Y EA13Y EA13X EA13Y EA14X EA14Y EA16Y EA17Y EA20X EA45 FA31 FA34 FA35 FA37 JA03 4H006 AA05 AC90 5B049 BB07 DD00 EE01 EE41 FF02 FF03 FF04

Claims (3)

[Claims] 1. The inside of a tower body is divided into a first chamber and a second chamber by a partition, a stock solution is supplied to a side of the tower, a distillate is discharged at a top of the tower, and a bottom is discharged at a bottom of the tower. In the distillation apparatus having a combined distillation column from which the side cut liquid is discharged on the side of the column, the first position set above the main column and the top of the side column are the first liquid flow path and A composite column connected by a first vapor flow path, wherein a second position set below the main tower and the bottom of the side tower are connected by a second liquid flow path and a second vapor flow path A simulation method for a distillation apparatus for performing a simulation using a simulation program for a distillation apparatus provided with: (a) a method for distributing a liquid descending from the top of the combined distillation column to a first chamber and a second chamber. The distribution ratio of the liquid descending from the top of the main tower The body is configured to be distributed to a liquid descending on the feed side in the main tower and a liquid sent to the side tower via the first liquid flow path and descending on the side cut side in the side tower. In addition, the flow rate of each liquid is input as a liquid distribution ratio, (b) the initial value of the flow rate of steam supplied from the feed side to the side cut side is input, and (c) the initial value of the flow rate of the steam is input. Calculating the pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower, and (d) changing the flow rate of the steam in accordance with the calculated pressure difference. A simulation method of a distillation apparatus characterized by the following. 2. The inside of the tower body is divided into a first chamber and a second chamber by a partition, a stock solution is supplied to the side of the tower, a distillate is discharged at the top of the tower, and a bottom liquid is discharged at the bottom of the tower. In the distillation apparatus having a combined distillation column from which the side cut liquid is discharged on the side of the column, the first position set above the main column and the top of the side column are the first liquid flow path and A composite column connected by a first vapor flow path, wherein a second position set below the main tower and the bottom of the side tower are connected by a second liquid flow path and a second vapor flow path A simulation method for a distillation apparatus for performing a simulation using a simulation program for a distillation apparatus provided with: (a) a method for distributing a liquid descending from the top of the combined distillation column to a first chamber and a second chamber. The distribution ratio of the liquid descending from the top of the main tower The body is configured to be distributed to a liquid descending on the feed side in the main tower and a liquid sent to the side tower via the first liquid flow path and descending on the side cut side in the side tower. In addition, the flow rate of each liquid is input as a liquid distribution ratio, (b) the initial value of the heating heat amount in the evaporator connected to the main tower is input, and (c) the retention time is calculated based on the initial value of the heating heat amount. A method for simulating a distillation apparatus, comprising: calculating a reflux ratio of a discharged liquid; and (d) changing a heating calorie according to the calculated reflux ratio. 3. The inside of the tower body is divided into a first chamber and a second chamber by a partition, a stock solution is supplied to the side of the tower, a distillate is discharged at the top of the tower, and a bottom liquid is discharged at the bottom of the tower. In the distillation apparatus having a combined distillation column from which the side cut liquid is discharged on the side of the column, the first position set above the main column and the top of the side column are the first liquid flow path and A composite column connected by a first vapor flow path, wherein a second position set below the main tower and the bottom of the side tower are connected by a second liquid flow path and a second vapor flow path A simulation method for a distillation apparatus for performing a simulation using a simulation program for a distillation apparatus provided with: (a) a method for distributing a liquid descending from the top of the combined distillation column to a first chamber and a second chamber. The distribution ratio of the liquid descending from the top of the main tower The body is configured to be distributed to a liquid descending on the feed side in the main tower and a liquid sent to the side tower via the first liquid flow path and descending on the side cut side in the side tower. Further, (b) an initial value of the flow rate of steam supplied from the feed side to the side cut side is input, and (c) an evaporator connected to the main tower. And (d) calculating a pressure difference between the pressure between the steam outlet and the steam inlet in the main tower and the pressure in the side tower based on the initial value of the steam flow rate. Then, (e) changing the flow rate of steam in accordance with the calculated pressure difference, (f) calculating the reflux ratio of the distillate based on the initial value of the heating calorie, and calculating (g) A method for simulating a distillation apparatus, wherein a heating amount is changed in accordance with a reflux ratio.