WO2003022389A1

WO2003022389A1 - Distillation device and distillation method using this device

Info

Publication number: WO2003022389A1
Application number: PCT/JP2002/001705
Authority: WO
Inventors: Hideo Noda; Hiroshi Yamaji
Original assignee: Kansai Chemical Engineering Co., Ltd.
Priority date: 2001-09-10
Filing date: 2002-02-25
Publication date: 2003-03-20
Also published as: JPWO2003022389A1; JP4058410B2

Abstract

A distillation device that is superior in energy saving and distillation efficiency, comprising an evaporation still having a liquid spraying device, a distillation column, a heat exchanger, a condenser, and a fraction receiver, the distillation device being a semicontinuous batch distillation device. The heat exchanger is disposed between the distillation column and the condenser and adapted to exchange heat with the raw liquid to be fed to the distillation column. The vapor from the distillation kettle passes through the distillation column and liquefied by the heat exchanger and/or said condenser, it being arranged that part of the resulting liquid is recovered by the fraction receiver, the rest of the liquid being refluxed to the distillation column, and that the bottom in the distillation column is returned to the evaporation still.

Description

Specification

Distillation apparatus and distillation method using the apparatus

Technical field

The present invention relates to a distillation apparatus and a steaming method using the apparatus. More specifically, the present invention relates to an evaporator having a liquid spraying device, a distillation device having a heat exchanger at a specific position, and a distillation method using the device.

Background art

In general, in batch distillation, the undiluted solution is put into a still pot and heated to evaporate the solution. The steam that reaches the top condenser at the top of the distillation column is condensed by the condenser using cooling water. The distillation is started by refluxing the condensed and liquefied liquid to the distillation column. It is very difficult to recover energy in such a batch distillation. That is, first, starting from heating the undiluted solution, it takes a long time to start the distillation, and a large amount of energy is consumed. Furthermore, when a small amount of undiluted solution is steamed, even if a small amount of undiluted solution is put into the evaporator, heat can not be given to the liquid because only the part containing the liquid can be used as heat transfer medium. It does not warm up and takes a long time to start distillation.

Furthermore, when distilling a stock solution containing multiple components, the components having the lowest boiling point (敁 low boiling components) are taken out from the top of the distillation column in order. Therefore, a mixture of components having a boiling point higher than the lowest boiling point component is called a cut, and is first collected in a separate 1 "1 collection tank, and then distilled twice. In addition, it is usual to carry out distillation, so energy efficiency is low. In addition, the remaining liquid in the evaporator ^ As the temperature decreases, the heat transfer area also decreases in proportion to the liquid volume. Therefore, the amount of evaporation decreases accordingly, and it takes time to evaporate. On the other hand, if the amount of evaporation is small, the distillation column is operated under inefficient conditions, and it is necessary to increase the reflux. That is, since the evaporation rate is reduced and the distillation efficiency is reduced, it is necessary to return more liquid to the distillation column by reflux. Therefore, the distillation time is further increased. Therefore, there is a problem that the more the multicomponent distillation proceeds, the lower the distillation efficiency (energy efficiency) becomes.

A continuous distillation apparatus for improving the distillation efficiency of a multi-component is described in Japanese Patent Application Laid-Open No. H10-137502. This device is a device in which a reboiler is installed at the bottom of the distillation column to evaporate, and the bottom solution is used as an intermediate kettle liquid receiver while continuously supplying undiluted solution. This device is designed to reduce the number of tanks in that it only has to prepare two intermediate tank liquid receivers. However, since a plurality of intermediate kettle liquid receivers are neglected, piping and pumps are required for that, and there is a problem that liquid remains in the piping. In addition, it is necessary to thoroughly clean the piping and the kettle in order to put another liquid into the intermediate kettle liquid receiver. Therefore, it is not suitable for precise distillation. In addition, in the method described in Japanese Patent Application Laid-Open No. H10-133752, a heat exchanger is provided between a steam tower and an intermediate kettle liquid receiver, and the intermediate kettle liquid receiver is returned to the steam tower. The liquid is heated by the heat of the liquid flowing to another intermediate pot liquid receiver. The heat exchanger in this unit became necessary due to the introduction of a process to collect the bottom liquid in the intermediate tank liquid receiver. If an intermediate pot liquid receiver is not required, there is no need to provide a heat exchanger. Therefore, equipment that is not required is attached. In addition, a pump is required to return the liquid to the distillation column. Also, energy is required to evaporate the supplied undiluted solution, so that the reboiler consumes a large amount of heat. Therefore, a simple distillation apparatus that can efficiently fractionate each component from a stock solution containing multiple components has not been provided yet. Disclosure of the invention

The present invention has been made in order to solve the above-mentioned problems, and its main purpose is to perform distillation efficiently in a short time and to efficiently fractionate multiple components with little energy. It is to provide a device.

That is, the present invention relates to a continuous [»1 minute steaming apparatus] equipped with an evaporator having a liquid spraying apparatus, a distillation column, a heat exchanger, a condenser and a fraction receiver, wherein the heat exchanger comprises: The heat exchanger is provided between the distillation column and the condenser, and is configured to exchange heat with a stock solution supplied to the distillation column. Liquefied in an exchanger and / or the condenser, a part of the liquefied liquid is collected in the fraction receiver, and the remaining liquid is configured to return to the distillation column, and the distillation is performed. Provided is a semi-continuous batch distillation device (hereinafter, device) configured to return the bottom liquid of the column to the evaporator.

In addition, the present invention also provides an undiluted solution that is passed through a heat exchanger to collect heat while supplying M to a distillation column in a narrow range, and the bottom liquid of the distillation column is quickly sent to an evaporator having a liquid spraying device. Providing a steaming method (hereinafter referred to as a first method) including a step of continuously supplying and evaporating components from the evaporator to pass through a distillation column, a heat exchanger, and a capacitor in that order to perform fractional distillation. I do.

In a preferred embodiment, the present invention relates to a distillation method in which the bottom liquid is further distilled to "1 minute".

Further, the present invention provides a method for continuously supplying an undiluted solution to a distillation column while recovering heat by passing through a heat exchanger, and continuously supplying a bottom liquid of the distillation column to an evaporating vessel having a liquid spraying device. The evaporating pot is supplied with a power to perform evaporation while controlling the amount of evaporation from the evaporating pot to a constant amount, or the evaporation is performed so that the amount of liquid in the evaporating pot becomes constant. Is passed through a distillation column, a heat exchanger, and a condenser in that order, and is refluxed to the distillation column or a fractional distillation without reflux is performed. (Hereinafter referred to as the second method).

The present invention further relates to a semi-continuous batch distillation apparatus having an evaporator having a liquid spraying device, a heat exchanger, a core and a fraction receiver, wherein the heat exchanger comprises the evaporator and the evaporator. A vapor exchange unit that is provided between the evaporator and the condenser and heat-exchanges with the undiluted liquid supplied to the evaporator; vapor from the evaporator is liquefied by the heat exchanger and / or the condenser and a fraction receiver Provided is a semi-continuous batch distillation apparatus (hereinafter, referred to as a second apparatus), which is configured to be accepted by a company.

Further, the present invention provides a method for continuously feeding a stock solution through a heat exchanger to an evaporating tank having a liquid spraying device, and evaporating components from the evaporating tank to the heat exchanger and the condenser. The present invention provides a distillation method including a step of performing fractional distillation by passing through sequentially (hereinafter, the third method).

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing an example of the distillation apparatus of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

(First device)

FIG. 1 shows the distillation apparatus (first apparatus) of the present invention. Basically, it is a combination of an evaporator 2 having a liquid spraying device 1, a distillation column 3, a heat exchanger 4, a condenser 5, and a fraction receiver 6, 7. The heat exchanger 4 is disposed between the distillation column 3 and the condenser 5, is configured to pass the undiluted solution 9 through the heat exchanger 4 and heat it, and to supply the heated liquid 9 to the distillation column 3. I have.

The evaporator 2 having the liquid spraying device 1 used in the first device of the present invention is an evaporator that keeps the inner surface of the evaporator 2, particularly a portion corresponding to the heat transfer area, always wet. In order to keep the inner surface of the kettle wet at all times, a method of spraying liquid into the kettle with a pump and circulating it may be used. The method of lifting and spraying the liquid with centrifugal force is

Revised ffl paper (Rule 91) When it is lost and when spraying the boiling liquid, it is particularly effective and is preferred. The method of spraying liquid using this centrifugal force is a method invented by the inventor of the present invention. For details, see Japanese Patent No. 32533212 (corresponding to this publication Gazette No. 10333164).

As described above, since the evaporating pot 2 used in the present invention is configured so that the portion corresponding to the heat transfer area is always kept wet, the entire heat transfer area is used effectively, and the heating efficiency and, consequently, the heating efficiency Extremely high evaporation efficiency. Therefore, according to the conventional ["1 minute method", even if the undiluted solution is stored to a certain amount and heated, it takes time for the phase to evaporate. In the present invention, this time is greatly reduced. In addition, since the heating surface is always wet, the device of the present invention is less likely to dry and adhere to non-volatile components, and is easy to clean.

The first device of the present invention is particularly effective when distilling a stock solution containing multiple components to fractionate each component. By using the evaporator 2 having the liquid dispersing device 1, the amount of the liquid containing the last component is very small, and even in such a case, heating can be performed with a heat transfer area of -1-minute. Therefore, as in the case where the evaporator 2 is filled with the liquid, it is possible to supply the distillation column 3 at a substantially maximum speed and a constant amount of vapor. Therefore, the distillation column 3 can be operated with almost the highest efficiency. In the case of the conventional apparatus, when the amount of steam decreases, the efficiency of the distillation column 3 itself decreases, so that the number of effective stages of the distillation column 3 decreases and the amount of reflux must be increased. Therefore, there is a problem that it takes time to collect the fraction. However, when the apparatus of the present invention is used, a substantially constant amount of steam is provided to the distillation column, so that the number of effective stages of the distillation column is increased, and distillation can be performed with optimum and highest efficiency. You need less. In other words, the amount of energy used: becomes smaller.

By providing a heat transfer member such as a coil or a plate inside the evaporator 2, the heat transfer area can be further increased and the evaporation efficiency can be increased. Such a heat transfer body may be provided inside the liquid. In addition, heat transfer body is

Corrected form (Rule 91) When placed in a reflector, a reflector can be provided, and the liquid lifted by centrifugal force can be applied to the reflector and dropped onto the heat transfer body, so that the surface of the heat transfer body can always be wetted. . Furthermore, the heat transfer area may be increased by inclining the evaporator I body. Further, while monitoring the amount of evaporation, the temperature (heating condition) of the heat transfer body may be adjusted so that evaporation a is constant. By increasing the heat transfer area and adjusting it so that a certain amount of evaporation is obtained, the steam efficiency is further improved. This effect can be obtained because the evaporator has a liquid spraying device, particularly a device for spraying liquid using centrifugal force. (First method)

A case where the stock solution 9 containing multiple components is distilled using this distillation apparatus (first apparatus) (first method) will be described. First, a small amount of the stock solution 9 is put into the evaporator 2. At the start, heat is not supplied to heat exchanger 4 because there is no steam from distillation column 3. Thus, stock solution 9 remains cold. However, the undiluted solution 9 enters the evaporating tank 2 having the liquid spraying device 1 and accumulates to some extent. When the evaporating device 2 having the liquid spraying device〗 is activated, the temperature of the liquid (undiluted solution 9) in the evaporating tank 2 immediately rises. And start boiling. The generated steam goes up the distillation column 3 and reaches the heat exchanger 4 and / or the condenser 5. Then, the steam is condensed to reflux 8 and distillation is started. The supply of the stock solution 9 to the distillation column 3 is performed at a calculated rate that matches the physical properties. When the distillation column 3 is stabilized, the lowest boiling component (lowest boiling component) passes through the top of the distillation column 3 and is cooled by the condenser 5 directly from the heat exchanger 4 or through the heat exchanger 4. A part is recirculated, and the rest is collected in fraction receiver 6.

While the stock solution 9 is being supplied, the distillation of the lowest boiling component proceeds while the heat is recovered in this way.

The bottom liquid of the distillation column 3 from which the lowest boiling components have been distilled off contains the remaining components. ing. The bottom liquid moves to the evaporator 2 having the liquid spraying device 1. Since the bottom liquid is sprayed on the inner wall of the evaporator 2 by the liquid spray device 1, it is evaporated at a substantially constant rate. The distillation column 3 has a maximum efficiency at a certain evaporation rate, and the efficiency falls if it is outside of the maximum value. In this evaporator, the heat transfer area is constant irrespective of the amount of liquid in the evaporator, that is, the evaporation rate can be almost always constant. Therefore, the device of the present invention can always be operated at near-maximum efficiency. The supply of the stock solution 9 is performed until the evaporator 2 becomes full, during which time distillation of the lowest boiling component can be performed. When the supply of the stock solution 9 is completed, the heat exchanger 4 for heat recovery has no effect. However, as described later, during continuous distillation (while the stock solution 9 is supplied), it contributes to significant energy saving. are doing.

(2nd method)

Next, the second method of the present invention will be described. Whereas the first method is an apparatus that performs sequential distillation from low-boiling components, the second method is a method of accumulating and collecting in a reboiler, that is, evaporator 2, in order from high-boiling components. It is. In particular, it is an excellent method for recovering small amounts of high boiling components from stock solution 9.

The second method of the present invention will be described based on FIG. First, a certain amount of the stock solution 9 is put into the evaporator 2. When the evaporating pot 2 is heated and the liquid spraying device 1 is operated, the entire heat transfer area of the evaporating pot 2 can be used, so that the liquid immediately rises in temperature and starts to boil. In the apparatus of the present invention, the amount of evaporation is maximum irrespective of the liquid level, and the distillation column 3 is immediately stabilized. When the distillation column 3 is stabilized, the stock solution 9 having passed through the heat exchanger 4 is supplied to the evaporator 2 at a constant speed. At this time, the supply of heat is controlled so that the amount of evaporation is constant. That is, if the supply of the stock solution 9 is continued, the high boiling components are accumulated in the evaporator 2, so that the boiling temperature rises. Therefore, the amount of evaporation is increased by raising the heating temperature. By this operation, the amount of evaporation is increased, and the amount of liquid in the evaporator 2 is kept constant. The supply of the undiluted solution 9 to the distillation tower 3 It is preferable to perform the process from the middle to the top of the distillation tower 3 (the distillation shelf of the distillation tower or the top of the packing). Depending on the substance to be distilled, the most preferable is to supply the stock solution 9 from the top of the distillation column 3. Note that the return flow 8 may or may not be performed. In particular, when the reflux 8 is not necessary, the heat can be directly recovered even if the raw material 9 is supplied from the top of the distillation column 3 without using the heat exchanger 4, which is advantageous in some cases. When the stock solution 9 containing multiple components is fractionated by this operation, the supply of the raw material 9 is terminated, and the concentration of the highest boiling component (highest boiling component) contained in the distillate received in the fraction receiver 6 If is less than the specified value, the first distillation is completed. If the concentration of the highest boiling component is higher than the specified value, it is necessary to perform distillation again. Fraction receiver

The distillate from (6) is passed through the heat exchanger (4), supplied again to the evaporator (2), and collected in the fraction receiver (7) so that the highest boiling point component in the fraction receiver (7) becomes lower than the specified value. Distillation is carried out. By this operation, the highest boiling point component is recovered in the evaporator 2. In the case of a two-component system, the distillate in the fraction receiver 6 is a low-boiling component, and the one recovered in the evaporator 2 is a high-boiling component.

After the distillation is completed, after the temperature in the tower is stabilized, the valve of the pipe between the bottom liquid of the distillation tower 3 and the evaporator 2 is closed to prevent the bottom liquid from entering the evaporator 2. After that, the heating of the evaporator 2 is stopped, and the highest boiling point component is extracted from the evaporator 2. After extracting the highest boiling point component from the evaporator 2, the valve is opened, and the bottom liquid is introduced into the evaporator 2. Next, heating of the evaporator 2 (reboiler) is started, and the evaporator 2 is washed, and then, the washed liquid is removed. Next, the liquid in the fraction receiver 7 is supplied to the distillation column 3 through the heat exchanger 4, and the same operation is repeated, whereby the second high-boiling component is recovered in the evaporator 2. By sequentially repeating this distillation operation, various components having different boiling points in the stock solution 9 are separated and recovered.

Although there is a problem that the high boiling point component will be heated to the end,

The advantage of the two methods is that the low-boiling substance of the stock solution 9 is not heated for a long time. According to the conventional method, the entire amount of the raw material is put into the evaporator 2 (reboiler) and distilled, so that the raw material (particularly, low-boiling components) is exposed to the boiling temperature for a long time. However, in this method, since the low-boiling components are heated only while passing through the distillation column 3, they are most suitable for distillation of heat-sensitive substances.

(2nd device)

A second apparatus according to the present invention is a semi-continuous batch distillation apparatus including an evaporator having a liquid spraying device, a heat exchanger, a capacitor and a fraction receiver, wherein steam from the evaporator is used as the heat source. The heat exchanger is provided between the evaporator and the condenser, and the undiluted solution passes through the heat exchanger. Then, it is configured to be supplied to the evaporator. It differs from the first device in that the distillation column 3 is not provided. That is, in the first apparatus, the function of the distillation column is stopped. Each element constituting the second device has the same function as the first invention.

(3rd method)

The distillation method (third method) using the second apparatus of the present invention will be described with reference to FIG. However, there is no distillation column 3 and the steam from the evaporator 2 is directly supplied to the heat exchanger 4 and there is no reflux 8. First, a certain amount of the stock solution 9 is put into the evaporator 2. When the evaporating pot 2 is heated and the liquid spraying device 1 is operated, the temperature of the liquid (stock solution 9) in the evaporating pot 2 immediately rises and starts boiling. Since the steam from the evaporator 2 is supplied to the heat exchanger 4, the supply stock solution 9 can recover heat when passing through the heat exchanger 4. In this method, evaporation can be started at the same time that the stock solution 9 is put into the evaporator 2, so that the operation time is reduced. In the conventional batch-type evaporation method, since the liquid is stored in the evaporator 2 and then heated, it takes time to store the liquid. However, in this method, heating can be performed while supplying undiluted solution 9, so undiluted solution 9 is evaporated Less time is needed to store in kettle 2.

This apparatus is particularly effective when distilling and recovering low-boiling components from a stock solution 9 which does not require a distillation column or reflux and contains a substance having a large difference in boiling point between high-boiling components and low-boiling components. The stock solution 9 having passed through the heat exchanger 4 is continuously supplied to the evaporator 2. While the stock solution 9 is being supplied, the distillate is received in the fraction receiver 6 and distillation is continued. Even if the supply of the stock solution 9 is completed, the distillation is continued as long as the concentration of the low-boiling components in the fraction receiver 6 is within the specified value. This operation is excellent in that distillation can be performed while recovering heat as compared with the conventional case in which the raw material 9 is entirely put into the evaporator 2 and then evaporated. Further, since the stock solution 9 can be supplied while removing the low-boiling components, the stock solution 9 in an amount corresponding to the amount of the low-boiling components can be further supplied to the evaporator 2. Therefore, it is superior to the above conventional case in that the processing amount of the stock solution 9 can be increased.

By providing the evaporating pot 2 of the present invention with the liquid spraying device 1, the heat transfer surface can be maximally used with a small amount of liquid. Therefore, unlike the conventional batch distillation apparatus, it is not necessary to put the whole amount of the stock solution 9 to be distilled into the evaporator 2 in advance. Further, by exchanging heat between the vapor and the stock solution 9, heat can be recovered to the stock solution 9 to be supplied. For example, if the undiluted solution 9 is 25 ° C and 1000 L water, the undiluted solution 9 is evaporated as before by raising the temperature of the undiluted solution supplied by the generated steam to 90 ° C. Compared to the method of starting heating after putting in kettle 2 (batch type), it is possible to recover about 7425 KCa1 of heat. Assuming that all the water evaporates, the required energy is 5390000 Kca1, so the recovered energy is more than 13%.

When the supply of the undiluted solution 9 is completed, there is no heat recovery. With the use of the apparatus of the present invention, when the supply of the undiluted solution 9 is completed, the evaporation has progressed considerably and the liquid volume of the evaporator 2 has been reduced. It can be small. It goes without saying that even if the device has the same or larger volume, it is good. (Example)

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Example 1 and Comparative Example 1

Semi-continuous batch distillation of a two-component system is performed using the first apparatus shown in FIG. 1 (Example 1). A description will be given of a case where a two-component stock solution 9 is distilled using an evaporator 2 equipped with a liquid spraying device 1 having an actual volume of 1000 L and a heat transfer area of a jacket of 4 m ² . However, for convenience of explanation, the boiling point of the low-boiling component is assumed to be 100 ° C. Supply 10 L of undiluted solution 9 to evaporator 2, and spray undiluted solution 9 on the inner wall of evaporator 2 using liquid spraying device 1. When heating is started at 150 ° C through the jacket of the evaporator 2, 10 L of the undiluted solution 9 rises from room temperature (25 ° C) to 100 ° C within one minute. Immediately, evaporation starts at a rate of about 100 L / hr. When the distillation column 3 is warmed and the reflux 8 is started, the undiluted solution 9 is supplied to the distillation column 3 while being heated through the heat exchanger 4. A part of the liquid condensed in the heat exchanger 4 and a part of the liquid condensed in the condenser 5 are returned to the distillation column 3, and a part is collected in the fraction receiver 6.

As Comparative Example 1, an evaporator with the same volume and heat transfer area as in Example 1 but without the liquid spraying device 1 was used. 100 L of the stock solution is put into the evaporator and heated in the same manner as in Example 1. Since the heat transfer area is the same as when a liquid sprayer is used and when the liquid is full, it takes 100 minutes for 100 L of the stock solution to reach 100 ° C. .

Therefore, when comparing the time until the start of evaporation (heating time), the apparatus of the present invention is earlier by 99 minutes. On the other hand, the distillation time of the low-boiling components in the case of using the apparatus of the present invention and the low-boiling components in the case where the entire amount of the stock solution was previously charged as in Comparative Example 1. Minute distillation time is theoretically the same time. However, in Comparative Example 1, as the liquid level decreases and the heat transfer area decreases, the evaporation rate decreases, and the distillation time becomes longer than that of the apparatus of the present invention. On the other hand, since the device of the present invention has the liquid spraying means 1, it is possible to always use the entire heat transfer area regardless of the amount of the liquid. Therefore, the distillation time is shorter than in Comparative Example 1. Thus, using the distillation apparatus of the present invention reduces the distillation time by at least 99 minutes + α compared to the conventional batch method.

When the apparatus of the present invention is used, heat is exchanged between the steam and the undiluted solution 9 in the heat exchanger 4, which saves energy. In this case, the energy saving (QKcal) is expressed by the formula Q = W X Δ from the stock solution (WKg) and its temperature rise (Δ Τ). Therefore, the amount of energy saving in this embodiment is about 900 X 75 = 7425 Kcal. In addition, a savings of at least 99 minutes in distillation time is achieved.

That is, by using the device of the present invention, two effects of energy saving and time saving are produced. It is understood that when the apparatus of the present invention is used, not only two components but also a multi-component stock solution is used, and time and energy are further greatly saved. Example 2 and Comparative Example 2

A case where a stock solution containing 45% by weight of the component A, 45% by weight of the component B, and 10% by weight of the component C will be described. The boiling point is A <B <C. Also in this case, for convenience of explanation, the description will be made assuming that the boiling point of the component A is 100 ° C.

Using an evaporator with an actual volume of 1000 L and a heat transfer area of about 25 m ² , a half using an evaporator with a liquid spraying device 1 of the present invention and a device with a heat exchanger 4. Continuous batch distillation (method of Example 2) and a case where 100 L of undiluted solution was put into evaporator 2 without liquid sprayer 1 and heat exchanger 4 from the beginning (Comparative Example) Method 2). In the case of Example 2, the stock solution was charged into an evaporator of about 100 L, the jacket was heated with steam at 150 ° C, and the liquid spraying device 1 was rotated. ° C) to 100 ° C within 1 minute. On the other hand, in the method of Comparative Example 2, it takes 100 minutes for 100 000 L of liquid to reach 100 ° C. Since the time during which evaporation starts and the distillation column 3 warms up is the same in either method, the method of Example 2 is reduced by 99 minutes as compared with the method of Comparative Example 2.

Next, distillation is started and in the method of the present invention in which the stock solution 9 is supplied through the heat exchanger 4, the heat recovery is 7425 OOKal. The time required to remove 45% by weight of the A component is shorter when the method of Example 2 is used than when the method of Comparative Example 2 is used. This is because the second embodiment uses the liquid spraying device 1 and therefore can use a maximum of 25 m ² as the heat transfer area even when the amount of liquid is small. In Comparative Example 2 in which the liquid spraying device 1 was not used, the amount of liquid was reduced and the heat transfer area was reduced due to the evaporation of the A component, so that extra time was required and energy loss occurred. Therefore, it is clear that the method of the present invention recovers energy more efficiently and has higher thermal efficiency.

When 100 L of the stock solution was treated and the A component was distilled off, both Example 2 and Comparative Example 2 weighed 45 wt. Capacity is reduced. Since this remaining liquid contains the B component and the C component, the B component is distilled next. The distillation rate of the component B is theoretically the same between the method of the present invention and the method of the comparative example. However, in the conventional method (Comparative Example 2) that does not use the liquid spraying device, the evaporation rate is reduced because the heat transfer area corresponding to the amount is not used because 45% by weight of the A component evaporates. Therefore, a further distillation time is required.

When the B component is distilled, about 1000 L of the last C component remains.

By the end of the recovery of component B, component A passed through heat exchanger 4

By continuously supplying the stock solution containing B and C components, 9 The A 000 L stock solution can be continuously processed to separate the A, B and C components. That is, by using the method of the present invention, 900 L of undiluted solution can be further processed while minimizing the time for heating and the energy for raising the temperature (that is, performing heat recovery). In contrast, the method of Comparative Example 2 requires a heating time and energy for heating. Industrial applicability

Conventionally, in batch distillation, it was necessary to start heating by putting a stock solution into an evaporator, but when using an evaporator with the liquid spraying device of the present invention, distillation can be performed continuously and at a high evaporation rate. The size of the evaporator may be smaller than the volume of the stock solution. For example, when low-boiling components are contained in the stock solution at 50% by volume, the stock solution can be supplied until the liquid (bottom liquid) from which the low-boiling components have been removed becomes full in the evaporator. In other words, it can process twice as much liquid as before, and the equipment has twice the capacity.

The conventional external circulation heating method can also distill low boiling components, but only while the liquid can circulate. Furthermore, this conventional method requires a considerable amount of liquid from the beginning, and in the latter half when the amount of liquid decreases, external circulation cannot be performed, and the distillation column cannot be operated. On the other hand, since the distillation apparatus of the present invention is provided with a liquid spraying apparatus, even if the amount of liquid is small, the liquid is pumped up by centrifugal force and sprayed on the inner wall of the evaporator to form a vaporizer. All heat transfer areas are available. Therefore, even if the amount becomes small, the amount of steam is constant, and the distillation column can be operated at the highest efficiency.

Claims

The scope of the claims

1. A semi-continuous batch distillation apparatus equipped with an evaporator, a distillation column, a heat exchanger, a condenser, and a fraction receiver having a liquid spraying device, wherein the heat exchanger includes the distillation column, the condenser, And heat exchange with the undiluted solution supplied to the distillation column. The steam from the evaporator passes through the distillation column, and the heat exchanger and / or the condenser A portion of the liquefied liquid is collected in the fraction receiver, the remaining liquid is refluxed to the distillation column, and the bottom liquid of the distillation column is collected in the evaporator. Semi-continuous turn, configured to return to

2. The undiluted solution is continuously supplied to the distillation column while recovering heat by passing through a heat exchanger, and the bottom liquid of the distillation column is continuously supplied to an evaporator having a liquid spraying device. A distillation method comprising a step of fractionally distilling an evaporating component from an evaporator through a distillation tower, a heat exchanger, and a condenser in this order.

3. The method according to claim 2, further comprising a step of subjecting the bottom liquid to batch distillation.

4. The undiluted solution is continuously supplied to the distillation column while recovering heat by passing through a heat exchanger, and the bottom liquid of the distillation column is continuously supplied to an evaporator having a liquid spraying device. Evaporation is performed while controlling the amount of evaporation from the evaporator to a constant amount, or evaporating so that the liquid volume in the evaporator becomes constant. , And a condenser, and then a fractional distillation step of refluxing or not refluxing the distillation column.

5. Evaporator with heat sprayer, heat exchanger, condenser and fraction receiver Wherein the heat exchanger is provided between the evaporator and the condenser, and is configured to exchange heat with a stock solution supplied to the evaporator. A semi-continuous batch distillation apparatus, wherein the steam from the evaporator is liquefied in the heat exchanger and / or the condenser and received in a fraction receiver.

6. The undiluted solution is continuously supplied to the evaporator having a liquid spraying device by passing through the heat exchanger, and the evaporating component from the evaporator is passed through the heat exchanger and the condenser in order to perform fractional distillation. A distillation method, comprising the step of:

Corrected form (Rule 91)