JPS63305917A - Production of ultrapure water and equipment thereof and method for using ultrapure water - Google Patents

Abstract

PURPOSE:To obtain high-purity ultrapure water by boiling raw water to gasify and remove volatile components and thereafter generating steam from this raw water and allowing this steam to permeate through a hydrophobic porous membrane and thereafter condensing it. CONSTITUTION:Raw water 111 is introduced into a removal tower 2 of volatile components and boiled by heating it with a heater 110 thereof to gasify carbon dioxide and volatile organic substance contained in raw water and these are discharged together with steam to the outside of the system through an outlet 112 of steam. The raw water wherein carbon dioxide and the volatile organic substance dissolved therein are removed is sent to a film distillation tower 1 with a conveying pump 106 and reheated with a heater 108 for raw water and evaporated. The steam 105 produced by evaporation is filtered with a hydrophobic porous membrane 101 and condensed on the condensation surface 113 of the surface of a pipeline in which cooling water 103 is allowed to flow and taken out as produced water (extra ultrapure water) 104.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for producing ultrapure water, and a method for using the produced ultrapure water. The present invention relates to a technology for producing ultrapure water from raw water containing volatile substances such as carbonic acid components and volatile organic substances, and non-volatile substances such as fine particles and microorganisms.

[Conventional technology]

Semiconductor manufacturing processes and pharmaceutical manufacturing require highly purified water containing as few impurities as possible, that is, ultrapure water. In particular, a large amount of ultrapure water is used in the cleaning process of semiconductor integrated circuits (LSI). The purity of this ultrapure water has a great effect on the product yield, and even higher purity water is required for cleaning modern high-level LSIs (1 megabit, 4 megabit, etc.).

Conventional ultrapure water production equipment uses various filtration membranes, ion exchange resins, germicidal lamps,
It includes a deaeration device and the like, and the entire device is constructed by combining these devices.

[Problem that the invention seeks to solve]

The above conventional technologies include various filtration membranes, ion exchange resin germicidal lamps,
Since it consists of many elemental equipment such as, it is necessary to upgrade each equipment in order to improve the quality of the produced ultrapure water. Also,
There are problems such as elution from piping connecting between elemental devices and elution from the elemental devices themselves.

For this reason, it is difficult to produce ultra-high purity water that is free of microorganisms and particulates using conventional techniques.

Table 1 on page 354 of the aforementioned publication "Environmental Technology" shows the changes in the quality of ultrapure water, but ultrapure water that does not contain microorganisms has not been obtained.

An object of the present invention is to provide a method and apparatus for producing ultrapure water that can obtain water with a higher purity than that of the prior art.

Another object of the present invention is to provide a method for using such ultrapure water.

[Means for solving problems]

The present invention boils raw water containing volatile and non-volatile components to vaporize and remove the volatile components, generates water vapor from the raw water from which the volatile components have been removed, and transfers the water vapor to a hydrophobic porous membrane. The purpose is to produce ultrapure water by permeating it and condensing it.

The hydrophobic porous membrane used is one that allows gas to pass through but not liquid. Specifically, raw water is first boiled by heating or depressurizing operations, and volatile impurities contained in the raw water, such as carbon dioxide components (H2C○s), are removed from the raw water.
+ HCOs-r CO82-), the organic matter is vaporized and removed, and the raw water free of volatile impurities is heated again and evaporated. When the generated steam passes through a hydrophobic porous membrane, it is separated from the accompanying mist, and only highly pure steam is condensed and taken out as produced water.

Note that ultrapure water of even higher purity can be obtained by maintaining the atmosphere in which water vapor is condensed to be saturated water vapor or an inert gas atmosphere to prevent contamination from the outside air.

According to the present invention, it is possible to produce ultrapure water that does not contain any microorganisms. In view of the above, the present invention
It can be said that this is an unprecedented method for producing ultrapure water of extremely high purity. Therefore, hereinafter, the ultrapure water obtained by the present invention will be referred to as ultra-superpure water.

The method for producing ultrapure water of the present invention includes a volatile component removal column equipped with a means for heating raw water containing volatile components and non-volatile components, and a means for exhausting volatile components vaporized by the heating;
The method is equipped with a heating means for evaporating water after removal of volatile components, a hydrophobic porous membrane for transmitting water vapor generated by the heating, and a cooling means for condensing the water vapor that has passed through the membrane. More preferably, it has means for supplying water vapor or an inert gas to the atmosphere in order to maintain the atmosphere in which the water vapor that has permeated through the hydrophobic porous membrane is condensed to be a saturated water vapor or inert gas atmosphere.

According to the present invention, ultra-ultra pure water heated to a temperature higher than room temperature can be obtained. Therefore, it is advantageous for cleaning LSI.

As for the properties of water, there are advantages such as the higher the temperature, the lower the surface tension, the better the affinity with the substrate, and the less affected by static electricity. For this reason, ultrapure water obtained at room temperature is heated before use, but according to the present invention, the above-mentioned advantages can be obtained without particular heating. Moreover, since the water obtained by the present invention has very few impurities, there are various problems in cleaning LSIs, such as not forming a desired LSI pattern, increasing leakage current of the pn junction, and deteriorating the withstand voltage of the gate oxide film. It is possible to alleviate the problem and improve the yield and characteristics of LSI.

Furthermore, according to the present invention, high-temperature ultra-ultra-pure water that does not contain any or almost no microorganisms can be obtained, and even if microorganisms are contained, their proliferation can be significantly suppressed by keeping them at a high temperature, so that they can be used in medical instruments. It is extremely effective for use in cleaning and manufacturing pharmaceutical products.

[Effect]

Normally, tap water and water that has been subjected to reverse osmosis treatment contain large amounts of various inorganic substances, ions, organic substances, and microorganisms. Ultrapure water is produced by gradually removing these impurities. In the present invention, only volatile substances that cannot be removed by distillation (carbon dioxide components, volatile organic components, inorganic components, ammonia, S○3 gas, etc.) are removed in the first stage using methods such as heating, reduced pressure, and ozone oxidation. Remove using. The raw water from which volatile components have been removed is further heated to generate steam. Since volatile components have already been removed from this water vapor, it is highly pure water vapor. When the water vapor further passes through the hydrophobic porous membrane, accompanying water droplets (mist) are removed, resulting in highly pure water vapor containing no impurities other than water. After that, it condenses and becomes ultra-ultra pure water.

Therefore, this poses a problem in ordinary distillation equipment. Components that volatilize at the same temperature (e.g. carbon dioxide components and low-boiling point organic substances) are removed in the previous volatile component removal step, and are prevented from mixing with minute droplets (mist) that are entrained in the steam generated during distillation. On the other hand, air (water vapor) is generated by a hydrophobic porous membrane.
- Because it is handled by liquid (mist) separation, ionic,
It has become possible to produce highly pure ultra-pure water that does not contain impurities such as organic matter, particulates, and viable bacteria.

In addition, by making the atmosphere in which the water vapor that has passed through the hydrophobic porous material condenses into a water vapor-saturated state or an inert gas atmosphere, it is possible to prevent contamination from the air and obtain ultra-ultra pure water with even higher purity. became.

The present inventors have confirmed the fact that the produced water obtained by membrane distillation method contains no or almost no non-volatile components. Based on this fact, we considered removing volatile components that cannot be removed by membrane distillation in a separate process, and arrived at the present invention.

The purpose of the present invention is to provide the step for removing volatile components in raw water before the membrane distillation step, and by doing so, the purity of the produced water can be increased compared to when the step is provided after the membrane distillation step. Specifically, pure water after membrane distillation has the property of easily dissolving substances, and when this pure water is heated to remove volatile components, components in the container may be eluted and the purity may decrease.

Further, heating to remove volatile components after the membrane distillation step also discharges a portion of the produced water, which is uneconomical.

The above-mentioned problem can be solved by providing a volatile component removal step before the membrane distillation step.

When raw water is heated to generate water vapor during the membrane distillation process, mist accompanies the water vapor, but the mist can be separated by passing through a hydrophobic porous membrane.

As a hydrophobic porous membrane, for example, JP-A-60-118
Polyethylene as described in No. 284.

Polyolefins such as polypropylene, polysulfones, polyethersulfones, silicone resins, fluororesins, etc. can be used. It is desirable that the hydrophobicity of the hydrophobic porous membrane also satisfy the conditions described in JP-A-60-118284.

It is known to produce pure water by membrane distillation, for example as shown in JP-A-61-230703.

However, membrane distillation alone is insufficient to remove volatile components and cannot produce ultra-ultra pure water. Specifically, when raw water is evaporated, the volatile components are also vaporized, but when the water vapor is condensed, some of the volatile components are taken in, and the produced water contains no volatile components. This results in a product with low purity.

The most effective means for removing volatile components in the present invention is to boil the raw water to vaporize and remove volatile components. As a means of boiling raw water, it is possible to heat the raw water to a temperature above the boiling point in the atmosphere or to reduce the pressure of the raw water and boil it.

When raw water is heated to vaporize volatile components, heating to a temperature lower than the boiling temperature of the raw water will not be effective in removing volatile components. For example, if the water is heated to a temperature of around 80° C., ultra-ultra pure water as obtained in the present invention cannot be obtained.

Further, when carrying out membrane distillation, it is desirable that only the water vapor of the raw water is brought into contact with the hydrophobic porous membrane. One of the major drawbacks in membrane distillation technology is membrane fouling. When raw water is brought into direct contact with a hydrophobic porous material, the membrane is contaminated by non-volatile components in the raw water, reducing the purity of the produced water. Also, when raw water is brought into contact with the membrane, water vapor is generated due to the sensible heat of the raw water and passes through the membrane, but in order to generate a large amount of water vapor using this method, the area of the membrane must be large and the raw water must be It is required to increase the contact area of the

On the other hand, by contacting only the water vapor generated from raw water from which volatile components have been removed in advance with the hydrophobic porous membrane, it is possible to prevent membrane contamination and increase the purity of the produced water. Furthermore, the size of the membrane can be made smaller compared to a method in which raw water is brought into contact with the membrane.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7. However, the present invention is not limited to these examples.

Example 1 FIG. 1 shows a basic example of the present invention. This device includes a volatile component removal tower 2 having a raw water heater 110 and a steam exhaust port 112, a black-black distillation tower 1 having a raw water heater 108, a hydrophobic porous membrane 101, and a condensation surface 113, and a volatile component removal tower. It is composed of a raw water pipe 114 that connects to the Haraguro Retention Tower, and a pump 106 that is installed in the middle of the pipe to send the raw water.

The raw water 111 to be treated is introduced into the volatile component removal tower 2, heated by the raw water heater 110 to boil, vaporize carbon dioxide gas and volatile organic matter in the raw water, and exit the system together with water vapor from the steam outlet 112. Release it outside. The raw water from which dissolved carbon dioxide gas and volatile organic matter have been removed is sent to the Haraguro distillation tower 1 by the water pump 106. The raw water that has entered the Haraguro Retention Tower 1 is heated again by the raw water heater 108 and evaporated. Water vapor 105 generated by evaporation is filtered by the hydrophobic porous membrane 101, condensed on the condensation surface 113 through which the cooling water 103 flows, that is, on the surface of the cooling water piping, and taken out as produced water (ultra-ultra pure water) 1o4. In this embodiment, cooling water 103 and a condensing surface 113 constitute a cooling means. Note that the hydrophobic porous membrane 101
Most of the steam passing through becomes ultra-ultra pure water, but a portion is blown through the valve 102 to remove non-condensable gases within the system. In addition, in order to prevent scale adhesion to the raw water heaters 108 and 110, the raw water is also connected to each drain valve 107,
It is preferable that the blower be blown by 109. According to this device, since carbon dioxide components and volatile organic components contained in raw water can be removed before the membrane distillation group, highly pure ultra-superpure water can be produced.

Next, the properties of ultra-ultra pure water obtained by this apparatus will be explained using FIGS. 2 and 3. FIG. 2 shows the specific resistance and pH of the produced water when straight raw water (reverse osmosis treated water was used) was fed into the membrane distillation group for comparison with this example. FIG. 3 is according to this embodiment. In both FIG. 2 and FIG. 3, the part ``■'' shown in the figure shows the point where water started to be supplied to the membrane distillation group, and the part ``■'' shows the point where the supply stopped. In FIG. 2, where the water does not pass through the volatile component removal column, the specific resistance of the produced water decreases as soon as the water supply starts, reaching several MΩ· mark. At this time, the pH value also decreases from about 6.7 to about 5.8, so it is thought that carbon dioxide gas mixes into the produced water and becomes carbonate ions and bicarbonate ions, lowering the specific resistance value.

However, in Figure 3, where water that has passed through a volatile component removal tower is supplied, there is no change in the specific resistance or pH of the produced water even when water is supplied, and highly pure produced water is continuously produced. It can be seen that the results are obtained.

According to an example in which the quality of the ultra-ultra pure water obtained in this example was analyzed, no microorganisms were detected. In addition, fine particles with a particle size of 0.1 μm or more in the produced water are 1 in 1 nyn8.
The results were 0 or less, and the total organic carbon content (TOC) was 10 ppb.

Water marks were created on silicon wafers using the water produced in this example and the water produced in the conventional ultrapure water production apparatus shown in FIG. 6, and the two were compared. Water
A mark is a residue on a silicon wafer that is created when a drop of water is placed on the wafer and allowed to dry. When we compared the water marks when dried at room temperature of 19.5°C, it was confirmed that the amount of residue was considerably smaller and the purity was higher when the produced water from the apparatus according to the present invention was dropped. In addition, when dried at 103℃,
The features of this device became even more obvious. In other words, when the silicon wafer was dried at high temperature, all water marks that would occur at room temperature disappeared, and nothing was observed on the silicon wafer. In comparison, a considerable amount of impurities were observed in the water produced using conventional equipment, although the amount was somewhat reduced. This is because the water produced by this device contains 1. Even if impurities are mixed in, they are all volatile, and if dried at high temperatures, as was done in this experiment, they will all evaporate. This shows that there are no impurities on the wafer. For this reason, the water produced according to the present invention is extremely effective for use in LSI manufacturing.

Embodiment 2 FIG. 4 shows another embodiment of the present invention. This device includes a volatile component removal tower 2 having a raw water heater 110, a heat exchanger 202 for heating raw water, a hydrophobic porous membrane 101, and a condensing surface 11.
a membrane distillation group 3 having a membrane distillation group 3 and a raw water pump 1 therebetween
06.

The raw water 111 to be treated is introduced into the volatile component removal tower 2, heated by the raw water heater 110 to boil, vaporizes carbon dioxide gas and volatile organic matter in the raw water, and discharges it to the outside of the yarn from the steam outlet 203. be done. The raw water from which dissolved carbon dioxide components and volatile organic matter have been removed is sent to the water pump 1.
06 to the membrane distillation group 3. The raw water that has entered the membrane distillation group 3 is heated again by the raw water heating heat exchanger 202 and evaporated. At this time, the heating medium in the raw water heating heat exchanger 202 is water vapor generated from the volatile component removal tower 2, and the water that has released latent heat and has become a liquid is transferred to the heat exchanger outlet 2.
01 and released outside the thread. Heat exchanger 202 for heating raw water
The water vapor 105 generated by heating passes through the hydrophobic porous membrane 101, and the accompanying mist is removed.
It condenses on the condensation surface 113 and is taken out of the system as produced water 104, that is, ultra-ultra pure water. According to this apparatus, high purity ultra-ultra pure water can be obtained as in Example 1, and since the heat used in the volatile component removal column 2 is recovered, the amount of energy can be reduced. Note that when the raw water heating heat exchanger 202 alone is insufficient as a raw water heating source for the membrane distillation group, a raw water heater 108 shown in FIG. 1 may be additionally provided.

Example 3 An example using flash evaporation as a means for removing volatile components in raw water will be described with reference to FIG.

This apparatus is composed of a spray pump 1, a raw water heater 302, a volatile component removal column 4 having a spray nozzle 303, and a membrane distillation group 3. The raw water 111 to be treated enters the suction side of the spray pump 301, is pressurized by the pump, and is then superheated by the raw water heater 302 to a temperature several degrees Celsius higher, for example, 5 to 10 degrees Celsius, than the saturation temperature in the volatile component removal tower. , is discharged into the system from the spray nozzle 303. Here, it is necessary to pressurize the space between the pump 301 and the spray nozzle 303 above the saturation pressure of the temperature raised by the raw water heater 302 to prevent evaporation (boiling) from occurring within the pipe. The raw water sprayed from the spray nozzle 303 rapidly evaporates to the temperature inside the volatile component removal tower 4, and becomes water vapor. At this time, carbonic acid and low boiling point organic components contained in the raw water are also gasified,
released into the air. The liquid that did not evaporate and accumulated in the volatile component removal tower 4 is led to the spray pump 301 again.
Perform flash evaporation. The steam, carbonic acid components, and low-boiling point organic components generated here are taken out of the thread through the steam outlet 203, sent to the raw water heating heat exchanger 202 of the membrane distillation group 3, and used as a heat source for membrane distillation. be done. The raw water treated in the volatile component removal column 4 is sent to the membrane distillation group 3 by a water pump 106. From now on, high-purity produced water can be obtained as in the embodiment shown in FIG. 4 above. In this embodiment, the raw water is supplied to the suction side of the spray pump 301, and before being sent into the volatile component removal tower 4, it is heated to the boiling point or higher by the raw water heater 302, and is flashed from the spray nozzle 303. Evaporate. Therefore, before being introduced into the water pump 106 to the membrane distillation unit 3, it passes through a flash evaporation process at least once, and untreated raw water is no longer fed into the membrane distillation unit 3.

Embodiment 4 FIG. 6 shows an example of multi-stage production considering the cost of produced water. Volatile component removal column 4 is removed by flash evaporation.
The raw water from which carbonic acid components and volatile T'OC components have been removed is sent to the first membrane distillation column 5. At this time, since the first membrane distillation column 5 is in a saturated state with lower pressure and temperature than the volatile component removal column 4, the raw water is sent to the first membrane distillation column 5 only by operating the valve 414. Here, the latent heat of the steam 410 generated in the volatile component removal column 4 is used to heat the raw water in the first membrane distillation column 5. Steam 411 generated in the first membrane distillation column is separated from mist when passing through the hydrophobic porous membrane 105, and is used to heat raw water in the second membrane distillation column 6 through a pipe 411. The water that is used to heat the second membrane distillation unit and releases latent heat and becomes a liquid is transferred to the heat exchanger outlet 413.
Released outside the strands. In the final stage of this multi-stage operation,
A simple condenser 7 is installed, and the generated high-purity steam is condensed into ultrapure water. In addition, the system was designed to remove generated water by operating the final stage at near atmospheric pressure to avoid contamination by dust from sliding parts such as pumps. However, as shown in Figure 7, a high-performance dust-free pump 4
If 01 is developed, it will be possible to install a small generated water tank 402 and send it out of the system. At this time, there is no problem even if the final stage is under considerably reduced pressure, and the oil can be placed in the produced water tank 402.

Conventional example Figure 8 shows an outline of a conventional ultrapure water production device.

After the raw water passes through pretreatment processes such as coagulation-sedimentation, filtration, and microfiltration, it is sent to the reverse osmosis process (R○), where most of the dissolved organic components and about 90% of inorganic salts contained in the raw water are removed. Ru. Furthermore, this permeated water is decarboxylated through a degassing tower and sent to an ion exchange resin process.

Usually, a vacuum deaerator is used for the deaerator, but
Deaeration modules using hydrophobic porous membranes are also beginning to be devised. For example, see JP-A-60-118284.

The ion exchange tower is a regeneration method using a construction method or a hot bed method, and salts are completely removed in this process, and the specific resistance is usually 10M.
Primary pure water of Ω・■ or higher is obtained and temporarily stored in a pure water tank. -The next pure water is further processed into a hot bed type ion exchange resin column (
After completely removing impurities, ultraviolet sterilization process eliminates viable bacteria, and ultrafiltration process (UF) removes remaining particulates and dead bacteria to obtain ultrapure water. .

In this conventional method, ultrapure water having a temperature of around 25°C is obtained.

Even at the highest level, the quality of ultrapure water obtained using this conventional device is 0.05 microorganisms/rn f: A r 0, 1
50-100 particles/m1 with a size of μrn or larger
2, TOCloopppb, and the electrical resistance was 18 megaΩ·mark.

〔Effect of the invention〕

The present invention boils raw water containing volatile and non-volatile components such as tap water to vaporize and remove the volatile components, then generates water vapor from the raw water and transfers the water vapor to hydrophobic porous The purpose is to produce ultra-ultra pure water by bringing it into contact with a membrane, allowing it to permeate, and condensing it.

According to the present invention, various conventional filtration membranes, ion exchange resins,
Compared to a method of producing ultrapure water using a combination of germicidal lamps, etc., it is possible to produce ultrapure water with fewer impurities.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an embodiment of the ultra-ultra pure water production apparatus of the present invention, Fig. 2 is a characteristic diagram showing water quality obtained by an ultra-pure water production method according to a comparative example, and Fig. 3 is a diagram of the present invention. 4 to 7 are schematic configuration diagrams showing another embodiment of the ultra-ultra pure water production apparatus of the present invention, and FIG. 8 is a conventional example. FIG. 1. Membrane distillation group, 2. Volatile component removal column, 101
・Fig. 1 10"l ---Trenvalve time hammer] Time (approx. system 4-factor

Claims (1)

[Scope of Claims] 1. A method for producing ultrapure water by generating water vapor from raw water, passing the water vapor through a hydrophobic porous membrane that allows gas to pass through but not liquid, and then condensing it to produce ultrapure water, A method for producing ultrapure water, which comprises boiling raw water to vaporize and remove volatile components in the raw water, generating steam, and bringing the steam into contact with the hydrophobic porous membrane. 2. In a method of producing ultrapure water by generating water vapor from raw water, passing the water vapor through a hydrophobic porous membrane that allows gases to pass through but not liquids, and then condensing it, the raw water is boiled and the raw water is boiled. After vaporizing and removing volatile components in water, water vapor is generated, and the water vapor is brought into contact with the hydrophobic porous membrane and permeated into an atmosphere of saturated vapor or inert gas to be condensed. Pure water production method. 3. In a method of producing ultrapure water by generating water vapor from raw water, passing this water vapor through a hydrophobic porous membrane that allows gases to pass through but not liquids, and then condensing it, the raw water is heated and boiled. 1. A method for producing ultrapure water, comprising the steps of vaporizing and removing volatile components, and generating water vapor from the raw water after the step, and bringing the water vapor into contact with the hydrophobic porous membrane. 4. In a method of producing ultrapure water by generating water vapor from raw water, passing this water vapor through a hydrophobic porous membrane that allows gases to pass through but not liquids, and then condensing it, the raw water is maintained under reduced pressure. Ultrapure water production characterized by comprising the steps of boiling and vaporizing and removing volatile components, and generating water vapor from the raw water after the step and bringing the water vapor into contact with the hydrophobic porous membrane. Method. 5. Boil the raw water containing volatile and non-volatile components to vaporize and remove the volatile components, then generate water vapor from the raw water, and convert only the water vapor into a hydrophobic material that is gas permeable and liquid impermeable. A method for producing ultrapure water, which is characterized by contacting with a porous membrane, allowing it to permeate, and then condensing it. 6. Boil the raw water containing volatile and non-volatile components to vaporize and remove the volatile components, then heat the raw water to generate water vapor, and make only the water vapor permeable to gas and impermeable to liquid. A method for producing ultrapure water, which comprises bringing it into contact with a hydrophobic porous membrane, permeating it into an atmosphere of saturated steam or an inert gas, and condensing it. 7. The raw water containing volatile and non-volatile components is heated and boiled to vaporize and remove the volatile components, then the raw water is reheated to generate water vapor, and only the water vapor is converted into a gas-permeable and liquid form. A method for producing ultrapure water characterized by contacting with an impermeable hydrophobic porous membrane to permeate it and then condensing it. 8. The raw water containing volatile and non-volatile components is heated and boiled to vaporize and remove the volatile components, then the raw water is reheated to generate water vapor, and only the water vapor is converted into a gas-permeable and liquid form. A method for producing ultrapure water, which comprises bringing it into contact with an impermeable hydrophobic porous membrane, permeating it into an atmosphere of saturated steam or an inert gas, and condensing it. 9. A step of heating and boiling the raw water containing volatile components and non-volatile components to vaporize and remove the volatile components, then reheating the raw water using the vaporized steam containing the volatile components as a heating source to produce water vapor. 1. A method for producing ultrapure water, comprising the steps of: generating water vapor; contacting and permeating only the water vapor with a gas-permeable and liquid-impermeable hydrophobic porous membrane; and condensing the water vapor. 10. A step of heating and boiling the raw water containing volatile components and non-volatile components to vaporize and remove the volatile components, and then reheating the raw water using the vaporized steam containing the volatile components as a heating source. An ultrapure method comprising the step of generating water vapor, contacting only the water vapor with a gas-permeable and liquid-impermeable hydrophobic porous membrane, allowing it to permeate into a saturated vapor or inert gas atmosphere, and condensing it. Water production method. 11. An ultrapure water production apparatus having a membrane distillation column equipped with a hydrophobic porous membrane that allows vapor of raw water containing volatile components and non-volatile components to pass therethrough, and a cooling means that condenses the water vapor that has passed through the membrane, An apparatus for producing ultrapure water, comprising a volatile component removal column provided upstream of the membrane distillation column and equipped with means for boiling raw water and means for discharging volatile components vaporized by boiling the raw water. 12. A volatile component removal tower equipped with a means for heating raw water containing volatile components and non-volatile components and a means for discharging volatile components vaporized by the heating, for evaporating the raw water treated in the tower. An ultrapure water production apparatus comprising a membrane distillation column equipped with a heating means, a hydrophobic porous membrane that transmits water vapor generated by the heating, and a cooling means that condenses the water vapor that has passed through the membrane. . 13. An ultrapure water production apparatus having a membrane distillation column equipped with a hydrophobic porous membrane that allows vapor of raw water containing volatile components and non-volatile components to pass therethrough, and a cooling means that condenses the water vapor that has passed through the membrane, A volatile component removal column is provided upstream of the membrane distillation column and includes a means for boiling raw water and a means for discharging volatile components vaporized by boiling the raw water, and saturates the atmosphere in which water vapor in the membrane distillation column is condensed. An ultrapure water production device characterized by comprising a gas supply means for supplying steam or inert gas. 14. A volatile component removal column equipped with a depressurizing means for boiling raw water containing volatile components and non-volatile components and a means for discharging volatile components vaporized by boiling the raw water; Ultrapure water characterized by comprising a membrane distillation column equipped with a heating means for evaporating, a hydrophobic porous membrane that transmits water vapor generated by the heating, and a cooling means for condensing the water vapor that has passed through the membrane. Manufacturing equipment. 15. An ultrapure water production apparatus having a membrane distillation column equipped with a hydrophobic porous membrane that allows vapor of raw water containing volatile components and non-volatile components to pass therethrough, and a cooling means that condenses the water vapor that has passed through the membrane, A volatile component removal column is provided upstream of the membrane distillation column and includes a heating means for boiling the raw water and a means for discharging volatile components vaporized by boiling the raw water, and the volatile components removed by the volatile component removal column are provided. An apparatus for producing ultrapure water, comprising means for heat-exchanging steam containing components with raw water in the membrane distillation column. 16. A step of boiling the raw water containing volatile and non-volatile components to vaporize and remove the volatile components, then heating the raw water to generate water vapor, which is passed through a hydrophobic porous membrane and condensed. 1. A method for cleaning a semiconductor integrated circuit, comprising producing ultrapure water heated to a temperature higher than room temperature through a step of cleaning the semiconductor integrated circuit using the ultrapure water. 17. A step of boiling the raw water containing volatile and non-volatile components to vaporize and remove the volatile components, then heating the raw water to generate water vapor, which is passed through a hydrophobic porous membrane and condensed. 1. A method for cleaning medical instruments, which comprises producing ultrapure water through the steps of: and washing medical instruments using the ultrapure water.