TWM570308U - No heat regeneration system - Google Patents

Abstract

An athermal regeneration system comprising: an adsorption unit; a water washing unit coupled to the adsorption unit; and a low-humidity gas supply unit coupled to the adsorption unit; wherein the adsorption unit is adsorbed a volatile organic substance, the washing unit is a washing or soaking process for desorbing the volatile organic substance adsorbed by the adsorption unit, the low-humidity air supply unit providing a low-humidity airflow to the washing or soaking process Adsorbing unit to dry the adsorption unit.

Description

No heat regeneration system

A heatless regeneration system and method thereof, in particular, a system for regenerating and desorbing adsorption units adsorbing volatile organic substances by using a non-hot water washing regeneration method

High-purity Isopropanol (IPA) solvent is used as a wafer cleaning agent, which has been used by the semiconductor industry for many years. Isopropanol removes organic or other impure substances remaining on the surface of the wafer, or is used in wafer etch cleaning and drying processes.

However, during the process, a large amount of isopropanol solvent is volatilized into the air, and it is necessary to treat the high-concentration isopropanol exhaust gas before it can be discharged to the atmosphere.

Existing methods for treating exhaust gas rich in isopropanol or water-soluble volatile organic compounds mostly use an activated carbon adsorption bed (tower) to adsorb isopropanol or water-soluble volatile organic compounds. However, if the gas concentration is too high, the adsorption bed (tower) will soon reach adsorption saturation or failure, so it must be replaced frequently, or the dynamic adsorbent desorption regeneration can continue to be used, and the existing regeneration methods are heated and regenerated. The method is carried out by external heating and temperature increase to increase the vibration energy of the adsorbate molecules, and the adsorption equilibrium relationship is changed to achieve desorption or thermal decomposition of the adsorbate from the adsorbent.

However, if the adsorbed substance is a volatile organic substance and the instantaneous desorption concentration is too high, it is easy to cause smoldering or flash fire accident due to improper heating and heat accumulation.

The semiconductor industry uses a wet gas scrubbing method that increases the gas-liquid contact area and residence time by the Raschig ring to absorb the isopropanol or water-soluble volatile organic compounds in the air in pure water. The liquid is discharged to the sewage treatment plant in the latter stage. The aforementioned wet gas washing method does not have any high temperature operation procedure, and has been widely used for the treatment of water-soluble organic and inorganic acid alkaline waste gas in a semiconductor process.

Due to the wet gas scrubbing method, the concentration of adsorbed water in the water will affect the rate and solubility of air dissolved in water. Therefore, in order to achieve high efficiency in removing washing efficiency, a large amount of pure water or a frequency of water exchange must be used, which will be derived. A large amount of wastewater treatment is rich in isopropanol.

In addition, the wet gas washing apparatus is a continuous operation, and therefore, under the long-term circulation operation of the washing liquid, various problems are inevitable. If the content of the granules in the washing liquid is too high, it will easily cause the accumulation of granules in the filler, the pipeline and the nozzle, causing the nozzle to be blocked. The precipitation of particulate contaminants carried in the exhaust gas, or the precipitation of crystals due to chemical reactions, will cause fouling of the filler. If the exhaust gas contains volatile organic compounds (providing a carbon source required for microbial growth) and the washing liquid used contains a nitrogen salt, the problem of bioadhesive adhesion occurs. The washed gas, due to the relatively high relative humidity, is about 85% RH to 90% RH, so the chimney emitted is prone to white smoke. If the circulating water volume is insufficient, the liquid dispersion is uneven, the gas contact time is insufficient, and the short-flow occurs, the processing efficiency of the washing tower may be inconspicuous.

In view of this, the main purpose of this creation is to propose a heatless regeneration system that utilizes a non-hot water washing regeneration method to regenerate the adsorption unit that has adsorbed volatile organic substances, and can avoid smoldering, flash fire accidents or A large number of isopropyl alcohol wastewater treatment problems.

The present invention relates to a heatless regeneration system comprising: an adsorption unit; a water washing unit coupled to the adsorption unit; and a low-humidity air supply unit coupled to the adsorption unit; The adsorption unit adsorbs volatile organic substances, and the water washing unit is a washing or soaking process to desorb the volatile organic substance adsorbed by the adsorption unit, and the low-humidity air supply unit provides a low-humidity airflow or dry compressed air. The adsorption unit after the washing or soaking process is applied to dry the adsorption unit.

In one embodiment, the adsorption unit is a double-tower hollow fiber material adsorption bed.

In an embodiment, the adsorption unit is a rotating wheel of a rotary wheel type hollow fiber material.

In one embodiment, the hollow fiber material has a porous material in the fiber material. The porous material may be zeolite, molecular sieve, silica gel, activated alumina, metal organic framework (MOF), activated carbon, carbon molecular sieve or a combination thereof; the hollow fiber has a set specific surface area, the set specific surface area It is 2500~3500 m ² /g.

In summary, the heatless regeneration system and the method thereof of the present invention can avoid the risk of the organic solvent being regenerated by heating, generating flash fire at high temperature, and greatly reducing the amount of waste water treated by conventional gas washing.

In addition, the hollow fiber material of the present invention has a set specific surface area of (2500 to 3500 m 2 /g), and thus has an extremely high adsorption rate and desorption rate. In actual operation, as long as the parameters of the gas flow surface velocity, the hollow fiber material or the molecular sieve bed depth or the gas residence time are adjusted, the optimization of the removal efficiency of the volatile organic substances can be easily accomplished, and the hollow fiber material has Hollow structure, so the pressure loss is also lower than the general particle stacked adsorption bed. The desorption regeneration process is carried out by means of a small amount of water washing, so that the amount of waste water generated by the wet gas washing method can be drastically reduced without requiring a high temperature operation procedure.

The embodiments of the present invention are described below by way of specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention by the contents disclosed in the present specification.

Referring to FIG. 1, the present invention is a first embodiment of a heatless regeneration system comprising an adsorption unit 10, a water washing unit 11, and a low-humidity air supply unit 12.

The adsorption unit 10 is coupled to an exhaust system (not shown). The adsorption unit 10 is a double-tower hollow fiber material adsorption bed. The hollow fiber material has a porous material in the fiber material. The porous material can be zeolite, molecular sieve, silica gel, activated alumina, metal organic framework, activated carbon, carbon molecular sieve or a combination of the above. The hollow fiber material has a set specific surface area, and the set specific surface area is 2500 to 3500 m ² /g. In the embodiment, the adsorption unit 10 has a first adsorption bed 100 of hollow fiber material and a second adsorption bed 101 of hollow fiber material. The first adsorbent bed 100 adsorbs volatile organic substances from the exhaust system, which is isopropanol or a water-soluble volatile organic compound. After the volatile organic substances adsorbed by the first adsorption bed 100 reach saturation, the exhaust system stops supplying the exhaust gas to the first adsorption bed 100. The exhaust system supplies exhaust gas to the second adsorbent bed 101 such that the second adsorbent bed 101 adsorbs volatile organic substances from the exhaust system.

The water washing unit 11 is coupled to the adsorption unit 10. The water washing unit 11 is a washing or soaking process to regenerate the volatile organic substances adsorbed by the desorption unit 10. If further stated, if the volatile organic substance adsorbed by the first adsorption bed 100 has reached saturation, the water washing unit 11 is subjected to a washing or soaking procedure to desorb the volatile organic substances adsorbed by the first adsorption bed 100, At the same time, the second adsorption bed 101 adsorbs volatile organic substances.

The low-humidity air supply unit 12 is coupled to the adsorption unit 10. The low-humidity air supply unit 12 provides a low-humidity airflow to dry the adsorption unit 10. The low humidity airflow is less than 45% relative humidity (RH). As further illustrated, the low humidity gas flow providing unit 12 provides a low humidity gas stream to dry the first adsorbent bed 100. If the first adsorption bed 100 has been dried, and the volatile organic substances adsorbed by the second adsorption bed 101 are saturated, the first adsorption bed 100 adsorbs volatile organic substances again, and the second adsorption bed 101 performs the above-mentioned water washing. The washing or soaking procedure of unit 11 and the drying of the low humidity gas stream providing unit 12 are procedures.

Referring to FIG. 2, the present invention is a second embodiment of a heatless regeneration system comprising an adsorption unit 20, a water washing unit 21 and a low-humidity air supply unit 22.

The adsorption unit 20 is coupled to an exhaust system (not shown). The adsorption unit 20 is a revolving wheel 200 of a rotary wheel type hollow fiber material. The adsorption wheel 200 has at least one adsorption zone 201 and at least one regeneration zone 202. The exhaust system provides an exhaust gas to the adsorption zone 201 of the adsorption wheel 200 such that the adsorption zone 200 adsorbs volatile organic substances in the exhaust gas, which is isopropanol or a water-soluble volatile organic compound.

The water washing unit 21 is coupled to the adsorption unit 20. If the volatile organic substance adsorbed by the adsorption zone 201 is saturated, the adsorption zone 201 is converted into the regeneration zone 202, and the water washing unit 21 is used for washing or soaking for a predetermined number of repeated cycles and a predetermined desorption time. The volatile organic material of the regeneration zone 202 is attached. And the exhaust system provides exhaust gas to another adsorption zone 201 while the other adsorption zone 201 adsorbs volatile organic matter.

The low-humidity air supply unit 22 is coupled to the adsorption unit 20. The low-humidity gas supply unit 22 provides a low-humidity gas stream to the regeneration zone 202 that has been subjected to a washing or soaking process for a predetermined drying time to dry the regeneration zone 202. When the volatile organic substance adsorbed by the other adsorption zone 201 reaches saturation, the other adsorption zone 201 is converted into the regeneration zone 202, and the washing or soaking of the water washing unit 21 described above and the drying of the low-humidity gas supply unit 22 are performed. program of. Further adsorption zone 201 is a procedure for adsorbing volatile organic substances.

Please refer to Figure 3 for a non-thermal regeneration method. The steps include:

In step S1, volatile organic substances are adsorbed. For ease of discussion, the author establishes a small heatless regeneration system and uses a hollow fiber material of 5×5×5 cm, which can be applied to the first embodiment or the second implementation of the above-described athermal regeneration system. example. The volatile organic material was isopropanol and was flowed into a hollow fiber at a surface velocity of 0.1 m/s at a flow rate of 15 LPM (l/min) at a concentration of 38 to 40 ppm (Parts Per Million).

In step S2, the adsorption unit is desorbed. When the removal efficiency of the volatile organic substance passing through the hollow fiber material reaches 30% or less, the hollow fiber material is washed or soaked, and the washing or soaking procedure is as described above. In the present embodiment, the procedure for washing the hollow fiber material is as follows: the hollow fiber material is immersed in 500 ml of pure water for 30 to 60 minutes, and repeatedly circulated for 3 to 5 times, and is easily dissolved by isopropyl alcohol. Under the characteristics of water, the isopropanol adsorbed on the hollow fiber material is dissolved in pure water to achieve the purpose of regeneration and desorption of the hollow fiber material.

In step S3, the adsorption unit is dried. After washing with water, the hollow fiber material is continuously dried for 180 to 240 minutes by using a low-humidity air flow. After the hollow fiber material is dried, the regeneration process of the hollow fiber material is completed.

Please refer to Figure 4 for a comparison of the adsorption curves of hollow fiber after high temperature desorption regeneration and water washing. Curve A is a high-temperature reclaimed hollow fiber material; curve B is a hollow fiber material that has been washed once; curve C is a hollow fiber material that has been washed twice; curve D is a hollow fiber material that has been washed three times; curve E is four times. Water-washed hollow fiber material. As shown in Fig. 4, the hollow fiber materials of the hot water washing and drying regeneration program and the hot air regeneration program of the present invention have similar performances.

In summary, the heatless regeneration system and method thereof of the present invention can be applied to a semiconductor process clean room with strict operating environment restrictions, and can avoid the risk of organic solvent being regenerated by heating and flashing at high temperature. It can greatly reduce the amount of wastewater treated by conventional gas washing.

10‧‧‧Adsorption unit

100‧‧‧First adsorption bed

101‧‧‧Second adsorption bed

11‧‧‧Washing unit

12‧‧‧Low humidity air supply unit

20‧‧‧Adsorption unit

200‧‧‧Adsorption wheel

201‧‧‧Adsorption zone

202‧‧‧Revitalization Zone

21‧‧‧Washing unit

22‧‧‧Low humidity air supply unit

S1~S3‧‧‧ steps

A~E‧‧‧ Curve

Figure 1 is a schematic illustration of a first embodiment of a non-thermal regeneration system of the present invention. Figure 2 is a schematic illustration of a second embodiment of a non-thermal regeneration system of the present invention. Figure 3 is a flow chart of a non-thermal regeneration method of the present invention. Fig. 4 is a comparison chart of adsorption curves of hollow fibers after high temperature desorption regeneration and water elution and regeneration.

Claims (7)

An athermal regeneration system comprising: an adsorption unit; a water washing unit coupled to the adsorption unit; and a low-humidity gas supply unit coupled to the adsorption unit; wherein the adsorption unit is adsorbed a volatile organic substance, the washing unit is a washing or soaking process for desorbing the volatile organic substance adsorbed by the adsorption unit, the low-humidity air supply unit providing a low-humidity airflow to the washing or soaking process Adsorbing unit to dry the adsorption unit. The non-thermal regeneration system of claim 1, wherein the adsorption unit is a double-tower hollow fiber material adsorption bed. The non-thermal regeneration system of claim 1, wherein the adsorption unit has a first adsorbent bed of hollow fiber material and a second adsorbent bed of hollow fiber material. The non-thermal regeneration system of claim 1, wherein the adsorption unit is a rotating wheel of a rotary hollow fiber material. The non-thermal regeneration system of claim 4, wherein the adsorption wheel has at least one adsorption zone and at least one regeneration zone. The non-thermal regeneration system of claim 2, 3 or 4, wherein the adsorbent in the hollow fiber material is a porous material. The non-thermal regeneration system of claim 6, wherein the porous material adsorbent may be zeolite, molecular sieve, silica gel, activated alumina, metal organic framework, activated carbon, carbon molecular sieve or a combination thereof; The hollow fiber has a set specific surface area, and the set specific surface area is 2500 to 3500 m ² /g.