Waste hydrogen power generation device

Abstract

The invention provides a waste hydrogen power generation device applied to manufacturing equipment of semiconductors and the like, the device can reduce the burden of purifying waste hydrogen, and hydrogen can be applied to power generation again, so that auxiliary power supply to facilities is realized. This waste hydrogen gas power generation device is provided with: a hydrogen gas generation unit such as an epitaxial growth device; a purification unit that recovers the waste hydrogen gas from the hydrogen gas generation unit and removes impurities other than hydrogen gas by contacting with water to prepare purified hydrogen gas; a storage unit for storing the purified hydrogen gas; and a power generation unit for driving a power generator by combusting the purified hydrogen gas supplied by the storage unit with oxygen gas in the atmosphere.

Description

Technical Field

[0001] The present invention relates to a waste hydrogen power generation device, and in particular to a device for recovering hydrogen discharged in a semiconductor manufacturing process to generate electricity. Background Art

[0002] Semiconductor manufacturing processes are usually composed of multiple complex and precise steps, and each step consumes a large amount of electricity. Therefore, research has begun on how to effectively utilize energy and resources that have been discharged, not reused or not utilized in semiconductor manufacturing equipment.

[0003] For example, some people have proposed to use the waste heat generated by the operation of semiconductor manufacturing equipment to generate electricity (see Patent Document 1 and Patent Document 2 for details). According to these technical proposals, some achievements have been made in the utilization of waste heat. However, research has found that in the semiconductor manufacturing process, in addition to waste heat, gases used for epitaxial growth such as epitaxial growth equipment also generate hydrogen and other gases.

[0004] At present, due to the high flammability of hydrogen, it is usually diluted to a safe concentration and then discharged to the outside of the building where the manufacturing equipment is located (that is, into the atmosphere) and directly discarded. In this regard, the present invention proposes a technical solution for using waste hydrogen as fuel cell fuel and making full use of it. However, the gas discharged from the epitaxial growth device contains other components in addition to hydrogen, and the fuel cell must use extremely high-purity hydrogen. Therefore, it is not easy to remove impurities in hydrogen to improve the purity of hydrogen, but it may lead to an increase in the cost of hydrogen purification.

[0005] Prior art literature

[0006] [Patent Document 1] Japanese Patent Publication No. JP2020-150045A

[0007] [Patent Document 2] International Patent Publication No. WO2013 / 047320 Summary of the invention

[0008] Problems to be solved by the present invention

[0009] The present invention is proposed in view of the above-mentioned problems, and aims to provide a waste hydrogen power generation device that can reuse the hydrogen generated in semiconductor manufacturing equipment for power generation while reducing the burden of hydrogen purification, and provide auxiliary power generation for facilities.

[0010] Means of solving the problem

[0011] That is, the waste hydrogen power generation device of this embodiment includes: a hydrogen generation unit, a purification unit for recovering the waste hydrogen discarded by the hydrogen generation unit and removing impurities other than hydrogen to prepare refined hydrogen, a storage unit for storing refined hydrogen, and a power generation unit for driving a generator by burning the refined hydrogen supplied by the storage unit with oxygen in the atmosphere.

[0012] Furthermore, in the waste hydrogen power generation device, the hydrogen generation unit may be an epitaxial growth device.

[0013] Furthermore, in the purification section of the waste hydrogen power generation device, the waste hydrogen is brought into contact with water to remove impurities.

[0014] Furthermore, in the waste hydrogen power generation device, the power generation unit also has a gas turbine unit that rotates by burning the purified hydrogen with oxygen in the atmosphere, and the rotational force generated by the gas turbine unit drives the generator to operate.

[0015] Furthermore, in the waste hydrogen power generation device, the power generation unit also has an internal combustion engine unit that rotates by burning the purified hydrogen with oxygen in the atmosphere, and the rotational force generated by the internal combustion engine unit drives the generator to operate.

[0016] Furthermore, the waste hydrogen power generation device further includes a power storage unit for storing the power generated by the power generation unit.

[0017] Furthermore, in the waste hydrogen power generation device, the purification section, the storage section, and the power generation section are integrated and packaged in one casing.

[0018] Effects of the Invention

[0019] Since the waste hydrogen power generation device of the present invention includes: a hydrogen generation unit, a purification unit for recovering the waste hydrogen discarded by the hydrogen generation unit and removing impurities other than hydrogen to prepare refined hydrogen, a storage unit for storing refined hydrogen, and a power generation unit for driving a generator by burning the refined hydrogen supplied by the storage unit with oxygen in the atmosphere, it is possible to reduce the burden of hydrogen purification in manufacturing equipment such as semiconductors and reuse waste hydrogen for power generation; it is also possible to provide auxiliary power supply for facilities, thereby reducing electricity consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] [ Figure 1 ]In the first embodiment, a schematic diagram of the overall structure of the waste hydrogen power generation device is shown.

[0021] [ Figure 2 ] represents the first schematic diagram of the power generation unit.

[0022] [ Figure 3] represents a second schematic diagram of the power generation unit.

[0023] [ Figure 4 ] In the second embodiment, a schematic diagram of the overall structure of the waste hydrogen power generation device is shown.

[0024] Explanation of symbols

[0025] 1A, 1B Abandoned hydrogen power generation equipment

[0026] 10 Hydrogen generation unit

[0027] 11 Epitaxial growth device

[0028] 12 Furnace Chamber

[0029] 13 Base

[0030] 14 Silicon Wafer

[0031] 15 Gas storage tank

[0032] 16 Gas inflow channel

[0033] 17 Gas outflow channel

[0034] 20 Purification Department

[0035] 21 Filters

[0036] 30 Storage

[0037] 40 Power Generation Department

[0038] 41 Generator

[0039] 42 Gas Turbine Division

[0040] 44 Engine shaft

[0041] 45 Internal combustion engine

[0042] 49 Crankshaft

[0043] 60 Power storage unit

[0044] 65 Electricity Usage Department

[0045] 70 Catheter

[0046] 71, 72, 73 Pressure section

[0047] 74 Check valve

[0048] 75 Flow Control Valve

[0049] 80 Power generation unit

[0050] 81 Casing.

[0051] Specific implementation form

[0052] The waste hydrogen power generation device of this embodiment is mainly a device that recovers the hydrogen that is discarded (or discharged) from the epitaxial growth device in the semiconductor manufacturing process, and burns it to drive the generator. In particular, a fuel cell that uses waste hydrogen as fuel is not used. Among them, the hydrogen used as fuel cell fuel must be purified to a high purity (more than 99%), otherwise it will cause the fuel cell device to malfunction or reduce the power generation efficiency, which will in turn increase the additional burden of equipment and time required in the purification process of the waste hydrogen. Based on this, the waste hydrogen power generation device of this embodiment adopts a method of obtaining electricity without a fuel cell, and applies it to a power generation device that generates electricity based on hydrocarbon fuels.

[0053] Figure 1 1 is a schematic diagram of the overall structure of the waste hydrogen power generation device 1A in the first embodiment. The waste hydrogen power generation device 1A includes: a hydrogen generation unit 10, a purification unit 20, a storage unit 30, and a power generation unit 40. Furthermore, it also has a power storage unit 60. The waste hydrogen power generation device 1B to be mentioned below also includes: a hydrogen generation unit 10, a purification unit 20, a storage unit 30, and a power generation unit 40 (generator 41), and a power storage unit 60.

[0054] The power storage unit 60 is connected to the power using unit 65 such as lighting devices and pumps of the manufacturing facilities and equipment. In addition, the following are provided at various locations of the conduit for transporting the gas: a pressure gauge 71, a pressure gauge 72, a pressure gauge 73, a check valve 74, a flow control valve 75, and other flow meters (not shown in the figure). Therefore, the pressure and flow rate of the transported gas (waste hydrogen gas, purified hydrogen gas) can be appropriately monitored.

[0055] The waste hydrogen power generation device 1A in the first embodiment and the waste power generation device 1B in the second embodiment (see Figure 4) uses an epitaxial growth device 11 as the hydrogen generation unit 10. The epitaxial growth device 11 is provided with a space (furnace chamber 12) of a suitable shape such as a cylindrical or hemispherical shape, and is also provided with a device (furnace) that can generate crystals on the surface of a single or multiple silicon wafers 14 placed on an internal base 13. Therefore, the gas required for crystal growth will be introduced into the furnace chamber 12 from the gas inflow channel 16 of each epitaxial growth device 11 through a gas storage tank 15. The gas generated after a predetermined chemical reaction is discharged to the outside of the furnace chamber 12 through a gas outflow channel 17. The gas inflow channel 16 and the gas outflow channel 17 of the epitaxial growth device 11 can also be set at a position other than that shown in the figure, and can be appropriately adjusted and redesigned according to the furnace chamber structure and production efficiency of the epitaxial growth device 11. For the convenience of explanation, three epitaxial growth devices 11 are shown in the figure. Of course, the epitaxial growth device 11 can also be configured with only one, or with 10 or more.

[0056] Generally speaking, the types and chemical reactions of representative gases supplied to the epitaxial growth device 11 are as follows:

[0057] (Formation of epitaxial growth film)

[0058] SiCl4+2H2→Si+4HCl

[0059] SiH2Cl2→Si+2HCl

[0060] SiH4→Si+2H2

[0061] SiHCl3+H2→Si+3HCl

[0062] (Formation of Silicon Oxide Thin Film)

[0063] SiH4+2O2→SiO2+2H2O

[0064] SiH4+2H2O→SiO2+4H2

[0065] SiCl4+2NO+2H2→SiO2+4HCl+N2

[0066] SiCl4+2CO2+2H2→SiO2+4HCl+2CO

[0067] SiH2Cl2+2N2O→SiO2+2HCl+2N2

[0068] (Formation of Silicon Nitride Thin Film)

[0069] 3SiH2Cl2+4NH3→Si3N4+6HCl+6H2

[0070] 3SiH4+4NH3→Si3N4+12H2

[0071] (Formation of polysilicon thin film)

[0072] SiH4→Si+2H2

[0073] As shown in the above chemical equation, when hydrogen is supplied to the epitaxial growth device 11, the gas supplied to the epitaxial growth device 11 will undergo a chemical reaction, and hydrogen generation can be confirmed according to the type of raw material gas. Therefore, in the epitaxial growth device 11, hydrogen that has not undergone a chemical reaction and hydrogen generated by a chemical reaction are recovered as waste hydrogen and reused as fuel for power generation.

[0074] However, as shown in the above chemical equation, there are components other than hydrogen in the components generated by the chemical reaction inside the epitaxial growth device. In response to this, a purification unit 20 is also provided on the lower side of the epitaxial growth device 11. The purification unit 20 is also called a scrubber, etc., and is responsible for recovering the waste hydrogen discarded by the hydrogen generation unit, and removing impurities other than hydrogen to modulate refined hydrogen. Adsorbents and water well known to the public are stored in the purification unit 20. Since hydrogen is almost insoluble in water, while hydrogen chloride is soluble in water. Therefore, by contacting the water stored in the purification unit 20 with the gas discharged from the gas outflow channel 17, the discharge of hydrogen chloride can be reduced. In addition, in order to improve the accuracy of hydrogen purification, a filter 21 is also provided on the lower side of the purification unit 20. The filter 21 is used to collect components other than hydrogen such as ammonia and hydrogen chloride.

[0075] In the process of preparing the refined hydrogen obtained by the purification unit 20, the waste hydrogen has been in contact with water, so the refined hydrogen will also contain moisture. Generally speaking, the hydrogen used as fuel cell fuel is almost 100% pure refined hydrogen. Therefore, after purification, it is necessary to equip equipment and processes for further removing moisture. In this regard, in this embodiment, in order to make the refined hydrogen burn, the factors affecting the purity such as the moisture content in the hydrogen can be ignored, thereby reducing the burden of the equipment and processing required to improve the purity of the hydrogen.

[0076] The hydrogen gas purified by the purification unit 20 is stored in the storage unit 30. The storage unit 30 is a gas tank for storing hydrogen gas. In order to provide a sufficient amount and pressure of hydrogen gas to the power generation unit 40, the purified hydrogen gas is stored in the storage unit 30. In the waste hydrogen power generation device 1A of the first embodiment, the hydrogen gas discharged from the plurality of epitaxial growth devices 11 is stored in the same storage unit 30.

[0077] A power generation unit 40 is provided at the lower side of the storage unit 30, and generates electricity by using the purified hydrogen as fuel. Figure 2The structure of the gas turbine shown in FIG. Figure 3 The internal combustion engine shown is used to burn refined hydrogen. The power generation unit 40 is provided with a generator 41 known to the public, and the specifications and number of the generators can be appropriately adjusted according to the scale of the facility.

[0078] exist Figure 2 In the schematic diagram, the power generation section 40 also includes a gas turbine section 42 that generates a rotational force by burning refined hydrogen with oxygen in the atmosphere. The rotational force generated by the gas turbine section 42 drives the generator 41 and generates electricity. In the figure, refined hydrogen is supplied to the gas turbine section 42 as fuel. Furthermore, air is supplied to the auxiliary turbine section 43 and pressurized by the auxiliary turbine section 43. Subsequently, the pressurized air is supplied to the gas turbine section 42. Therefore, compared to normal pressure, the oxygen concentration at this time will increase, and the combustion efficiency of hydrogen will also increase, thereby increasing the rotation speed of the gas turbine section 42, that is, the turbine shaft 44. In addition, the turbine shaft 44 is connected to the generator 41, and electricity is generated by the generator 41.

[0079] The gas turbine unit 42 can cope with various sizes from large to small. However, it is not very suitable for the gradual change from the low speed area to the high speed area. In this case, the refined hydrogen is stored in the storage unit 30 in a specified amount and can be supplied to the gas turbine unit 42 at a specified pressure, so that the gas turbine unit 42 can rotate at a relatively stable speed. Therefore, the method of using the gas turbine unit 42 for power generation is suitable for large semiconductor factories that have a relatively high demand for the supply of refined hydrogen.

[0080] exist Figure 3 In the schematic diagram of FIG. 4 , the power generation section 40 further includes an internal combustion engine section 45 that generates a rotational force by burning refined hydrogen with oxygen in the atmosphere. The internal combustion engine section 45 is a piston engine having a structure similar to that of a gasoline engine, a diesel engine, etc., and uses refined hydrogen as a fuel instead of gasoline or light oil. The internal combustion engine section 45 shown in the figure includes a piston 47 inserted into a cylinder 46. Refined hydrogen and air are supplied to a space defined by the cylinder 46 and the piston 47 of the internal combustion engine section 45; the piston 47 moves in the cylinder 46 by explosion. The piston 47 is connected to a connecting rod 48, and the connecting rod 48 is connected to a crankshaft 49. Thus, the linear motion of the piston 47 is converted into the rotational motion of the crankshaft 49. The crankshaft 49 is connected to the generator 41, and the rotational force generated by the crankshaft 49 causes the generator 41 to generate electricity. In addition, in addition to the piston engine using refined hydrogen as fuel, this mechanism can also be applied to a rotary engine.

[0081] When the supply of purified hydrogen changes, the internal combustion engine unit 45 can flexibly adjust the rotation speed of the crankshaft 49. Therefore, it can flexibly respond to the supply and demand relationship of power generation. In general, the internal combustion engine unit 45 is more suitable for the waste hydrogen power generation device 1B of the second embodiment (see Figure 4 ).

[0082] Figure 2 and Figure 3 The disclosed structure of the power generation unit 40 is only an example of a power generation device and structure using purified hydrogen as fuel. In addition, the device structure other than that described and illustrated is naturally included in the structure of the power generation unit, and the necessary structure not described or illustrated is also appropriately included.

[0083] The storage unit 60 is equipped with a secondary battery for storing the electricity generated by the power generation unit 40, for example, a lead storage battery, a sodium sulfur (NaS) battery, a lithium ion battery, etc. In addition, the number and type of the storage unit 60 can be determined according to the power generation capacity and the power usage. It should be noted that the power is stored in direct current, and the power usage unit 65 requires alternating current, so the storage unit 60 can be further configured with an inverter or other device that converts direct current into alternating current. Once the power generated by the power generation unit 40 (generator 41) is stored in the secondary battery of the storage unit 60 for charging, the secondary battery can release the power from the storage unit 60 for discharge. In this way, stable power can be provided to semiconductor factory equipment and the like having an epitaxial growth device 11 through the storage unit 60.

[0084] Figure 4 1 is a schematic diagram of the overall structure of the waste hydrogen power generation device 1B of the second embodiment. In the waste hydrogen power generation device 1B, each hydrogen generation unit 10 is correspondingly configured with a power generation unit 80. The power generation unit 80 is composed of a single casing 81. The purification unit 20, the storage unit 30, and the power generation unit 40 are encapsulated inside the casing 81 in which the power generation unit 80 is installed. As shown in the figure, the power storage unit 60 is also encapsulated in the casing 81. The common structure of the waste hydrogen power generation device 1B in the second embodiment and the waste hydrogen power generation device 1A of the first embodiment will be explained using the same symbols. A conduit is connected to the casing 81 in which the power generation unit 80 is installed, and a pressure gauge, a check valve and a flow control valve are provided on the conduit.

[0085] As shown in the figure, each epitaxial growth device 11 as a hydrogen generation unit 10 is correspondingly configured with a power generation unit 80. Therefore, each epitaxial growth device 11 can generate electricity. In the waste hydrogen power generation device 1B, the refined hydrogen obtained after purification of the hydrogen discarded from any epitaxial growth device 11 will not be mixed with the refined hydrogen generated by other epitaxial growth devices 11. For example, when an abnormality occurs in a certain epitaxial growth device, it is not necessary to stop the entire hydrogen power generation device, but only the power generation unit connected to the epitaxial growth device with the problem needs to be stopped, thereby reducing the risk of reduced operating efficiency of the equipment.

[0086] In addition, since the power generation unit 80 itself has the ability to process waste hydrogen, there is no need to install gas tanks and other equipment separately, which makes the installation and removal (or moving in and out) of the power generation unit 80 in semiconductor manufacturing plants and facilities relatively easier. At the same time, it can also reduce the burden of pipeline construction required for transporting and supplying waste hydrogen and refining hydrogen. Furthermore, the number of power generation units 80 can be adjusted according to the number of operating epitaxial growth devices 11 as the hydrogen generation unit 10, so that it can be suitable for the scale of the semiconductor factory.

[0087] The size of the power generation unit 80 (its housing 81) can be designed according to the size and capacity of the built-in purification unit 20, storage unit 30, power generation unit 40, and even power storage unit 60. In addition, two epitaxial growth devices 11 can be connected to the same power generation unit 80 (its housing 81).

[0088] As described above, by using the waste hydrogen power generation device of the above embodiment, the waste hydrogen from semiconductor manufacturing equipment can be purified with less burden and reused for power generation, thereby realizing auxiliary power generation for facilities. In particular, by making hydrogen and air burn together as fuel, it is not necessary to deliberately require the concentration required by the fuel cell, which reduces the burden of equipment and processing required for hydrogen purification.

[0089] Since the hydrogen generation unit is an epitaxial growth device, the hydrogen exhausted during the semiconductor manufacturing process can be used to generate electricity, thereby reducing power consumption.

[0090] Since impurities in the waste hydrogen can be removed by contacting it with water, the equipment required for preparing purified hydrogen from the waste hydrogen and its processing process can be simplified.

[0091] The power generation unit is equipped with a gas turbine unit that rotates by burning hydrogen and oxygen in the atmosphere. Since the rotational force generated by the gas turbine unit can drive the generator, stable power generation can be achieved even in large facilities.

[0092] The power generation unit is equipped with an internal combustion engine that generates rotational force by burning hydrogen and oxygen in the atmosphere. Since the rotational force generated by the internal combustion engine can drive the generator, flexible power generation can be achieved even in small facilities.

[0093] Since a power storage unit is provided to store the generated power, it is possible to stably supply power to facilities and equipment.

[0094] Since the purification section, storage section, and power generation section are enclosed in a single casing, the power generation unit section can be easily installed in or removed from manufacturing plants and facilities, thereby reducing the burden on pipelines used to transport and supply waste hydrogen and refined hydrogen.

[0095] Furthermore, although the main purpose of the epitaxial growth equipment is as a hydrogen generation unit, the power generation unit unit can also be introduced into other factories that emit hydrogen during the manufacturing process, such as steel production facilities, thereby more effectively utilizing the waste hydrogen.

Claims

1. A waste hydrogen power generation device, characterized in that: Hydrogen generation unit; A purification section, which recovers the waste hydrogen discarded by the hydrogen generation section and removes impurities other than hydrogen to prepare refined hydrogen; A storage section, used for storing refined hydrogen; The power generation unit drives a generator by burning the purified hydrogen gas supplied from the storage unit with oxygen in the atmosphere.

2. The waste hydrogen power generation device according to claim 1, characterized in that: The hydrogen generation unit is an epitaxial growth device.

3. The waste hydrogen power generation device according to claim 1, characterized in that: In the purification section, the waste hydrogen gas is brought into contact with water to remove impurities.

4. The waste hydrogen power generation device according to claim 1, characterized in that: The power generation unit further includes a gas turbine unit that rotates by burning the purified hydrogen with oxygen in the atmosphere, and the rotational force generated by the gas turbine unit drives the generator to operate.

5. The waste hydrogen power generation device according to claim 1, characterized in that: The power generation unit further includes an internal combustion engine unit that rotates by burning the purified hydrogen with oxygen in the atmosphere, and the rotational force generated by the internal combustion engine unit drives the generator to operate.

6. The waste hydrogen power generation device according to claim 1, characterized in that: A power storage unit is further provided for storing the power generated by the power generation unit.

7. The waste hydrogen power generation device according to claim 1, characterized in that: The purification section, the storage section, and the power generation section are integrated and packaged inside a casing.

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