Apparatus and method for producing hydrogen using waste

Abstract

The present invention relates to an apparatus and method for producing hydrogen using waste, wherein the waste is compressed and fed into a gasification furnace under an airtight condition to generate synthesis gas, and a series of processes are successively carried out, wherein the synthesis gas is highly purified to collect a useful gas of high purity, thereby improving the efficiency of hydrogen production. The hydrogen production apparatus using waste may comprise: a waste supply device (100) for compressing and forcibly conveying waste; a gasification furnace (200) that melts the compressed waste supplied from the waste supply device (100) to produce slag and synthesis gas; a cooling device (300) that cools the synthesis gas discharged from the gasification furnace (200); a neutralization and desulfurization cleaning device (500) that neutralizes, desulfurizes, and dechlorinates the cooled synthesis gas discharged from the cooling device (300); a water gas conversion device (700) that processes the synthesis gas discharged from the neutralization and desulfurization cleaning device (500) to produce water gas containing carbon dioxide and hydrogen; and a hydrogen refining device (800) that extracts the hydrogen from the water gas discharged from the water gas conversion device (700).

Description

Hydrogen production device and method using waste

[0001] The present invention relates to a device and method for producing hydrogen by gasifying waste, and more specifically, to a device and method for producing hydrogen using waste, which compresses waste and supplies it to a gasification furnace, cools the synthesis gas produced in the gasification furnace and sequentially supplies it to a water-gas conversion device and a hydrogen purification device, and then captures hydrogen.

[0002] Industrial development has led to the generation of diverse types of waste at various industrial sites. This waste is primarily disposed of through landfill or incineration. Conventional disposal methods like landfill and incineration lead to environmental pollution and the generation of secondary pollutants. In particular, soil contamination from landfill and hazardous substances like dioxin generated during incineration can cause serious environmental problems.

[0003] As an alternative to landfill or incineration, a gasification process can be proposed, which involves gasifying waste at high temperatures and then refining it. The waste gasification process involves feeding the waste into a gasification furnace, heating it to high temperatures, and reacting it with pure oxygen to produce a synthesis gas. Carbon monoxide (CO) and hydrogen (H2) are separated and collected. The waste is then heated, and the remaining slag is discharged separately.

[0004] However, to improve the efficiency of hydrogen production from waste, there is a need for more efficient compression and supply of waste, and improvements in the process to collect high-purity useful gases from synthesis gas.

[0005] The present invention aims to provide a device and method for producing hydrogen using waste, in which a series of processes are continuously performed, in which waste is compressed and supplied to a gasification furnace in a sealed state to produce synthesis gas, and the synthesis gas is highly purified to collect high-purity useful gas, thereby improving hydrogen production efficiency.

[0006] A hydrogen production device using waste according to one embodiment of the present invention may include a waste supply device (100) that compresses and forcibly transports waste; a gasification furnace (200) that melts the compressed waste supplied from the waste supply device (100) to produce slag and synthesis gas; a cooling device (300) that cools the synthesis gas discharged from the gasification furnace (200); a neutralization and desulfurization cleaning device (500) that neutralizes, desulfurizes, and desalts the cooled synthesis gas discharged from the cooling device (300); a water gas conversion device (700) that processes the synthesis gas discharged from the neutralization and desulfurization cleaning device (500) to produce water gas containing carbon dioxide and hydrogen; and a hydrogen purification device (800) that extracts hydrogen from the water gas discharged from the water gas conversion device (700).

[0007] It may further include at least one of a buffer tank (600) for temporarily storing the synthesis gas introduced from the neutralization and desulfurization cleaning device (500) and discharging it to the water gas conversion device (700); and a hydrogen compressor (900) for compressing the hydrogen discharged from the hydrogen purification device (800) and sending it to a storage.

[0008] The above waste supply device (100) may include a continuous heating furnace (110) and a crushing and pressurizing screw (120).

[0009] The above crushing and pressurizing screw (120) is installed at the entrance of the continuous heating furnace (110) into which waste is introduced, and can crush the introduced waste while rotating in place and then forcibly transport it to the exit.

[0010] The continuous heating furnace (110) may include a hopper (111) installed at the entrance to allow waste to flow in, an inclined inner surface (112) inclined in the middle portion to compress the crushed waste forcibly conveyed by the crushing and pressurizing screw (120), and an exhaust port (113) installed near the inclined inner surface (112) to discharge air.

[0011] By applying heat to some sections including the inner surface of the above-mentioned slope (112), the air retained during the compression of the waste material that has become flexible can be discharged to the outside through the exhaust port (113).

[0012] The above waste supply device (100) can utilize waste that further includes at least one of a heating means installed to apply heat to a portion of the section including the inner surface of the slope (112), and a cutting means installed in the continuous heating furnace (110) to cut the compressed waste that is continuously forcibly conveyed in a cylindrical shape at regular intervals.

[0013] A method for producing hydrogen using waste according to another embodiment of the present invention may include a 10th step (S10) of compressing waste; a 20th step (S20) of melting and gasifying the compressed waste to produce synthesis gas; a 30th step (S30) of cooling the synthesis gas; a 40th step (S40) of neutralizing, desulfurizing, and desalting the cooled synthesis gas; a 50th step (S50) of injecting steam into the neutralized, desulfurized, and desalted synthesis gas to convert the synthesis gas into water gas containing carbon dioxide and hydrogen; and a 60th step (S60) of extracting hydrogen from the water gas.

[0014] In the above 10th step (S10), the waste fed into the continuous heating furnace (110) is crushed and forcibly transported toward the exit while being caught in the crushing and pressurizing screw (120) and the inner surface of the continuous heating furnace (110), and while the waste is forcibly transported, the waste is compressed by passing through the inwardly inclined inner surface (112) of the continuous heating furnace (110), and when the waste is compressed, air is discharged to the outside of the continuous heating furnace (110) so as to maintain airtightness.

[0015] In the above 10th step (S10), while the waste is compressed on the inner surface of the slope (112), the waste is heated, and the waste can be compressed into a cylindrical shape and discharged continuously or cut at regular intervals and discharged.

[0016] The above 50th step (S50) can heat the feed water in the boiler (710) and inject steam into the synthesis gas.

[0017] The above step 60 (S60) can utilize waste that is collected separately from off-gas other than hydrogen, supplied as fuel to a boiler (710), or combusted and discharged from a flare stack (810).

[0018] According to the present invention, a series of processes in which waste is compressed and supplied to a gasification furnace and the resulting synthesis gas is cooled and purified can be continuously performed, so that high-purity hydrogen can be efficiently produced.

[0019] In addition, by crushing waste fed into a continuous heating furnace by a crushing and pressurizing screw that rotates in place and pressurizing the waste through an outlet, and continuously or cutting the waste into a cylindrical shape into a certain length and supplying it to the gasification furnace, the phenomenon of the internal temperature dropping momentarily that occurs when conventional block-based waste is supplied one by one is minimized, and the temperature inside the gasification furnace can be maintained stably.

[0020] In addition, the lime powder absorbs carbon dioxide from the synthesis gas in the cooling device and is then returned to the recovery chamber, heated by the high temperature of the synthesis gas to separate the carbon dioxide, and the separated carbon dioxide is captured separately, so that the captured carbon dioxide can be utilized separately, and the temperature of the synthesis gas moving to the cooling device is first cooled, so that the cooling burden of the cooling device can be reduced, and the carbon dioxide recovery burden of the hydrogen purification device can be reduced.

[0021] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0022] FIG. 1 is a schematic diagram illustrating a hydrogen production system using waste according to a first embodiment of the present invention.

[0023] FIG. 2 is a schematic diagram of a carbon dioxide purification device according to a second embodiment of the present invention.

[0024] Figure 3 is a flowchart schematically illustrating a hydrogen production method using the system of Figure 1.

[0025] Hereinafter, with reference to the attached drawings, preferred embodiments will be described in detail so that those skilled in the art can easily practice the present invention. Furthermore, among the components mentioned in the various embodiments, similar and related components may be replaced, exchanged, or added to each embodiment. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a specific description of a related, known function or component is deemed to unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted.

[0026] A hydrogen production device using waste according to a first embodiment of the present invention may include a waste supply device (100), a gasification furnace (200), a cooling device (300), a neutralization and desulfurization cleaning device (500), a buffer tank (600), a water gas conversion device (700), a hydrogen purification device (800), and a hydrogen compressor (900), as shown in FIG. 1.

[0027] First, the waste supply device (100) can be manufactured to crush and compress waste into a certain size and supply it to a gasification furnace (200). To this end, the waste supply device (100) can include a continuous heating furnace (110) and a crushing and pressurizing screw (120).

[0028] A continuous heating furnace (110) may be manufactured to have a certain length, and to allow waste to be introduced through a hopper (111) installed at an inlet portion, and then supplied to a gasification furnace (200) through an outlet on the opposite side. This continuous heating furnace (110) may be provided with an inwardly inclined inner surface (112) for compressing waste in the middle portion, and an exhaust port (113) installed near this inclined inner surface (112). In addition, the continuous heating furnace (110) may further include a heating means for applying heat to a portion of the section including the inclined inner surface (112). By this heating means, the waste is heated, dried, and pyrolyzed, and in addition, the flexibility thereof is improved due to the heating, so that the waste may be highly compressed at the inclined inner surface (112), and during this compression process, all air contained in the waste may be discharged to the outside through the exhaust port (113).

[0029] The crushing and pressurizing screw (120) may be placed near the hopper (111) of the continuous heating furnace (110) and may be installed to continuously rotate in place. The crushing and pressurizing screw (120) may be installed to crush the waste introduced through the hopper (111) and push it out to the outlet of the continuous heating furnace (110). At this time, the waste may be crushed while being transported while being caught between the crushing and pressurizing screw (120) and the inner surface of the continuous heating furnace (110). In this way, while the crushing and pressurizing screw (120) is operating, the waste is crushed and forcibly transported, and is compressed by interlocking with the inclined inner surface (112) of the continuous heating furnace (110), and the air generated while the waste is compressed may be discharged to the outside through the exhaust port (113). Accordingly, the waste discharged from the continuous heating furnace (110) can be continuously fed into the gasification furnace (200) in an uninterrupted cylindrical shape. Here, by continuously feeding the cylindrical waste, when the waste packages in block units are fed into the gasification furnace (200) one by one, the phenomenon of the internal temperature of the gasification furnace (200) instantly decreasing is prevented, so that the internal temperature of the gasification furnace (200) can be maintained stably. In addition, a cutting means for cutting the continuous compressed waste at regular intervals can be further provided.

[0030] Next, the gasification furnace (200) may be manufactured so that waste supplied from the waste supply device (100) is gasified inside at a high temperature to generate synthesis gas and slag. For example, waste is introduced into an inside heated by oxygen and a burner at approximately 1,600 to 2,000°C, and as the waste melts, an oxidation reaction or a gasification reaction rapidly proceeds to generate slag and synthesis gas. The furnace may be manufactured so that the slag is discharged to the outside while the synthesis gas is discharged to a cooling device (300).

[0031] Next, the cooling device (300) can be manufactured to cool the synthesis gas discharged from the gasification furnace (200) at approximately 1,200 to 1,500°C to approximately 70°C or lower when introduced. This cooling device (300) can be manufactured by applying the structure of a cyclone dust collector. That is, the cooling device (300) is configured to spray cleaning water while the synthesis gas rotates inside, so that dust within the synthesis gas can be collected and removed while the synthesis gas rotates and is discharged.

[0032] Next, the neutralization and desulfurization cleaning device (500) contains various unnecessary gases including, in addition to the main components of carbon monoxide and hydrogen among the gases contained in the synthesis gas, hydrogen chloride (HCl), hydrogen cyanide (HCN), ammonia (NH3), hydrogen sulfide (H2S), methane (CH4), etc. It can be manufactured to neutralize these unnecessary gases and provide various catalysts for desalination and desulfurization work. In addition, the process water discharged from this neutralization and desulfurization cleaning device (500) passes through the wastewater treatment device (510) and is separated into purified process water and sludge and discharged, the sludge is collected, and the purified process water can be re-injected and recycled.

[0033] Next, the buffer tank (600) can be manufactured to temporarily store the synthesis gas that has passed through the neutralization and desulfurization cleaning device (500) so that it can be calmed down, and then supplied to the water gas conversion device (700).

[0034] Next, a water-to-gas conversion device (700) may be manufactured to convert carbon monoxide in the synthesis gas introduced from the buffer tank (600) into carbon dioxide and hydrogen. This water-to-gas conversion device (700) may be, for example, a WGS. In addition, the water-to-gas conversion device (700) may be installed to receive steam from a boiler (710).

[0035] Next, the hydrogen purification device (800) can be manufactured to extract hydrogen from the gas discharged from the water-to-gas converter (700). This hydrogen purification device (800) can produce high-purity hydrogen with a purity of approximately 99.99% from the gas flowing into the water-to-gas converter (700). This hydrogen purification device (800) can be, for example, a PSA device. Then, the hydrogen purification device (800) transfers the produced hydrogen to a hydrogen compressor (900), and other impurities (off-gas) such as carbon dioxide and nitrogen can be stored in a separate tank, supplied as fuel to a boiler (710), or transferred to a flare stack (810) to be combusted and discharged.

[0036] Finally, the hydrogen compressor (900) can be manufactured to compress hydrogen discharged from the hydrogen purification device (800) and transport it to a storage tank.

[0037] Hereinafter, a method for producing hydrogen using waste according to a preferred embodiment of the present invention will be described with reference to FIG. 2.

[0038] First, the waste is compressed and supplied to the gasification furnace (200) (S10). Here, the waste is fed through the hopper (111) of the continuous heating furnace (110), and the waste is crushed by the crushing and pressurizing screw (120) installed inside the continuous heating furnace (110), and can be pressurized and forcibly conveyed toward the outlet. While the crushed waste is forcibly conveyed, it is compressed while passing through the inwardly inclined inner surface (112) of the continuous heating furnace (110), and when compressed, the air can be exhausted to the outside through the exhaust port (113). In this state where the airtightness is maintained, the compressed waste is discharged in a long cylindrical shape, for example, like a rice cake, and can be continuously fed into the gasification furnace (200). Of course, if necessary, the compressed waste can be cut at regular intervals.

[0039] Next, the compressed waste is melted and gasified in a gasification furnace (200) to generate synthesis gas (S20). When the compressed waste is melted inside the gasification furnace (200) to generate synthesis gas and slag, the slag can be separately discharged and collected, and the synthesis gas can be transported for purification.

[0040] Next, the synthesis gas transported from the gasification furnace (200) is cooled (S30). The high-temperature synthesis gas discharged from the gasification furnace (200) can be introduced into a cooling device (300) to lower the temperature for purification. As the synthesis gas flows in a cyclone manner in the cooling device (300), the temperature is lowered, and dust and other particles in the synthesis gas can be collected. In addition, the lime powder introduced into the cooling device is mixed with the synthesis gas and absorbs carbon dioxide, and sinks downward together with the dust, thereby being separated from the synthesis gas, and after being separated from the dust by a separation filter built into the cooling device (300), can be discharged through the lime powder recovery line (430).

[0041] Next, the cooled synthesis gas is neutralized and desulfurized (S40). Various catalysts are added to the cooled synthesis gas discharged from the cooling device (300), and desulfurization and desalination can be performed while neutralizing it through chemical reactions. At this time, the supplied process water can be discharged and purified to a wastewater treatment device (510) and separated into purified process water and sludge. The purified process water can be recycled and reused. In addition, the wastewater treatment device (510) can receive and process dust separated from the cooling device (300).

[0042] Next, the synthesis gas undergoes a water-to-gas conversion process (S50). The neutralized, desulfurized, and desalinated synthesis gas undergoes a water-to-gas conversion process, along with steam injection, thereby converting carbon monoxide within the synthesis gas into carbon dioxide and hydrogen. Steam may be generated in a separate boiler (710) and injected into the water-to-gas conversion device (700).

[0043] Finally, hydrogen is extracted from the water-gas-converted gas (S60). At this time, the hydrogen may have a high purity of approximately 99.99%. The extracted hydrogen may be compressed in a hydrogen compressor (900) and then stored. In addition, impure gases (off-gas) other than hydrogen may be stored in a separate tank, supplied as fuel to a boiler (710), or transferred to a flare stack for combustion and discharge.

[0044] Meanwhile, a process for capturing carbon dioxide generated when lime powder is indirectly heated by high-temperature synthesis gas discharged from a gasification furnace (200) is further included (S21). A recovery chamber (410) is installed in a synthesis gas line (210) that guides synthesis gas discharged from a gasification furnace (200) to a cooling device (300), and lime powder contained in this recovery chamber (410) is heated by heat released from the synthesis gas line (210), and at this time, carbon dioxide generated from the lime powder is discharged through an exhaust line (440) and can be captured. For example, lime powder is heated to 750°C or higher by heat released from a synthesis gas line (210) through which synthesis gas of approximately 1,000 to 1,200°C flows, so that carbon dioxide is separated and the separated carbon dioxide can be captured. Of course, the high-temperature synthesis gas can be somewhat cooled through heat exchange with the lime powder.

[0045] Here, lime powder from which carbon dioxide has been separated is supplied to a cooling device (300) through a lime powder supply line (420), and when carbon dioxide is absorbed from the mixed synthesis gas by cyclone motion in the cooling device (300), it flows to a recovery chamber (410) through a lime powder recovery line (430). In this way, the process of separating carbon dioxide from lime powder in the recovery chamber (410) and absorbing carbon dioxide in the cooling device (300) can be repeated.

[0046]

[0047] As described above, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering its technical spirit or essential characteristics. Therefore, the above-described embodiments should be understood as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims below rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included within the scope of the present invention.

Claims

1. A waste supply device (100) that compresses and forcibly transports waste; A gasification furnace (200) that melts compressed waste supplied from the above waste supply device (100) to produce slag and synthesis gas; A cooling device (300) for cooling the synthesis gas discharged from the above gasification furnace (200); A neutralization and desulfurization cleaning device (500) that neutralizes, desulfurizes, and desalts the cooled synthesis gas discharged from the above cooling device (300); A water gas conversion device (700) that processes the synthesis gas discharged from the neutralization and desulfurization cleaning device (500) to produce water gas containing carbon dioxide and hydrogen; and A hydrogen production device using waste, comprising a hydrogen purification device (800) that extracts hydrogen from water gas discharged from the water gas conversion device (700).

2. In claim 1, A buffer tank (600) that temporarily stores the synthesis gas introduced from the neutralization and desulfurization cleaning device (500) and discharges it to the water gas conversion device (700); and A hydrogen production device using waste, further comprising at least one of a hydrogen compressor (900) that compresses hydrogen discharged from the hydrogen purification device (800) and sends it to a storage facility; 3. In claim 1, The above waste supply device (100) includes a continuous heating furnace (110) and a crushing and pressurizing screw (120), The above crushing and pressurizing screw (120) is a hydrogen production device using waste that is installed at the entrance of the continuous heating furnace (110) into which waste is introduced, and crushes the introduced waste while rotating in place and then forcibly transports it to the exit.

4. In claim 1, The above waste supply device (100) includes a continuous heating furnace (110) and a crushing and pressurizing screw (120), The above continuous heating furnace (110) is A hopper (111) installed at the entrance to allow waste to flow in, An inwardly inclined inner surface (112) in the middle section to compress the crushed waste forcibly conveyed by the crushing and pressurizing screw (120), and It includes an exhaust port (113) installed near the inner surface of the above slope (112) to discharge air, A hydrogen production device using waste, which applies heat to some sections including the inner surface of the above-mentioned slope (112) to compress the waste material, thereby allowing the air contained therein to be discharged to the outside through the exhaust port (113).

5. In claim 1, The above waste supply device (100) includes a continuous heating furnace (110) and a crushing and pressurizing screw (120), The above waste supply device (100) is a hydrogen production device using waste, which further includes at least one of a heating means installed to apply heat to a portion of the section including the inner surface of the slope (112), and a cutting means installed in the continuous heating furnace (110) to cut the compressed waste continuously forcibly conveyed in a cylindrical shape at regular intervals.

6. Step 10 of compressing waste (S10); Step 20 (S20) of melting and gasifying compressed waste to produce synthesis gas; Step 30 (S30) of cooling the above synthesis gas; Step 40 (S40) of neutralizing, desulfurizing and desalting the cooled synthesis gas; Step 50 (S50) of converting the neutralized, desulfurized and desalinated synthesis gas into water gas containing carbon dioxide and hydrogen by injecting steam into the synthesis gas; and A method for producing hydrogen using waste, comprising a 60th step (S60) of extracting hydrogen from the above-mentioned water gas; 7. In claim 6, The above 50th step (S50) is a method for producing hydrogen using waste by heating feed water in a boiler (710) and injecting steam into synthesis gas.

8. In claim 6, The above step 60 (S60) is a method for producing hydrogen using waste by separately capturing off-gas excluding hydrogen, supplying it as fuel to a boiler (710), or burning and discharging it in a flare stack (810).

9. In claim 6, A method for producing hydrogen using waste, wherein in the above 10th step (S10), waste fed into a continuous heating furnace (110) is crushed and forcibly transported toward an exit while being caught by a crushing and pressurizing screw (120) and the inner surface of the continuous heating furnace (110), and the waste is compressed by passing through an inwardly inclined inner surface (112) of the continuous heating furnace (110) while being forcibly transported, and air is discharged to the outside of the continuous heating furnace (110) when the waste is compressed to maintain airtightness.

10. In claim 5, A method for producing hydrogen using waste, wherein in the above 10th step (S10), the waste is heated while being compressed on the inner surface of the slope (112), and the waste is compressed into a cylindrical shape and discharged continuously or cut at regular intervals.

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