Waste heat recycling system using waste steam from activated carbon regeneration device

Abstract

The present invention relates to a resource recovery technology using high-temperature steam generated while regenerating activated carbon by means of superheated steam. Waste steam discharged after regenerating activated carbon is filtered by a filter module before being used, in order to prevent fine carbon particles contained in the steam from causing failure and reduced efficiency in a power generation device and maximize power generation efficiency.

Description

Waste heat recycling system using waste steam from activated carbon regeneration device

[0001] The present invention relates to a technology that utilizes high-temperature steam generated during a process of regenerating activated carbon using superheated steam for resource recycling. This patent application was filed as a result of the 'Development of Regenerative Thermal Combustion Oxidation Process Technology for Reducing Environmental Load of Regeneration Process Flue Gas (Research Period: July 1, 2024 – December 31, 2027)' under the Materials and Components Technology Development Project (Project No.: RS-2024-00460398) of the Ministry of Trade, Industry and Energy of Korea.

[0002] Activated carbon, used as an adsorbent in most industrial wastewater treatment facilities, undergoes a rapid decline in water purification capacity over time as organic matter fills the pores formed on its surface. Consequently, the activated carbon is currently replaced or regenerated periodically. In large-scale facilities handling large volumes of wastewater, the regeneration of activated carbon is typically the most burdensome aspect in terms of both cost and operation. Consequently, there is a growing trend to focus on ensuring overall operational efficiency by organically linking wastewater treatment operations with activated carbon regeneration operations. Currently, the activated carbon regeneration method utilizes superheated steam at temperatures of approximately 500–700°C to remove organic matter and water pollutants from within the pores of the activated carbon.

[0003] The regeneration process of activated carbon is carried out by injecting high-temperature superheated steam into spent activated carbon in an activated carbon regeneration tank, as described in the applicant’s Korean Registered Patent No. 10-2092541 and Korean Registered Patent No. 10-2455283. In this case, during the regeneration process, effluents such as high-temperature condensate discharged when regenerating activated carbon with superheated steam, or high-temperature exhaust steam generated after the regeneration is completed, are produced. Since the discharge of such high-temperature condensate or high-temperature exhaust steam causes serious environmental pollution, while there is extensive research on technologies to purify them, there is a significant lack of research and utilization methods regarding the recycling of these effluents.

[0004] Recently, Korean Patent No. 2203665 proposed an organic Rankine cycle power generation system using waste heat from an automatic activated carbon regeneration device, presenting an idea to generate electricity using waste heat. However, the high-temperature exhaust steam generated during the activated carbon regeneration process contains a large amount of pulverized coal, which causes frequent breakdowns in the power generation system and reduces efficiency. Furthermore, there is no method for treating wastewater such as condensate, revealing limitations in terms of practicality.

[0005] The present invention was devised to solve the aforementioned problems, and the objective of the present invention is to provide a system that utilizes high-temperature waste steam (exhaust steam) discharged from a regeneration facility that regenerates spent activated carbon using superheated steam as a heat source, produces electricity through an organic Rankine module to enable the use of electricity in the regeneration facility system, thereby realizing the production and utilization of electricity through the recycling of waste steam, while simultaneously removing fine coal from the waste steam to increase the operational efficiency of the system and removing discharge water such as condensate by burning it to achieve eco-friendliness.

[0006] As a means to solve the above-mentioned problem, in an embodiment of the present invention, as shown in FIGS. 1 to 6, a filter module (200) including a filter member that receives exhaust steam discharged from the activated carbon regeneration module (100) and filters and discharges pulverized coal contained within the steam; a power generation module (300) that receives the exhaust steam filtered by the filter module (200), evaporates an organic medium within an evaporator, and drives a turbine using the evaporated organic medium as a heat source to produce power generation electricity; a temperature increase module (400) that receives the exhaust steam used in the power generation module (300), reheats it through a heating unit (420) to remove moisture, and raises the temperature; a combustion module (500) that receives the exhaust steam passing through the temperature increase module (400), burns it to remove it; a superheated steam supply module (10, 20) that generates superheated steam using the power generated through the power generation module (300); and the A waste heat recycling system using waste steam from an activated carbon regeneration device is provided, comprising a rectification module (600) that converts unstable generated power into commercial electricity levels for use in a heating module (400) and a combustion module (500) and distributes it.

[0007] According to an embodiment of the present invention, high-temperature waste steam (exhaust steam) discharged from a regeneration facility that regenerates spent activated carbon using superheated steam is used as a heat source to produce electricity through an organic Rankine module, thereby enabling the use of electricity in the regeneration facility, and thus enabling the production and utilization of electricity through the recycling of waste steam.

[0008] In particular, the advantage of maximizing power generation efficiency is realized by filtering the waste steam through a filter module to prevent failures and reduced efficiency of the power generation device caused by pulverized coal contained in the waste steam after activated carbon regeneration.

[0009] In addition, the used steam emitted after power generation is heated using the generated electricity and combusted in a combustion module, thereby enabling the establishment of an eco-friendly and economical emission treatment system.

[0010] FIG. 1 is a main block diagram of a waste heat recycling system using waste steam from an activated carbon regeneration device according to an embodiment of the present invention.

[0011] FIG. 2 is a conceptual diagram illustrating an example of the structure and function of an activated carbon regeneration tank applied to a waste heat recycling system using waste steam from an activated carbon regeneration device according to an embodiment of the present invention.

[0012] FIGS. 3 and FIGS. 4 are configuration diagrams and exemplary conceptual diagrams for explaining the configuration and function of the filter module of the present invention.

[0013] FIG. 5 is a configuration diagram for explaining the configuration and function of the power generation module of the present invention.

[0014] FIG. 6 is a configuration diagram for explaining the configuration and function of the heating module of the present invention.

[0015] FIG. 7 is a conceptual diagram illustrating the configuration and function of the combustion module of the present invention.

[0016] [Explanation of the symbol]

[0017] 100: Activated carbon regeneration module 200: Filter module

[0018] 300: Power generation module 400: Temperature raising module

[0019] 500: Combustion module 600: Rectification module

[0020] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the present invention is sufficiently conveyed to those skilled in the art.

[0021] The present invention will be described in detail below with reference to the attached drawings.

[0022] FIG. 1 is a main block diagram of a waste heat recycling system using waste steam from an activated carbon regeneration device according to an embodiment of the present invention (hereinafter referred to as the 'present invention').

[0023] Referring to FIG. 1, the present invention comprises: an activated carbon regeneration module (100) that receives superheated steam and regenerates waste activated carbon within an activated carbon regeneration tank (110); a filter module (200) including a filter member that receives exhaust steam discharged from the activated carbon regeneration module (100) and filters and discharges fine coal within the steam; a power generation module (300) that receives the exhaust steam filtered from the filter module (200), evaporates an organic medium within an evaporator, and drives a turbine using the evaporated organic medium as a heat source to produce power generation; a heating module (400) that receives the exhaust steam used in the power generation module (300) and raises the temperature by removing moisture through reheating in a heating unit (420); a combustion module (500) that receives the exhaust steam passing through the heating module (400) and removes it by combustion; and a superheated steam generating power generated through the organic languishing module (300). It may be configured to include a superheated steam supply module (10, 20) and a rectification module (600) that converts unstable generated power into commercial electricity levels for use in the heating module (400) and combustion module (500).

[0024] Specifically, the activated carbon regeneration module (100) is defined as encompassing an entire facility that performs the function of regenerating the spent activated carbon by bringing the spent activated carbon into contact with the superheated steam, by providing an internal receiving space in the activated carbon regeneration tank (110), introducing spent activated carbon into the receiving space, and injecting superheated steam formed from an external superheated steam supply module (10, 20) into the interior.

[0025] For example, as shown in FIG. 2, a process of regenerating is performed by injecting high-temperature superheated steam into spent activated carbon through a superheated steam injection unit (30) disposed inside an activated carbon regeneration tank (110). Afterward, the regenerated activated carbon is discharged through a discharge section (31a) and goes out to a storage facility, and the exhaust steam generated during the regeneration process is discharged through a steam discharge section (31b). That is, a facility including a regeneration tank structure that has an internal receiving space and implements a regeneration process by bringing superheated steam into contact with spent activated carbon within the receiving space can be considered to be included in the activated carbon regeneration module (100) of the present invention.

[0026] The above activated carbon regeneration module (100) performs a regeneration process by bringing superheated steam and waste activated carbon into contact within an activated carbon regeneration tank (110) that has an internal receiving space. When regenerating activated carbon using superheated steam, the superheated steam transfers latent heat to the activated carbon (saturated carbon) and dissolves contaminants within the activated carbon, which are then discharged to the outside as waste steam (hereinafter referred to as 'exhaust steam'), and the temperature at this time is 120℃ to 130℃ or higher.

[0027] In this case, the present invention enables the implementation of a system that produces electricity using the exhaust steam, simultaneously removes pulverized coal from the exhaust steam to ensure the efficiency of the power generation facility, and removes the used exhaust steam through combustion to ensure eco-friendliness.

[0028] That is, as shown in FIGS. 1 and 2, the exhaust steam generated during the regeneration process in the activated carbon regeneration tank (110) is discharged with a temperature of 120 to 130°C or higher, and the exhaust steam discharged through the steam discharge part (31b) is introduced into the filter module (200) of the present invention.

[0029] The filter module (200) above performs the function of removing fine coal that comes out during discharge and discharging only steam components.

[0030] FIG. 3 illustrates the configuration of the filter module (200) of the present invention, and FIG. 4 illustrates an example of the implementation of the filter module as an example of FIG. 3.

[0031] Referring to FIGS. 3 and 4, the filter module (200) of the present invention may be configured to include a receiving body (210) that receives and receives exhaust steam discharged from an activated carbon regeneration tank (110), a plurality of filter members (220) disposed inside the receiving body (210), a dust discharge unit (230) disposed below the receiving body (210) to discharge and collect fine coal filtered by the filter members (220), and an air cleaning unit (250) that applies high-pressure air into the receiving body (210) to remove dust adsorbed on the surface of the filter members (220).

[0032] The above filter member (220) is an air purification filter member and is an annular structure made of filter cloth, and a plurality of them can be arranged in a spaced-apart structure, and dust structures such as pulverized coal contained in the exhaust steam are adsorbed onto the surface of the filter member.

[0033] When a large amount of dust is attached to the surface of the filter member, the dust collection ability decreases. Therefore, when the dust collection ability begins to decrease, the attached dust is dropped downward by backwashing (pulse jet), and the dropped dust is discharged through the dust discharge section (230) and accumulated in a ton bag, etc., and discharged regularly.

[0034] In addition, dust accumulated on the surface of the filter member can be removed using a blower installed separately or an air cleaning unit (250) implemented with plant air.

[0035] The steam passing through the filter module (200) of the present invention is transferred to the power generation module (300) at the rear end in a state where dust, such as pulverized coal, has been removed.

[0036] The above-mentioned power generation module (300) receives exhaust steam filtered from the above-mentioned filter module (200), evaporates an organic medium within an evaporator, and drives a turbine using the evaporated organic medium as a heat source to produce power. Preferably, an Organic Rankine Cycle (hereinafter 'ORC') can be applied.

[0037] The Organic Rankine Cycle (ORC) is a type of steam turbine power generation system that uses waste heat to convert an organic solvent into steam, and that steam rotates a turbine to produce electricity.

[0038] Unlike the conventional Rankine cycle, the Organic Rankine Cycle (ORC) uses organic compounds as refrigerants, enabling effective power conversion into heat at lower temperatures. This technology is widely used in applications such as geothermal power generation and industrial waste heat recovery.

[0039] In the present invention, such an organic Rankine cycle (ORC) is applied, but it differs in that high-temperature exhaust steam (via filter module) discharged from the activated carbon regeneration process of the present invention is used as a heat source to heat the organic Rankine cycle (ORC), and it is differentiated in that it is removed by combustion and oxidation in the combustion module described later.

[0040] It is also possible to utilize the waste heat of the exhaust steam generated from the activated carbon regeneration facility and return it to the superheated steam generator to use it again as superheated steam. However, since this method involves the pulverized coal not being removed and the steam still contains pollutants or oil vapor components, it puts strain on the equipment and causes problems that reduce regeneration efficiency. Therefore, it is desirable to treat the exhaust steam, after utilizing only the waste heat, by efficiently combusting and oxidizing it as in the present invention.

[0041] To this end, the power generation module (300) of the present invention may be configured to include, as shown in FIG. 5, an evaporator (310) that receives filtered steam via the filter module (200) and evaporates a working fluid, a generator (330) that receives the working fluid evaporated in the evaporator (310), rotates an internal turbine (320), and produces electricity, a condenser (340) that condenses the evaporated working fluid used in the turbine (320) using cooling water supplied from a cooling water supply unit, and a circulation pump (360) that circulates the working fluid condensed in the condenser (340) and recirculates it to the evaporator.

[0042] Specifically, in the above-mentioned power generation module (300), an organic heat medium having a lower evaporation temperature and higher vapor pressure than water is used as the working fluid, and in the present invention, the working fluid is heated and vaporized by utilizing the heat source of waste steam generated when saturated activated carbon is regenerated by superheated steam in the regeneration facility.

[0043] That is, the power generation module of the present invention is composed of a pump, an evaporator (heat exchanger), an expander (turbine), and a condenser, and each process of an ideal cycle consists of a compression process in the pump, a heat absorption process in the evaporator, an expansion process in the turbine, and a heat dissipation process in the condenser.

[0044] Specifically, as shown in FIG. 5, first, waste heat (heat source) contained in the exhaust steam generated from the activated carbon regeneration tank is transferred to the working fluid, which is an organic fluid present in the ORC evaporator (310), evaporates it, and then is transferred to the turbine (320). ② In the turbine (320), this vapor expands to rotate the turbine while simultaneously producing electricity from the generator (330) connected by the shaft. ③ Subsequently, the working fluid vapor, to which energy has been transferred for electricity production, is condensed in the condenser (340) through cooling water supplied from the cooling water supply unit (350). ④ This condensed working fluid is pressurized again by the circulation pump (360) and then sent back to the evaporator, thereby completing the cycle.

[0045] In this case, in particular, in the present invention, the initial incoming steam reaches a temperature of 120°C to 130°C or higher, but after passing through a heat exchanger to vaporize the working fluid, the temperature drops to 100°C or lower.

[0046] As described above, in the present invention, the exhaust steam used is not reused as superheated steam but is combusted and removed in the combustion module described later. However, in this case, exhaust steam with a temperature of 100°C or lower undergoes a heating process to raise its temperature to a certain extent so that combustion can be easily achieved.

[0047] To this end, the present invention is provided with a heating module (400) that receives used steam introduced into a power generation module (300), heats it through a heating unit (420) to remove moisture, and raises the temperature.

[0048] The above-described heating module (400) may be configured to include, as shown in FIG. 6, a heating body (401) having an inlet (410) for receiving exhaust steam from the above-described power generation module (300), a heating part (420) having a heater member stacked in a multi-layered structure and spaced apart from each other inside the heating body (401), and a discharge part (430) for discharging the exhaust steam heated inside the heating body (401).

[0049] In this case, the exhaust steam discharged through the discharge section (430) is heated to 80-90% of the temperature of the initial exhaust steam flowing into the filter module (200). That is, the exhaust steam, which has dropped below 100°C after vaporizing the working fluid, is brought into contact with the heater member described above, and is heated to a range of 110°C to 120°C when discharged. Afterward, the heated exhaust steam is supplied to the combustion module (500).

[0050] FIG. 7 is a conceptual diagram to explain the structure and function of such a combustion module (500).

[0051] The combustion module (500) receives the exhaust steam passing through the heating module (400), burns it, and removes it.

[0052] Referring to FIG. 7 and FIG. 1, the combustion module (500) may be configured to include a mixing chamber (510) that collects and receives exhaust including exhaust steam discharged from the activated carbon regeneration module (100) and heated exhaust steam discharged from the heating module (400), an inlet (520) that introduces exhaust from the mixing chamber (510) into the combustion chamber (530), and a combustion device (540) that burns exhaust flowing from the inlet (520) into the combustion chamber.

[0053] Specifically, first, some of the exhaust steam and discharge water (x4) generated during the initial stage of the activated carbon regeneration process (1 to 3 hours after the introduction of superheated steam) inside the activated carbon regeneration tank (110) can be temporarily stored in a discharge water storage tank (not shown), then divided according to the process stage and moved to a mixing chamber (510) to form a mixed gas, and then transferred to a combustion chamber (530) for combustion treatment.

[0054] Furthermore, other exhaust steam (x3) generated inside the activated carbon regeneration tank (110) passes through the filter module (200), the power generation module (300), and the heating module (400) as in the present invention, and after being heated, is transferred to the mixing chamber (510) and combusted in the combustion chamber (530). In the case of the heated exhaust steam, efficient oxidation occurs during the combustion process in the combustion chamber.

[0055] More preferably, the exhaust steam, etc. introduced into the mixing chamber (510) of the combustion module (500) of the present invention is circulated and introduced with the high-temperature circulating gas (800°C) generated during the combustion reaction in the combustion chamber (530), thereby allowing it to undergo an additional heating process.

[0056] That is, a portion of the high-temperature exhaust gas (y2) generated during the heating process in the heating module (400) and the combustion process in the combustion module (500) is circulated and introduced into the mixing chamber (510) to perform additional heating. A portion of the other high-temperature exhaust gas (y1) discharged from inside the combustion module (500) can be used through a Hot-by-pass line to prevent a rapid increase in temperature within the combustion chamber. In this case, the "Hot-by-pass line" is a line used to control the temperature by diverting the high-temperature exhaust gas from the combustion module or engine system so that it is not sent directly to the combustion chamber. Through this, a rapid rise in temperature within the combustion chamber can be prevented, and the stability and efficiency of the system can be increased.

[0057] The exhaust steam (x3) and the exhaust steam and discharge water (x4) (hereinafter referred to as 'mixed discharge (y3)') that have undergone an additional heating process are heated to 120~130°C or higher when introduced into the inlet (520), and are introduced into the combustion chamber (530), where a process of combustion at 900°C or higher is implemented by the combustor (540), and the combustion heat is recovered in the heat storage material inside the combustion chamber (530) and lowered to 200°C or lower (a2) and discharged to the stack.

[0058] As described above, the high-temperature oxidizing gas in the combustion chamber is reintroduced into the mixing chamber as circulating gas (y2) through the valve of the circulation unit (550).

[0059] The combustion module (500) of the present invention described above burns and oxidizes effluents such as wastewater, exhaust steam, and oil vapor generated in part from the activated carbon regeneration facility, thereby eliminating the need for separate facilities to treat excessive wastewater, making the facility structure more efficient, and enabling an environmentally friendly process.

[0060] In addition, as shown in FIG. 1, the electricity (E) produced in the power generation module (300) of the present invention is transferred (E1, E2, E3, E4) to a rectification module (600) that converts unstable generated power to a commercial electricity level and distributes it so that it can be used in the superheated steam supply module (10, 20), the heating module (400), and the combustion module (500), and is used as power for the system, thereby enabling very economical system operation. That is, through the rectification module (600), the stability of the electricity supply is increased, and various electrical facilities of the present invention can be operated safely.

[0061]

[0062] As described above, the technical concept of the present invention has been specifically described in preferred embodiments; however, the aforementioned preferred embodiments are for illustrative purposes only and are not intended to be limiting. As such, a person skilled in the art will understand that various embodiments are possible within the scope of the technical concept of the present invention through the combination of embodiments thereof.

Claims

1. An activated carbon regeneration module (100) that regenerates spent activated carbon in an activated carbon regeneration tank (110) by receiving superheated steam; A filter module (200) comprising a filter member that receives exhaust steam discharged from the activated carbon regeneration module (100) and filters and discharges fine coal contained within the steam; A power generation module (300) that receives filtered steam from the filter module (200), evaporates an organic medium inside an evaporator, and drives a turbine using the evaporated organic medium as a heat source to produce power generation; A heating module (400) that receives used steam introduced into the power generation module (300) and raises the temperature by removing moisture through reheating in the heating section (420); A combustion module (500) that receives exhaust steam passing through the above-mentioned heating module (400) and burns and removes it; A rectification module (600) that converts unstable generated power into a commercial electricity level and distributes it so that the power generated through the power generation module (300) can be used in the superheated steam supply module (10, 20) that generates superheated steam, the heating module (400), and the combustion module (500); including, Waste heat recycling system using waste steam from an activated carbon regeneration device.

2. In Claim 1, The filter module (200) above is, A receiving body (210) that receives and receives exhaust steam discharged from the above activated carbon regeneration tank (110); A plurality of filter members (220) disposed inside the above receiving body part (210); A dust discharge unit (230) disposed at the lower part of the receiving body (210) and discharges and collects fine coal filtered by the filter member (220); An air cleaning unit (250) that applies high-pressure air into the receiving body (210) to remove dust adsorbed on the surface of the filter member (220); including, Waste heat recycling system using waste steam from an activated carbon regeneration device.

3. In Claim 2, The above power generation module (300) is, An evaporator (310) that receives filtered exhaust steam via the filter module (200) and evaporates the working fluid; A generator (330) that receives the working fluid evaporated in the above evaporator (310), rotates an internal turbine (320), and produces electricity; A condenser (340) that condenses the evaporated working fluid used in the turbine (320) using cooling water supplied from a cooling water supply unit; A circulation pump (350) that circulates the working fluid condensed in the condenser (340) and reintroduces it into the evaporator; including, Waste heat recycling system using waste steam from an activated carbon regeneration device.

4. In Claim 3, The above-mentioned heating module (400) is, A heating body part (401) provided with an inlet (410) for receiving exhaust steam flowing in from the above-mentioned power generation module (300); A heating unit (420) having heater members that are spaced apart from each other and stacked in a multi-layer structure inside the above-mentioned heating body (401); It includes a discharge section (430) for discharging steam heated inside the above-mentioned heating body section (401); The exhaust steam discharged through the discharge section (430) is heated to 80-90% of the temperature of the initial exhaust steam flowing into the filter module (200). Waste heat recycling system using waste steam from an activated carbon regeneration device.

5. In Claim 4, The above combustion module (500) is, The discharge including exhaust steam discharged from the above activated carbon regeneration module (100) and A mixing chamber (510) that collects and receives heated steam discharged from the above-mentioned heating module (400); An inlet section (520) for introducing the discharge from the above mixing chamber (510) into the combustion chamber (530); A combustor (540) for combusting the discharge flowing from the inlet (520) into the combustion chamber; comprising Waste heat recycling system using waste steam from an activated carbon regeneration device.

6. In Claim 5, The above combustion module (500) is, The combustion gas (y2) generated during the combustion process of the exhaust is supplied to the mixing chamber (510), A gas circulation unit (550) that raises the temperature inside the mixing chamber (510); including, Waste heat recycling system using waste steam from an activated carbon regeneration device.

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