KR100293805B1 - PDBS (PARALLELDUAL-BEDSYSTEM) PROCESSING DEVICE FOR MAXIMIZING Utilization of CO₂ Removal Solid Media - Google Patents

Abstract

The present invention relates to a new "Parallel Dual-Bed System" (PDBS) process for maximizing the utilization of CO ₂ removal solid medium for more efficient removal of carbon dioxide, a global warming gas. A feature of the present invention is a " SRO " (SRO) which uses two sets of packed layers alternately by constructing a packed bed of solid medium for CO ₂ removal as a "PDBS" which is a double parallel layer rather than a single layer. operation), and the processing equipment development of methods, a new process equipment has a driving ease and continuity, and high removal efficiency of the conventional removal method, unlike the CO ₂ removal process device also removes itdeo be the utilization of a solid medium to maximize There is a big advantage in terms of economics due to cost reduction.

Description

Parallel Dual-Bed System (PDBS) Equipment for Maximizing the Utilization of Sorbent Materials to CO₂Removal (PDBS) for Maximizing Utilization of CO₂ Removal Solid Media

The present invention relates to a PDBS (Parallel Dual-Bed System) processing apparatus for maximizing the utilization rate of the CO ₂ removal medium, CO ₂ which is a global warming gas due to the greenhouse effect in terms of preventing global environmental pollution. The present invention relates to a PDBS (Parallel Dual-Bed System) process device using a SRO (Stop-Restart Operation) method as a new dry removal process device that removes more efficiently and considers the economics of using a solid medium.

The present invention relates to ¹⁴ CO ₂ and general industrial facilities, which generate about 350 ppm in nuclear facilities, in particular CANDU (Canadian Deuterium Uranium Reactor) reactors or DUPIC (Direct Use of spent PWR fuel In CANDU reactors) processes that process spent nuclear fuel. It is a new technology that develops new process equipment for improving the removal efficiency and maximizing the utilization of solid media for CO ₂ generated from factories, general chemical plants, cement plants, and coal and oil-fired power plants.

Existing methods of CO ₂ removal through many studies and experiences so far are largely based on the liquid scrubbing process, the removal by reaction with solid materials, the adsorption by physical adsorption, and the membrane ( membrane or cryogenic separation, and reaction processes using catalysts. Especially, the removal efficiency is not very high to remove large amounts of CO ₂ generated in thermal power plants, petroleum refining plants, and cement plants. The situation is only to apply the absorption method by the cleaning solution.

However, considering the characteristics and removal efficiency of CO ₂ removal process, and stability and recycling aspect of immobilized adsorbent, dry removal process using solid adsorbent is the most appropriate. In particular, when Ca (OH) ₂ (slaked lime), which has high CO ₂ removal efficiency, is used as a solid medium, proper moisture is present in the gas when a single bed is used in the conventional technique using a solid adsorbent. It shows a high removal efficiency under the relative humidity of about 85%), which increases the macroporous of the carbonate layer formed to decrease the diffusion resistance of CO ₂ gas, thereby increasing the reaction rate and increasing the utilization rate of the reactants. Do it. However, these prior arts require energy to increase the relative humidity of the injected gas by about 85%, and economics such as recycling and reuse of the reactants once used (in this case, the regeneration rate is not high) or disposal. In addition, there are difficulties in terms of removal efficiency, continuity and ease of operation, and maximization of utilization rate of the solid medium.

Currently, studies are underway to remove CO ₂ by alternately bypassing two beds by connecting two beds in parallel, but this method also increases the relative humidity of the injected gas in order to increase the removal efficiency during the reaction. Has to be maintained at about 85% at all times and also in terms of maximizing the utilization of solid media.

Therefore, the present invention was devised to solve the problems of the conventional CO ₂ removal process apparatus, and even when the relative humidity is 55%, the utilization rate of the solid medium is increased and the relative humidity is 85 according to the reoperation after a certain period of time. The purpose is to apply a Parallel Dual-Bed System (PDBS) device and a Stop-Restart Operatin (SRO) method, which exhibit the same removal effect as%, to a conventional CO ₂ removal process.

In addition, another object of the present invention is to increase the CO ₂ removal efficiency without maintaining the relative humidity of the injection gas up to 85% when the 'PDBS' process equipment is applied to the actual field (pilot-scale) scale and maintains high humidity conditions In order to reduce the energy consumption to maximize the use of the resulting solid medium is to significantly reduce the removal cost.

Ultimately, the present invention is the Earth's environment by main cause of global warming is more effectively removed than before the CO ₂ target world of micro-interest in a carbon tax driving light according to the Climate Change Convention, and also maximize the utilization of the solid medium for CO ₂ removal It is to revitalize the conservation industry.

1 is a schematic diagram illustrating one embodiment of a PDBS processing apparatus according to the present invention;

2A and 2B are detailed views of a bed of a PDBS process apparatus in accordance with the present invention.

Figure 3 is a graph showing the CO ₂ removal efficiency test results applying the SRO (Stop-Restart Operation) method to the PDBS process apparatus according to the present invention.

Figure 4 is a graph showing the results of using the solid medium by the PDBS processing apparatus according to the present invention.

Figure 5 is a graph showing the measurement results for the relative humidity change of the PDBS process apparatus according to the present invention.

* Explanation of symbols for main parts of the drawings

1: PDBS device 3,5,7,9: bed

10 alkaline earth metal hydroxide 11 CO ₂ tank

13: humidity generator 15: mixing tank

16-1, -2: air tank 17: PLC

19: analysis device

21,23,25,27,29,31,33,35,37,39: On-off valve

In order to achieve this purpose, the present invention is a new process equipment development that has not been attempted until now, and the packed bed of the solid medium is a double bed instead of a single bed, and each of them is set in parallel. It is to provide a new CO ₂ removal process device using 'SRO' (Stop-Restart Operatin) method, which consists of a new Parallel Dual-Bed System (PDBS) arranged as

The present invention takes advantage of the fact that moisture is generated when the CO ₂ gas reacts with Ca (OH) ₂ or Ba (OH) ₂ , which is a highly efficient removal medium. If the set is stopped for a certain period of time, the 'PDBS' device is configured to bypass the injection gas to the other bed set to enable continuous operation, and the 'SRO' method is applied to it.

The present invention is relative of the gas when the single bed in was shown that the utilization of the solid medium is increased, indeed CO ₂ removal experiment according to the fortune ships specified time after shutdown when using 'PDBS' Device relative humidity of 55% When the humidity is about 85%, the highest removal efficiency is shown, but in the present invention, the relative humidity of the injected gas is 55%, and the relative humidity of the gas exiting the bed bed is maintained at about 85% for 4 to 5 hours. Using the 'PDBS' device of the present invention can sufficiently increase the CO ₂ removal efficiency even if the relative humidity of the initial injection gas does not necessarily increase to 85%.

As such, the increase in the utilization rate of the solid medium in accordance with the re-operation after a certain period of time stops due to the moisture generated during the reaction between the CO ₂ and the solid medium and the carbonate layer formed from the surface of the solid medium when the operation is stopped and the internal unreacted layer. This is because the porosity of the carbonate layer is greatly increased in the process of redistribution of the formed product layer due to diffusion into the interior due to the concentration gradient at the interface, so that the unreacted bed layer is easily exposed, thereby easily reacting with CO ₂ . Therefore, the present invention applying the 'SRO' method to the new 'PDBS' process equipment does not need to increase the relative humidity of the injected gas to 85%, and it can reduce energy consumption to maintain high humidity conditions and thereby increase the utilization rate of the solid medium. It can be maximized and also continuous operation.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

'PDBS' device according to the present invention is four beds (3, 5, 7) consisting of two sets of beds (3, 5) and beds (7, 9), respectively, as shown schematically in FIG. 10) Solenoid valves (21, 23, 25, 27, 29, 31, 33) connected to a programmable logic controller (PLC) 17 used as an automatic valve opening and closing device and a gas chromatography (19). , 35,37,39). In addition, the average relative humidity of the exhaust gas in the atmosphere or in an industrial facility is about 50 to 55%, but in the present process apparatus 1, the humidity generator 13 and the mixing tank 15 and Install the air tanks (16-1) (16-2). Here, before supplying the CO ₂ gas, air and CO ₂ gas from the humidity generator 13 are uniformly mixed through the mixing tank 15 to adjust the desired CO ₂ concentration and humidity. At this time, in the case of the air tank (16-1) to control the relative humidity by supplying dry air to the mixing tank (15), the air from the air tank (16-2) is a bubble (bubble) in the humidity generator (13) It is used to generate and generate wet air.

Here, all four fixed bed beds (3,5,7,9) used in the CO ₂ removal process are made of glass tubes. You may. Each fixed bed bet 3,5,7,9 used in the 'PDBS' device was made of a glass tube with an inner diameter of 22 mm and a length of 300 mm, respectively, as shown in detail in FIGS. 2A and 2B. The thermostat tube 41, which surrounds the beds 3, 5, 7, and 9, and has an inlet 43 and an outlet 45 formed on the upper left side and the lower right side, respectively, has an inlet 43 and an outlet 45 if necessary. Connected to a constant temperature water beth to control the temperature in the bed. And a thermocouple 47 installed in the middle part of the bed is used to control and measure the temperature in the bed if necessary.

The bed 3 and the bed 5, which form one set of each of the beds 3, 5, 7, and 9 thus formed, are connected by a line 51, and the bed 7 which forms another set. And bed 9 are connected by line 53 and arranged in parallel, respectively, and have constant concentration and humidity from mixing tank 15 via line 55 to bed 3 and bed 7, respectively. CO ₂ gas is supplied. In addition, the line 51 and the line 53 are connected to the analyzer 19 through the line 57, respectively, and the lines 59 and 61 and the line 63 connected to the lower ends of the beds 5 and 9, respectively. 65 is connected to the exhaust or analysis device 19.

Referring to the CO ₂ removal method by the 'PDBS' device (1) according to the present invention.

'PDBS' device (1) as shown in Figure 1 first, then filling the adsorbent of the desired amount in each fixed-bed bed (3,5,7,9), CO ₂ gas through the _second tank (11) CO Before supplying the CO ₂ concentration is adjusted and, if necessary, the humidifier (13; humidifier) by supplying wet air to adjust the relative humidity.

Then, the process goes through four steps according to the 'SRO' method as follows.

First, the valves 21, 25, 27, 35 are opened and the valves 23, 29, 31, 33, 37, 39 are closed when a certain concentration of CO ₂ gas is injected. At this time, the concentration of the exhaust gas from the bed 3 is analyzed by the analyzer 19 through the valve 25 and the exhaust gas from the bed 5 is exhausted through the valve 35.

Then, the valves 21, 27, 33, 35 are opened and the valves 23, 25, 29, 31, 37, 39 are closed. In this step, the concentration ratio of the flue gas passing through the valve 25 and the CO ₂ injection gas (C / Co, where C is the concentration of the exhaust gas passing through the bed 3, Co is the concentration of the CO ₂ injection gas), When the breakthrough point C / Co is 0.5, the valve 25 is closed and the valve 33 is opened to measure the concentration of the exhaust gas passing through the bed 5.

In the next step, the valves 21, 25, 27, 33, 35, 37 are closed and the valves 23, 29, 31, 39 are open. The introduction of CO ₂ gas into the beds 3 and 5, the first set of fixed beds, by the 'SRO' method is shut down and bypassed by the second set, the beds 7, and 9. In addition, the concentration of the exhaust gas passing through the valve 29 is measured.

Finally, the valves 21, 25, 27, 29, 33, 35 are closed and the valves 23, 31, 37, 39 are open. Here, the operation of the beds 3 and 5 is stopped for a certain time and the concentration of the exhaust gas passing through the valve 37 is measured.

The process cycle of the 'PDBS' device 1 according to the invention comprises such a four step process, after which the operation is repeated again in the first step. This repetition can be operated automatically or manually by the PLC 17 which is an automatic valve opening and closing device.

Specific experimental results according to the 'PDBS' device (1) of the present invention operated as follows are as follows.

3 is a CO ₂ removal efficiency test applying the SRO method to the PDBS process apparatus 1, where the CO ₂ gas is a single bed set under a condition of injection concentration of 550 ppm and bed height of 12 cm (3, 5) Bypassing the inflow to the other set of beds (7, 9) and stopping the operation for 8 hours and restarting (restart) after the change in the concentration of CO ₂ discharged from the bed (3) as a result As shown in the figure, when the operation is stopped after a certain period of time, the concentration of the outflowing CO ₂ gas is greatly reduced. In other words, if the relative humidity is 55% and the breakthrough point (C / Co) is 0.5, the operation is restarted after the operation is stopped and the CO ₂ gas is almost removed up to about 100 minutes after the operation. CO ₂ entering the bed (5) was 100% removed.

In the case of CO ₂ removal experiment, the single bed shows the highest removal efficiency when the relative humidity of the gas is about 85%, but in the present invention, as shown in the experimental results of FIG. 5, the layer is formed when the relative humidity of the injection gas is 55%. Relative humidity of the gas passing through was maintained at about 85% for 4 to 5 hours, and using the high humidity environment generated by itself can greatly improve the removal efficiency and utilization of the solid medium. That is, when using the 'PDBS' device (1) of the present invention it can be seen that the CO ₂ removal efficiency can be sufficiently increased without increasing the relative humidity of the initial injection gas to 85%.

4 shows the optimum conditions for maximizing the utilization rate of the solid medium according to the change in relative humidity and breakthrough point by fixing the injection concentration of CO ₂ gas to 550, 1000 and 2000ppm, respectively, by applying the results of FIG. 3. The definition of utilization is as follows.

Utilization (%) = (Restart time / Continuous operation time) / 100

The utilization rate is expressed as the ratio of continuous operation time to reoperation time after stopping operation. That is, how much more solid medium can be used while maintaining high removal efficiency. Among the four results shown in FIG. 4, the utilization rate of the solid medium is higher than that of the other three cases when the relative humidity of the injection gas is 55% and the break point (C / Co) is 0.5 after restarting for a predetermined time. Much superior. Therefore, in the present invention using the 'PDBS' device (1), when the relative humidity is 55%, it appears that the utilization rate of the solid medium increases according to the re-operation after a certain time stop operation, and the new 'PDBS' process device (1) ' The present invention applying the SRO 'method does not need to increase the relative humidity of the injection gas to 85%, can reduce energy consumption to maintain high humidity conditions, thereby maximizing the utilization of the solid medium, and also continuous operation It can be seen that.

As another embodiment of the present invention, first, as shown in the 'PDBS' device (1) of Figure 1 using the PLC 17, the automatic valve opening and closing device 'PDBS' process for each single bed, double bed or each set as needed The device can be used and can be operated manually or automatically, for a certain time or continuously, depending on the amount of CO ₂ generated. In addition, the method of reversibly desorbing the fixed CO ₂ instead of the 'SRO' method of the present invention, in which one bed set has already been reacted, bypasses the inflow gas to the other bed set, and stops and restarts the operation for a while during continuous operation. It is possible, however, to take into account the economics of subsequent cost savings, such as the secondary waste treatment and the complexity of the process system reoccurring upon desorption.

By using the 'PDBS' process device and the 'SRO' method of the present invention instead of the dry removal method using the conventional solid medium, it is possible to increase the CO ₂ removal efficiency without having to increase the relative humidity of the injected gas to 85%, and high humidity conditions. In order to reduce the energy consumption to maintain and thereby maximize the utilization of the solid medium there is an advantage that can significantly reduce the CO ₂ removal cost. Also be either manual or automatic operation by using the PLC device, as needed, and the four beds each two by two by two by a Settles shift the CO ₂ gas by-pass to the can talk continuity of operation CO ₂ removal process It can save time. There is no need to consider a separate regeneration unit for the reuse of the reactants there is a great advantage, such as the ease of operation and the economics of reducing the device manufacturing cost due to the simplicity of the process equipment.

While the invention has been shown and described with respect to particular embodiments, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the appended claims. Anyone can grow up easily.

Claims (4)

(Correct) The beds 3 and 5 and beds 7 and 9 made of alkaline earth metal hydroxides are connected in series in series by a line 51 and a line 53, and a line 55 at the top and a line at the bottom ( 63 or 65, and each of the lines 51, 53, 55, 63, 65 connected to the solenoid valves 25, 27, 29, 31, 21, controlled by the PLC 17; 23, 35, 39, 33, 37 by the opening and closing process equipment for CO ₂ characterized in that the opening and closing. The process apparatus for removing CO ₂ according to claim 1, wherein the alkaline earth metal hydroxide (10) is Ba (OH) ₂ . (Correction) The humidifier 13 is connected to the line 55 connected to the bed (3, 5, 7 or 9) to adjust the humidity of the CO ₂ gas to be introduced. Process equipment for CO ₂ removal. (Correct) The beds 3 and 5 and beds 7 and 9 made of alkaline earth metal hydroxides are connected in series in series by a line 51 and a line 53, and a line 55 at the top and a line at the bottom ( 63 or 65, and each of the lines 51, 53, 55, 63, 65 connected to the solenoid valves 25, 27, 29, 31, 21, controlled by the PLC 17; In the process apparatus 1 for removing CO ₂ , which is opened and closed by 23, 35, 39, 33 and 37, the valve 21 and the CO ₂ gas are injected into the beds 3 and 5 to be discharged as exhaust gas. Opening the lines (51, 59) and closing the valve (23) and the lines (53, 61), and the valve (23) and the line ( ₂ ) so that CO ₂ gas is injected into the beds (7, 9) and discharged as exhaust gas A method of removing CO ₂ characterized by the PDBS operation, which repeats the steps of opening 53, 61 and closing the valve 21 and the lines 51, 59.