TWI706806B - Carbonator and carbon dioxide capture system - Google Patents

Abstract

A carbon dioxide capture system is provided, which includes a carbonator, a calcinator connected to the carbonator, and a hydrator connected to the calcinator and the carbonator. Metal hydroxide of high temperature is introduced to the carbonator from top, flue gas of low temperature is introduced into the carbonator from bottom, and the metal hydroxide and the flue gas are heat exchanged in the carbonator containing cyclone dust collectors. As such, a heater for heating the flue gas and a cooler for controlling the carbonator temperature can be omitted.

Description

Carbonation reactor and carbon dioxide capture system

This disclosure relates to the carbon dioxide capture system, and more particularly to the carbonation reactor it uses.

Global energy demand continues to grow, and it is estimated that the future will still need to rely on the supply of fossil energy. The International Energy Agency emphasized in the "Energy Technology Outlook 2010" (International Energy Agency, 2010) that in order to maintain energy security, promote economic development, and reduce energy Related to carbon dioxide emissions, efforts should be made to improve power generation efficiency, energy use efficiency, and develop carbon capture and storage technologies. Following the trend of the world, Taiwan has set CO2 emissions reduction policy goals in the Sustainable Energy Policy Program: From 2016 to 2020, return to 2005’s CO2 emissions, and in 2025, return to 2000 emissions (215 million tons). In order to achieve this goal, from an energy perspective, in addition to improving energy efficiency, developing clean energy, and ensuring stable energy supply, in the case where the continued use of fossil fuels is still unavoidable, carbon dioxide capture, storage and reuse technologies must be used. In order to effectively slow down the deterioration of the greenhouse effect.

At present, most of the calcium loop carbon dioxide capture procedures use a two-stage cycle system of carbonation reactor and calciner to capture carbon dioxide and regenerate adsorbent. However, although the reaction of the two-stage circulation system is simple, the reaction rate of CaO and CO ₂ is slow, and the efficiency of treating a large amount of waste gas is poor.

In order to solve the above problems, some documents propose a carbon dioxide capture system with a three-stage cycle system including a carbonation reactor, a calciner, and a hydration reactor. Although this carbon dioxide capture system is more complicated, the reaction rate of calcium hydroxide and carbon dioxide is faster, which can greatly improve the efficiency of carbon dioxide capture. However, this system faces new problems when it is scaled up to an industrial scale. For example, the reaction in the carbonation reactor is an exothermic reaction, so a cooler is required to control the temperature to avoid overheating the carbonation reactor and cause work safety problems. On the other hand, the temperature of the carbon dioxide-containing flue gas introduced into the carbonation reactor at the beginning is too low to effectively react with calcium hydroxide and requires additional heating of high carbon dioxide. In short, the carbonation reactor needs to heat the flue gas containing carbon dioxide and cool the flue gas and adsorbent after the carbonation reaction. These necessary devices and operations will consume energy. On the other hand, the hydration reactor needs to use superheated steam to react with calcium oxide. The step of generating superheated steam is to first heat water to generate saturated steam, and then heat the saturated steam to form superheated steam. These heating steps require additional heating equipment, which further consumes energy and increases carbon dioxide emissions.

In summary, there is an urgent need for a new system design to overcome the problems caused by the aforementioned three-stage circulation system.

The carbonation reactor provided by an embodiment of the present disclosure includes a plurality of connected and upright cyclone dust collection units and a plurality of rising pipes, wherein each cyclone dust collection unit includes a side inlet and a top exhaust port , With a discharge port at the bottom, among the two adjacent cyclone dust collection units, the discharge port of the cyclone dust collection unit on the upper side is connected to the lower riser pipe, and the riser pipe is connected to the lower cyclone dust collection unit The feed port of the cyclone dust collection unit on the upper side is also connected to the exhaust port of the cyclone dust collection unit on the lower side by the rising pipe on the next upper side, which is connected to the inlet of the cyclone dust collection unit on the next upper side. The feed port receives the metal hydroxide through the upper side ascending pipe, and the feed port of the cyclone dust collection unit on the lower side receives the flue gas through the lowermost ascending pipe, and the temperature of the metal hydroxide is greater than the temperature of the flue gas , Wherein the metal hydroxide in each of the cyclone dust collection unit falls from the feed port toward the discharge port, and exchanges heat with the reverse flue gas and reacts to form metal carbonate powder, which is discharged from the exhaust port. Low carbon dioxide concentration flue gas, and discharge metal carbonate and unreacted metal hydroxide from the discharge port.

In an embodiment, the temperature of the flue gas received by the lowermost riser is between 50°C and 200°C and is supplied to the feed inlet of the lowermost cyclone dust collection unit, and the feed of the next upper riser The temperature of the metal hydroxide received at the port is between 200°C and 500°C and is provided to the feed port of the cyclone dust collection unit on the next upper side.

In one embodiment, the temperature after the metal hydroxide in the carbonation reactor reacts with the reverse flue gas and heat exchange is between 350°C and 650°C. The carbon dioxide capture system provided by an embodiment of the present disclosure includes: a carbonation reactor, including: a plurality of connected and upright cyclone dust collection units and a plurality of risers, wherein each cyclone dust collection unit includes a side feed inlet , The exhaust port on the top, and a discharge port on the bottom. Among the two adjacent cyclone dust collection units, the discharge port of the cyclone dust collection unit on the upper side is connected to the lower riser pipe, and the riser pipe is connected to the lower The feed port of the cyclone dust collection unit on the side, and the feed port of the cyclone dust collection unit on the upper side is also connected to the exhaust port of the cyclone dust collection unit on the lower side by a rising pipe on the next upper side, which is connected to the The feed inlet of the cyclone dust collection unit receives the metal hydroxide through the upper side ascending pipe, and the feed inlet of the lowermost cyclone dust collection unit receives the flue gas through the lowermost ascending pipe, and the metal hydroxide The temperature is greater than the temperature of the flue gas, where the metal hydroxide in each of the cyclone dust collection units falls from the feed port toward the discharge port, and exchanges heat with the reverse flue gas and reacts to form metal carbonate powder, The flue gas with lower carbon dioxide concentration is discharged from the exhaust port, and the metal carbonate and unreacted metal hydroxide are discharged from the discharge port; the calciner is connected to one of the cyclone dust collection units on the lower side of the carbonation reactor The discharge port is used to receive the powder of metal carbonate and calcinate the metal carbonate to form metal oxides and high-temperature and high-concentration carbon dioxide; a hydration reactor is connected to the calcining furnace to receive metal oxides and make metal oxides It reacts with superheated steam to form metal hydroxide, wherein the feed port of the cyclone dust collection unit on the next upper side of the carbonation reactor is connected to the hydration reactor to receive the metal hydroxide from the hydration reactor.

In an embodiment, the temperature of the flue gas received by the lowermost riser is between 50°C and 200°C and is supplied to the feed inlet of the lowermost cyclone dust collection unit, and the feed of the next upper riser The temperature of the metal hydroxide received at the port is between 200°C and 500°C and is provided to the feed port of the cyclone dust collection unit on the next upper side.

In one embodiment, the temperature after the metal hydroxide in the carbonation reactor reacts with the reverse flue gas and heat exchange is between 350°C and 650°C.

In one embodiment, the temperature at which the metal carbonate is calcined in the calciner is between 850°C and 1200°C.

In one embodiment, the carbon dioxide produced by the calciner is used for heat exchange with saturated steam to form superheated steam for the hydration reactor.

In one embodiment, the high-temperature and high-concentration carbon dioxide produced by the calciner is used to indirectly heat the carbon dioxide-containing flue gas passing into the carbonation reactor.

In one embodiment, the temperature at which the metal oxide reacts with the superheated steam in the hydration reactor is between 200°C and 500°C.

FIG. 1 is a schematic diagram of a carbon dioxide capture system 100 in an embodiment of the present disclosure. It has a carbonation reactor 110, a calciner 120, and a hydration reactor 130 connected to it. In this design, the reaction temperature (350°C to 650°C) of the carbonation reactor 110 is higher than the temperature of the flue gas before treatment and the flue gas 101 containing carbon dioxide. Therefore, an additional heater 140 is needed to heat the flue gas 101, and then the flue gas 101 is passed into the carbonation reactor 110, so that the carbon dioxide in the flue gas 101 reacts with the metal hydroxide (such as calcium hydroxide), and then the carbonation reaction The device 101 discharges the treated flue gas 101'. The carbon dioxide concentration of the flue gas 101' after treatment is lower than that of the flue gas before treatment, but its temperature is higher than that of the flue gas 101 before heating. However, the reaction of metal hydroxides with carbon dioxide to form metal carbonates (such as calcium carbonate) and water is an exothermic reaction. In order to prevent the temperature of the carbonation reactor 110 from being too high, a cooler 150 needs to be additionally provided to prevent the carbonation reactor 110 from overheating. It can be understood that the heating method of the heater 140 is to burn fuel, which not only consumes energy but also generates additional carbon dioxide. In other words, the heater 140 used to treat the carbon dioxide in the flue gas 101 will additionally generate carbon dioxide to be treated. In addition, regardless of the mode of the cooler 150 (such as air-cooled or water-cooled), the circulating cooling medium also requires additional energy. In short, the heater 140 and the cooler 150 consume additional energy, generate carbon dioxide, and increase equipment costs.

Next, the metal carbonate (such as calcium carbonate) produced by the carbonation reactor 110 is introduced into the calciner 120 to thermally decompose the metal carbonate (such as calcium carbonate) into metal oxides (such as calcium oxide) and high-concentration carbon dioxide 105 (carbon dioxide). Concentration>80%). However, in the calcining furnace 120, the reaction temperature of thermal decomposition of metal carbonates into metal oxides and high-concentration carbon dioxide 105 is high (850°C to 1200°C), so an additional combustion furnace 160 is required to heat the calcining furnace 120. On the other hand, the high-concentration carbon dioxide 105 produced by the calcining furnace 120 has a very high temperature and needs to be cooled before further processing. If an additional cooler (not shown) is used to cool the high-concentration carbon dioxide 105, the cost of the additional cooler and additional energy consumption are required. If the high-temperature and high-concentration carbon dioxide 105 is allowed to cool naturally, time-consuming and large-volume storage equipment is required.

Next, the metal oxide (such as calcium oxide) produced by the calciner 120 is introduced into the hydration reactor 130, and the metal oxide (such as calcium oxide) reacts with water/steam to form a metal hydroxide (such as calcium hydroxide). The hydration reactor 130 may adopt a solution type hydration reactor or a steam type hydration reactor. If the metal hydroxide (such as calcium hydroxide) produced by the solution-type hydration reactor (not shown) is soluble in water, additional water needs to be removed to obtain the metal hydroxide dry powder, which will consume additional energy. The superheated steam 135 used in the steam-type hydration reactor 130 is formed as follows: the boiler 170 heats water 131 into saturated steam 133, then the superheater 180 heats the saturated steam 133 into superheated steam 135, and then introduces the superheated steam 135 into the hydration reaction The reactor 130 reacts with the metal oxide to form a metal hydroxide. Both the boiler 170 and the superheater 180 are necessary energy-consuming equipment for generating superheated steam 135. Since the reaction of metal oxides and water to form metal hydroxides is exothermic, it is necessary to discharge higher-temperature superheated steam 137 (temperature higher than superheated steam 135) to maintain the temperature of the hydration reactor 130 at an appropriate reaction temperature (200 ℃ to 500 ℃). Then, the metal hydroxide produced by the hydration reactor 130 and a small amount of unreacted metal oxide are introduced into the carbonation reactor 110. In the carbonation reactor 110, metal oxides (such as calcium oxide) can also react with carbon dioxide to form metal carbonates (such as calcium carbonate), but the required reaction temperature is higher (for example, higher than 550°C).

In summary, when the above system is scaled up to industrial applications, the carbonation reactor 110, the calciner 120, and the hydration reactor 130 all require additional heaters and/or coolers (such as heater 140, cooler 150). , The combustion furnace 160, the boiler 170, and the superheater 180) to achieve the required reaction temperature or reactants, will increase equipment costs and energy consumption and increase additional carbon dioxide.

Another embodiment of the present disclosure provides another carbon dioxide capture system 200, as shown in FIG. 2. In the carbonation reactor 110, a high-temperature metal hydroxide powder (about 200°C to 500°C) is introduced from the top, and a low-temperature and carbon dioxide-containing flue gas 101 (about 50°C to 200°C) is introduced from the bottom. , The low-temperature and carbon dioxide-containing flue gas 101 and the high-temperature metal hydroxide powder (may contain a small amount of metal oxide) heat exchange and react to form metal carbonate. For example, the upper part of the carbonation reactor 110 belongs to the reaction zone, that is, the metal hydroxide powder (which may contain a small amount of metal oxide) reacts with carbon dioxide in the flue gas 101 to form metal carbonates. The lower part of the carbonation reactor 110 is a heat exchange zone, that is, high temperature metal carbonate and low temperature and carbon dioxide-containing flue gas 101 generate heat exchange. It is further explained as follows that the metal carbonate falls to the bottom of the carbonation reactor 110 due to gravity and contacts the rising flue gas 101 to generate heat exchange, that is, the temperature of the metal carbonate decreases while the temperature of the flue gas 101 increases. Finally, the carbon dioxide concentration of the treated flue gas 101' is reduced (can be reduced to no carbon dioxide) and is discharged from the top of the carbonation reactor 110. Through the above design, the heater 140 for heating the flue gas 101 and the cooler 150 for cooling the carbonation reactor 110 in FIG. 1 can be omitted.

In one embodiment, the carbonation reactor 110 includes a plurality of connected and upright cyclone dust collection units and a plurality of risers, as shown in FIG. 3. It is worth noting that the carbonation reactor 110 in FIG. 3 has five cyclone dust collection units (such as cyclone dust collection units C0 to C4) and risers (such as risers L0 to L4), but the carbonation reactor 110 can There are more or fewer cyclone dust collection units and risers, such as 3 to 10 cyclone dust collection units and 3 to 10 risers, depending on actual needs. Each cyclone dust collection unit includes a side feed port 410, a top exhaust port 420, and a bottom discharge port 430, as shown in FIG. 4.

In Figures 3 and 4, in two adjacent cyclone dust collection units (such as cyclone dust collection units C1 and C2), the upper side of the cyclone dust collection unit (such as C1) has the discharge port 430 connected to the lower riser The pipe (such as L2) is connected to the feed inlet 410 of the cyclone dust collection unit (such as C2) on the lower side by a rising pipe. In detail, this is the direction of solid travel, as shown by the dotted line in FIG. 3. In addition, the feed inlet 410 of the upper cyclone dust collection unit (such as C1) is connected to the rising pipe (such as L1) of the exhaust port 420 of the lower cyclone dust collection unit (such as C2). In detail, this is the gas traveling direction, as shown by the solid line in FIG. 3. Furthermore, the dashed line is the traveling direction of the solid, and the solid line is the traveling direction of the gas, and the solid and the gas travel in the same riser. Taking Figure 3 as an example, first, the carbon dioxide-containing flue gas 101 is supplied to the feed inlet 410 of the cyclone dust collection unit C4 through the riser L4, and its traveling direction in the cyclone dust collection unit C4 is shown in Figure 4 , After turning downwards, blow up the exhaust port 420 of the cyclone dust collection unit C4, and then enter the feed port 410 of the cyclone dust collection unit C3 through the rising pipe L3. Similar to the foregoing, the flue gas 101 is sequentially blown through the cyclone dust collection unit C3, the riser tube L2, the cyclone dust collection unit C2, the riser tube L1, the cyclone dust collection unit C1, the riser tube L0, and the cyclone dust collection unit C0 for final treatment. The subsequent smoke 101' is discharged from the exhaust port of the cyclone dust collection unit. When the carbon dioxide-containing flue gas 101 leaves the exhaust port 420 of the cyclone dust collection unit C2, the high temperature metal hydroxide powder (such as Ca(OH) ₂ , such as the metal hydrogen from the hydration reactor 130) can be removed through the riser L1. Oxide powder, which may contain a small amount of metal oxides such as calcium oxide, and the powder from the discharge port 430 of the cyclone dust collection unit C0 (as described below) are blown into the cyclone dust collection unit C1 together to make the cyclone dust collection The metal hydroxide in the unit C1 falls from the feed port 410 toward the discharge port 430, and reacts with the carbon dioxide-containing flue gas 101 that first swirls downwards and then sucks upwards (ie, reverse) to form metal carbonates. In this way, the treated flue gas 101' can be discharged from the exhaust port 420 of the cyclone dust collection unit C1. The carbon dioxide concentration of the treated flue gas 101' is lower than that of the flue gas 101 before treatment entering the carbonation reactor, and the metal carbonate and unreacted metal carbonate are discharged from the discharge port 430 of the cyclone dust collection unit C1 Metal hydroxide.

The flue gas 101' discharged from the cyclone dust collection unit C1 may contain a small amount of powder, so it enters the inlet 410 of the cyclone dust collection unit C0, and a small amount of powder is discharged from the discharge port 430 of the cyclone dust collection unit C0. As shown in Figures 3 and 4, the powder discharged from the discharge port 430 of the cyclone dust collection unit C0 can be fed into the cyclone through the riser L1 with the carbon dioxide-containing flue gas 101 discharged from the exhaust port 420 of the cyclone dust collection unit C2 Dust collection unit C1. The powder discharged from the discharge port 430 of the cyclone dust collecting unit C1 sends the flue gas 101 discharged from the spinning dust collecting unit C3 to the cyclone dust collecting unit C2 through the rising pipe L2, and the reaction is the same as described above. With the sequence of metal hydroxide powder self-rising tube L1 → cyclone dust collection unit C1 → rising tube L2 → cyclone dust collection unit C2 → rising tube L3 → cyclone dust collection unit C3 → rising tube L4 → cyclone dust collection unit C4 Finally, the solid composition discharged from the bottom discharge port 430 of the spin-cyclone dust collection unit C4 is mainly metal carbonate. On the other hand, the flue gas containing carbon dioxide 101 from the rising pipe L4 → cyclone dust collection unit C4 → rising pipe L3 → cyclone dust collecting unit C3 → rising pipe L2 → cyclone dust collecting unit C2 → rising pipe L1 → cyclone dust collecting unit C1 The sequence of → rising pipe L0 → cyclone dust collection unit C0, and finally the exhaust port 420 at the top of the spin wind dust collection unit C0 discharges treated flue gas 101' with low carbon dioxide concentration, that is, the purpose of carbon dioxide capture is achieved. It is worth noting that in the upper cyclone dust collection unit (such as C1 and C2), the powder is mainly composed of metal hydroxides, so the metal hydroxides and carbon dioxide react to form metal carbonates. In the lower cyclone dust collection unit (such as C3 and C4), the powder is mainly composed of metal carbonate, so the heat exchange between the powder and the carbon dioxide-containing flue gas 101 is mainly carried out, that is, the temperature and the temperature of the carbon dioxide-containing flue gas 101 are increased. Lower the temperature of the powder. However, it is understandable that the upper cyclone dust collection unit may still have heat exchange. For example, when the temperature of the metal carbonate produced by the exothermic reaction is higher than the temperature of the flue gas 101, the flue gas 101 will generate heat with the metal carbonate. Exchange to increase the temperature of the flue gas 101 and decrease the temperature of calcium carbonate. On the other hand, if the powder in the lower cyclone dust collection unit contains metal hydroxides, it may also react with the carbon dioxide in the flue gas 101 to form metal carbonates. In addition, the length of the lower riser pipe (such as L4 and L3) is longer than the length of the upper riser pipe (such as L0 and L1), so that the upper cyclone dust collection unit (such as C1 and C2) mainly conducts metal hydrogen Oxides react with carbon dioxide to form metal carbonates, and the lower cyclone dust collection unit (such as C3 and C4) is mainly designed for heat exchange between flue gas 101 and powder.

The positions of the cyclone dust collection units C0, C1, C2, C3, and C4 in FIG. 3 are only examples. Those skilled in the art can adjust the relative positions of the cyclone dust collection units according to actual needs. On the other hand, the cyclone dust collection units C0, C1, C2, C3, and C4 in Figure 3 have similar sizes, but in fact, different cyclone dust collection units C0, C1, C2, C3, and C4 can also have different sizes. It depends on the design requirements.

In one embodiment, the mass flow rate of the metal hydroxide (calcium hydroxide here) from the hydration reactor 130 is 2.15 ton/h, which is used to capture 0.16 ton/h of carbon dioxide. Set the temperature of the carbon dioxide-containing flue gas 101 to 100°C, 150°C, and 200°C, and calculate the temperature of the cyclone dust collection unit and the rising pipe as shown in Table 1. It can be seen from Table 1 that when the temperature of the flue gas 101 is higher, the temperature of the more risers and the more cyclone dust collection units can reach the temperature of calcium hydroxide carbonation (for example, higher than 300℃) and calcium oxide carbonic acid. Temperature (for example, higher than 550°C).

Table 1 Flue gas temperature (℃) Heat exchange efficiency (%) Temperature(℃) L4 C4 L3 C3 L2 C2 L1 C1 100 50 193 209 243 259 292 308 407 423 70 229 252 302 324 370 392 527 548 100 283 315 381 412 476 506 693 722 150 50 241 257 291 307 340 356 454 469 70 277 299 234 371 417 439 573 594 100 330 361 426 457 521 551 737 766 200 50 290 306 339 355 388 404 501 516 70 326 348 394 416 461 482 614 635 100 378 409 473 503 566 596 780 809

Returning to Figure 2, the metal carbonate formed above is sent to the calcining furnace 120 for high-temperature calcination to decompose the metal carbonate into metal oxides and high-temperature high-concentration carbon dioxide 105, and the high-temperature high-concentration carbon dioxide 105 is introduced into the heat exchanger 190 , To exchange heat with saturated steam 133 to form superheated steam, as follows. On the other hand, the high-temperature high-concentration carbon dioxide 105 can be introduced into the high-temperature combustion furnace 160 to increase the mass flow rate of the high-temperature flue gas, so as to facilitate the operation of the pure oxygen calciner 120 and improve the powder transportation efficiency of the calciner 120.

Next, the metal oxide produced by the calcining furnace 120 is introduced into the steam-type hydration reactor 130 to react the metal oxide with water to form a metal hydroxide. The superheated steam 135 used in the steam-type hydration reactor 130 is formed as follows: the boiler 170 heats the water 131 into saturated steam 133, and then the heat exchanger 190 makes the saturated steam 133 and the high-concentration carbon dioxide 105 produce heat exchange, reducing The temperature of high-temperature high-concentration carbon dioxide 105 is increased, and the temperature of saturated steam 133 is increased to form superheated steam 135. The heat exchanger 190 can save the energy consumption of heating the saturated steam 133 and the extra carbon dioxide produced, and save the equipment, time, energy consumption, and extra carbon dioxide required to cool the high temperature and high concentration carbon dioxide 105 produced by the calciner 120.

The superheated steam 135 is then introduced into the hydration reactor 130 to react with the metal oxide to form a metal hydroxide. Since the reaction of metal oxides and water to form metal hydroxides is exothermic, it is necessary to discharge higher temperature superheated steam 137 (temperature higher than superheated steam 135) to maintain the temperature of the hydration reactor 130 at an appropriate reaction temperature (200 ℃ to 500 ℃). In this embodiment, the superheated steam 137 can be sent back to the heat exchanger 190 to reduce the saturated steam 133 required by the boiler 170 and also reduce the heat energy required to form the superheated steam 135 from the saturated steam 133 in the heat exchanger 190 . Next, the metal hydroxide produced in the hydration reactor 130 is introduced into the carbonation reactor 110.

As shown in Figure 5, the high-temperature and high-concentration carbon dioxide 105 generated by the calciner 120 can also be used to heat (unmix) the flue gas 101 passing into the carbonation reactor 110 to reduce the carbonation reactor 110 to make the flue gas and metal hydrogen The number of heat exchange cyclone dust collection units required for oxide heat exchange.

In the above embodiment, the metal carbonate can be placed in the calciner 120, the metal oxide can be placed in the hydration reactor 130, or the metal hydroxide can be placed on the top of the carbonation reactor 110 at the beginning. In some embodiments, metal carbonate can be added to the calciner 120, metal oxides can be added to the hydration reactor 130, and metal hydroxide can be added to the top of the carbonation reactor 110 during the process. In the above embodiments, the metal of the metal carbonate, metal hydroxide, and metal oxide may be calcium. In other embodiments, the metal of the metal carbonate, metal hydroxide, and metal oxide may be magnesium or other suitable metals.

Table 2 shows the effect of Ca(OH) ₂ and CaO converting different ratios of CO2 at different temperatures. As shown in Table 2, the carbonation conversion rate of Ca(OH) ₂ at 350°C is 60%, and when the reaction temperature of CaO is higher than 500°C, the carbonation conversion rate is greatly increased. In addition, Ca(OH) _{2 has a} higher carbonation conversion rate, a wider operating temperature range, and greater flexibility in the overall reaction program design, and the carbon dioxide concentration will not affect the results. In short, Ca(OH) _{2 is} more suitable for capturing carbon dioxide than CaO.

Table 2 Temperature(℃) Calcium oxide carbonation conversion rate (%) Calcium hydroxide carbonation conversion rate (%) 100%CO ₂ 30% CO ₂ 15% CO ₂ 100%CO ₂ 30% CO ₂ 15% CO ₂ 350 12.61 8.16 8.15 60.69 60.29 59.57 400 16.99 12.50 11.29 69.18 69.84 63.00 450 20.99 17.05 14.92 71.45 72.36 72.02 500 26.64 24.15 21.24 73.07 74.21 74.00 550 38.07 38.90 37.23 74.87 75.95 74.79 600 54.81 57.44 57.77 77.07 77.46 75.79 650 59.82 61.61 62.07 79.76 78.67 76.69

In summary, this application provides a novel carbon dioxide capture system that can effectively reduce energy consumption and additional carbon dioxide generated.

Although the present disclosure has been disclosed in several embodiments as above, it is not intended to limit the present disclosure. Anyone with ordinary knowledge in the technical field can make any changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of this disclosure shall be subject to those defined by the attached patent application scope.

C0, C1, C2, C3, C4: cyclone dust collection unit L0, L1, L2, L3, L4: rising tube 100, 200: carbon dioxide capture system 101, 101’: Smoke 105: high concentration of carbon dioxide 110: Carbonation reactor 120: Calciner 130: Hydration reactor 131: Water 133: saturated steam 135, 137: Superheated steam 140: heater 150: cooler 160: Burning furnace 170: boiler 180: Superheater 190: Heat Exchanger 410: Inlet 420: exhaust port 430: Discharge opening

Fig. 1 is a schematic diagram of a carbon dioxide capture system in an embodiment of the present disclosure. FIG. 2 is a schematic diagram of the carbon dioxide capture system in an embodiment of the present disclosure. Figure 3 is a schematic diagram of a carbonation reactor in an embodiment of the present disclosure. 4 is a schematic diagram of the cyclone dust collection unit in an embodiment of the present disclosure. FIG. 5 is a schematic diagram of the carbon dioxide capture system in an embodiment of the present disclosure.

101, 101’: Smoke

105: high concentration of carbon dioxide

110: Carbonation reactor

120: Calciner

130: Hydration reactor

131: Water

133: saturated steam

135, 137: Superheated steam

160: Burning furnace

170: boiler

190: Heat Exchanger

200: Carbon dioxide capture system

Claims (12)

A carbonation reactor includes: Connected and upright multiple cyclone dust collection units and multiple risers, Each of these cyclone dust collection units includes an inlet at one side, an exhaust at the top, and a discharge at the bottom, In the two adjacent cyclone dust collection units, the discharge port of the cyclone dust collection unit on the upper side is connected to a rising pipe below, and the ascending pipe is connected to the cyclone dust collection unit on the lower side. The feed port, and the feed port of the cyclone dust collection unit on the upper side is also connected to the exhaust port of the cyclone dust collection unit on the lower side by a riser pipe on the upper side, The feed inlet of the cyclone dust collection unit connected to the secondary upper side receives a metal hydroxide through a riser pipe on the secondary upper side, and the feed inlet of the cyclone dust collection unit on the lowermost side passes through the lowermost A riser tube receives a flue gas, and the temperature of the metal hydroxide is greater than the temperature of the flue gas, The metal hydroxide in each of the cyclone dust collection units falls from the feed port toward the discharge port, and exchanges heat with the flue gas in the reverse direction and reacts to form metal carbonate powder. The exhaust port discharges the flue gas with a lower carbon dioxide concentration, and the metal carbonate and unreacted metal hydroxide are discharged from the discharge port. The carbonation reactor as described in item 1 of the scope of patent application, wherein the temperature of the flue gas received by the lowermost riser is between 50°C and 200°C and is supplied to the lowermost cyclone collection The feed port of the dust unit, and the temperature of the metal hydroxide received by the rising pipe on the secondary upper side is between 200°C and 500°C and is supplied to the feed of the cyclone dust collection unit on the secondary upper side mouth. According to the carbonation reactor described in item 1 of the scope of the patent application, the temperature of the reaction between the metal hydroxide and the reverse flue gas in the carbonation reactor is between 350°C and 650°C. A carbon dioxide capture system, including: Monocarbonation reactor, including: Connected and upright multiple cyclone dust collection units and multiple risers, Each of these cyclone dust collection units includes an inlet at one side, an exhaust at the top, and a discharge at the bottom, In the two adjacent cyclone dust collection units, the discharge port of the cyclone dust collection unit on the upper side is connected to a rising pipe below, and the ascending pipe is connected to the cyclone dust collection unit on the lower side. The feed port, and the feed port of the cyclone dust collection unit on the upper side is also connected to the exhaust port of the cyclone dust collection unit on the lower side by a riser pipe on the upper side, The feed inlet of the cyclone dust collection unit connected to the secondary upper side receives a metal hydroxide through a riser pipe on the secondary upper side, and the feed inlet of the cyclone dust collection unit on the lowermost side passes through the lowermost A riser tube receives a flue gas, and the temperature of the metal hydroxide is greater than the temperature of the flue gas, The metal hydroxide in each of the cyclone dust collection units falls from the feed port toward the discharge port, and exchanges heat with the flue gas in the reverse direction and reacts to form metal carbonate powder. The exhaust port discharges the flue gas with a lower carbon dioxide concentration, and the metal carbonate and unreacted metal hydroxide are discharged from the discharge port; A calcining furnace is connected to the discharge port of the cyclone dust collection unit on the lowermost side of the carbonation reactor to receive metal carbonate powder and calcinate the metal carbonate to form a metal oxide and high temperature And high concentration of carbon dioxide, A hydration reactor connected to the calciner to receive the metal oxide, and react the metal oxide with a superheated steam to form a metal hydroxide, Wherein, the feed port of the cyclone dust collection unit on the next upper side of the carbonation reactor is connected to the hydration reactor to receive the metal hydroxide from the hydration reactor. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the temperature of the flue gas received by the lowermost riser pipe is between 50°C and 200°C and is supplied to the lowermost cyclone dust collection unit The feed port and the temperature of the metal hydroxide received by the rising pipe on the secondary upper side is between 200° C. and 500° C. and is provided to the feed port of the cyclone dust collection unit on the secondary upper side. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the reaction temperature of the metal hydroxide and the reverse flue gas in the carbonation reactor is between 350°C and 650°C. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the temperature at which the metal carbonate is calcined in the calcining furnace is between 850°C and 1200°C. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the carbon dioxide produced by the calciner is used for heat exchange with saturated steam to form the superheated steam used in the hydration reactor. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the carbon dioxide produced by the calciner is supplied to a heat exchanger for heat exchange with saturated steam to form the superheated steam used in the hydration reactor. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the carbon dioxide generated by the calciner is used to heat the flue gas passing into the carbonation reactor. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the carbon dioxide generated by the calciner is provided to the carbonation reaction gas for heating the flue gas passed into the carbonation reactor. The carbon dioxide capture system described in item 4 of the scope of patent application, wherein the reaction temperature of the metal oxide and the superheated steam in the hydration reactor is between 200°C and 500°C.

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