TWI524038B - Method of reusing carbon dioxide produced by calcinatory - Google Patents

Description

Recycling method of carbon dioxide produced by calciner

The present invention relates to a method of utilizing carbon dioxide, and more particularly to a method of recycling carbon dioxide produced by a calciner.

In order to slow down the pace of global warming and maintain the living environment of mankind, countries around the world are working to reduce carbon dioxide emissions. To this end, a system for capturing carbon dioxide has been proposed.

Conventional systems for capturing carbon dioxide can be classified into physical adsorption, chemical adsorption, cryogenic distillation, and membrane separation. Among them, the adsorption method has the potential to reduce the cost of capture, and thus has attracted attention from many studies.

Figure 1A shows a schematic diagram of a conventional calcium circuit capture system (CaO/CaCO ₃ Calcium Looping) 100. The calcium circuit capture carbon dioxide system 100 includes a carbonation furnace 110 (performing the reaction formula (1)) and a calciner 120 (performing the reaction formula (2)),

CO ₂ +CaO→CaCO ₃ ---(1)

CaCO ₃ →CO ₂ +CaO---(2)

The calcined fuel gas 102 and the calcium oxide 108 are sent to the carbonation furnace 110, the calcium oxide 108 is adsorbed by the calcium oxide 108 to form calcium carbonate 106, and the calcium carbonate 106 is sent to the calcining furnace 120 for calcination, wherein the carbonation furnace 110 is used. A small amount of exhaust gas 104 (such as carbon dioxide or sulfur dioxide) is emitted. In the calcining furnace 120, the combustion reaction of the calcium carbonate 106 is assisted by the addition of oxygen 122, and the carbon dioxide 124 of the product after the reaction is further compressed and sealed to the ground via heat exchange.

Figure 1B shows a schematic of a conventional oxy-combustion calciner 120. In order to increase the concentration of the carbon dioxide product after calcination, pure oxygen 154 and hydrocarbon fuel 140 (for example, diesel) are sent to the burner 130 for combustion, and the heat 132 generated after the combustion is supplied to the calciner 120.

However, the source of pure oxygen 154 requires the use of an air separation system 150 to separate the air 152 and provide pure oxygen 154 (exhaust nitrogen 156), while the air separation system 150 requires additional process costs.

In addition, since the flow rate of the pure oxygen 154 is reduced by about 80% compared with the air 152, and the temperature at which the 100% pure oxygen 154 is burned is too high (greater than 1000 ° C, the calcium oxide in the calciner 120 is deactivated), so the calciner is to be used. The carbon dioxide tail gas 126 produced by 120 is sent to the burner 130 to dilute the pure oxygen 122. Since the carbon dioxide tail gas 126 has originally cooled down, it is necessary to heat up again for combustion, and this step increases the energy consumption.

In order to solve the above disadvantages of the oxy-combustion calciner, the present invention provides a method for recycling carbon dioxide produced by a calciner.

The present invention provides a method for recycling carbon dioxide produced by a calciner, comprising the steps of: providing a calciner, wherein the calciner produces carbon dioxide; transferring carbon dioxide and a carbon source to a reduction furnace to produce carbon monoxide; and carbon monoxide The oxygen is delivered to a burner to provide a heat to the calciner.

The present invention further provides a method for recycling carbon dioxide produced by a calciner, comprising: providing a carbonation furnace, wherein the carbonation furnace produces a metal carbonate compound; transferring the metal carbonate compound to a calciner, wherein the calciner is produced Carbon dioxide; transporting carbon dioxide and a carbon source to a reduction furnace to produce carbon monoxide; and delivering carbon monoxide and oxygen to a burner to provide a heat to the calciner.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The present invention provides a method for recycling carbon dioxide produced by a calciner. Referring to FIG. 2, the method includes the following steps: providing a calcining furnace 220 having a metal carbonate compound in which the carbonic acid metal compound generates carbon dioxide 226 after combustion reaction. The carbon dioxide 226 produced by the calciner 220 can perform two paths, the path A sends the carbon dioxide 226 to the sequestration system 250, and the path B reuses the carbon dioxide 226, transfers the carbon dioxide 226 to the reduction furnace 240, and path A and path B. The ratio of carbon dioxide is (9-1): (1-9).

The above metal carbonate compound includes calcium carbonate (CaCO ₃ ), zinc carbonate (ZnCO ₃ ), magnesium carbonate (MgCO ₃ ), manganese carbonate (Mn(CO ₃ ) ₂ ), nickel carbonate (NiCO ₃ ) or lead carbonate (PbCO _{3 )} ).

Further, the carbon source 242 is transferred to the reduction furnace 240 together with the carbon dioxide 226 to carry out the following reaction formula (3), the reaction product is carbon monoxide 244, and the temperature of the reduction furnace 240 is about 800-900 ° C:

C+CO ₂ →2CO-------------(3)

Carbon source 242 includes biochar, coke or activated carbon.

It should be noted that in the conventional pure oxygen combustion calciner system (see Figure 1B), the carbon dioxide tail gas 126 produced by the calciner 120 is sent to the burner 130. However, since the carbon dioxide tail gas 126 has originally cooled down, it is necessary to heat up again for combustion, and this step increases the energy consumption.

In the present invention, since the temperature of the carbon dioxide 226 generated in the calcining furnace 220 is about 800-900 ° C, according to the carbon dioxide reduction reaction, when the reaction temperature is 850 ° C under normal pressure, the conversion efficiency of the reaction can reach 90%, therefore, The high-temperature, high-concentration carbon dioxide 226 generated in the calciner 220 can be "directly" transferred to the reduction furnace 240 without further treatment by cooling.

Thereafter, carbon monoxide 244 and oxygen 222 are passed to combustor 230 to provide heat to calciner 220. In addition, in other embodiments, a hydrocarbon fuel (not shown) may be additionally added to the combustor 230 to aid combustion.

In a preferred embodiment, the hydrocarbon fuel may be first added to the burner 230 before the initial generation of the carbon monoxide 244. After the combustion reaction and the reduction reaction cycle are repeated multiple times, the hydrocarbon fuel is not added, and the carbon monoxide 244 is directly added. It suffices to use the fuel of the burner 230.

It should be noted that the present invention can effectively save energy by replacing the hydrocarbon fuel in the conventional pure oxygen combustion calcining furnace with carbon monoxide. In addition, since the carbon monoxide 244 is introduced into the burner 230, the combustion efficiency in the calcining furnace 220 can be improved, and therefore, the pure oxygen 222 content required for the reaction in the burner 230 can be reduced to the pure oxygen combustion calciner system (Fig. 1B). One-third of the pure oxygen 154 content.

In addition, a cyclone 260 (not shown in FIG. 2, please refer to FIG. 3) may be disposed between the reduction furnace 240 and the burner 230. The purpose of the apparatus is to "react carbon" in the reduction furnace 240. Source 262" is returned to reduction furnace 240 for more efficient use of carbon source 242.

Furthermore, the hydrocarbon fuel used in the prior art has a component of water vapor, and after the plurality of cycles of the calciner 220 of the present invention, it is not necessary to add a hydrocarbon fuel, so only a high concentration of carbon dioxide is generated, and the generation of the anhydrous steam It can make the high concentration of carbon dioxide in the path A easier to seal.

The present invention further provides a method for carbon dioxide reuse generated by a calciner, see FIG. 3, comprising the steps of first providing a carbonation furnace 310 in which a metal carbonate compound 312 is produced in a carbonation furnace 310, and a metal carbonate compound 312 is delivered. To the calciner 220. The calciner 220 undergoes a combustion reaction to produce a metal oxide 314, and the metal oxide 314 is transferred to the carbonation furnace 310, wherein a loop circulation system is formed between the carbonation furnace 310 and the calciner 220. Taking calcium carbonate (CaCO ₃ ) as an example, calcium carbonate is produced in the carbonation furnace 310, and calcium carbonate is sent to the calcining furnace 220 for combustion reaction to produce calcium oxide (CaO), and the calcium oxide is sent back to the carbonation furnace 310. A calcium loop circulation system is formed between the carbonator 310 and the calciner 220.

The above metal carbonate compound 312 includes calcium carbonate (CaCO ₃ ), zinc carbonate (ZnCO ₃ ), magnesium carbonate (MgCO ₃ ), manganese carbonate (Mn(CO ₃ ) ₂ ), nickel carbonate (NiCO ₃ ) or lead carbonate (PbCO). ₃ ). The above metal oxide 314 includes calcium oxide (CaO), zinc oxide (ZnO), magnesium oxide (MgO), manganese oxide (MnO ₂ ), nickel oxide (NiO) or lead oxide (PbO).

After the combustion reaction of the calciner 220, carbon dioxide 226 is produced. The carbon dioxide 226 can carry out two paths. The path A sends the carbon dioxide 226 to the storage system 250, and the path B reuses the carbon dioxide 226 to transfer the carbon dioxide 226 to the reduction furnace 240.

Thereafter, carbon dioxide 226 and carbon source 242 are passed to reduction furnace 240 to produce carbon monoxide 244.

Carbon monoxide 244 and oxygen 222 are then passed to combustor 230 to provide heat to calciner 220.

Further, a cyclone 260 is disposed between the reduction furnace 240 and the burner 230, and the apparatus can return the unreacted carbon source 262 in the reduction furnace 240 to the reduction furnace 240 to utilize the carbon source 242 more efficiently.

In summary, the method for recycling carbon dioxide produced by the calciner provided by the present invention has the following advantages:

(A) Carbon monoxide (CO) is used to replace the hydrocarbon fuel of the original pure oxygen combustion system (Fig. 1B) to save energy.

(B) Since carbon monoxide is introduced into the burner, the combustion efficiency in the calciner can be increased, so that the total amount of pure oxygen required for the reaction in the burner can be reduced to pure oxygen in the pure oxygen combustion calciner system (Fig. 1B). One third of the total.

(C) The high temperature (about 800-900 ° C) carbon dioxide emitted from the calciner can be directly sent to the reduction furnace without cooling.

(D) After several cycles of the calciner, the high-concentration carbon dioxide can be produced without adding hydrocarbon fuel, and the generation of anhydrous steam makes the high-concentration carbon dioxide easier to seal.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the scope of the present invention, and any one of ordinary skill in the art can make any changes without departing from the spirit and scope of the invention. And the scope of the present invention is defined by the scope of the appended claims.

100. . . Calcium loop captures carbon dioxide system

102. . . exhaust

104. . . Exhaust gas

106. . . Calcium carbonate

108. . . Calcium Oxide

110. . . Carbonation furnace

120. . . Calciner

122. . . oxygen

124. . . carbon dioxide

126. . . Carbon dioxide tail gas produced by calciner

130. . . burner

132. . . Heat

140. . . Hydrocarbon fuel

150. . . Air separation system

152. . . air

154. . . Pure oxygen

156. . . Nitrogen

220. . . Calciner

222. . . oxygen

226. . . carbon dioxide

230. . . burner

240. . . Reduction furnace

242. . . Carbon source

244. . . Carbon monoxide

250. . . Storage system

260. . . Cyclone dust collector

262. . . Unreacted carbon source

310. . . Carbonation furnace

312. . . Metal carbonate compound

314. . . Metal oxide

A, B. . . path

Figure 1A is a schematic diagram illustrating a conventional calcium circuit capture system (CaO/CaCO ₃ Calcium Looping).

Figure 1B is a schematic diagram illustrating a conventional oxy-combustion calciner system.

Figure 2 is a cross-sectional view showing a preferred embodiment of the present invention.

Figure 3 is a cross-sectional view showing another embodiment of the present invention.

220. . . Calciner

222. . . oxygen

226. . . carbon dioxide

230. . . burner

240. . . Reduction furnace

242. . . Carbon source

244. . . Carbon monoxide

250. . . Storage system

A, B. . . path

Claims (13)

A method for recycling carbon dioxide produced by a calciner, comprising the steps of: providing a calciner, wherein the calciner produces carbon dioxide; transferring a mixture to a reduction furnace to produce carbon monoxide, wherein the mixture comprises carbon dioxide and carbon The source is composed, and the temperature of the reduction furnace is about 800 to 900 ° C; and the carbon monoxide and oxygen are sent to a burner to provide a heat to the calciner. The method for recycling carbon dioxide produced by the calciner according to claim 1 of the patent application, further comprising: adding a hydrocarbon fuel to the burner. The method for recycling carbon dioxide produced by the calciner according to the first aspect of the patent application includes: partially carbon dioxide produced by the calciner for carbon dioxide sequestration. A method for recycling carbon dioxide produced by a calciner according to claim 1, wherein the temperature of the carbon dioxide produced by the calciner is about 800 to 900 °C. A method of carbon dioxide reuse by a calciner according to claim 1, wherein the carbon source comprises coke, bio-carbon or activated carbon. The method for recycling carbon dioxide generated by the calciner according to claim 1, further comprising: providing a cyclone dust collector between the reduction furnace and the burner to unreact carbon in the reduction furnace Returned to the reduction furnace. A method for recycling carbon dioxide produced by a calciner, comprising: providing a carbonation furnace, wherein the carbonation furnace produces a metal carbonate compound; transferring the metal carbonate compound to a calciner, wherein the calciner produces carbon dioxide; Transferring the mixture to a reduction furnace to produce carbon monoxide, wherein the mixture is composed of the carbon dioxide and a carbon source, and the temperature of the reduction furnace is about 800 to 900 ° C; and transferring the carbon monoxide and oxygen to a burner To provide a heat to the calciner. A method of recycling carbon dioxide produced by a calciner according to claim 7, wherein the calciner produces a metal oxide, and the metal oxide is transferred to the carbonation furnace. A method for recycling carbon dioxide produced by a calciner according to claim 7, wherein the metal carbonate compound comprises calcium carbonate (CaCO ₃ ), zinc carbonate (ZnCO ₃ ), magnesium carbonate (MgCO ₃ ), manganese carbonate. (Mn(CO ₃ ) ₂ ), nickel carbonate (NiCO ₃ ) or lead carbonate (PbCO ₃ ). The method for recycling carbon dioxide produced by the calciner according to claim 7 of the patent application, further comprising: adding a hydrocarbon fuel to the burner. The method for recycling carbon dioxide produced by the calciner according to claim 7 of the patent application, further comprising: partially carbon dioxide produced by the calciner for carbon dioxide storage. A method for recycling carbon dioxide produced by a calciner according to claim 7, wherein the calciner produces carbon dioxide at a temperature of about 800 to 900 °C. The method for recycling carbon dioxide generated by the calciner according to claim 7 of the patent application, further comprising: providing a cyclone dust collector between the reduction furnace and the burner to unreact carbon in the reduction furnace Returned to the reduction furnace.