KR102574042B1 - A composition for oxygen carrier material, oxygen carrier using the same and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a raw material composition for producing oxygen-transferring particles, oxygen-transferring particles manufactured using the same, and a method for producing oxygen-transferring particles. In one embodiment, the raw material composition for preparing the oxygen delivery particles includes 58 to 80% by weight of nickel hydroxide (Ni(OH) ₂ ); 12-35% by weight of boehmite; 5 to 15% by weight of magnesium hydroxide (Mg(OH) ₂ ); Aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) 1 to 4% by weight; and 0.5 to 2% by weight of magnesium hydrolase phosphate (MgHPO ₄ ).

Description

Raw material composition for producing oxygen-transferring particles, oxygen-transferring particles manufactured using the same, and method for producing oxygen-transferring particles

The present invention relates to a raw material composition for producing oxygen-transferring particles, oxygen-transferring particles manufactured using the same, and a method for producing oxygen-transferring particles. More specifically, the present invention relates to a raw material composition for preparing phosphorus-containing nickel oxide oxygen transfer particles, oxygen transfer particles manufactured using the same, and a method for preparing oxygen transfer particles.

As the global average temperature rises due to the greenhouse effect caused by the increase in the concentration of carbon dioxide (CO ₂ ) in the atmosphere, the damage from climate change is increasing. Thermal power plants, which burn large amounts of coal and natural gas, are the stationary sources of anthropogenic carbon dioxide emissions. Emission reduction from large stationary sources of carbon dioxide, such as thermal power plants, can be achieved through carbon dioxide capture and storage (CCS). However, when the conventional capture technology is applied, a large reduction in thermal efficiency and a corresponding increase in cost follow. Accordingly, a new technology for minimizing the reduction in thermal efficiency and lowering the CO ₂ capture cost is required.

Chemical looping combustion (CLC) technology is attracting attention as a technology that can separate CO ₂ from the source inside the process while reducing thermal efficiency degradation. In CLC technology, combustion occurs by reacting fuel with oxygen contained in solid particles (oxygen transfer particles) whose main components are metal oxides instead of air, so the exhausted gas contains only water vapor and CO ₂ . Therefore, when water vapor is condensed and removed, only CO ₂ remains, so there is no need for a separate CO ₂ collection facility at the rear of the fuel combustion facility. In the CLC process, oxygen contained in the oxygen transfer particles is transferred to the fuel, and the oxygen transfer particles receive oxygen contained in the fuel reactor and air where the reduction reaction occurs, and the reduced oxygen transfer particles are oxidized again. It consists of a combination of air reactors that are regenerated in a state connected to each other. Both reactors use fluidized bed reactors, and the entire process is a circulating fluidized-bed process. Therefore, the oxygen delivery particles must satisfy various conditions suitable for the characteristics of the fluidized bed process. First of all, it must have physical properties suitable for the fluidized bed process, that is, sufficient strength, shape and packing density suitable for flow, average particle size and particle size distribution, and a pore structure favorable to the diffusion of the reaction gas. In addition, since it has a high oxygen transfer capacity in terms of reactivity, sufficient oxygen required for fuel combustion must be supplied while the fuel passes through the fuel reactor.

A spray-drying method is used as a method for producing a large amount of oxygen transporting particles having properties suitable for a fluidized bed process and having a high metal oxide content. Oxygen-transporting particles manufactured by the spray drying method shown in the prior art show that a significant portion of the manufactured particles have a donut-shaped or grooved shape, which needs improvement.

Oxygen transfer particles are composed of a metal oxide as an active material and a support. The support serves to increase the dispersion of the metal oxide, impart strength to the particles, and suppress sintering of the metal oxide that may occur during the firing process and the chemical roofing combustion process operated at high temperatures. Depending on the type of support selected, the reactivity and physical properties of the finally prepared oxygen delivery particle show a great difference.

Conventionally, gamma-alumina and alpha-alumina were mainly used as supports in the manufacture of nickel oxide (NiO)-based oxygen transfer particles. Gamma alumina combines with NiO during the firing process of the particles to easily form nickel aluminate (NiAl ₂ O ₄ ), which is a stable compound, and thus has a problem in that the oxygen transfer amount of the finally obtained oxygen delivery particles is reduced. Due to its very stable structure, alpha-alumina must be fired at a temperature of 1400 ° C or higher to impart sufficient strength (abrasion resistance) for application in the fluidized bed process. At the same time, more NiAl ₂ O ₄ ) is produced compared to low-temperature firing, and the oxygen transfer performance decreases as the sintering phenomenon of the active material increases. That is, the utilization efficiency of NiO as an active material is reduced.

On the other hand, in order to reduce the circulation amount of oxygen delivery particles and supply sufficient oxygen required for complete combustion of fuel while passing through the fuel reactor, the higher the content of the active material (metal oxide) is, the more advantageous it is. In NiO-based oxygen-transferring particles, when only alumina is used as a support when producing oxygen-transferring particles with a high NiO content, agglomeration between particles occurs during the continuous oxidation-reduction reaction cycle of the oxygen-transferring particles, which prevents fluidization. this can happen Accordingly, in order to suppress agglomeration of NiO-based oxygen delivery particles, magnesia (MgO) is mixed with alpha-alumina and used as a support material, or magnesium aluminate (MgAl ₂ O ₄ ) is used as a support material and sprayed. Magnesium (Mg)-containing NiO-based oxygen delivery particles prepared by a drying method are presented. However, even in this case, alpha-alumina (α-Al ₂ O ₃ ), magnesia (MgO), and magnesium aluminate (MgAl ₂ O ₄ ), which have a very stable structure, were used as supports to obtain the strength required for the application of the fluidized bed process. The spray-molded particles must be fired at a high temperature of 1,400°C or higher. Accordingly, the oxygen transfer performance (oxygen transfer rate and oxygen transfer amount) is significantly reduced due to the increase in the interaction strength between NiO and the support and sintering of the active material.

Summarizing the above conventional technologies for oxygen transporting particles, they are manufactured in a method unsuitable for mass production, or physical properties such as shape, strength, and density are unsuitable for application to a fluidized bed process or require improvement. In addition, in order to reduce the bond between the metal oxide and the support, a support raw material having a stable structure is used, and firing at a high temperature is required to obtain sufficient strength required in the process. Accordingly, bonding between the active material and the support and sintering of the active material occur, resulting in a significant decrease in oxygen transfer performance and a problem in that fluidization is not possible due to aggregation between particles during the reaction. On the other hand, when the content of the metal oxide is lowered, there are problems in that the amount of oxygen transfer is small and the fuel combustion efficiency is deteriorated or the amount of particle circulation must be greatly increased.

Therefore, in order to improve the fuel combustion efficiency and commercialization of the medium circulation combustion technology, it has physical properties suitable for the fluidized bed process and sufficient strength, suppresses the aggregation between particles that may occur during the oxidation-reduction cycle reaction, and transfers oxygen even at high temperature firing. There is a need for a composition design and manufacturing technology for NiO-based oxygen transport particles capable of lowering the sintering temperature with little degradation in performance.

Background art related to the present invention is Korean Patent Registration No. 2018-0112889 (published on October 15, 2018, title of the invention: loop seal separator using magnetic oxygen transfer particles and magnetic separator, medium circulation combustor having the loop seal separator) and its operation method).

One object of the present invention is to provide a raw material composition for oxygen transfer particles capable of securing sufficient strength and oxygen transfer performance under low firing temperature conditions.

Another object of the present invention is to provide a raw material composition for oxygen transporting particles that is excellent in the effect of increasing the rate of oxidation-reduction reaction and the amount of oxygen delivered.

Another object of the present invention is to provide a raw material composition for oxygen transfer particles capable of minimizing aggregation between oxygen transfer particles during an oxidation-reduction cycle reaction.

Another object of the present invention is to provide a raw material composition for oxygen transporting particles having excellent mixability, dispersibility and formulation stability of the raw material composition.

Another object of the present invention is to provide a raw material composition for oxygen transporting particles having excellent mechanical strength, productivity and economy.

Another object of the present invention is to provide a slurry for preparing oxygen transfer particles comprising the raw material composition for oxygen transfer particles.

Another object of the present invention is to provide oxygen-transferring particles prepared using the raw material composition or slurry for oxygen-transferring particles.

Another object of the present invention is to provide a method for preparing the oxygen delivery particles.

Another object of the present invention is to provide a chemical roofing combustion method using the oxygen delivery particles.

Another object of the present invention is to provide a chemical roofing combustion device for chemical roofing combustion using the oxygen transfer particles.

One aspect of the present invention relates to a raw material composition for oxygen delivery particles. In one embodiment, the raw material composition for oxygen-transporting particles is a nickel oxide (NiO)-based raw material composition for oxygen-transferring particles, comprising 58 to 80% by weight of nickel hydroxide (Ni(OH) ₂ ); 12-35% by weight of boehmite; 5 to 15% by weight of magnesium hydroxide (Mg(OH) ₂ ); Aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) 1 to 4% by weight; and 0.5 to 2% by weight of magnesium hydrolase phosphate (MgHPO ₄ ).

In one embodiment, the nickel hydroxide may have an average particle size greater than 0 and 10 μm or less, and a purity of 98% or more.

In one embodiment, the boehmite may have an average particle size greater than 0 and less than 1 μm, and a purity of 98% or more.

In one embodiment, the magnesium hydroxide may have an average particle size greater than 0 and 10 μm or less, and a purity of 97% or more.

In one embodiment, the aluminum dihydrogen phosphate may have an average particle size greater than 0 and 25 μm or less, and a purity of 97% or more.

In one embodiment, the magnesium hydroelectric phosphate may have an average particle size greater than 0 and less than or equal to 25 μm, and a purity of 97% or more.

Another aspect of the present invention is to provide a slurry for preparing oxygen transfer particles comprising the raw material composition for oxygen transfer particles. In one embodiment, the slurry for preparing the oxygen delivery particles includes a solid raw material including the raw material composition; and a solvent;

In one embodiment, the solid raw material may be included in an amount of 15 to 40% by weight based on the total weight of the slurry.

In one embodiment, the solvent may include water.

In one embodiment, the slurry may further include one or more additives of a dispersing agent, an antifoaming agent, and an organic binder.

In one embodiment, 0.01 to 5.0 parts by weight of the dispersant, 1.0 to 5.0 parts by weight of an organic binder, and 0.01 to 1.0 parts by weight of an antifoaming agent may be included with respect to 100 parts by weight of the solid raw material.

In one embodiment, the dispersant may include one or more of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

In one embodiment, the anionic surfactant may include at least one of a polycarboxylic acid salt and a polycarboxylic acid amine salt.

In one embodiment, the antifoaming agent may include at least one of a silicone-based antifoaming agent, a metal soap-based antifoaming agent, an amide-based antifoaming agent, a polyether-based antifoaming agent, a polyester-based antifoaming agent, a polyglycol-based antifoaming agent, and an alcohol-based antifoaming agent.

In one embodiment, the organic binder may include at least one of polyvinyl alcohol, polyethylene glycol, and methylcellulose.

Another aspect of the present invention relates to a method for preparing the oxygen delivery particles. In one embodiment, the method for preparing oxygen-transporting particles includes preparing a slurry for preparing oxygen-transferring particles by mixing the raw material composition with a solvent; Homogenizing the slurry by stirring; spray drying the homogenized slurry to form solid particles; and drying and calcining the solid particles.

Homogenizing the slurry in one embodiment may include adding one or more additives of a dispersant, an antifoaming agent, and an organic binder to the slurry; And stirring and grinding the slurry; may be made including.

In one embodiment, after the step of stirring and grinding the slurry, the step of removing foreign substances in the slurry; may further include.

In one embodiment, the drying may be to perform the solid particles at 110 ~ 150 ℃ for 2 to 24 hours.

In one embodiment, the sintering may be carried out by raising the solid particles to 1150 to 1250 °C at a heating rate of 1 to 5 °C/min, and then maintained for 2 to 10 hours.

In one embodiment, the additives may include 0.01 to 5.0 parts by weight of the dispersant, 1.0 to 5.0 parts by weight of the organic binder, and 0.01 to 1.0 parts by weight of the antifoaming agent, based on 100 parts by weight of the raw material composition.

Another aspect of the present invention relates to oxygen-transferring particles manufactured by the method for producing oxygen-transferring particles.

In one embodiment, the oxygen delivery particle may have an Attrition Index (AI) of 10% or less represented by Equation 1 below:

[Equation 1]

AI(%) = [(W ₂ )/(W ₁ )]

(In Equation 1, W ₁ is the weight (g) of the oxygen delivery particle sample before the abrasion test, and W ₂ is the weight (g) of the fine particles collected for 5 hours immediately after the abrasion test of the sample).

In one embodiment, the oxygen delivery particles may be spherical, have an average particle size of 60 to 150 μm, a particle size distribution of 30 to 400 μm, and a packing density of 1.0 to 3.0 g/mL.

In one embodiment, the oxygen delivery particle may have an oxygen delivery amount of 8% by weight (8 g Oxygen / 100 g Oxygen Carrier) or more.

Another aspect of the present invention relates to a chemical roofing combustion method using the oxygen delivery particles. In one embodiment, the chemical looping combustion method includes reacting the oxygen transfer particles with fuel to reduce the oxygen transfer particles and burn the fuel; and regenerating the reduced oxygen delivery particles by reacting with oxygen.

Another aspect of the present invention relates to a chemical roofing combustion device for chemical roofing combustion using the oxygen delivery particles. In one embodiment, the chemical looping combustion device includes a fuel reactor that reacts the oxygen delivery particles with fuel to reduce the oxygen delivery particles and burns the fuel; and an air reactor in which the reduced oxygen-transferring particles are transported and reacted with oxygen to oxidize the oxygen-transferring particles.

The present invention can secure sufficient strength and oxygen transfer performance (oxygen transfer rate and oxygen transfer amount) under low firing temperature conditions, has an excellent effect of increasing the oxidation-reduction reaction rate and oxygen transfer amount, and has a high oxygen transfer rate between oxygen transfer particles during the oxidation-reduction cycle reaction. It can minimize aggregation, have excellent mixability, dispersibility and formulation stability of the raw material composition, and have excellent mechanical strength, productivity and economy.

1 shows a method for manufacturing oxygen delivery particles according to one embodiment of the present invention.
Figure 2 shows a slurry manufacturing method according to one embodiment of the present invention.
3 shows a solid particle molding method according to one embodiment of the present invention.
Figure 4 shows solid particle drying and firing according to one embodiment of the present invention.
5 shows a chemical looping combustion device according to one embodiment of the present invention.
6 is a photomicrograph showing the oxygen delivery particles of Example.
7 is a graph comparing oxygen transfer performance of oxygen transfer particles of Examples and Comparative Examples.

In describing the present invention, if it is determined that a detailed description of a related known technology or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

In addition, the terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator, so the definitions should be made based on the content throughout this specification describing the present invention.

Raw Material Composition for Oxygen Transfer Particles

One aspect of the present invention relates to a raw material composition for oxygen delivery particles. In one embodiment, the raw material composition for oxygen-transporting particles is a nickel oxide (NiO)-based raw material composition for oxygen-transferring particles, comprising 58 to 80% by weight of nickel hydroxide (Ni(OH) ₂ ); 12-35% by weight of boehmite; 5 to 15% by weight of magnesium hydroxide (Mg(OH) ₂ ); Aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) 1 to 4% by weight; and 0.5 to 2% by weight of magnesium hydrolase phosphate (MgHPO ₄ ).

The nickel hydroxide (Ni(OH) ₂ ) acts as a raw material for the active material, and nickel oxide (NiO) is formed as water escapes during the firing process. The NiO transfers oxygen to the fuel during the chemical looping combustion reaction to efficiently burn the fuel, is itself reduced, and is regenerated by receiving oxygen from the air again.

When the nickel hydroxide is used as a raw material for the active material, sufficient strength suitable for use in the fluidized bed process can be obtained even at a lower firing temperature than when nickel oxide (NiO) is applied, and magnesium (Mg) is maintained while maintaining oxygen transmission performance. Since the content can be increased, aggregation between oxygen delivery particles that may occur during oxidation and reduction cycle reactions of chemical roofing combustion can be prevented.

In one embodiment, the nickel hydroxide is included in an amount of 58 to 80% by weight based on the total weight of the raw material composition. When the nickel hydroxide is included in an amount of less than 58% by weight, the oxygen transfer capacity of the oxygen transfer particles decreases, and the interaction strength with the support used together in the firing process of the spray-dried oxygen transfer particles increases. Therefore, the oxygen transfer performance is lowered, and when the content exceeds 80% by weight, the physical properties such as the wear resistance of the oxygen transfer particles are lowered after firing, and the sintering phenomenon between the nickel oxide (NiO) grains in the particles is reduced during the firing process. There is a risk that it will happen. For example, 65 to 75% by weight may be included.

In one embodiment, the nickel hydroxide may have an average particle size greater than 0 and less than 10 μm. The average size may mean "maximum length" or "diameter" of the nickel hydroxide, boehmite, magnesium hydroxide, aluminum dihydrogen phosphate, and magnesium hydraulic phosphate. Under the condition of the average particle size of the nickel hydroxide, the raw material composition may have excellent mixability and dispersibility, and the oxygen delivery particles may have excellent durability and mechanical strength. For example, the nickel hydroxide may have a purity of 98% or more, but is not limited thereto.

In the NiO-based oxygen transporting particle of the present invention, boehmite and magnesium hydroxide may be included as support materials. The boehmite supports the active ingredient NiO to be evenly distributed throughout the particles to increase the utilization of the active ingredient, provides a pore structure necessary for diffusion of the reaction gas, and simultaneously serves as an inorganic binder to transfer oxygen after firing. Sufficient strength required in the fluidized bed process can be provided to the particles.

That is, the boehmite can simultaneously serve as a function of supporting metal oxide, that is, nickel oxide (NiO), which is an active material, and as an inorganic binder that bonds with each other during firing and gives strength to oxygen transfer particles. In addition, it suppresses the phenomenon of aggregation of metals and sintering of the active material (NiO) while repeating redox cycles at high temperatures, and the passage for smooth entry (diffusion) of gases before and after the reaction between the outside of the particles and the active material. can play a role in creating

The boehmite is structurally unstable compared to gamma alumina and alpha alumina, and is transformed into gamma alumina or alpha alumina as water (H ₂ O) is discharged as the firing temperature increases. This has the advantage of imparting stronger strength and higher porosity to the particles at a lower firing temperature.

In one embodiment, the boehmite is included in an amount of 12 to 35% by weight based on the total weight of the raw material composition. When the boehmite is included in an amount of less than 12% by weight, physical properties such as a decrease in porosity are deteriorated, and sintering between active materials in the oxygen transfer particles may occur. If the content exceeds 35 wt%, the oxygen transfer amount of the oxygen transfer particles becomes small, and the interaction strength with the active material increases, so there is a concern that the oxygen transfer performance may be deteriorated. For example, 15 to 25% by weight may be included.

In the present invention, boehmite, which is a raw material for the support, is not limited in the form in which it is supplied. For example, boehmite mixed in a solvent in a sol state or boehmite supplied in a solid powder state may be used as the boehmite.

In one embodiment, the average particle size of the boehmite may be greater than 0 and less than or equal to 1 μm. Under the average particle size condition, the mixing and dispersibility of the raw material composition may be excellent, and the oxygen transporting particles may have excellent oxygen transporting performance, durability and mechanical strength. For example, boehmite diluted and dispersed in a solvent may have an average particle size of greater than 0 and less than or equal to 1 μm. For example, the boehmite may have a purity of 98% or more, but is not limited thereto.

The magnesium hydroxide (Mg(OH) ₂ ) may serve to impart pores and strength to the oxygen delivery particles while combining with each other or with boehmite, which is a raw material for the support used together, during the firing process. The magnesium hydroxide (Mg(OH) ₂ ) is combined with each other or with boehmite used as a support while water escapes and is transformed into magnesia (MgO) as the firing temperature increases.

Accordingly, compared to the prior art of manufacturing oxygen-transferring particles containing magnesium using alpha-alumina or magnesium aluminate, sufficient strength required in the fluidized bed process can be obtained even when oxygen-transferring particles are manufactured at a lower firing temperature. let it be When a magnesium (Mg) component is added to the oxygen delivery particles by the addition of magnesium hydroxide (Mg(OH) ₂ ), oxidation and reduction cycle reactions of chemical roofing combustion using nickel oxide (NiO)-based oxygen delivery particles may occur. It is possible to obtain the effect of suppressing the problem of aggregation between particles.

In one embodiment, the magnesium hydroxide is included in an amount of 5 to 15% by weight based on the total weight of the raw material composition. When the magnesium hydroxide is dried and calcined at a high temperature, water escapes and may become magnesium oxide (MgO). When the magnesium hydroxide is included in an amount of less than 5% by weight, physical properties such as a decrease in porosity of oxygen delivery particles are deteriorated, and aggregation between particles and sintering between active materials may occur during the chemical roofing combustion cycle reaction, and 15 weight When it is contained in excess of %, sintering between active materials occurs due to an increase in firing temperature to obtain the strength of oxygen transfer particles, resulting in a small amount of oxygen transfer and a slow oxygen transfer rate. There is a possibility that the oxygen transfer performance may deteriorate, such as not being regenerated to an initial state. For example, it may be included in 5 to 8% by weight.

In one embodiment, the magnesium hydroxide may have an average particle size greater than 0 and less than 10 μm. Under the average particle size condition, the mixing and dispersibility of the raw material composition may be excellent, and the oxygen transporting particles may have excellent oxygen transporting performance, durability and mechanical strength. For example, the magnesium hydroxide may have a purity of 97% or more, but is not limited thereto.

The inorganic binder included in the raw material composition is a material that imparts strength to the oxygen transfer particles and reduces particle loss due to abrasion so that the oxygen transfer particles can be used for a long period of time. In the present invention, the inorganic binder may be a mixture of aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) and magnesium hydraulic phosphate (MgHPO ₄ ).

When the content of the inorganic binder is increased, the content of the active material or support is lowered, and problems such as increased sintering of the active material due to a decrease in oxygen delivery amount and a decrease in dispersion of the active material may occur. It is used by limiting the content to 6% by weight.

In one embodiment, the aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) is included in an amount of 1 to 4% by weight based on the total weight of the raw material composition. When the aluminum dihydrogen phosphate is included in an amount of less than 1% by weight, the strength and wear resistance of the oxygen delivery particles are lowered, and when it is included in an amount exceeding 4% by weight, the mixing and dispersibility of the raw material composition is reduced, and the amount of oxygen delivery is reduced. Sintering of the active material may occur due to the decrease and the decrease in dispersion of the active material. For example, it may be included in 2 to 3.5% by weight.

In one embodiment, the aluminum dihydrogen phosphate may have an average particle size greater than 0 and less than or equal to 25 μm. Under the average particle size condition, the mixing and dispersibility of the raw material composition may be excellent, and the oxygen transporting particles may have excellent oxygen transporting performance, strength, abrasion resistance and mechanical strength. For example, the aluminum dihydrogen phosphate may have a purity of 97% or more, but is not limited thereto.

In one embodiment, the magnesium hydrolase phosphate (MgHPO ₄ ) is included in an amount of 0.5 to 2% by weight based on the total weight of the raw material composition. When the magnesium hydrophobic phosphate is included in an amount of less than 0.5% by weight, strength and abrasion resistance of the oxygen delivery particles are reduced, and when included in an amount exceeding 2% by weight, the mixability and dispersibility of the raw material composition are deteriorated and the amount of oxygen delivery is reduced. And active material sintering may occur due to a decrease in dispersion of the active material. For example, it may be included in 1 to 2% by weight.

In one embodiment, the magnesium hydrogel phosphate may have an average particle size greater than 0 and less than or equal to 25 μm. Under the average particle size condition, the mixing and dispersibility of the raw material composition may be excellent, and the oxygen transporting particles may have excellent oxygen transporting performance, strength, abrasion resistance and mechanical strength. For example, the magnesium hydrolysis phosphate may have a purity of 97% or more, but is not limited thereto.

In one embodiment, the sum of the aluminum dihydrogen phosphate and the magnesium hydroelectric phosphate and magnesium hydroxide may be included in a weight ratio of 1:1 to 1:3. When included in the weight ratio range, the mixing and dispersibility of the raw material composition may be excellent, and the oxygen delivery performance, strength, abrasion resistance and mechanical strength of the oxygen delivery particles may be excellent. For example, it may be included in a weight ratio of 1:1 to 1:1.5.

Slurry for preparing oxygen transfer particles comprising a raw material composition for oxygen transfer particles

Another aspect of the present invention is to provide a slurry for preparing oxygen transfer particles comprising the raw material composition for oxygen transfer particles. In one embodiment, the slurry for preparing the oxygen delivery particles includes a solid raw material including the raw material composition; and a solvent;

In one embodiment, the solid raw material may be included in an amount of 15 to 40% by weight based on the total weight of the slurry. If the content of the solid raw material is less than 15% by weight, the amount of slurry for producing oxygen delivery particles increases and the amount of solvent in the slurry to be evaporated in the spray drying process increases, ultimately reducing production efficiency. If it exceeds 40% by weight, the viscosity of the slurry increases as the concentration of the slurry increases, making it difficult to pulverize and lowering the fluidity, so that spray drying may become difficult.

The type of the solvent is not particularly limited, and solvents commonly used in this field may be used. Specifically, water may be included as the solvent.

In one embodiment, the slurry may further include one or more additives of a dispersing agent, an antifoaming agent, and an organic binder. Specifically, in the process of preparing a fluid colloidal slurry using the solid raw material, for homogenization of the solid raw material, concentration, viscosity, stability, flowability of the solid raw material, and control of the strength and density of the particles after spray drying, a dispersing agent and an antifoaming agent and one or more additives selected from the group consisting of organic binders. When mixing only the solid raw material itself with water, it is difficult to disperse the raw material, which may cause problems in mixing and preparing a colloidal slurry. This problem can be solved by further incorporating an organic additive. For example, the slurry may include a dispersing agent, an antifoaming agent, and an organic binder as additives.

In one embodiment, the slurry may include 0.01 to 5.0 parts by weight of the dispersant, 1.0 to 5.0 parts by weight of an organic binder, and 0.01 to 1.0 parts by weight of an antifoaming agent, based on 100 parts by weight of the solid raw material.

The dispersant is used to prevent agglomeration of the raw material particles during the grinding process to be described below. That is, in the grinding process for controlling the particle size of the raw material components constituting the oxygen delivery particles, the dispersing agent may be used to prevent reduction in grinding efficiency due to aggregation of the fine powder particles.

In one embodiment, the dispersant may include one or more of anionic surfactants, cationic surfactants, and nonionic surfactants. In one embodiment, the anionic surfactant may include at least one of a polycarboxylic acid salt and a polycarboxylic acid amine salt. For example, as the dispersant, poly carboxylate ammonium salts or poly carboxylate amine salts may be used as an anionic surfactant. The dispersant used in the present invention has a function of controlling charge control, dispersion, and aggregation of the particle surface, so that the slurry is highly concentrated. When the slurry with poor dispersion is spray-dried, the shape of the oxygen delivery particle assembly, that is, the green body, deviates from a spherical shape such as a donut or dimple, and adversely affects the final product.

In one embodiment, the dispersant may be included in an amount of 0.01 to 5.0 parts by weight based on 100 parts by weight of the solid raw material. Within this range, the dispersing effect of the particles of the solid raw material may be excellent.

The organic binder is added in the slurry preparation step to impart plasticity and fluidity to the slurry and ultimately impart strength to the oxygen-transporting particles assembled by spray-drying molding, thereby forming an assembly before pre-drying and firing, that is, Handling of green bodies can be facilitated. In one embodiment, the organic binder may include at least one of polyvinyl alcohol, polyethylene glycol, and methylcellulose.

In one embodiment, the organic binder may be included in an amount of 1.0 to 5.0 parts by weight based on 100 parts by weight of the solid raw material. It is possible to easily maintain a spherical shape until drying and firing by preventing deterioration of the bonding force of the molded solid particles during spray drying under the above conditions, and preventing the performance of the final material from deteriorating due to residual ash after firing.

The defoamer may be used to remove bubbles of the slurry to which the dispersant and the organic binder are applied. In one embodiment, the antifoaming agent may include at least one of a silicone-based antifoaming agent, a metal soap-based antifoaming agent, an amide-based antifoaming agent, a polyether-based antifoaming agent, a polyester-based antifoaming agent, a polyglycol-based antifoaming agent, and an alcohol-based antifoaming agent.

In one embodiment, the antifoaming agent may be included in an amount of 0.01 to 1.0 parts by weight based on 100 parts by weight of the solid raw material. If the amount of the antifoaming agent is too small, bubbles may be generated during the slurry manufacturing process and a spherical shape may not be obtained during spray drying, and if the amount of the antifoaming agent is too large, the performance of the final material may be deteriorated due to residual ash after firing there is. The content of the antifoaming agent may be adjusted according to the amount of bubbles generated during slurry preparation.

Oxygen delivery particle manufacturing method

Another aspect of the present invention relates to a method for preparing the oxygen delivery particles. 1 shows a method for manufacturing oxygen delivery particles according to one embodiment of the present invention. Referring to FIG. 1, the method for preparing the oxygen delivery particles includes (S10) a slurry manufacturing step; (S20) slurry homogenization step; (S30) forming solid particles; and (S40) a solid particle firing step. More specifically, the method for preparing the oxygen delivery particles includes (S10) preparing a slurry for preparing the oxygen delivery particles by mixing the raw material composition with a solvent; (S20) homogenizing the slurry by stirring; (S30) forming solid particles by spray drying the homogenized slurry; and (S40) drying and calcining the solid particles.

(S10) Slurry manufacturing step

In the above step, the slurry for preparing the oxygen-transporting particles may be prepared by mixing the raw material composition (solid raw material) for preparing the NiO-based oxygen-transporting particles according to the present invention in a solvent. As the raw material composition, the same ones as described above can be used. At this time, in order to prevent the raw material composition from clumping together and mix smoothly, a dispersant and an antifoaming agent may be added to the solvent before inputting the solid raw material and mixed.

(S20) Slurry homogenization step

This step is a step of homogenizing the slurry by stirring the slurry. Figure 2 shows a slurry manufacturing method according to one embodiment of the present invention. Referring to FIG. 2, the preparation of the slurry includes adding an additive (eg, an organic additive) to a solvent (water) (S11); mixing a raw material composition (solid raw material) with the solvent (water) (S12); preparing a slurry by adding an additive to a mixture containing the solvent (water) and the raw material composition (S13); Grinding, stirring, and dispersing the slurry to prepare a homogeneous and dispersed slurry (S21); and removing foreign substances included in the slurry (S22).

In the step of adding the additive to the solvent (S11) and the step of preparing a slurry by adding the additive to a mixture containing the solvent (water) and the raw material composition (S13), the additive is composed of a dispersant, an antifoaming agent and an organic binder One or more selected from the group may be used. Preferably, all of them can be used. The content may be used within the above-described content range in consideration of the amount of the additive added in the steps of adding the additive to the mixture (S11 and S13).

For another example, the homogenizing of the slurry may include adding one or more additives of a dispersant, an antifoaming agent, and an organic binder to the slurry; And stirring and grinding the slurry; may be made including.

The additive may include at least one of a dispersing agent, an antifoaming agent and an organic binder. Preferably, all of the above can be used. The dispersing agent, antifoaming agent and organic binder may be the same as those described above.

In one embodiment, the additives may include 0.01 to 5.0 parts by weight of the dispersant, 1.0 to 5.0 parts by weight of the organic binder, and 0.01 to 1.0 parts by weight of the antifoaming agent, based on 100 parts by weight of the raw material composition.

The stirring may be performed in the process of adding the components included in the slurry or/and in a state in which all are added. At this time, stirring may be performed using a stirrer.

In one embodiment, by pulverizing the mixed slurry using a grinder, the particle size in the slurry can be reduced to several microns (μm) or less. The particles pulverized in the above process are more homogeneously dispersed in the slurry, and the aggregation of the particles in the slurry is suppressed by the already added dispersant, thereby preparing a homogeneous and stable slurry. The grinding process can be repeated several times as needed, and the fluidity of the slurry is controlled by adding a dispersant and an antifoaming agent between each grinding process. In addition, an organic binder is added to maintain the particle shape during spray drying.

In one embodiment, a wet milling method may be used to improve the grinding effect and solve problems such as scattering of particles that occur during dry grinding. Characteristics such as concentration and viscosity of the slurry may be adjusted by further using a dispersing agent, an antifoaming agent, or an additional solvent in the slurry after the pulverization is complete.

On the other hand, if the particle diameter of the solid raw material particles in the slurry is less than several micrometers, the grinding process may be omitted.

In one embodiment, after the step of stirring and pulverizing the slurry, the step of removing foreign substances in the stirred and pulverized slurry; may be further included. Through the above steps, it is possible to remove foreign substances or lumpy raw material components that may cause nozzle clogging during spray molding. Removal of the foreign matter may be performed through sieve.

There is no particular limitation on the fluidity of the final slurry prepared by the present invention, and any viscosity is possible as long as it can be pumped.

(S30) solid particle forming step

This step is a step of spray-drying the slurry and forming it into solid particles (green bodies of oxygen-transporting particles). 3 shows a solid particle molding method according to one embodiment of the present invention. Referring to FIG. 3, the step of shaping the solid particles may include (S31) transferring the solid particles to a spray dryer; and (S32) spray-drying the transferred solid particles by spraying them with a spray dryer.

Molding of the slurry may be performed using a spray dryer. For example, in the above step, solid particles may be formed by transferring the slurry to the spray dryer using a pump and then spraying the transferred slurry into the spray dryer.

In order to mold the oxygen delivery particles in the spray dryer, suitable operating conditions of the spray dryer are required. In the spray dryer of the present invention, operating conditions generally used in this field can be applied to the operating conditions of the spray dryer for forming oxygen delivery particles. For example, a flowable slurry is sprayed in a countercurrent spray method in which a pressurized nozzle is sprayed in the opposite direction to the flow of drying air to form oxygen delivery particles, and the inlet temperature of the spray dryer is 260 to 300 ° C and the outlet temperature It is preferable to maintain 90-150 degreeC.

(S40) solid particle firing step

This step is a step of drying and calcining the solid particles. In the above step, the molded solid particles may be dried and then calcined to prepare oxygen delivery particles.

Figure 4 shows solid particle drying and firing according to one embodiment of the present invention. Referring to FIG. 4 , the drying and firing of the solid particles may be performed by drying and firing the green body of the oxygen delivery particle formed by the spray drying method to manufacture the final oxygen delivery particle. For example, a step of drying the solid particles (shaped oxygen delivery particle green body) (pre-drying) (S41); and calcining the solid particles (S42); through which final oxygen delivery particles may be produced.

In one embodiment, the drying may be to perform the solid particles at 110 ~ 150 ℃ for 2 to 24 hours. By performing the drying under the above temperature and time conditions, it is possible to prevent cracks in the particles due to expansion of moisture in the particles during firing of the solid particles. At this time, drying is performed in an air atmosphere.

In one embodiment, the firing may be carried out by introducing the solid particles into a firing furnace, raising the temperature to 1150 to 1250 ° C at a temperature rising rate of 1 to 5 ° C / min, and maintaining it for 2 to 10 hours. When the elevated temperature is maintained for less than 2 hours during the firing, the strength of the particles may be weakened, and when the firing time exceeds 10 hours, the firing cost may increase. In the present invention, it may be fired after giving a stagnation section of 30 minutes or more each at two or more stages of stagnation temperature until the final firing temperature.

In the present invention, firing may use a firing furnace such as a muffle furnace, a tubular furnace, or a kiln.

In the present invention, organic additives (dispersing agent, antifoaming agent, and organic binder) introduced during slurry preparation are burned by the firing, and the strength of the particles is improved by bonding between the raw material compositions.

Oxygen-transferring particles manufactured by the method for producing oxygen-transferring particles

Another aspect of the present invention relates to oxygen-transferring particles manufactured by the method for producing oxygen-transferring particles.

In one embodiment, the oxygen delivery particle may have a spherical shape without blow-holes. When the shape is not spherical, but a donut shape or grooved shape, wear loss of the oxygen delivery particles may increase.

In one embodiment, the oxygen delivery particles may have an average particle size of 60 to 150 μm, a particle size distribution of 30 to 400 μm, and a packing density of 1.0 to 3.0 g/mL. For example, the average size of the oxygen delivery particles may be 80 to 120 μm, and the size distribution of the oxygen delivery particles may be 30 to 400 μm, more specifically 38 to 350 μm.

In one embodiment, the oxygen delivery particle may have an Attrition Index (AI) of 10% or less represented by Equation 1 below:

[Equation 1]

AI(%) = [(W ₂ )/(W ₁ )]

(In Equation 1, W ₁ is the weight (g) of the oxygen delivery particle sample before the abrasion test, and W ₂ is the weight (g) of the fine particles collected for 5 hours immediately after the abrasion test of the sample).

The abrasion resistance is expressed as an abrasion index (AI), and the lower the abrasion index, the better the abrasion resistance of the oxygen delivery particles. In one embodiment, the abrasion resistance may be measured with an abrasion tester. For example, it can be measured with an abrasion tester according to ASTM D5757-95. For example, it can be obtained by measuring 50 g of oxygen delivery particles at a flow rate of 10.00 L/min (273.15 K, 1 bar standard) for 5 hours to measure the amount of fine powder generated, and then calculating it through Equation 1 above.

In the present invention, the wear index of the oxygen delivery particles may be 10% or less. If the abrasion index exceeds 10%, the abrasion loss rate increases and the amount of oxygen transfer particles to be supplemented during process operation increases, which may increase operating cost. This may cause process operation to be difficult. In the present invention, the lower limit of the wear index is not particularly limited, and the closer to 0%, the better. For example, it may be 9% or less. For another example, it may be 7% or less.

In the present invention, the oxygen transfer capacity of the oxygen carrier is not particularly limited, and the higher the better. In one embodiment, the oxygen delivery particle may have an oxygen delivery amount of 8% by weight (8 g Oxygen / 100 g Oxygen Carrier) or more. For example, the oxygen transfer amount of the oxygen transfer particles may be 10% by weight or more. For another example, the oxygen delivery particle may have an oxygen delivery amount of 12.5% by weight or more.

Chemical roofing combustion method using oxygen transfer particles

Another aspect of the present invention relates to a chemical roofing combustion method using the oxygen delivery particles. In one embodiment, the chemical looping combustion method includes reacting the oxygen transfer particles with fuel to reduce the oxygen transfer particles and burn the fuel; and regenerating the reduced oxygen delivery particles by reacting with oxygen.

Here, the fuel is not particularly limited, and all solid, liquid, and gaseous fuels may be used, and preferably gaseous fuels. The gaseous fuel used in the present invention is not particularly limited, and for example, a group consisting of methane, hydrogen, carbon monoxide, alkanes (alkanes, C _n H _{2n + 2} ), natural gas (LNG) and syngas (syngas) It may be one or more selected from.

When the oxygen-transferring particles react with the fuel, the metal oxides in the oxygen-transferring particles are reduced while transferring oxygen to the fuel, and carbon dioxide and water are generated. When the reduced oxygen delivery particle reacts with oxygen, it is oxidized and regenerated into a metal oxide. Oxygen may be provided to the reduced oxygen transfer particles through air. In the chemical looping combustion method of the present invention, the above process is repeated.

Chemical roofing combustion device for chemical roofing combustion using oxygen transfer particles

Another aspect of the present invention relates to a chemical roofing combustion device for chemical roofing combustion using the oxygen delivery particles. 5 shows a chemical looping combustion device according to one embodiment of the present invention.

Referring to FIG. 5, the chemical looping combustion device includes a fuel reactor that reacts the oxygen transfer particles with fuel to reduce the oxygen transfer particles and burn the fuel; and an air reactor in which the reduced oxygen-transferring particles are transported and reacted with oxygen to oxidize the oxygen-transferring particles. For example, the fuel may include methanol.

Referring to FIG. 5, in the fuel reactor, the metal oxide (M _x O _y ) in the oxygen delivery particle reacts with the fuel to become a metal oxide (M _x O _y-1 ) in a reduced state. At this time, the fuel is burned. The reduced oxygen transfer particle moves to an air reactor, where it reacts with oxygen in the air and is oxidized again. The oxidized oxygen transfer particles are circulated to the fuel reactor and the above process is repeated.

Reactions in the fuel reactor and the air reactor are shown in Schemes 1 and 2 below. Reaction Equation 1 below is a reaction in a fuel reactor, and Reaction Equation 2 shows a reaction occurring in an air reactor:

[Scheme 1]

4M _{x Oy} + CH ₄ → 4M _{x Oy-1} + 2H ₂ O + CO ₂

[Scheme 2]

M _x O _y-1 + 0.5 O ₂ → M _x O _y

In Schemes 1 and 2, one oxygen atom (O) is transferred from one molecule of metal oxide, but less than one or more than one may be transferred. In this case, Schemes 1 and 2 are changed according to the number of oxygen atoms transferred. It can be.

In order to solve the above problems, the present invention is a solid for preparing oxygen delivery particles having sufficient strength while lowering the firing temperature in manufacturing oxygen delivery particles having a high nickel oxide (NiO) content by a manufacturing process including a spray drying method. It is an object of the present invention to provide a raw material and an oxygen delivery particle raw material composition comprising the same. In addition, an object of the present invention is to provide oxygen transfer particles prepared using the oxygen transfer particle composition. Another object of the present invention is to provide a method for producing the oxygen delivery particles.

In the present invention, a hydroxide-type active material and a support material are used so that sufficient strength can be obtained through bonding between support materials even at a low firing temperature, and a phosphorus-containing compound is added as a strength reinforcing material to obtain NiO oxygen transfer particles. was manufactured. Nickel hydroxide (Ni(OH) ₂ ), magnesium hydroxide (Mg(OH) ₂ ), aluminum oxide hydroxide (AlOOH), aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) and When NiO oxygen transfer particles are manufactured using magnesium hydroelectric phosphate (MgHPO ₄ ) as a raw material, MgAl ₂ O ₄ is formed as AlOOH and Mg(OH) ₂ are combined during the firing process, and Ni(OH) ₂ and AlOOH are combined. It reduces the amount of NiAl ₂ O ₄ produced by Al(H ₂ PO ₄ ) ₃ and MgHPO ₄ contribute to the formation of strength of oxygen delivery particles while being combined with the used raw materials. In addition, when NiO oxygen transfer particles are prepared using the raw material, sufficient strength suitable for the fluidized bed process can be secured even at a firing temperature of 1200 ° C., and thus, oxygen transfer performance degradation due to sintering of NiO as an active material can be reduced.

The NiO-based oxygen delivery particle according to the present invention uses nickel hydroxide (Ni(OH) ₂ ) instead of nickel oxide (NiO) as a raw material for providing an active ingredient, and uses powder or sol-type bore as a main raw material for the support. By using mite (ALOOH), magnesium hydroxide (Mg(OH) ₂ ) as a raw material for imparting magnesium components necessary for suppressing aggregation, and aluminum dihydrogen phosphate and magnesium hydrogel phosphate as raw materials for strength reinforcement, Compared to the prior art, the oxygen transfer performance and wear resistance were improved while the firing temperature for obtaining strength applicable to the fluidized bed process was low. Accordingly, it is possible to reduce the filling amount of particles in the chemical roofing combustion process and the amount of replenishment according to wear loss occurring during long-time operation, thereby improving the compactness and economic efficiency of the chemical roofing combustion process.

In addition, in the slurry for preparing NiO-based oxygen-transporting particles according to the present invention, solid raw materials of oxygen-transferring particles pulverized to an average size of 1 μm or less are stably and evenly dispersed, so that the long-term durability improvement effect of the final oxygen-transferring particles fired after spray drying is achieved. there is.

In addition, according to the NiO-based oxygen-transferring particles according to the present invention, oxygen-transferring particles having a spherical shape, particle size, particle size distribution, packing density, strength, and excellent oxygen transfer performance suitable for a fluidized bed process are obtained compared to the prior art. Since it can be manufactured at a relatively low firing temperature, manufacturing costs can be reduced during mass production.

In addition, according to the NiO-based oxygen transfer particles according to the present invention, carbon dioxide is fundamentally reduced while reducing system energy loss due to carbon dioxide capture compared to conventional combustion methods by increasing the degree of completion of chemical looping combustion technology in which high-performance oxygen transfer particles are essential. can be separated and collected. In addition, due to the nature of the chemical roofing combustion process, it does not use a solution to capture carbon dioxide, so it has the advantage of using less water and generating almost no wastewater.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention by this in any sense. Contents not described herein can be technically inferred by those skilled in the art, so descriptions thereof will be omitted.

Examples and Comparative Examples

This embodiment shows the dispersion and strength of nickel hydroxide (Ni(OH) ₂ ) nickel oxide (NiO) to provide NiO as an active ingredient as a raw material for producing nickel oxide (NiO)-based oxygen transporting particles. Boehmite (AlOOH) in the form of a sol as a support raw material for imparting , magnesium hydroxide (Mg(OH) ₂ ) as a support raw material for imparting a magnesium component that suppresses particle aggregation during continuous oxidation/reduction reaction cycles, and particle strength This is an example of manufacturing NiO-based oxygen delivery particles using a raw material composition containing aluminum dihydrogen phosphate (Al(H ₂ PO 4 ) ₃ ) and magnesium hydro lasic phosphate (MgHPO ₄ ) as components for reinforcement.

When the nickel hydroxide (Ni(OH) ₂ ), boehmite (AlOOH), and magnesium hydroxide (Mg(OH) ₂ ) are calcined at a high temperature, water (H ₂ O) is discharged, respectively, as nickel oxide (NiO), alumina (Al ₂ O ₃ ) and magnesium oxide (MgO). In the embodiment, the nickel oxide (NiO) was designed to be 70% by weight based on the total weight of the dried raw material sample in the form of H ₂ O discharged by high-temperature firing.

Example 1

In order to manufacture NiO-based oxygen delivery particles, industrial nickel hydroxide (Ni(OH) ₂ ) (purity of 98% or more, powder form), boehmite in sol form (boehmite in sol form in which the solvent is water, Boehmite (AlOOH) content is 20 parts by weight in the form of alumina (Al ₂ O ₃ ) when the sol is dried and calcined), Mg(OH) ₂ (powder form, average particle diameter 4.5 ㎛, purity 98.5% or more), aluminum Dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ , powder form) and magnesium hydrosulfate (MgHPO ₄ , powder form) were prepared.

Raw materials were weighed according to the composition ratio of the final NiO-based oxygen transport particles (final weight after firing: 5 kg) to be manufactured. A dispersing agent (anionic surfactant) and an antifoaming agent (metal soap type) were added to distilled water and mixed with a stirrer. A mixed slurry was prepared by adding solid raw materials to water mixed with an organic additive while stirring with a stirrer. The mixed slurry was pulverized with a high energy ball mill three times. In the pulverization process, water and the aforementioned organic additives were additionally added if necessary after the primary pulverization in order to smoothly proceed with the pulverization. After the second grinding, polyethylene glycol was added and the third grinding was performed to prepare a stable and homogeneous flowable colloidal slurry mixture. Foreign substances were removed from the pulverized slurry through a sieve, and the solid concentration in the final slurry was measured. The total amount of added additives and the measured concentration of the solid raw material in the final slurry are shown in Table 1.

The prepared colloidal slurry was transferred to a spray dryer by a pump and spray-dried to form solid particles. The molded solid particles (oxygen-transporting particle assembly, ie, green body) were preliminarily dried in an air atmosphere reflux dryer at 120° C. for 12 hours, and then calcined in a firing furnace at 1200° C. for 5 hours to prepare oxygen-transferring particles. did It stayed at 200, 300, 400, 500, 650, 800 and 950 ° C for about 1 hour before reaching the firing temperature, and the temperature increase rate was about 5 ° C / min.

A detailed description of the manufacturing process of the oxygen delivery particles based on Example 1 is as follows. After high-temperature firing, Ni(OH) was added to 70 parts by weight, 22 parts by weight, 5 parts by weight, 2 parts by weight, and 1 part by weight based on NiO, Al ₂ O ₃ , MgO, Al(H ₂ PO ₄ ) ₃ , and MgHPO ₄ , respectively. ₂ , AlOOH, Mg(OH) ₂ , Al(H ₂ PO ₄ ) ₃ , and MgHPO ₄ were weighed at 4.34 kg, 1.1 kg, 0.36 kg, 0.1 kg, and 0.05 kg, respectively. A dispersing agent (anionic surfactant) and an antifoaming agent (metal soap type) were added to 20 liters of water and mixed with a stirrer. A mixed slurry was prepared by adding solid raw materials to water mixed with an organic additive while stirring with a stirrer. The mixed slurry was first pulverized with a high energy ball mill. In order to smoothly proceed with the grinding, water was additionally added after the first grinding. After the second grinding, polyethylene glycol was added and the third grinding was performed to prepare a stable and homogeneous flowable colloidal slurry mixture. The total amount of added additives is as shown in Table 1. The solid concentration in the final slurry measured after removing foreign substances through a sieve after grinding was 20.7% by weight.

The prepared colloidal slurry was transported by a pump to a spray dryer and spray-dried to form solid particles. The green body thus molded was preliminarily dried in an air atmosphere reflux dryer at 120° C. for 12 hours, and then calcined at 1200° C. for 5 hours in a firing furnace to prepare oxygen delivery particles. 200, 300, 400, 500, 650, 800 and 950 ° C were held for about 1 hour before reaching the firing temperature, and the temperature increase rate was about 5 ° C / min.

Example 2

NiO-based oxygen delivery particles were prepared in the same manner as in Example 1, except that the components and contents in Table 1 below were applied.

Table 1 below shows the constituent components of the raw material compositions for NiO-based oxygen transporting particles of Examples 1 and 2 and the solid raw material contents in the slurry.

Comparative Examples 1 to 5

As an active material, nickel oxide (NiO) used in conventional oxygen delivery particles was used. In addition, oxygen delivery particles were prepared in the same manner as in Example 1, except that gamma alumina, alpha alumina, magnesia, and magnesium aluminate were used as support raw materials, except that the components and contents in Table 2 were applied.

(In Tables 1 and 2, the dispersant, antifoaming agent and organic binder are contents (parts by weight) with respect to 100 parts by weight of the raw material composition).

Experimental Example (1)

(1) Measurement of shape, average particle size and particle size distribution of oxygen delivery particles: The oxygen delivery particles prepared in Examples 1 and 2 were measured using an industrial microscope, and the results are shown in FIG. 6 below. In addition, the average particle size and particle size distribution of the oxygen transfer particles of the above Examples and Comparative Examples were measured by using a MEINZER-II Shaker and a standard sieve based on ASTM E-11 of the American Society for Testing Materials (ASTM) to obtain 10 g. A sample of was measured by sorting for 30 minutes.

(2) Measurement of Packing Density: Examples and Comparative Examples The packing density of the oxygen transporting particles was measured using an AutoTap (Quantachrome) packing density meter according to ASTM D 4164-88.

(3) Measurement of abrasion resistance: Examples and Comparative Examples The abrasion resistance of the oxygen delivery particles was measured with an abrasion tester according to ASTM D 5757-95, and the abrasion resistance was evaluated by measuring the abrasion index according to Equation 1 below. The wear index (AI) was determined at 10 std L/min (standard volume per minute) over 5 hours as described in the ASTM method, and the wear index represents the percentage of fines generated over 5 hours. The lower the abrasion index (AI), the stronger the strength of the particles. For comparison, the wear index (AI) of the Akzo FCC (Fluid Catalytic Cracking) catalyst used in oil refineries measured in the same way was 22.5%.

[Equation 1]

AI(%) = [(W ₂ )/(W ₁ )]

(In Equation 1, W ₁ is the weight (g) of the oxygen delivery particle sample before the abrasion test, and W ₂ is the weight (g, nominal 50 g) of the fine particles collected for 5 hours immediately after the abrasion test of the sample).

(4) Measurement of oxygen transfer performance: The oxygen transfer performance of the oxygen transfer particles of Examples and Comparative Examples was evaluated using thermogravimetric analysis (TGA). Examples and Comparative Examples The composition of the reaction gas used for the reduction reaction of oxygen transfer particles was 15 vol% CH ₄ and 85 vol% CO ₂ , and air was used as a reaction gas for oxidizing the reduced oxygen transfer particles. Between the oxidation and reduction reactions, 100% nitrogen was supplied to prevent direct contact between fuel and air in the reactor. The sample amount of oxygen delivery particles used in the experiment was about 30 mg. The flow rate of each reaction gas was 300 std mL/min, and the oxidation/reduction reaction of the oxygen delivery particles was repeated at least 10 times. Oxygen transfer performance was compared by dividing into oxygen transfer capacity and oxygen transfer rate. Oxygen transfer amount is the amount of oxygen transferred by oxygen transfer particles to fuel. The weight of the oxygen transfer particles measured when the reduction reaction of the oxygen transfer particles is completed under the given experimental conditions is calculated from the weight of the oxygen transfer particles when the oxygen transfer particles are completely oxidized. It is a value expressed as a weight percentage by dividing the weight change obtained by subtraction by the weight of the oxygen-transferring particle when the oxygen-transferring particle is completely oxidized. Oxygen transfer rates were compared relative to how fast the weight change of oxygen transfer particles occurred during oxidation and reduction reactions.

Table 3 below shows the physical properties and oxygen delivery amount measurement results of the oxygen delivery particles of Examples and Comparative Examples, and the weight change according to oxygen delivery during the elapse of reaction time is shown in FIG. 7 below. In FIG. 7 , the mass-based conversion on the vertical axis is a value obtained by dividing the weight of the oxygen-transferring particle sample at any time during the reaction by the weight of the initial oxygen-transferring particle sample in a completely oxidized state.

Referring to Table 3, it can be seen that when the oxygen delivery particles were prepared using the raw material compositions of Examples 1 and 2, they exhibited high-strength characteristics with an abrasion index of 10% or less even at a firing temperature of 1200 ° C and had physical properties suitable for a commercial fluidized bed process. can Examples 1-2 Oxygen-transporting particles are spherical in shape, have an average particle size within the range of 95-100 μm, a particle size distribution within the range of 49-302.5 μm, and a packing density within the range of 2.1-2.3 g/mL , it can be seen that the wear index satisfies 10% or less.

6 shows industrial micrographs of the oxygen delivery particles of Examples 1 and 2 of the present invention. Referring to FIG. 6, the oxygen delivery particles of Examples 1 and 2 all have a spherical shape.

Referring to Table 3, it is shown that the oxygen delivery particles of Comparative Examples 1 to 5 prepared from the material presented in the prior art must be fired at 1400° C. or higher to obtain high strength characteristics with an abrasion index of 10% or less. The oxygen transfer particles of Comparative Example 1 and Comparative Example 2 using alpha-alumina (α-Al ₂ O ₃ ) exhibited high strength characteristics with an abrasion index of 10% or less at a firing temperature of 1500 ° C, and gamma alumina (γ-Al ₂ O ₃ Oxygen transfer particles of Comparative Example 3 and Comparative Example 4 using ) exhibited high strength characteristics with an abrasion index of 10% or less at a firing temperature of 1400 °C. It can be seen that the oxygen delivery particles of Comparative Example 5 using magnesium aluminate (MgAl ₂ O ₄ ) as a support have a wear index of 20% or more even at a firing temperature of 1500 ° C, making it difficult to manufacture high-strength particles.

7 is a graph comparing the oxygen transfer performance of the oxygen transfer particles of Examples 1 and 2 and Comparative Examples 1 and 3; 7 shows the oxygen transfer performance of the oxygen transfer particles of Examples 1 and 2; Comparative Example 1, which had the best oxygen transfer performance among the oxygen transfer particles, and Comparative Example 3, which showed incomplete regeneration characteristics when contacted with air after completion of the reaction with methane. It is shown in comparison with the particle performance of . Referring to Table 3 and FIG. 7, the oxygen transfer amount of the oxygen transfer particles of Examples 1 and 2, which exhibit high strength characteristics with an abrasion index of 10% or less, was 12.6% to 14.7% by weight, and the oxygen transfer amount of the oxygen transfer particle of Comparative Example 1 (12.1% by weight) increased by up to 20%. In addition, referring to FIG. 7 , the oxygen transfer rates of the oxygen transfer particles of Examples 1 and 2 were equal to or higher than those of the oxygen transfer particles of Comparative Examples 1 and 3 in all oxidation-reduction reactions.

In Comparative Examples 1 to 5, it was confirmed that the performance deteriorated when oxygen delivery particles were prepared using nickel oxide, alumina, and magnesium-containing raw materials used in the prior art as support raw materials. In addition, when the components of the composition applied in Comparative Examples 1 to 5 are applied, as in the examples, the oxygen delivery particles have excellent oxygen delivery amount and oxygen delivery rate while having high strength characteristics of 10% or less wear index even at a firing temperature of 1250 ° C or less. It can be seen that it cannot be produced.

From the above results, by using the oxygen delivery particle raw material composition and the oxygen delivery particle manufacturing method using the same presented in the present invention, high-strength NiO-based oxygen delivery particles suitable for the fluidized bed process that can effectively burn fuel in the chemical roofing combustion technology were obtained. It was shown that it can be prepared even at a firing temperature of 1250 ° C.

Oxygen delivery particles according to such a raw material composition and manufacturing method can be a competitive technology because mass production is easy and the economic efficiency of the chemical roofing combustion process is improved due to particle performance improvement. As shown in Table 3 and FIG. 7, the oxygen delivery particles of Examples 1 and 2 according to the present invention have physical properties and reactivity suitable for the fluidized bed process of chemical roofing combustion technology. Compared to NiO-based oxygen transporting particles manufactured using NiO and other support materials, high-strength characteristics can be obtained at a lower firing temperature, which can lower manufacturing costs, and excellent wear resistance prevents wear due to rapid solid circulation in the fluidized bed process. Since the loss of particles due to this is small, the amount of replenishment of particles can be reduced. In addition, since the oxygen transfer performance is excellent, the amount of particles used can be relatively reduced, and the process can be simplified (compact), so it is economical.

So far, the present invention has been looked at mainly through embodiments. Those skilled in the art to which the present invention pertains will be able to understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent scope will be construed as being included in the present invention.

Claims (27)

Nickel hydroxide (Ni(OH) ₂ ) 58-80% by weight;
12-35% by weight of boehmite;
5 to 15% by weight of magnesium hydroxide (Mg(OH) ₂ );
Aluminum dihydrogen phosphate (Al(H ₂ PO ₄ ) ₃ ) 1 to 4% by weight; and
A raw material composition for oxygen delivery particles comprising 0.5 to 2% by weight of magnesium hydrophobic phosphate (MgHPO ₄ ).
The raw material composition for oxygen delivery particles according to claim 1, wherein the nickel hydroxide has an average particle size of greater than 0 and less than 10 μm and a purity of 98% or more.
The raw material composition for oxygen transfer particles according to claim 1, wherein the boehmite has an average particle size of greater than 0 and less than 1 μm and a purity of 98% or more.
The raw material composition for oxygen delivery particles according to claim 1, wherein the magnesium hydroxide has an average particle size of greater than 0 and less than 10 μm and a purity of 97% or more.
The raw material composition for oxygen delivery particles according to claim 1, wherein the aluminum dihydrogen phosphate has an average particle size of greater than 0 and less than 25 μm and a purity of 97% or more.
The raw material composition for oxygen delivery particles according to claim 1, wherein the magnesium hydrogel phosphate has an average particle size of greater than 0 and less than 25 μm and a purity of 97% or more.
A solid raw material comprising the raw material composition according to any one of claims 1 to 6; and
A slurry for preparing oxygen delivery particles, comprising a solvent.
The slurry for preparing oxygen delivery particles according to claim 7, wherein the solid raw material is contained in an amount of 15 to 40% by weight based on the total weight of the slurry.
[Claim 8] The slurry for preparing oxygen delivery particles according to claim 7, wherein the solvent includes water.
8. The slurry for preparing oxygen delivery particles according to claim 7, wherein the slurry further comprises at least one additive selected from a dispersing agent, an antifoaming agent and an organic binder.
The slurry for preparing oxygen delivery particles according to claim 10, wherein 0.01 to 5.0 parts by weight of the dispersant, 1.0 to 5.0 parts by weight of the organic binder, and 0.01 to 1.0 parts by weight of the antifoaming agent are included with respect to 100 parts by weight of the solid raw material.
11. The slurry for preparing oxygen delivery particles according to claim 10, wherein the dispersant comprises at least one of an anionic surfactant, a cationic surfactant, an amphoteric surfactant and a nonionic surfactant.
[Claim 13] The slurry for preparing oxygen delivery particles according to claim 12, wherein the anionic surfactant comprises at least one of a polycarboxylic acid salt and a polycarboxylic acid amine salt.
11. The method of claim 10, wherein the antifoaming agent comprises at least one of a silicone-based antifoaming agent, a metal soap-based antifoaming agent, an amide-based antifoaming agent, a polyether-based antifoaming agent, a polyester-based antifoaming agent, a polyglycol-based antifoaming agent, and an alcohol-based antifoaming agent. Slurry for preparing delivery particles.
11. The slurry for preparing oxygen delivery particles according to claim 10, wherein the organic binder comprises at least one of polyvinyl alcohol, polyethylene glycol and methyl cellulose.
preparing a slurry for preparing oxygen delivery particles by mixing the raw material composition according to any one of claims 1 to 6 with a solvent;
Homogenizing the slurry by stirring;
spray drying the homogenized slurry to form solid particles; and
Drying and calcining the solid particles; Oxygen delivery particle manufacturing method comprising the.
The method of claim 16, wherein the step of homogenizing the slurry,
adding one or more additives of a dispersant, an antifoaming agent and an organic binder to the slurry; and
Stirring and pulverizing the slurry; Oxygen delivery particle manufacturing method characterized in that it comprises a.
[Claim 18] The method of claim 17, further comprising the step of removing foreign substances in the slurry after the step of stirring and pulverizing the slurry.
The method of claim 16, wherein the drying is performed for 2 to 24 hours at 110 to 150° C. for the solid particles.
The method of claim 16, wherein the firing is performed by raising the solid particles to 1150 to 1250° C. at a heating rate of 1 to 5° C./min and then maintaining the temperature for 2 to 10 hours. .
The preparation of oxygen delivery particles according to claim 17, wherein the additive comprises 0.01 to 5.0 parts by weight of the dispersant, 1.0 to 5.0 parts by weight of the organic binder, and 0.01 to 1.0 parts by weight of the antifoaming agent, based on 100 parts by weight of the raw material composition. method.
Oxygen-transporting particles produced by the method of claim 16.
23. The oxygen delivery particle according to claim 22, wherein the oxygen delivery particle has an Attrition Index (AI) represented by the following formula 1 of 10% or less:
[Equation 1]
AI(%) = [(W ₂ )/(W ₁ )]
(In Equation 1, W ₁ is the weight (g) of the oxygen delivery particle sample before the abrasion test, and W ₂ is the weight (g) of the fine particles collected for 5 hours immediately after the abrasion test of the sample).
23. The method of claim 22, wherein the oxygen delivery particles are spherical,
Oxygen transporting particles, characterized in that the average particle size is 60 ~ 150㎛, the particle size distribution is 30 ~ 400㎛, and the packing density is 1.0 ~ 3.0 g / mL.
23. The oxygen transfer particle according to claim 22, wherein the oxygen transfer amount of the oxygen transfer particle is 8% by weight or more (8 g Oxygen/100 g Oxygen Carrier).
reacting the oxygen transfer particles according to claim 22 with fuel to reduce the oxygen transfer particles and burn the fuel; and
Chemical roofing combustion method comprising a; regenerating the reduced oxygen transfer particles by reacting with oxygen.
a fuel reactor that reacts the oxygen transfer particles according to claim 22 with fuel to reduce the oxygen transfer particles and burn the fuel; and
A chemical looping combustion device comprising: an air reactor in which the reduced oxygen delivery particles are transported and reacted with oxygen to oxidize the oxygen delivery particles.