阅读说明：本技术 一种用于化学链燃烧的复合载氧体组合物及其制备方法 (Composite oxygen carrier composition for chemical looping combustion and preparation method thereof ) 是由 陈伟 于 2020-07-02 设计创作，主要内容包括：本发明属于化学链燃烧领域,涉及载氧体领域,具体涉及一种用于化学链燃烧的复合载氧体组合物,以复合氧化钛为载体,以复合氧化铁为活性组分,并提供了具体的制备方法。本发明解决了现有载氧体循环反应性低的问题,以缺氧体系的氧化钛结构为载体,有效的提升了载体的氧活性和稳定性。(The invention belongs to the field of chemical looping combustion, relates to the field of oxygen carriers, and particularly relates to a composite oxygen carrier composition for chemical looping combustion, which takes composite titanium oxide as a carrier and composite iron oxide as an active component and provides a specific preparation method. The invention solves the problem of low cyclic reactivity of the existing oxygen carrier, and effectively improves the oxygen activity and stability of the carrier by taking the titanium oxide structure of an oxygen-deficient system as the carrier.)

1. A composite oxygen carrier composition for chemical looping combustion, characterized by: the composite titanium oxide is used as a carrier, and the composite iron oxide is used as an active component.

2. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 1, characterized in that: the composite titanium oxide takes titanium monoxide as a framework and titanium dioxide as a surface film to form a composite titanium oxide carrier.

3. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 1, characterized in that: the composite ferric oxide takes ferrous oxide as an inner layer and ferric oxide as a surface layer to form a composite ferric oxide structure.

4. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 1, characterized in that: the preparation method of the oxygen carrier comprises the following steps:

step 1, putting titanium monoxide into anaerobic distilled water, performing wet ball milling and stirring to form viscous slurry, and performing vacuum drying to form titanium monoxide powder particles;

step 2, adding polyvinylpyrrolidone into absolute ethyl alcohol, adding titanium monoxide powder, performing low-temperature ultrasonic dispersion, then performing constant-temperature solidification in a mold to form particles, performing constant-temperature extrusion to form titanium monoxide particles, and soaking the titanium monoxide particles into absolute ethyl alcohol to obtain porous titanium monoxide particles;

step 3, adding n-butyl titanate into the anhydrous ethanol, and uniformly stirring to form titanium alcohol liquid; the concentration of the tetrabutyl titanate in the absolute ethyl alcohol is 100-200g/L, and the stirring speed is 1000-2000 r/min;

and 4, spraying half of titanium alcohol solution on the specific surface of the porous titanium monoxide particles, sealing and drying, and repeating for 2-4 times to obtain the titanium membrane, wherein the spraying amount of spraying is 2-5g/cm²Sealing and drying at 80-90 deg.C;

step 5, adding ferrous chloride into the remaining half titanium alcohol solution, uniformly stirring to form a mixed solution, uniformly coating the mixed solution on the surface of the titanium film, and quickly drying to obtain film-coated titanium monoxide particles;

and 6, coating hydrogen peroxide on the surfaces of the coated titanium monoxide particles, then adding the coated titanium monoxide particles into a sealed reaction kettle to react for 10-30min at a constant temperature, taking out the titanium monoxide particles, and washing the titanium monoxide particles with ethanol to obtain the composition.

5. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 4, characterized in that: the adding amount of the anaerobic distilled water in the step 1 is 10-20% of the mass of the titanium monoxide, the wet ball milling stirring is sealed ball milling stirring in a nitrogen environment, the pressure is 2-4MPa, the stirring speed is 300-500r/min, the temperature is 10-20 ℃, the vacuum drying temperature is 100-110 ℃, the vacuum is firstly filled with nitrogen, then the nitrogen is extracted to achieve the vacuum effect, and the air oxygen in the environment is removed as much as possible.

6. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 4, characterized in that: the polyvinylpyrrolidone in the step 2 forms saturated liquid in the absolute ethyl alcohol, the adding amount of the titanium monoxide powder particles is 200-500% of the mass of the polyvinylpyrrolidone, the temperature of low-temperature ultrasonic dispersion is 10-20 ℃, the ultrasonic frequency is 40-70kHz, the temperature of constant-temperature curing is 80-90 ℃, the pressure of constant-temperature extrusion is 2-4MPa, and the temperature is 80-90 ℃, and is the same as the temperature of constant-temperature curing.

7. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 4, characterized in that: the concentration of the ferrous chloride in the titanium alcohol solution in the step 5 is 120-400g/L, the stirring speed is 1000-2000r/min, and the total coating amount is 1-3g/cm²Coating can be carried out in a mode of 2-4 times of coating; the quick drying is drying in a nitrogen environment, and the drying temperature is 80-100 ℃.

8. The composite oxygen carrier composition for chemical looping combustion as claimed in claim 4, characterized in that: the hydrogen peroxide in the step 6 is a mixture of hydrogen peroxide and water, the mass concentration of the hydrogen peroxide is 40-60%, ammonia gas is introduced into the hydrogen peroxide, the introduction amount of the ammonia gas is 70-90% of the mass of the hydrogen peroxide, and the coating amount is 0.4-0.9g/cm²The constant temperature is 300-500 ℃.

Technical Field

The invention belongs to the field of chemical looping combustion, relates to the field of oxygen carriers, and particularly relates to a composite oxygen carrier composition for chemical looping combustion.

Background

Fossil fuels are inexpensive and abundantly stored, and are considered a major source of energy for human activities. It is expected that by 2030, the electrical energy generated by the combustion of fossil fuels will increase to 450GW, of which only 6GW will be replaced by other energy sources. The most important harm of coal combustion is air pollution; these pollutants are of widespread interest and regulation in china and even worldwide, where the amount of carbon dioxide produced by the combustion of fossil fuels is quite large.

Addressing the current combustion problems, the ability to produce high concentrations of CO2 or gas phase mixtures that facilitate separation of CO2 during combustion, while eliminating the formation of other pollutants, would greatly reduce the energy and cost required to capture and store CO 2. Chemical looping combustion is a new combustion mode with the above characteristics and is receiving more and more attention. Oxygen carriers have been the focus of research in chemical looping combustion. The oxygen carrier is used as a medium and circulates between the two reactors, and oxygen in the air reactor and heat generated by the reaction are continuously transferred to the fuel reactor for reduction reaction, so that the property of the oxygen carrier directly influences the operation of the whole chemical-looping combustion. However, the current oxygen carriers have a problem of low cyclic reactivity.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a composite oxygen carrier composition for chemical looping combustion, which solves the problem of low cyclic reactivity of the existing oxygen carrier, and effectively improves the oxygen activity and stability of the carrier by taking the titanium oxide structure of an anoxic system as the carrier.

In order to achieve the technical purpose, the technical scheme of the invention is as follows:

a composite oxygen carrier composition for chemical-looping combustion uses composite titanium oxide as carrier and composite iron oxide as active component.

The composite titanium oxide takes titanium monoxide as a framework and titanium dioxide as a surface film to form a composite titanium oxide carrier.

The composite ferric oxide takes ferrous oxide as an inner layer and ferric oxide as a surface layer to form a composite ferric oxide structure.

The preparation method of the oxygen carrier comprises the following steps:

step 1, putting titanium monoxide into anaerobic distilled water, performing wet ball milling and stirring to form viscous slurry, and performing vacuum drying to form titanium monoxide powder particles; the adding amount of the anaerobic distilled water is 10-20% of the mass of the titanium monoxide, the wet ball milling stirring is sealed ball milling stirring in a nitrogen environment, the pressure is 2-4MPa, the stirring speed is 300-500r/min, the temperature is 10-20 ℃, the vacuum drying temperature is 100-110 ℃, the vacuum is filled with nitrogen firstly, then the nitrogen is extracted to achieve the vacuum effect, and the air oxygen in the environment is removed as much as possible;

step 2, adding polyvinylpyrrolidone into absolute ethyl alcohol, adding titanium monoxide powder, performing low-temperature ultrasonic dispersion, then performing constant-temperature solidification in a mold to form particles, performing constant-temperature extrusion to form titanium monoxide particles, and soaking the titanium monoxide particles into absolute ethyl alcohol to obtain porous titanium monoxide particles; the polyvinylpyrrolidone forms a saturated liquid in the absolute ethyl alcohol, the adding amount of the titanium monoxide powder particles is 200-500% of the mass of the polyvinylpyrrolidone, the temperature of low-temperature ultrasonic dispersion is 10-20 ℃, the ultrasonic frequency is 40-70kHz, the temperature of constant-temperature curing is 80-90 ℃, the pressure of constant-temperature extrusion is 2-4MPa, the temperature is 80-90 ℃, and the temperature is the same as the constant-temperature curing temperature;

step 3, adding n-butyl titanate into the anhydrous ethanol, and uniformly stirring to form titanium alcohol liquid; the concentration of the tetrabutyl titanate in the absolute ethyl alcohol is 100-200g/L, and the stirring speed is 1000-2000 r/min;

and 4, spraying half of titanium alcohol solution on the specific surface of the porous titanium monoxide particles, sealing and drying, and repeating for 2-4 times to obtain the titanium membrane, wherein the spraying amount of spraying is 2-5g/cm²Sealing and drying at 80-90 deg.C;

step 5, adding ferrous chloride into the remaining half titanium alcohol solution, uniformly stirring to form a mixed solution, uniformly coating the mixed solution on the surface of the titanium film, and quickly drying to obtain film-coated titanium monoxide particles; the concentration of the ferrous chloride in the titanium alcohol solution is 120-400g/L, the stirring speed is 1000-2000r/min, and the total coating amount is 1-3g/cm²Coating can be carried out in a mode of 2-4 times of coating; the rapid drying is drying in a nitrogen environment, and the drying temperature is 80-100 ℃;

step 6, coating hydrogen peroxide on the surfaces of the coated titanium monoxide particles, then adding the coated titanium monoxide particles into a sealed reaction kettle for constant-temperature reaction for 10-30min, taking out the titanium monoxide particles, washing the titanium monoxide particles with ethanol to obtain a composition, wherein the hydrogen peroxide is a mixture of hydrogen peroxide and water, the mass concentration of the hydrogen peroxide is 40-60%, ammonia gas is introduced into the hydrogen peroxide, the introduction amount of the ammonia gas is 70-90% of the mass of the hydrogen peroxide, and the coating amount is 0.4-0.9g/cm²The constant temperature is 300-500 ℃.

From the above description, it can be seen that the present invention has the following advantages:

1. the invention solves the problem of low cyclic reactivity of the existing oxygen carrier, and effectively improves the oxygen activity and stability of the carrier by taking the titanium oxide structure of an oxygen-deficient system as the carrier.

2. According to the invention, ferrous oxide is used as an inner layer, ferric oxide is used as an outer layer, composite ferric oxide with good activity is formed, and simultaneously, the ferrous oxide and the internal titanium dioxide form a perovskite-like structure, so that the stability of the whole structure is improved.

Detailed Description

The present invention is described in detail with reference to examples, but the present invention is not limited to the claims.