阅读说明：本技术 一种用于固化封存二氧化碳的改性粉煤灰及其制备方法 (Modified fly ash for curing and sealing carbon dioxide and preparation method thereof ) 是由 刘毅 卢嘉誉 闫东明 于 2019-09-03 设计创作，主要内容包括：本发明公开了一种用于固化封存二氧化碳的改性粉煤灰,包括：粉煤灰,2-氨基对苯二甲酸,及水,粉煤灰中所含铝和铁元素、2-氨基对苯二甲酸和水的摩尔比为1:0.15-0.60:153。本发明还公开了一种改性粉煤灰的制备方法,包括以下步骤：1)粉煤灰过筛后按照粉煤灰中所含铝和铁元素、2-氨基对苯二甲酸和水的摩尔比为1:0.15-0.60:153的比例混合,球磨25-30分钟；2)将混合物置入密闭水热釜中,在130-140℃下,反应3-4小时；3)反应结束后冷却至室温,反应得到的产物用去离子水洗涤多次；4)将反应产物置入干燥箱中烘干。本发明提供的改性粉煤灰能够使占粉煤灰成分组成30％左右的氧化铝、氧化铁也参与吸收二氧化碳,大大提高粉煤灰对二氧化碳的固化封存能力,制备方法操作简单,加工成本低。(The invention discloses a modified fly ash for curing and sealing carbon dioxide, which comprises the following components: the fly ash comprises fly ash, 2-amino terephthalic acid and water, wherein the molar ratio of aluminum and iron elements in the fly ash to the 2-amino terephthalic acid to the water is 1:0.15-0.60: 153. The invention also discloses a preparation method of the modified fly ash, which comprises the following steps: 1) sieving the fly ash, mixing the sieved fly ash according to the molar ratio of aluminum and iron elements in the fly ash to 2-amino terephthalic acid to water of 1:0.15-0.60:153, and carrying out ball milling for 25-30 minutes; 2) placing the mixture into a closed hydrothermal kettle, and reacting for 3-4 hours at the temperature of 130-; 3) after the reaction is finished, cooling to room temperature, and washing the product obtained by the reaction with deionized water for many times; 4) and (5) placing the reaction product into a drying box for drying. The modified fly ash provided by the invention can enable alumina and ferric oxide which account for about 30% of the components of the fly ash to participate in absorbing carbon dioxide, greatly improve the curing and sealing capacity of the fly ash to the carbon dioxide, and has the advantages of simple preparation method operation and low processing cost.)

1. A modified fly ash for use in the solidification of sequestered carbon dioxide, comprising: the composite material comprises fly ash, 2-amino terephthalic acid and water, wherein the molar ratio of aluminum and iron elements in the fly ash to the 2-amino terephthalic acid to the water is 1:0.15-0.60: 153.

2. The modified fly ash of claim 1, wherein: the molar ratio of aluminum and iron elements, 2-amino terephthalic acid and water in the fly ash is 1:0.45-0.60: 153.

3. The preparation method of the modified fly ash is characterized by comprising the following steps:

1) sieving the fly ash, mixing the sieved fly ash according to the molar ratio of aluminum and iron elements in the fly ash to 2-amino terephthalic acid to water of 1:0.15-0.60:153, and carrying out ball milling for 25-30 minutes;

2) placing the mixture obtained in the step 1) into a closed hydrothermal kettle, and reacting for 3-4 hours at the temperature of 130-140 ℃;

3) after the reaction is finished, cooling to room temperature, and washing the product obtained by the reaction with deionized water for many times;

4) and (3) placing the reaction product washed in the step 3) into a drying oven at the temperature of 40-50 ℃ for 2-3 hours for drying.

4. The method for preparing modified fly ash according to claim 3, characterized in that: and (2) sieving the fly ash with a 300-mesh sieve in the step 1).

5. The method for preparing modified fly ash according to claim 3, characterized in that: the ball milling time in the step 1) is 30 minutes.

6. The method for preparing modified fly ash according to claim 3, characterized in that: the temperature of the hydrothermal kettle in the step 2) is 140 ℃.

7. The method for preparing modified fly ash according to claim 3, characterized in that: the reaction time in the step 2) is 4 hours.

8. The method for preparing modified fly ash according to claim 3, characterized in that: the drying temperature in the step 4) is 50 ℃.

Technical Field

The invention belongs to the technical field of carbon dioxide utilization and building material maintenance, and particularly relates to modified fly ash for solidifying and sealing carbon dioxide and a preparation method thereof.

Background

Greenhouse gases refer to any gas that absorbs and releases infrared radiation and that is present in the atmosphere. In 1997, the third contractual nation of the compendium for climate change of the united nations called kyoto in japan performed reduction control on six greenhouse gases including carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride through the kyoto protocol. The latter three gases have the strongest greenhouse effect, but contribute to global warming at a maximum rate of about 25% due to their high carbon dioxide content. Especially after the industrial revolution, there is a clear trend towards an increase in the carbon dioxide concentration year by year.

In 2015, nearly 200 contracting parties in the climate change framework convention of United nations reach Paris agreement on the Paris climate change meeting, and arrangement is made for global climate change actions after 2020. The main objective of Paris protocol is to control the global average temperature rise in this century to within 2 degrees Celsius and to within 1.5 degrees Celsius above the previous level of industrialization. The great Committee of China approved Paris protocol in China on 2016, 9, 3, and the Chinese commitment reaches the peak value of carbon emission in 2030.

Therefore, it is the responsibility of our country to control and reduce carbon emissions. In addition to reducing the use of fossil fuels, another approach is carbon capture and carbon sequestration. At present, the methods of carbon capture and carbon sequestration mainly include geological sequestration, ocean sequestration, mineral sequestration and the like. Wherein, mineral sealing refers to the process of solidifying ores containing alkaline and alkaline earth metal oxides by reacting with carbon dioxide to generate more stable carbonate.

Fly ash is fly ash and ash slag which are burned by a boiler in the power generation process of a coal-fired power plant and collected by a dust remover after passing through flue gas, and is the main solid waste of the coal-fired power plant. In recent years, the emission of fly ash in China is increased year by year, the emission in 2018 is over 6.4 hundred million tons, and the fly ash is listed as a waste for key treatment by the nation.

Fly ash has been used in large quantities in the building materials industry, but is rarely used to solidify carbon dioxide. This is because of the main chemical composition of fly ashIs Al₂O₃、SiO₂Also contains a certain amount of CaO and Fe₂O₃And the like. In general, alumina and iron oxide cannot react with carbon dioxide, so that Ca element in fly ash is generally used for curing carbon dioxide, and the content of Ca element in fly ash is generally about 20%, so that the fly ash has poor carbon dioxide curing capability.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the modified fly ash for curing and sealing carbon dioxide and the preparation method thereof, wherein the modified fly ash has good capability of curing and sealing carbon dioxide by using alumina and ferric oxide with high content in the fly ash to absorb carbon dioxide.

The technical scheme adopted by the invention for solving the technical problems is as follows: a modified fly ash for use in curing sequestered carbon dioxide, comprising: the composite material comprises fly ash, 2-amino terephthalic acid and water, wherein the molar ratio of aluminum and iron elements in the fly ash to the 2-amino terephthalic acid to the water is 1:0.15-0.60: 153.

Further, the molar ratio of aluminum and iron elements, 2-amino terephthalic acid and water in the fly ash is 1:0.45-0.60: 153.

The invention also discloses a preparation method of the modified fly ash, which comprises the following steps:

1) sieving the fly ash, mixing the sieved fly ash according to the molar ratio of aluminum and iron elements in the fly ash to 2-amino terephthalic acid to water of 1:0.15-0.60:153, and carrying out ball milling for 25-30 minutes;

2) placing the mixture obtained in the step 1) into a closed hydrothermal kettle, and reacting for 3-4 hours at the temperature of 130-140 ℃;

3) after the reaction is finished, cooling to room temperature, and washing the product obtained by the reaction with deionized water for many times;

4) and (3) placing the reaction product washed in the step 3) into a drying oven at the temperature of 40-50 ℃ for 2-3 hours for drying.

Preferably, the fly ash in the step 1) is sieved by a 300-mesh sieve.

Preferably, the ball milling time in the step 1) is 30 minutes.

Preferably, the temperature of the hydrothermal kettle in the step 2) is 140 ℃.

Preferably, the reaction time in the step 2) is 4 hours.

Preferably, the drying temperature in the step 4) is 50 ℃.

The fly ash is solid waste generated by coal burning, has extremely large quantity and needs to be treated urgently; carbon dioxide is the most dominant greenhouse gas, and sequestration of carbon dioxide is one of the methods to mitigate global warming. The content of aluminum and iron in the fly ash is higher, but the capability of solidifying and sealing carbon dioxide is not provided, the invention changes the traditional method of solidifying and sealing carbon dioxide by using CaO in the fly ash, and Al which can not absorb carbon dioxide before is used₂O₃、Fe₂O₃Fully utilizes the aluminum and iron elements in the modified fly ash of the invention to generate NH with 2-amino terephthalic acid₂MIL-53(Al) and NH₂MIL-53(Fe), and the two reaction products can realize the function of solidifying and sealing carbon dioxide so as to obviously improve the capability of solidifying and sealing carbon dioxide by the fly ash.

The invention has the beneficial effects that: 1) the modified fly ash provided by the invention can enable alumina and ferric oxide which account for about 30% of the components of the fly ash to participate in absorbing carbon dioxide, so that the curing and sealing capacity of the fly ash to the carbon dioxide is greatly improved; 2) the preparation method of the modified fly ash is simple to operate and low in processing cost; 3) the modified fly ash provided by the invention can be widely applied to the manufacture of concrete blocks, absorbs and seals carbon dioxide in the manufacturing process, expands the utilization field of the fly ash, and achieves the purposes of reducing carbon emission and utilizing solid wastes; 4) the modified fly ash can improve the carbon dioxide sealing capability of the fly ash, and can be used for producing concrete blocks cured by carbon dioxide to absorb the sealed carbon dioxide in the manufacturing process so as to achieve the aim of reducing carbon emission; 5) the invention is low-carbon and environment-friendly, can simultaneously realize energy conservation, emission reduction and waste utilization, and has wide application prospect.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.