CN107617309B

CN107617309B - Absorb CO2Medium and absorption method

Info

Publication number: CN107617309B
Application number: CN201711048114.3A
Authority: CN
Inventors: 李林; 荆晓玲; 陆琴; 甄树聪
Original assignee: Jiangxi Normal University
Current assignee: Jiangxi Normal University
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2020-03-13
Anticipated expiration: 2037-10-31
Also published as: CN107617309A

Abstract

The invention provides CO₂Absorption medium and a CO₂An absorption method. CO 2₂The absorption medium is composed of55% of the molecular formula is (CH)₂CH₂HO)₂NR¹Amino acid-containing alcohol amines of COONa (wherein R is¹Is an n-alkyl group having 1 to 10 carbon atoms), 10% of a secondary alcohol amine (DEA), 5% of sodium hydroxide (NaOH), 15% of nano-TiO₂(particle size 10-20 nm) and 15% of distilled water. Wherein N-methyldiethanolamine and secondary alcohol amine are in liquid state, sodium hydroxide and nano TiO₂The materials are solid, and are mixed according to the proportion to prepare the liquid absorbing medium. CO 2₂Absorption process of CO₂Gas or containing CO₂The gas mixture of (2) is contacted with an absorption medium to thereby convert CO into₂And (4) absorbing. The method of the invention has the advantages that: CO 2₂High absorption rate, high absorption speed, effective reduction of the circulation amount of the absorption liquid, strong absorption capacity to emulsified micro bubbles and easy desorption operation. CO of the invention₂The absorption medium can effectively solve the problem of CO₂And (4) discharge problems.

Description

Absorb CO2Medium and absorption method

Technical Field

The invention relates to the preparation of CO from a plurality of compounds₂Absorbent method, specifically using MEDA, DEA, NaOH, nano-TiO₂Is mixed with distilled water to form a mixture, which is used for treating CO₂High absorption rate, high absorption speed, effective reduction of circulation volume of absorption liquid, strong absorption capacity to emulsified micro bubbles, and effective solution of CO₂And (4) discharge problems. The invention belongs to the field of resource environment.

Background

The carbon dioxide has the function of heat preservation and can gradually raise the surface temperature of the earth. In the last 100 years, the global temperature rises by 0.6 ℃, and is predicted to rise by 1.5-4.5 ℃ in the middle of the 21 st century. The rise of sea level caused by greenhouse effect also has great influence on the living environment of human beings. The ice cubes of the bipolar ocean will also melt completely. All these changes were no different from a disaster of extinction for wild animals.

By 2013, 5 months, the concentration of carbon dioxide in the earth's atmosphere has exceeded 400ppm (400 parts per million). The rate of increase in concentration between 2000 and 2009 is 2.0ppm per year and accelerates year by year. The concentration is much higher than the 280ppm concentration before industrialization, and human factors are the main reasons for the sharp rise of the carbon dioxide concentration. Of the released carbon dioxide, 57% enters the atmosphere and the remainder enters the ocean, causing acidification of the ocean.

Up to four fold ground carbon dioxide emissions are due to volcanic eruptions. It is estimated that each year volcanic eruptions release about 130-230 million tonnes (145-255 million tonnes) of carbon dioxide into the atmosphere. Hot springs and the like also produce large amounts of carbon dioxide. In a city in italy, local carbon dioxide concentrations rise to over 75% overnight enough to kill insects and small animals, but during the day when sunlight shines rather quickly as the temperature rises, causing gas convection to disperse. The carbon dioxide discharged by human beings exceeds volcanic explosion discharge amount by more than 130 times: 270 hundred million metric tons a year.

The sea level rises due to the increase of carbon dioxide, in nearly 100 years, the sea level rises by 14 cm, and by the middle of the 21 st century, the sea level will rise by 25-140 cm, the amazon rainforest will disappear, and most of ice blocks of the two-polar ocean will also melt. All these changes are no different from top-dead disasters for wild animals and plants.

The air generally contains about 0.03% of carbon dioxide, but the "kyoto protocol" aiming at suppressing excessive emission of carbon dioxide, which is caused by a drastic increase in the content of carbon dioxide due to the influence of human activities such as combustion of fossil fuel, has come into effect, and is expected to suppress the greenhouse effect through international cooperation, due to global warming, glacier thawing, and sea level elevation … ….

In view of the above, measures must be taken to control CO₂And (4) discharging. Currently, carbon dioxide capture technologies are divided into four categories, absorption, adsorption, membrane technologies and cryogenic, and two patents relating to absorbents have been searched for, application No. 201280067833.9 (for absorbing CO from gas mixtures)₂The method and the absorption medium) of (a): CN104334251A (absorption of CO from gas mixtures₂The method of (1). Both of these patents are international patents of German, both of which are based on the molecular formula R¹R²CHNHCH₂COOK (R¹And R²Is an n-alkyl group) amino acid salt is taken as an adsorbent, and the method can not rapidly and completely absorb CO due to the fact that the absorbent is single₂There are certain limitations.

Disclosure of Invention

To solve the problemWith CO being captured in the carbon dioxide capture technology₂The invention provides a CO adsorbent, which has the problems of poor absorption effect and incomplete absorption₂Absorption medium and absorption method, said CO₂Absorption medium for absorbing CO by organic, inorganic and nano material₂。

The technical scheme for solving the problems of the invention is as follows:

CO (carbon monoxide)₂The absorption medium is prepared by mixing the following substances in percentage by mass:

(1) 50-60% of molecular formula (CH)₂CH₂HO)₂NR¹Amino acid-carrying alcohol amines of COONa, in which R is¹Is an n-alkyl group having 1 to 10 carbon atoms;

(2) 5-15% of a paraolamine (DEA);

(3) 5-10% sodium hydroxide (NaOH);

(4) 10-20% of nano-grade TiO₂(particle size 10-20 nm);

(5) 10-20% of distilled water.

Wherein N-methyldiethanolamine and secondary alcohol amine are in liquid state, sodium hydroxide and nano TiO₂The materials are solid, and are mixed according to the proportion to prepare the liquid absorbing medium.

Preferably, the above formula is (CH)₂CH₂HO)₂NR¹COONa alcohol amine with amino acid group, secondary alcohol amine, sodium hydroxide and nano TiO₂The mass percentages of distilled water are 55%, 10%, 5%, 15%, and 15%, respectively, which are the optimum ratios.

CO as described above₂The absorption medium can be used for absorbing CO in the gas mixture₂The gas mixture refers to combustion waste gas, natural gas or biogas.

CO (carbon monoxide)₂Absorption method, in which CO in a gas mixture is brought into contact with an absorption medium₂Absorption, characterized by: the absorption medium is the CO₂An absorption medium.

Absorption of CO in an absorption medium₂Thereafter, the absorption into the absorption medium can be effected by means of a method of increasing the temperature or reducing the pressure CO₂Desorbing, and reusing the desorbed absorption medium for absorbing CO₂. In this manner, the absorption and desorption can be repeated.

The absorption is carried out at 0-90 deg.C, and the desorption is carried out at 100-120 deg.C.

The pressure reduction means that the air pressure is reduced to 100-1000 Pa, and the rest is normal pressure.

CO as described above₂The pH value of the absorption medium is between 7 and 9.

The invention has the beneficial effects that: the invention adopts organic absorbent alcohol amine, inorganic absorbent NaOH and nano TiO₂Absorption of CO as an absorbent₂The alcohol amine with amino acid group has the characteristics of better selectivity, higher absorption capacity, better thermal stability, low alkalinity, low volatility and low corrosivity, the reaction rate of the N-methyldiethanolamine can be improved after the secondary alcohol amine is added, and the nano TiO₂Can absorb CO in emulsified state₂The micro bubbles can completely absorb the residual CO after the alcohol amine is absorbed by the coaction with NaOH₂Absorption is carried out. Thus, the CO of the present invention₂The absorption medium is absorbed quickly and completely, and is essentially different from the method in the background art; but also can effectively reduce the circulating amount of absorption liquid, has strong absorption capacity to emulsified micro-bubbles and is easy to desorb.

Detailed Description

The features of the present invention are further illustrated by the following examples, but the scope of protection of this patent is not limited by the examples.

Comparative example

Taking 200ml of 20 wt% secondary hydroxylamine solution, putting the 20 wt% secondary hydroxylamine solution into a four-neck flask with stirring and temperature metering functions, heating the solution in a constant-temperature water bath at 40 ℃, wherein the stirring speed is 150r/min, and CO with the concentration of 99.9% is mixed at the flow rate of 110ml/min₂Introducing into solution, measuring with wet type anticorrosion flowmeter to calculate CO₂The amount of absorption of (c). After the absorption test is finished, the above-mentioned material is absorbed with CO₂The solution of (2) was heated and kept at a temperature of 110 ℃ for the regeneration test, with a stirring speed of 150 r/min. Measuring with a wet corrosion-resistant flowmeter to calculate CO₂The regeneration rate of (3). The results are shown in tables 1 and 2.

Example 1

Take 110g (CH)₂CH₂HO)₂NCH₂COONa, 20g of secondary alcohol amine, 15g of sodium hydroxide and 25g of nano TiO₂40g of distilled water are put into a four-neck flask with the functions of stirring and temperature measurement, the mixture is heated in a constant-temperature water bath at 40 ℃, the stirring speed is 150r/min, and CO with the concentration of 99.9 percent is added at the flow rate of 110ml/min₂Introducing into solution, measuring with wet type anticorrosion flowmeter to calculate CO₂The amount of absorption of (c). After the absorption test is finished, the above-mentioned material is absorbed with CO₂The solution of (2) was heated and kept at a temperature of 110 ℃ for the regeneration test, with a stirring speed of 150 r/min. Measuring with a wet corrosion-resistant flowmeter to calculate CO₂The regeneration rate of (3). The results are shown in tables 1 and 2.

Example 2

Take 120g (CH)₂CH₂HO)₂NC₃H₆COONa, 25g of secondary alcohol amine, 10g of sodium hydroxide and 20g of nano TiO₂40g of distilled water are put into a four-neck flask with the functions of stirring and temperature measurement, the mixture is heated in a constant-temperature water bath at 40 ℃, the stirring speed is 150r/min, and CO with the concentration of 99.9 percent is added at the flow rate of 110ml/min₂Introducing into solution, measuring with wet type anticorrosion flowmeter to calculate CO₂The amount of absorption of (c). After the absorption test is finished, the above-mentioned material is absorbed with CO₂The solution of (2) was heated and kept at a temperature of 110 ℃ for the regeneration test, with a stirring speed of 150 r/min. Measuring with a wet corrosion-resistant flowmeter to calculate CO₂The regeneration rate of (3). The results are shown in tables 1 and 2.

Example 3

Take 100g (CH)₂CH₂HO)₂NC₈H₁₆COONa, 30g of secondary alcohol amine, 20g of sodium hydroxide and 30g of nano TiO₂35g of distilled water are put into a four-neck flask with stirring and temperature measuring functions, the flask is heated in a constant-temperature water bath at 40 ℃, the stirring speed is 150r/min, and CO with the concentration of 99.9 percent is added at the flow rate of 110ml/min₂Introducing into solution, measuring with wet-type antiseptic flowmeter,from this, CO was calculated₂The amount of absorption of (c). After the absorption test is finished, the above-mentioned material is absorbed with CO₂The solution of (2) was heated and kept at a temperature of 110 ℃ for the regeneration test, with a stirring speed of 150 r/min. Measuring with a wet corrosion-resistant flowmeter to calculate CO₂The regeneration rate of (3). The results are shown in tables 1 and 2.

TABLE 1 different solvents vs. CO₂Absorption of

TABLE 2 different solvents CO₂Regeneration situation of

Claims

1. CO (carbon monoxide)₂The absorption medium is prepared by mixing the following substances in percentage by mass:

(2) 5-15% of secondary hydroxylamine;

(3) 5-10% sodium hydroxide;

(4) 10-20% of nano-grade TiO₂Said nano-sized TiO₂The particle size is 10-20 nm;

(5) 10-20% of distilled water.

2. CO according to claim 1₂An absorbent media characterized by: the molecular formula is (CH)₂CH₂HO)₂NR¹COONa alcohol amine with amino acid group, secondary alcohol amine, sodium hydroxide and nano TiO₂The mass percentages of the distilled water are respectively 55%, 10%, 5%, 15% and 15%.

3. CO (carbon monoxide)₂Absorption method by using an absorption mediumThe substance is contacted with the gas mixture to remove CO in the gas mixture₂Absorption, characterized by: the absorption medium is CO according to claim 1₂An absorption medium.

4. The method of claim 3, wherein: the absorption is carried out at 0-90 ℃.

5. The method of claim 3, wherein: absorption of CO in an absorption medium₂Thereafter, the CO absorbed into the absorption medium is reduced by increasing the temperature or reducing the pressure₂Desorbing, and reusing the desorbed absorption medium for absorbing CO₂。

6. The method of claim 5, wherein: the desorption is carried out at 100-120 ℃.

7. The method of claim 5, wherein: the pressure reduction means reducing the pressure to 100 to 1000 Pa.

8. The method of claim 3, wherein: the CO is₂The pH value of the absorption medium is between 7 and 9.