Method using high-viscosity absorbent to separate CO2 based on dissolution assisting effect

Abstract

The invention relates to a method using a high-viscosity absorbent to separate CO2 based on a dissolution assisting effect and belongs to the technical field of gas separation and the field of environment protection. The method is characterized in that due to the dissolution assisting effect of amine, a novel absorbent can be obtained by mixing an organic solvent which does not dissolve in water with the high-viscosity amine absorbent; the novel absorbent reacts with to-be-separated CO2, the novel absorbent forms liquid-liquid phases or liquid-solid phases due to the fact that the amine is reduced during the reaction and the dissolution assisting effect is weakened, and the two phases are respectively a CO2-loaded rich phase and a CO2-loaded poor phase; desorption is performed only on the CO2-loaded rich phase to obtain CO2; the absorbent after the desorption is mixed with the CO2-loaded poor phase to perform circulation absorption. The method has the advantages that the viscosity of the absorbent is lowered during the absorption, the concentration of the absorbent is increased during the desorption, the treatment quantity of a desorption unit is reduced, water evaporation amount and temperature rising energy consumption are lowered, and the high-viscosity absorbent can be used to separate the CO2 with low energy consumption.

Description

technical field

[0001] The invention belongs to the technical field of gas separation and the field of environmental protection, and relates to a method for separating CO based on a cosolvent effect by applying a high-viscosity absorbent 2 Methods. Background technique

[0002] The massive emission of carbon dioxide is the main cause of the greenhouse effect and poses a great threat to the living environment of human beings. Therefore, it is necessary to capture carbon dioxide gas. Existing carbon dioxide capture technologies include chemical absorption method, physical absorption method, membrane separation method, adsorption method, biological method, etc. Among them, chemical absorption method is widely used in industry. Although chemical absorption method is widely used, it still faces the problem of high energy consumption for regeneration.

[0003] CO 2 The energy consumption of the regeneration process mainly includes three parts: (1) the reaction heat required fo...

Examples

Embodiment 1

[0025] 24 g of an aqueous solution with a mass fraction of ethanolamine (MEA) of 50% was prepared, and 16 g of n-butanol was added thereto to obtain 40 g of a novel absorbent. The mass of n-butanol added is 66.7% of the original high-viscosity amine absorbent. Then, at a temperature of 20°C and under normal pressure, it is absorbed to saturation, and the absorbent forms a liquid-liquid two-phase, and the upper liquid phase is CO 2 Loaded lean liquid phase, volume 20.0 mL, CO 2 The load is 0.179mol / L, and the lower liquid phase is CO 2 Loaded rich liquid phase, volume 24.0 mL, CO 2 The load was 4.915 mol / L. will CO 2 The loaded rich phase is separated and desorbed to obtain CO. 2 ; Desorbed absorbent and CO 2 The lean phase of the load is mixed, and then the cycle reaction absorption is carried out.

Embodiment 2

[0027] 24 g of an aqueous solution with a mass fraction of triethanolamine (TEA) of 50% was prepared, and 16 g of n-butanol was added thereto to obtain 40 g of a novel absorbent. The mass of n-butanol added is 66.7% of the original high-viscosity amine absorbent. Then, at a temperature of 20°C and under normal pressure, it is absorbed to saturation, and the absorbent forms a liquid-liquid two-phase, and the upper liquid phase is CO 2 Loaded lean liquid phase, volume 24.5 mL, CO 2 The load is 0.200mol / L, and the lower liquid phase is CO 2 Loaded rich liquid phase, volume 17.5 mL, CO 2 The load was 1.635 mol / L. will CO 2 The loaded rich phase is separated and desorbed to obtain CO. 2 ; Desorbed absorbent and CO 2 The lean phase of the load is mixed, and then the cycle reaction absorption is carried out.

Embodiment 3

[0029] Prepare 30 g of an aqueous solution with a mass fraction of benzylamine of 66.7%, add 10 g of benzene to it, and obtain 40 g of a novel absorbent. The mass of benzene added is 33.3% of the original high-viscosity amine absorbent. Then, at a temperature of 20 °C and under normal pressure, it is absorbed to saturation, and the absorbent forms a liquid-solid two-phase, and the liquid phase is CO. 2 Loaded lean phase, solid phase is CO 2 Load rich phase. will CO 2 The loaded rich phase is separated and desorbed to obtain CO. 2 ; Desorbed absorbent and CO 2 The lean phase of the load is mixed, and then the cycle reaction absorption is carried out.

technical field

[0001] The invention belongs to the technical field of gas separation and the field of environmental protection, and relates to a method for separating CO based on a cosolvent effect by applying a high-viscosity absorbent 2 Methods. Background technique

[0002] The massive emission of carbon dioxide is the main cause of the greenhouse effect and poses a great threat to the living environment of human beings. Therefore, it is necessary to capture carbon dioxide gas. Existing carbon dioxide capture technologies include chemical absorption method, physical absorption method, membrane separation method, adsorption method, biological method, etc. Among them, chemical absorption method is widely used in industry. Although chemical absorption method is widely used, it still faces the problem of high energy consumption for regeneration.

[0003] CO 2 The energy consumption of the regeneration process mainly includes three parts: (1) the reaction heat required fo...

Examples

Embodiment 1

[0025] 24 g of an aqueous solution with a mass fraction of ethanolamine (MEA) of 50% was prepared, and 16 g of n-butanol was added thereto to obtain 40 g of a novel absorbent. The mass of n-butanol added is 66.7% of the original high-viscosity amine absorbent. Then, at a temperature of 20°C and under normal pressure, it is absorbed to saturation, and the absorbent forms a liquid-liquid two-phase, and the upper liquid phase is CO 2 Loaded lean liquid phase, volume 20.0 mL, CO 2 The load is 0.179mol / L, and the lower liquid phase is CO 2 Loaded rich liquid phase, volume 24.0 mL, CO 2 The load was 4.915 mol / L. will CO 2 The loaded rich phase is separated and desorbed to obtain CO. 2 ; Desorbed absorbent and CO 2 The lean phase of the load is mixed, and then the cycle reaction absorption is carried out.

Embodiment 2

[0027] 24 g of an aqueous solution with a mass fraction of triethanolamine (TEA) of 50% was prepared, and 16 g of n-butanol was added thereto to obtain 40 g of a novel absorbent. The mass of n-butanol added is 66.7% of the original high-viscosity amine absorbent. Then, at a temperature of 20°C and under normal pressure, it is absorbed to saturation, and the absorbent forms a liquid-liquid two-phase, and the upper liquid phase is CO 2 Loaded lean liquid phase, volume 24.5 mL, CO 2 The load is 0.200mol / L, and the lower liquid phase is CO 2 Loaded rich liquid phase, volume 17.5 mL, CO 2 The load was 1.635 mol / L. will CO 2 The loaded rich phase is separated and desorbed to obtain CO. 2 ; Desorbed absorbent and CO 2 The lean phase of the load is mixed, and then the cycle reaction absorption is carried out.

Embodiment 3

[0029] Prepare 30 g of an aqueous solution with a mass fraction of benzylamine of 66.7%, add 10 g of benzene to it, and obtain 40 g of a novel absorbent. The mass of benzene added is 33.3% of the original high-viscosity amine absorbent. Then, at a temperature of 20 °C and under normal pressure, it is absorbed to saturation, and the absorbent forms a liquid-solid two-phase, and the liquid phase is CO. 2 Loaded lean phase, solid phase is CO 2 Load rich phase. will CO 2 The loaded rich phase is separated and desorbed to obtain CO. 2 ; Desorbed absorbent and CO 2 The lean phase of the load is mixed, and then the cycle reaction absorption is carried out.