Method and equipment for collecting carbon dioxide from fuel gas by using ammonia water fine spraying

Abstract

The invention provides a method for collecting carbon dioxide from fuel gas by using ammonia water fine spraying. The method comprises the following steps that: step A, flue gas passes through an absorbing tower from bottom to top, and CO2 within the fuel gas is absorbed by sprayed ammonia water; step B, carbon-containing pregnant solution is processed through thermal desorbing in a desorbing tower; step C, NH3 is removed from the desorbed gas in a washing tower, and the resulting gas is processed through a dewatering procedure by a condenser, such that carbon dioxide gas with high density isobtained; step D, weak ammonia water obtained from the above steps is pumped into an ammonia distilling tower to be concentrated; step E, concentrated ammonia water is diluted with water in an ammonia absorbing tower, such that the concentration of the ammonia water for spraying is adjusted. Correspondingly, the invention provides equipment for collecting carbon dioxide from fuel gas by using ammonia water fine spraying. The method and the equipment provided by the present invention are suitable for power stations with conditions of large flue gas flux and low carbon dioxide concentration, and assists in removing carbon dioxide effectively. According to the present invention, ammonia and water are used circularly, such that energy is saved, and cost for operation and maintenance are substantially reduced. Preferably, CO2 gas separated by the equipment is prepared into industrial grade liquid carbon dioxide.

Description

technical field [0001] The invention belongs to the field of carbon dioxide emission reduction, and in particular relates to a method and equipment for capturing carbon dioxide in power plant flue gas by fine spraying of ammonia water. Background technique [0002] As the impact of the greenhouse effect on global climate change becomes more and more serious, the control of the main greenhouse gas—CO 2 The emission of pollution has become an international and urgent problem to be solved. At present, for a long period of time, new energy cannot become the main source of energy that human beings rely on, and the contribution of energy conservation and emission reduction and improvement of energy use efficiency to carbon emission reduction is limited after all, while carbon capture and storage technology (CCS-Carbon capture and storage) storage) is considered to be an effective way to achieve carbon emission reduction. About 40% of the world's CO 2 It is produced by fossil fu...

AI Technical Summary

Problems solved by technology

The use of alcohol amines for carbon capture mainly has the following problems: first, the reaction rate between alcohol amines and carbon dioxide is low, and the absorption efficiency is not high; second, its rich solution has a corrosive effect on the system; third, due to oxidation, thermal degradation, Irreversible reaction and evaporation will cause the loss of alcohol amine solvent and the change of solution properties, and alcohol amine is a relatively expensive chemical product, which will inevitably increase the cost of recovering carbon dioxide

Finally, due to the large flue gas flow rate of the power plant, the carbon dioxide concentration is not high (about 10-15%). When the alcohol amine solution is used to remove carbon dioxide, the volume of the absorption tower will be large, and the construction, operation and equipment maintenance will be difficult.

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