System and method for trapping acid gas in smoke

Abstract

The invention relates to a system and a method suitable for trapping acid gas in smoke of a fired power plant by a chemical absorption method. The system comprises an absorption tower, a rich and barren liquor heat exchanger, a regenerating tower, a reboiler and a gas-liquid separator, and a liquid film concentrating device is arranged additionally, so that part of water in rich liquor is removed in the liquid film concentrating device before the rich liquor enters the rich and barren liquor heat exchanger, thus avoiding consumption of excessive unnecessary energy due to the heating of excessive water in the liquor when the rich liquor is regenerated. Removed water and barren liquor flowing out from the regenerating tower are combined, and enter the upper part of the absorption tower for spraying and recycling, so that the energy consumption of the whole system is reduced effectively.

Description

technical field [0001] The invention relates to a chemical purification of flue gas, in particular to a system and method suitable for collecting acid gas by the chemical absorption method of flue gas in coal-fired power plants. Background technique [0002] Acid gases mainly refer to carbon dioxide, sulfur oxides, nitrogen oxides, hydrogen sulfide and other gases produced during the coal conversion process. Carbon dioxide is the main culprit of the current greenhouse effect. Sulfur oxides form acid rain in rainy days, which damage trees and buildings on the ground The damage is huge. At present, the emission reduction of acid gas has become one of the environmental protection issues that governments, academic circles and even business circles are very concerned about. However, carbon dioxide is widely used in soda industry, sugar industry, and welding fields, so carbon capture and storage is an important strategic choice for my country to deal with climate change. Thermal...

AI Technical Summary

Problems solved by technology

At present, most of the R&D and demonstration applications are the alcohol amine method. Its essence is the acid-base neutralization reaction. Carbon dioxide is captured from flue gas at low partial pressure levels, but the absorption load is limited by the reaction equilibrium

The acid-base reaction is reversible with temperature changes. Generally, salt is formed at about 40°C, carbon dioxide is absorbed, and the reaction is reversed above 100°C to release carbon dioxide. Therefore, the absorption tower and regeneration tower can be used to form a system to complete the capture of carbon dioxide. Collection, application number is 200810018343.5 patent of invention discloses above-mentioned technical feature, but this device and method are because the content of water in the circulating absorption liquid is very high (> 60%), excessive water consumption in the heating solution consumes too much energy, its Periodic heating and cooling make the system energy consumption too high

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