Carbon dioxide capturing compression system using flue gas and multistage compressing waste heat

Abstract

The invention discloses a carbon dioxide capturing compression system using flue gas and multistage compressing waste heat. The system comprises a flue gas pipeline and a heating water pipeline. The flue gas pipeline comprises a first heat exchanger and a second heat exchanger, a four-way reversing valve, a first temperature swing adsorption tower unit and a second temperature swing adsorption tower unit, a first three-way valve and a first compressor and a second compressor. The heating water pipeline comprises a water pump, a second three-way valve and a cooling tower. A multistage compressing cooling device formed by multistage of alternately connected heat exchangers and compressors can be connected between the outlet of the second compressor and the outlet of the flue gas pipeline, and the outlet of the last stage compressor is the outlet of the flue gas pipeline; and a water pump is connected in series to the low-temperature sides of all the heat exchangers. According to the system disclosed by the invention, by virtue of multistage compression and intermediate cooling, the compressing energy consumption before carbon dioxide is reduced; by combining the intermediate cooling and flue gas waste heat utilization of the compressor with temperature swing adsorption carbon capturing, the capacity of energy conservation and emission reduction of a coal-fired power plant is ensured; the two groups of temperature swing adsorption towers same in quantity ensure the industrial operating persistence so as to maintain the gas generating capacity of the system.

Description

technical field [0001] The invention relates to a system for utilizing low-grade thermal energy and flue gas waste heat of multi-stage compression and intercooling technology to realize temperature-swing adsorption carbon capture and treatment of boiler flue gas in coal-fired power plants, and at the same time reduce the energy consumption of compressed carbon dioxide. The combination of adsorption carbon capture technology as the core, and the use of multi-stage compression and intercooling technology at the same time meet the needs of low energy consumption capture and compression of carbon dioxide from power plant boiler flue gas. Background technique [0002] The environmental distress caused by the greenhouse effect seriously affects the normal life of human beings. According to relevant reports from the International Energy Agency, the culprit is CO 2 , the massive use of fossil fuels in the energy and industrial sectors directly leads to CO 2 The emission of carbon d...

AI Technical Summary

Problems solved by technology

[0003] The capture process of carbon dioxide physical adsorption method is simple, the desorption capacity of the adsorbent is strong, and it has been widely used in engineering. At present, the temperature swing adsorption method is used as the design basis to design the CO2 capture device, and the adsorption tower is heated to realize the desorption process of the adsorbent. Huge energy consumption has become the main reason for limiting the development of carbon dioxide capture technology. After obtaining high-concentration carbon dioxide product gas, the compression process before canning and transportation requires a lot of energy consumption

However, the carbon dioxide capture achieved by chemical absorption is not as energy-intensive as the adsorption method, and no measures have been taken to reduce the high energy consumption in the process of carbon dioxide compression

[0004] In addition, there are also improvements to the carbon dioxide adsorption and capture technology. For example, the Chinese utility model patent with the publication number CN203990246U proposes a carbon dioxide capture baffle fixed-bed adsorption tower, which can achieve good gas uniformity, long gas flow, and With the advantages of high utilization rate of adsorbent and stable bed, it can be applied to carbon dioxide capture pressure swing adsorption projects of various scales, large, medium and small, but it can be seen that it lacks the overall advantages of system improvement, and its effect alone is limited; the publication number is CN105749696A The Chinese invention patent application discloses a carbon dioxide absorption and desorption system and method based on low-grade thermal energy utilization, which combines waste heat utilization and carbon dioxide capture double-effect energy-saving effects, and uses low-grade thermal energy in flue gas as an energy source. Combined with physical temperature change to achieve cyclic adsorption and desorption, it improves efficiency, reduces system running time, reduces system energy consumption by about 60%, reduces pollution caused by flue gas in thermal power plants, and also does not consider energy consumption in the compression process

[0005] To sum up, the existing technology has made some progress in both "flue gas waste heat utilization" and "temperature swing adsorption carbon capture", but there is no perfect system that can utilize the low-grade heat energy of flue gas in the coal-fired power plant system. Simultaneously with thermal swing adsorption carbon capture, and taking appropriate measures to reduce energy consumption in the subsequent compression process

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