Performance analysis and comparison of cryogenic CO₂ capture system

ABSTRACT

Excessive energy requirement for the cryogenic condition is still the challenge for the current cryogenic CO₂ capture system. In this work, the capture performance is investigated for the aim of energy savings on different cryogenic CO₂ capture system, based on the combination of pressure recovery and cold energy utilization on the process residual gas. Based on this, two novel energy saving CO₂ capture processes are proposed, which are defined as the post-expansion and the pre-cooled processes, respectively. The study presents a detailed comparison of the proposed process with conventional one regarding CO₂ recovery and energy consumption. Also, the energy saving potential of two proposed processes is analyzed by varying the operating parameters, including process temperature, compression pressure, and inlet gas CO₂ concentration. The simulation results show that the specific energy consumption can be decreased by 3.9% and 7.4% in the proposed post-expansion and pre-cooled process due to the effect of less cooling energy and compression work consumption, respectively.

KEYWORDS:

• Cryogenic CO₂ capture
• process improvement
• energy saving
• post-expansion process
• pre-cooled process

Nomenclature

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Highlights

1. Performance improving path for cryogenic CO₂ capture process is investigated.

2. Two novel improved cryogenic CO₂ capture processes are investigated.

3. Capture performance of proposed process is enhanced in different conditions.

4. The most suitable energy saving condition for the novel process is pointed out.

Acknowledgments

This work was supported by a grant from the National Natural Science Foundation of China (No. 51676133). The authors gratefully acknowledge them for support of this work.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [No. 51676133].