Energy Integration of Air Separation System Utilizing LNG Cryogenic Energy Based on Gradual Energy Integration and Optimization Strategy

Abstract:

Applying gradual energy integration and optimization strategy, the energy utilization system of the air separation system utilizing LNG cryogenic energy is optimized. By analyzing the original process T-H diagram, reducing the pressure of N₂ compression cycle will be a more reasonable way to use the LNG cold energy, and decrease the system power consumption. Due to N₂ liquefaction temperature falling under the LNG gasification temperature when N₂ compression pressure is decreased from 4.0 MPa to 3.0 MPa, a new LNG cold energy utilization method is proposed. Firstly, LNG is throttled to 0.12 MPa, gasification, and then re-compressed to 0.3 MPa. By adjusting the amount of N₂ in compression cycle and LNG, hot and cold streams achieved a complete match. The heat transfer temperature difference is significantly reduced. Two basic parallel composite curves are constructed, and the energy is reasonable utilized. After improvement, the power consumption is reduced 44.6 kW, which prove this energy integration is effective.

• Periodical: Advanced Materials Research (Volumes 781-784)
• Pages: 2534-2537
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.781-784.2534
• Online since: September 2013
• Authors: Xian Li Wu, Lian Ying Wu, Kai Wang, Yang Dong Hu
• Keywords: Air Separation, Cryogenic Energy Utilization, Energy Integration, Liquefied Nature Gas, T-H Diagram

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