Energy Efficiency Study of Waste Heat Recovery-Based Chemical Absorption Decarbonization and Liquefaction for Natural Gas

YunHe Li; YiQian Yang; Qian Yang; ZiYi Guo; Siyuan Jiang

doi:10.63313/AERpc.9020

Authors

YunHe Li College of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China Author
YiQian Yang College of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China Author
Qian Yang College of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China Author
ZiYi Guo College of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China Author
Siyuan Jiang College of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China Author

DOI:

https://doi.org/10.63313/AERpc.9020

Keywords:

Biogas purification, MDEA-PZ solvent, CO2 removal, Waste heat recovery, LNG production, Process simulation

Abstract

This study presents an integrated approach for biogas purification and liquefaction, combining methyldiethanolamine (MDEA)-piperazine (PZ) solvent absorption with waste heat recovery from gas turbine exhaust. Through Aspen HYSYS simulation of a high-CO₂ (10%) feed gas system, we demonstrate a cascading energy utilization scheme that achieves both effective decarbonization (reducing CO₂ to <0.5%) and enhanced energy efficiency. Key findings reveal optimal absorption pressure at 1.5 MPa, where specific power consumption reaches 0.584 kW·h/kg LNG. The waste heat recovery system delivers 84.9% utilization efficiency, fully meeting the regeneration heat demand (828.99 kJ/m³) without external energy input. This configuration shows superior performance compared to conventional biogas treatment methods, particularly for CO₂-rich (≥10%) feedstocks, offering significant energy savings for LNG production facilities.

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