A Study on the Minimization of the Refrigeration Power Consumptions Through the Determination of Demethanizer Top Pressure in the NGL Recovery Process Using Turbo-expander

터보 팽창기를 활용한 NGL 회수공정에서 최적의 탈메탄탑의 운전압력 결정을 통한 냉동 소요동력 최소화에 대한 연구

  • Kim, Yu-Mi (Department of Chemical Engineering, Kongju National University) ;
  • Cho, Jung-Ho (Department of Chemical Engineering, Kongju National University)
  • Received : 2011.01.14
  • Accepted : 2011.02.10
  • Published : 2011.02.28


In this study, simulation and optimization works for a demethanizer column have been performed to obtain ethane and heavier products from a pretreated natural gas stream. Pretreated natural gas feed stream was partially condensed after being precooled by exchanging heat with demethanizer top vapor stream and by using an external refrigeration cycle with a propane refrigerant. Vapor stream was cooled further and partially condensed through a turbo-expander. The power generated from the expansion of turbo-expander was delivered to the compressor for the residue gas compression. Liquid stream was cooled by Joule-Thomson expansion valve and was fed to the middle section of the demethanizer. Recovery percent of ethane for feed natural was set to 80% and methane to ethane molar ratio was fixed as 0.0119. On the other hand, some of the cold heat could be recovered by splitting the feed stream and by exchanging heat with side reboiler in order to reduce the heat duty in the propane refrigeration cycle.


NGL recovery process;Turbo-expander;Demethanizer;Natural gas;Joule-Thomson expansion


  1. Arthur J. Kidnay and William R. Parrish, "Fundamentals of Natural Gas Processing", Taylor & Franscis, 2006.
  2. Gas Processors Suppliers Association, "Engineering Data Book", Gas Processors Assication, 2004.
  3. 조정호, 김성태, 박종기, "PRO/II with PROVISION을 이용한 화학공정의 모사", 도서출판 아진, 2004.
  4. Soave, G., "Equilibrium Constants from a Modified Redlich-Kwong Equation of State", Chem. Eng. Sci., vol. 35, pp. 1197-1203, 1972.