Liquefied natural gas (LNG) is attracting significant interest as a clean energy alternative to other fossil fuels, mainly for its ease of transport and low carbon dioxide emission. As worldwide demand for LNG consumption has increased, liquefied natural gas floating, production, storage, and offloading (LNG-FPSO) operations have been studied for offshore applications. In particular, the LNG-FPSO topside process systems are located in limited areas. Therefore, the process plant layout of the LNG-FPSO topside systems will be optimized to reduce the area cost occupied by the topside equipment, and this process plant layout will be designed as a multifloor concept. We describe an optimal layout for a generic offshore LNG liquefaction process operated by the dual mixed refrigerant (DMR) cycle. To optimize the multifloor layout for the DMR liquefaction cycle process, an optimization was performed by dividing it into first and the second cycles. A mathematical model of the multifloor layout problem based on these two cycles was formulated, and an optimal multifloor layout was determined by mixed integer linear programming. The mathematical model of the first cycle consists of 725 continuous variables, 198 equality constraints, and 1,107 inequality constraints. The mathematical model of the second cycle consists of 1,291 continuous variables, 286 equality constraints, and 2,327 inequality constraints. The minimization of the total layout cost was defined as an objective function. The proposed model was applied to DMR liquefaction cycle process to determine the optimal multifloor layout.

Process Plant Layout MILP Optimization Dual Mixed Refrigerant Cycle

Hwang JH, Roh MI, Lee KY, Comput. Chem. Eng., 49, 25 (2013)
Hwang JH, Ku NK, Roh MI, Lee KY, Ind. Eng. Chem. Res., 52(15), 5341 (2013)
Lim W, Choi K, Moon I, Ind. Eng. Chem. Res., 52(9), 3065 (2013)
Lee S, Nguyen VDL, Lee M, Ind. Eng. Chem. Res., 51(30), 10021 (2012)
Amorese L, Cena V, Mustacchi C, Chem. Eng. Sci., 32, 119 (1991)
Georgiadis MC, Rotstein GE, Macchietto S, Ind. Eng. Chem. Res., 36(11), 4852 (1997)
Georgiadis MC, Schilling G, Rotstein GE, Macchietto S, Comput. Chem. Eng., 23(7), 823 (1999)
Jayakumar S, Reklaitis GV, Comput. Chem. Eng., 14, 441 (1994)
Jayakumar S, Reklaitis GV, Comput. Chem. Eng., 20(5), 563 (1996)
Castell CML, Lakshmanan R, Skilling JM, Banares-Alcantara R, Comput. Chem. Eng., 22S, S993 (1998)
Papageorgiou LG, Rostein GE, Ind. Eng. Chem. Res., 37(9), 3631 (1998)
Penteado FD, Ciric AR, Ind. Eng. Chem. Res., 35(4), 1354 (1996)
Suzuki A, Fuchino T, Muraki M, J. Chem. Eng. Jpn., 24, 226 (1991)
Patsiatzis DI, Papageorgiou LG, Comput. Chem. Eng., 26(4-5), 575 (2002)
Patsiatzis DI, Knight G, Papageorgiou LG, Chem. Eng. Res. Des., 82(5), 579 (2004)
Park K, Koo J, Shin D, Lee CJ, Yoon ES, Korean J. Chem. Eng., 28(4), 1009 (2011)
Ozyurt DB, Realff MF, AIChE J., 45(10), 2161 (1999)
Shukri T, LNG Technology Selection, Hydrocarbon Engineering, USA (2004).
Ku NK, Hwang JH, Lee JC, Roh MI, Lee KY, Ships and Offshore Structure, 9, 311 (2014)
Hwang J, Lee KY, Comput. Chem. Eng., 63, 1 (2014)
Won W, Lee SK, Choi K, Kwon Y, Korean J. Chem. Eng., 31(5), 732 (2014)