Natural gas (NG) and liquefied NG (LNG), which is one trade type of NG, have attracted great attention because their use may alleviate rising concerns about environmental pollution produced by classical fossil fuels and nuclear power plants. However, when gas reserves are located in stranded areas and a portion of the offshore reserves is a significant amount of the total gas reserves, LNG is not suitable because (i) installation of pipelines for the transfer of NG to onshore LNG facilities is expensive and difficult, and (ii) it still has environmental and security problems._x000D_ As a result, there are many efforts to excavate and monetize these stranded and offshore reserves with floating facilities where offshore liquefaction of NG is possible. Therefore, the development of floating LNG (FLNG) technology is becoming important. Although the FLNG technologies have advantages over conventional LNG technologies, there are still several roadblocks. To overcome the challenges, modular designs related to the main and typical stages of the FLNG process . gas pretreatment, liquefaction and regasification topsides, hulls, mooring, and transfer systems should be enhanced. Regarding FLNG ongoing operations and future plans, there are six nations (Argentina, Brazil, Kuwait, UAE, UK, and USA) operating FLNG, and a variety of FLNG liquefaction projects will be finished soon. Shell and Petrobras are making rapid strides to build FLNG facilities, and Flex LNG, Hoegh LNG, SBM Linde, MODEC, and Saipem are_x000D_ also building their FLNGs. In this review paper, we initially review the LNG concept and compare it with FLNG. In turn, new and typical FLNG technologies are introduced and the main challenges are also explained with insight into how these challenges are overcome. The main market drivers for FLNG industry are also considered.

Liquefied Natural Gas Floating Liquefied Natural Gas Liquefaction Process Hull and Mooring Process Offloading Process

World Energy Outlook 2010, International Energy Agency (2010)
Lim W, Choi K, Moon I, Ind. Eng. Chem. Res., 52(9), 3065 (2013)
Kumar S, Kwon HT, Choi KH, Cho JH, Lim W, Moon I, Energy Policy, 39(7), 4097 (2011)
Global FLNG market outlook with a touch of FPSO 2011-2017, Douglas-Westwood (2011)
The world FLNG Market Report 2010-2016, Douglas-Westwood (2009)
The world FLNG Market Report 2011-2015, Douglas-Westwood (2011)
Bukowski J, Liu YN, Boccella S, Kowalski L, Proceedings of the International Gas Union Research Conference 2011, Seoul, Korea (2011)
Newton S, Proceedings of the Floating LNG 2011, Perth, Australia (2011)
World LNG Report - 2013 Edition, International Gas Union (2013)
Global LNG - Will new demand and new supply mean new pricing, Ernst & Young (2013)
Mollard F, Proceedings of the 17th International Conference and Exhibition on Liquefied Natural Gas (LNG 17), Houston, USA (2013)
Finn AJ, Johnson GL, Tomlinson TR, Hydrocarb. Process., 78(4), 47 (1999)
Kirillov NG, Chem. Pet. Eng., 40, 401 (2004)
Greer SA, International Bar Association Annual Conference, Chicago, USA (2006)
Kerbers I, Hartnell G, 24th World Gas Conference, Buenos Aires, Argentina (2009)
Pettersen J, Nilsen O, Vist S, Giljahus LEN, Fredheim AO, Aasekjaer K, Neeraas BO, Proceedings of the 17th International Conference and Exhibition on Liquefied Natural Gas (LNG 17), Houston, USA (2013). (2013)
Pek B, Van der velde H, Proceedings of the 17th International Conference and Exhibition on Liquefied Natural Gas (LNG 17), Houston, USA (2013)
Kumar S, Kwon HT, Choi KH, Lim W, Cho JH, Tak K, Moon I, Appl. Energy, 88(12), 4264 (2011)
Jamieson D, Johnson P, Redding P, Proceedings of the 12th International Conference and Exhibition on Liquefied Natural Gas (LNG 12), Perth, Australia (1998)
Pwaga SS, Dissertation MS, Norwegian University of Science and Technology, Norway (2011)
Emmitt P, Songhurst B, Proceedings of the Global Forum on Flaring and Venting Reduction and Natural Gas Utilization, Amsterdam, Netherlands (2008)
Roberts MJ, Agrawal R, Daugherty TL, US Patent, 6,347,531 (1999)
Kahn MS, Lee M, Energy, 49, 146 (2013)
Singh A, Hovd M, Proceedings of the 2006 AIChE Annual Meeting, San Francisco, USA (2006)
Bosma P, Nagelvoort RK, Proceedings of the 1st Annual Gas Processing Symposium, Doha, Qatar (2009)
Majzoub M, Dissertation MS, Norwegian University of Science and Technology, Norway (2012)
Jensen JB, Skogestad S, Comput. Aided Chem. Eng., 21, 1569 (2006)
Hwang JH, Roh MI, Lee KY, Comput. Chem. Eng., 49, 25 (2013)
Roberts MJ, Agrawal R, US Patent, 6,269,655 (2001)
Venkatarathnam G, Timmerhaus KD, Cryogenic Mixed Refrigerant Processes, Springer, New York (2008)
Almasi A, Aust. J. Mech. Eng., 10, 195 (2012)
Wang K, Zhang X, Zhang ZQ, Xu W, Acta Mech. Sin., 28, 870 (2012)
Howard JL, Andersen PG, Kvamsdal R, Offshore Technology Conference, Houston, USA (1979)
Tang X, Chen X, Dong Y, Wei X, Yang Q, Appl. Mech. Mater., 291, 843 (2013)
http://en.wikipedia.org/wiki/Floating_production_storage_and_offloading.
http://www.tge-marine.com/files/tge_marine_lng_fpso-fsru_presentation_flng_02_2008_rev1_internet.pdf.
Wilkerson SM, Nagarajaiah S, J. Offshore Mech. Arct. Eng.,131, 021603-1 (2009)
Jain RK, Appl. Ocean Res., 17, 1 (1980)
Morishita HM, De Souza JR, Proceedings of the International Offshore and Polar Engineering Conference, Kitakyushu, Japan (2002)
Guedes SC, Fonseca N, Pascoal R, Proceedings of the International Offshore and Polar Engineering Conference, Stavanger, Norway (2001)
Sii HS, Wang J, Eleye-Daturo A, Liu J, Yang JB, Mar. Technol., 42, 88 (2002)
Huang K, Judge S, Proceedings of the Offshore Technology Conference, Houston, USA (1996)
Howell GB, Duggal AS, Heyl C, Ihonde O, Proceedings of the Leading the World in Deepwater E&P Offshore West Africa Conference & Exhibition, Abuja, Nigeria (2006)
Zhao W, Yang J, Hu Z, Xie B, Ocean Eng., 57, 150 (2013)
Sphaier SH, Fernandes AC, Correa SHS, Castro GAV, J. Offshore Mech. Arct. Eng., 124, 196 (2002)
Koo BJ, Kim MH, Appl. Ocean Res., 27, 292 (2006)
Wang Q, Sun LP, Ma S, J. Mar. Sci. Appl., 9, 200 (2010)
Koop A, Klaij C, Vaz G, Proceedings of the International Offshore and Polar Engineering Conference, Shanghai, China (2010)
Lee DH, Choi HS, J. Mar. Sci. Appl., 10, 53 (2011)
Chen HB, Moan T, Haver S, Larsen K, J. Offshore Mech. Arct. Eng., 126, 235 (2004)
Marc C, Proceedings of the 17th International Conference and Exhibition on Liquefied Natural Gas (LNG 17), Houston, USA (2013)