CoTE Focus: LNG and gas carrier ship technology

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A significant innovation at the Gastech exhibition is a series of free-to-attend theatres dedicated to delivering knowledge, education and awareness of technological innovations in natural gas. 

At the next Gastech in South Korea in March, these Centres of Technical Excellence (CoTEs) will feature over 60 seminars at which industry leaders will showcase their latest developments. In advance of these seminars, Gastech News has asked them for their views on key industry trends. 

Here, we examine their replies on the theme of LNG and gas carrier ship technology, focusing on floating liquefaction and regasification and trends in gas carrier propulsion systems.

From both technology and commercial perspectives these are exciting times for the LNG and LPG shipping industries. And one of the most exciting developments is the growing trend for liquefaction of natural gas and regasification of LNG to be carried out offshore.  Offshore regas has become well established, with the number of projects set to grow significantly over coming years. What we are seeing now is the construction of the first three floating production, storage and offloading (FPSO) LNG vessels, which when they begin operation will mark the birth of an industry that has been decades in

Attitudes to the range of applicability of floating LNG (FLNG) have shifted over the past couple of years, with near-shore projects looking increasing attractive as an alternative to onshore liquefaction plants.

Of the three projects now being constructed in Korean and Chinese shipyards, two – the Shell-led Prelude project and the Petronas FLNG 1 project – are targeted at monetising remote fields hundreds of kilometres offshore. The third, however, for Pacific Rubiales in Colombia, will be moored near-shore to liquefy onshore gas. Moreover, several other near-shore projects are in development, especially in the United States. This raises the question of which is likely to be the most popular of these two options over the long run.

The consensus of three exports we contacted was neatly summarised by Luis Benito, responsible for global strategic marketing at Lloyd’s Register: “The location of FLNGs will depend on the combination of investment rationale, contract requirements and operating conditions/geography. Technology options, regulatory requirements as well as the commercial contracts in place will all affect decision-making . . . Therefore, every FLNG project needs to be considered as a one-off investment decision where multiple factors are at play, no matter the FLNG’s proximity to shore.”

The view of  David Colson, Commercial Vice-President at GTT, is that: “Each project is different and has specific requirements. It is likely that the large-scale platforms will find further applications – Shell has already indicated this and Petronas has already one on order and another nearly at FID.”

Meanwhile, Bill Howe, CEO of Gasconsult LNG, agrees that “this is a project and location specific issue” and adds that: “For projects monetising smaller remote gas reserves we see that simpler lower-cost technology is required for FLNG. Our internal studies indicate that using our ZR-LNG technology this is commercially viable for fields up to 2 Tcf with production capacities of 2 mtpa.”

Ship-to-ship transfer: The increasing popularity of Floating Storage and Regasification Units (FSRUs) and the expected growth in LNG FPSO vessels has led to the development of several technologies for ship-to-ship (STS) LNG transfer, which has become an increasingly common practice. It was at one time a controversial practice from a safety perspective but the industry appears to be much more accepting today.

“At Lloyd's Register we worked in the birth of the first STS gas transfer procedure back in 2006,” says Benito. “A large number of STS transfers of gas have been performed since, where our approved procedure have been applied, so far safely. We are comfortable with the way we address the safety of gas STS and continue to work with many different terminals and operators around the world, since each STS arrangement and operation may be different from others already established.”

Colson’s view is that: “The safety of LNG transfers at sea must be maintained. This said, the current application of STS is successful and has been proven. The Society of International Gas Tanker and Terminal Operators (SIGTTO)  has clear guidelines for the transfer of liquid gases at sea.”

LNG carrier propulsion systems: Another major area of innovation is in the propulsion systems used for LNG carriers, made particularly topical by the announcement that Qatar’s LNG companies are planning to convert some of their huge fleet to use LNG as fuel.

Traditionally, LNG carriers were equipped with steam turbine-driven propulsion plants. However, over the past decade, other types of propulsion systems have been considered, using various configurations of diesel engines, electric drives and gas turbines. So which is likely to be the most popular system in the future?

Colson was unequivocal: “Efficiencies and fuel optimisation are the future. Dual-fuel or tri-fuel diesel electric is now the dominant system, replacing the less efficient steam plants – except for the Japanese wish to maintain this type of system. Future improvements in efficiency may be obtained with the ME-GI system or the new Wärtsilä competing design.”

Benito’s view is that: “Operating costs drive decisions. With an increase in the price of conventional heavy fuel oils, new regulations governing emissions from ships, and changing perceptions about future pricing, we are seeing a change in views on the best engines for gas ships.

“New engineering solutions have been developed creating engines which are increasing ship’s efficiency compared with steam-plant propulsion solutions and the industry is developing several alternative energy-saving devices which will optimised the handling of the boil-off gas (BOG).

“Nakilat [Qatar’s LNG shipping company] has just announced it is retrofitting LNG carriers with gas-capable diesel engines. This is likely to become an increasingly attractive solution for new-builds, based on prevailing sentiment.”

See you in Seoul! All our experts agreed on the importance of Gastech, both the conference and the exhibition. “The exhibition includes all the relevant big names in the world of gas and is an excellent chance to connect with key people attending throughout the week,” says Benito. “The conference sessions present the opportunity to pinpoint where the thought leadership is and how to capitalise from it for our own business.

“We will launch fresh issues of our Gas Technology Report at Gastech and will present some fresh studies related to gas as fuel.”

Related Events:

Luis Benito is a presenter at the following sessions at the CoTES programme 2014 at Gastech, Korea.

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