LNG Transfer: Strengthening the Chain Of Custody With Integrated Monitoring

By Richard Hepworth, President of Trelleborg’s marine and infrastructure operation

Last year, we saw the LNG shipping sector hit new heights. LNG carrier orders were strong; in February 2019, according to Cleaves Securities, the LNG orderbook stood at a record high, with ship owners planning to order as many as 69 LNGCs, up from 65 in 2018 and only 17 in 2017.

As the orderbook grows, so too does the range of technologies available to ship owners and operators to increase efficiency. Many of these newer ships will be equipped with smart ship technologies and lighter containment systems that will help reduce fuel consumption, increase capacity and lower transportation costs to keep LNG competitively priced.

And as the LNG market continues to grow, a wider range of business opportunities are presenting themselves. Since Trelleborg first introduced the Cryoline solution for LNG transfer, we’ve advocated that the LNG sector requires fresh thinking to thrive. It has allowed operators to rethink some of the CAPEX and OPEX issues around the costs of delivering jetties to help handle LNG cargoes.These developments demonstrate exactly the kind of value that innovation in this sector can bring, and how necessary they are in realizing the potential of LNG as an affordable, cleaner alternative power source to traditional fuels.

It’s vital that this innovation does not stop at the vessel. As the bar is being constantly raised onboard the ship, it is imperative that transfer solutions preserve these benefits, by ensuring that cargo loss to boil-off is minimized during cargo transfer or bunkering.

To maximize the effectiveness of the flexible hoses that are commonly used in LNG transfer, monitoring is a crucial part of the transfer process. The design of these hoses is highly specialized. Trelleborg’s Cryoline hoses, for example, use a hose-in-hose design consisting of an inner cryogenic hose – which safely transfers the LNG or cold vapor, with benchmarking minimal pressure drop – and an outer hose designed to provide protection from the external environment or mishandling as well as buoyancy when in a floating application.

It also incorporates state-of-the-art temperature measurement technology, which – when integrated to an Emergency Shutdown System (ESDS) – enhances the safety of transfers. The technology, which also acts as an integrated monitoring system, is based on cutting-edge optical fibre technology, which allows detection of even the slightest leak that may occur in ‘real-time’ in the hose structure. If a leak occurs, the cryogenic fluid or vapor enters the annular space between the inner and outer hose. This leads to a local temperature drop, instantly detected and positioned by the Distributed Thermal Sensing (DTS) system. This then triggers an alarm on the user interface, which permits the operator to manage and control the LNG transfer operation, enhancing hose management and maintenance planning. The residual leak gas is guided to the end of the transfer line where it is re-routed or burned off – avoiding any loss to the atmosphere.

Temperature and monitoring for potential containment failure is, however, essential to maximize the benefit of this design. Trelleborg’s market-leading Ship-shore Link (SSL) technology can provide the interface for this monitoring system within the vessel’s ESDS, thanks to a number of our installations, which are providing access to the systems onboard the world’s LNGC fleet.

It’s vital that, while the physical hardware we use to handle and transport LNG is as effective as it can be, the informational layer is used to full effect; that we can use information quickly and intelligently, and ensure that data is not lost as different technology providers collaborate. At every stage of the cargo’s journey, from aerospace-inspired holding tanks to cutting-edge monitoring, the pace of innovation is inextricably linked to the speed of LNG’s growth around the world.

In 2018, our operation partnered with Synertec to further enhance LNG transfer across the globe. With the formation of the strategic partnership, we are meeting the global demand for more accurate and efficient LNG custody transfer. With more LNG capacity coming on stream year on year, we are also seeing increasing demand not just for large-scale transportation of cargoes, but also for more FSRU applications. All of these applications have the same key requirements in common – the safe, efficient and timely transfer of LNG from one tank system to another.

Last year, Trelleborg acquired KLAW LNG, a leader in ship-to-ship transfer technology as part of the wider acquisition of Signum Technology. This complements and extends our product portfolio, strengthening Trelleborg as a system provider to the fast-growing LNG transfer market segment.