Gas to Power
Aug. 17 2018
The future looks bright for LNG. With demand driven by environmental regulation, it is taking an ever-greater share of the world’s energy mix, expected to grow almost 2% faster than oil and coal over the next five years. China is particularly gas-hungry: in its search for cleaner energy solutions, the government aims to more than double LNG’s share of the country’s primary energy mix to 15% by 2030. And with IMO imposing a sulfur cap of 0.5% from 2020, LNG is also likely to gain further popularity as a marine fuel.
LNG infrastructure coming of age
The LNG opportunity is ripe, as many of the traditional challenges associated with exploiting LNG discoveries are gradually being removed.
New technologies have cut the costs of processing and transport, enabling operators to sell the fuel at attractive prices to customers thousands of kilometers away. Floating production units (FLNG) offer flexibility, while floating storage and regasification units (FSRUs) operating as terminals enable producers to move gas to market quickly in countries with little existing infrastructure. And large gas carriers lower the cost of transport. The rapid yet safe development of these technologies has been made possible with the support of classification societies such as Bureau Veritas.
Yet many infrastructure challenges still remain, if offshore operators are to capitalize on demand for LNG.
- The first transformation has been in size. In 1995, when the first membrane LNG carriers were built, they could carry 130,000 m3 of gas. Today, the capacity of the largest gas carriers exceeds 260,000m3. While future growth in ship size may be constrained by shipping routes (notably by the Panama Canal’s maximum beam limitations), ships plying fixed routes could get bigger. Inpex’s BV-classed vessel, built to serve the Ichthys Project in Australia, for example, is capable of carrying 182,000 m3 of cargo to its customers in Taiwan and Japan.
- The second area of innovation is in containment systems. Companies such as GTT have developed new concepts and solutions to reduce boil-off gas rates to around 0.07% per day in their latest Mark III Flex system from a historic level of 0.15%. Vessels are more efficient, sailing at slower speeds, with boil-off gas used to propel the vessel: engine manufacturers have developed new two-stroke propulsion engines that usually propel ships at an economical speed of approximately 16 knots.
- The third – closely linked – area of innovation relates to liquefaction. Charterers of ocean-going ships prefer to have a choice of fuel. They want the flexibility to re-liquefy boil-off gas and use heavy fuel oil (HFO) outside Emission Control Areas. While fuel economics are expected to change in the next five years as the global IMO cap comes into force, for the moment this flexibility remains attractive.
Bureau Veritas is supporting these innovations through its assessments for containment systems following structural and safety analysis on containment systems; and approvals of new propulsion engines and reliquefaction systems.
A typical example is Excelerate Energy’s Moheshkhali Floating LNG ordered by Bangladesh’s national oil company Petrobangla. The BV-classed FSRU, which will be positioned off the country’s southeastern coastline, is seen as an essential part of the country’s plan to meet its future energy demands.
Bureau Veritas offers dedicated classification Rules with different notations used depending on whether the unit will be able to transport LNG or not. The unit without propulsion can eventually be used to transport LNG if pushed or towed. To maintain production availability, fixed FSRUs typically carry the in-water survey notation for example, avoiding the need to return to dry dock for surveys. For units that need to move, or subject to wave action, additional mooring and sloshing class notations may be added depending on the application.
The changing face of FSRUs
FSRUs are becoming ever more versatile. Countries are interested in terminals that can also generate power – essentially transforming the FSRU into an offshore power station connected to the national power grid. Bureau Veritas has developed the POWERGEN notation, based on our experience in real projects.
One project takes the concept even further. Bureau Veritas has issued an Approval in Principle for MODEC’s floating storage, regasification, water-desalination and power-generation (FSRWP) vessel.
The new concept could provide clean energy and water faster and cheaper than current solutions and is a striking example of the flexibility of this type of unit. Where next will the industry go?
Photo credits ©Karmol, Wison, Anthony Veder, Excelerate