Mid-scale is scaling out A new class of LNG production plants

Natural gas accounts for approximately 30 percent of the world’s energy consumption, and this figure is set to rise over the coming years. Natural gas is used for the production of electricity and to process heat. It heats public buildings and private homes. It fuels cars, busses, trucks – and even ships. During incineration, neither fine dust nor nitrogen oxide is emitted. And in form of liquefied natural gas (LNG) it can be stored in huge tanks and transported for long distances at relatively low cost using carrier ships. The global liquefaction capacity has more than tripled over the last 25 years.

For years, the LNG market was separated into two classifications. On the one hand are small-and mid-scale production capacities that typically produce up to 0.5 million tons per year. On the other hand, world-scale plants have liquefaction capacities between 3.5 and 7.8 million tons per year. But recently, the trend has moved toward mid-scale LNG plants that produce about one to two million tons per year. These plants combine features of both plant types. They use pre-treated feed gas coming from a pipeline, but produce large quantities of LNG for export to high-value markets.

Today, such mid-class LNG plants can be constructed using the standardised machines, equipment and instruments that are used for smaller plants. Prefabricated modules can significantly reduce on-site construction efforts, especially in remote areas, or in environments where construction work is difficult or costly. This greater level of standardisation and modularisation, along with well-established equipment sizes, means that contractors can draw on a much larger pool of vendors and offer more competitive pricing. In addition, by using general agreements for long lead items and design blueprints as far as possible, the lead times from tendering to commercial production can be significantly reduced for mid-scale plants compared to world-scale projects.

For this purpose, The Linde Group’s Engineering Division and The Elliott Group have developed a highly standardised and modularised concept for the main refrigerant-cycle compression section of small- to mid-scale LNG plants and a respective cooperation agreement was signed in March 2016. The agreement enables Linde Engineering to significantly increase speed to market.

Linde engineers based the concept for a new class of mid-scale LNG production plants on its StarLNG technology, which was developed for small-scale plants. It is assumed that such plants will become increasingly attractive for the international LNG market, combining the strengths of both mid-scale and world-scale plant types and markets. For customers, there are significant advantages: The concept reduces the processing effort for already pre-treated feed gas and offers benefits through economy of scale compared to small-scale LNG plants. Additionally, it makes use of established sizes without pushing technical limitations and reduces construction costs by applying a fully modularised concept that can be realised in a competitive environment. Furthermore, it significantly reduces overall project  risk and complexity compared to world-scale LNG projects (shorter time to market and reduced complexity of financing). Finally, the concept enables new players, besides big oil and gas majors, to enter the LNG export market.