Oil & Gas: LNG solutions: safe and sound

Japan has always been at the vanguard of the LNG industry. Taking first LNG delivery as far back as 1969 it has been one of the pioneers of the modern LNG age. Today it imports more LNG than any other country and its coast lines are dotted with LNG receiving terminals providing clean natural gas supplies for a country which lacks sufficient own natural gas resources. One project that demonstrates how Siemens Energy can help Japan feeding its hunger for clean natural gas is a floating LNG storage and regasification terminal in Italy. Such terminals require sturdy rotating equipment and a reliable and efficient solution for boil-off gas compression.

OLT Offshore LNG Toscana S.p.A. (OLT) is the company that developed and now owns and manages the “FSRU Toscana” floating regasification terminal. The mission of OLT is to provide LNG regasification service to support the Italian natural gas grid in times of peak demand. Some 300 meters long and almost 50 meters wide, the terminal is anchored about 20 kilometers off the coast of Livorno, Italy, and connected to the mainland via a pipeline.

Large volumes of boil-off gas are generated while storing the cargo from delivering ships as well as during the regasification process. A Siemens Energy LNG solution based on a boil-off compressor helps keep these transfers safe, reliable and enables the boil-off gas to be sent ashore instead of vented or burned. This lowers the facility’s environmental impact and increases efficiency while ensuring reliable gas supply for the Italian mainland. “The boil-off gas compressor is a core part of our terminal, making it possible for an offshore terminal to perform as well as a traditional onshore terminal during offloading operations,” says Giovanni Giorgi, Operation & Maintenance Manager of the FSRU Toscana.

Siemens Energy ensures efficient, reliable and safe LNG plant operation with a broad range of technologies, including electrification, compression and process automation. Fully packaged functional modules are available to help meet the space and weight requirements for offshore service and support project economics in challenging onshore construction environments.

Overall, the production of LNG is an energy-intensive process. In the coming years, enhancing LNG production by improving efficiency, reducing energy consumption and minimizing emissions will play a crucial role in enhancing the attractiveness of LNG as a fuel source throughout the world. The liquefaction process typically accounts for anywhere from 30 to 40% of the total cost to deliver LNG to market. The selection of the driver type and configuration has proven to have a significant impact on overall performance, efficiency and profitability of LNG plants. In general, there are four different driver options that can be used for LNG liquefaction: steam turbines, heavy-duty industrial gas turbines, aeroderivative gas turbines, or electric motors.

Speaking at the 2016 World Energy Congress (WEC) in Istanbul, Patrice Bardon, Vice President of LNG Client Service at Siemens’ Dresser-Rand business, presented his paper on “Optimizing LNG Liquefaction Operations Through Proper Refrigeration Compressor Driver Selection”, explaining how equipment configurations can be used to drive main refrigeration compressors for liquefaction processes, and discussing the relative benefits of each. The paper has been selected as one of the best LNG-related papers submitted to the 23rd WEC.

Focusing on the power consumption of the main refrigeration island, it compares several configurations and their relative financial return. This topic is of key importance to the future LNG projects in Japan. As Bardon states, “Future LNG plants in Japan will need to assess the utility of modern light industrial gas turbines and aero derivative gas turbines for these applications.” After all, such drive systems will serve to support efforts in Japan feeding the countries’ hunger for clean natural gas.

March 03, 2017

Picture credits: Siemens