Ethane Goes To Sea
By Jack Burke19 May 2017
MAN Diesel & Turbo said the world’s first ME-GIE (-Gas Injection Ethane) two-stroke engine has successfully passed gas trials on board the Gaschem Beluga, a liquefied ethylene gas (LEG) carrier, while sailing between Houston and the Bahamas.
The Mitsui-MAN B&W 7G50ME-C9.5-GIE unit is the first in a series of two engines acting as main propulsion for two such LEG carriers of 36 000 m3 ordered by Hartmann Reederei of Germany and Ocean Yield of Norway, and constructed at Sinopacific Offshore Engineering (SOE) in China.
MAN Diesel & Turbo personnel monitored proceedings aboard the vessel and reported successful operation on ethane with the ME-GIE responding as expected to different loads. No gas leaks were observed while ethane levels in the double-walled piping were constant and comfortably under the gas’s LEL (Lower Explosive Limit).
The Gaschem Beluga subsequently crossed the Atlantic on its way to Europe, powered solely by ethane, and has already achieved a total of 550 operational hours.
“Developing and finalizing this type of vessel was hard work for the whole team and the process took several years. Therefore, we already knew that GasChem Beluga is a very good ship with a pioneering technology,” said Capt. Ulrich Adami, fleet manager of Hartmann Reederei. “But there is always a difference between a plan and its successful implementation. We are proud that we achieved the expected results entirely.”
René Sejer Laursen – Sales & Promotion manager, MAN Diesel & Turbo – said: “The reports from the ME-GIE trials and first operational experiences are very encouraging and confirm our faith in this groundbreaking technology. While the engine is primarily designed for the combustion of ethane gas, our research shows that it is also possible to operate the engine on other gas types. This development is particularly exciting as it opens the prospect for multi-fuel combustion, including the combustion of methane, waste gas, and volatile organic compounds (VOCs).”
Indeed, MAN Diesel & Turbo said its research recently confirmed that ME-GIE operation on VOCs is feasible, making it an eminently suitable main driver within the shuttle tanker and VLCC segments.
The Gaschem Beluga is equipped with a propulsion package supplied by MAN Diesel & Turbo, Frederikshavn (Denmark). It includes a remote control system AT3000, a VBS 1350 – ODS Mk5 CP Propeller, and a shaft generator with frequency converter that enables it to run on variable speed between 80 to 100rpm.
MAN Diesel & Turbo currently has eight ME-GIE engines on order.
The company said the benefits of the ME-GIE’s diesel-type combustion can now be fully exploited by its ability to operate on almost any gas quality – without any reduction in efficiency – and through a complete combustion maintained by a relatively high gas-injection pressure.
The engine will be able to run on a mixture of LPG and methane, or ethane, with an unchanged gas-mode efficiency. Such a mixture may comprise as much as 50% LPG, while MAN Diesel & Turbo’s findings thus far indicate that an even greater LPG percentage can be used.
MAN Diesel & Turbo sees significant opportunities in the development of the ME-GIE as the engine can also run on almost any form of waste gas. Such gases could be the light hydrocarbons or VOCs emitted from crude oil during storage and during the loading/unloading of crude oil. This opens the door for new applications for the engine in, for example, shuttle tankers, for power generation in remote power plants, or in off-shore applications – such as floating production storage and offloading vessels (FPSOs) – where VOC is abundant and poses a potential environmental hazard.