A Memorandum of Understanding was signed by Shell and Swedish Alfa Laval for the creation of a new gas combustion unit (GCU) for use on liquid hydrogen carriers.
As part of a new liquid hydrogen carrier, Alfa Laval will create a mechanism to securely burn hydrogen boil-off gas (BOG) from a vessel’s storage tank.
Alfa Laval will create and engineer the new GCU for hydrogen with the intention of obtaining an IACS classification society’s approval in principle (AIP). A GCU prototype will be constructed for testing and type approval after the AIP has been reached.
The existing Alfa Laval GCU for liquefied natural gas will serve as the model for the new GCU system for hydrogen (LNG).
Internal combustion engines find hydrogen to be a desirable fuel because it burns cleanly and emits no greenhouse gases. However, in order to store hydrogen safely at such low temperatures while maintaining the structural integrity of the tanks and the entire vessel, a vessel must be compressed (to a pressure of 700 bar) or liquified (to a temperature of -253 °C). This demands significant engineering inventiveness.
In this situation, a GCU offers a way to reduce tank pressure/temperature when the BOG poses safety issues beyond the tank’s design parameters because the venting of cargo is constrained.