Real-scale investigation of liquid CO2 discharge from the emergency release coupler of a marine loading arm

•Marine loading and unloading operations in large-scale CO2 shipping can be de-risked through emergency release systems.•This work investigated the real-scale discharge behaviour of liquefied CO2 from the emergency release coupler during an emergency shutdown.•A boiling liquid expanding vapour behaviour takes place over 0.4 - 0.6 s with variations related to initial pressure and temperature conditions.•Solid CO2 residuals having a temperature of approximately 190 K are observed on the vessel surfaces at the end of the tests.•Findings from these real-scale tests can be used in support of design and operation of emergency release systems for liquefied CO2 loading arms.