what is the minimum temperature of VCM (vinyl chloride monomer) for the carriage on board a semi-refrigerated LPG vessel?
02 Aug '20, 14:32
The boiling point of VCM is −13.4 °C which is the maximum temperature for carrying the VCM in the liquid state. The minimum temperature is limited by the reliquefaction plant design (normally -48 °C) and cargo tank material.
Taking into account the low vapor pressure of VCM at 20 °C (3.44 Bar) and energy efficiency requirements, this product does not need deep cooling for safe transportation. The limiting factor here is the maximum working pressure of the cargo tanks (4 - 8 bar for semi-refrigerated vessels). Higher transportation temperatures lead to higher pressure inside the tank. Exceeding maximum allowed transportation pressure leads to losing cargo through pressure relief valves and danger of cargo tanks damage.
09 Aug '20, 12:56