gas 12 is cooled against a working fluid to form cooled fluid 32 cooled fluid 32 which can be condensed liquid or just cooled gas is then reintroduced to liquid storage tank 10 effectively providing refrigeration to liquid storage tank 10 in the embodiment shown the working fluid is nitrogen liquid nitrogen storage tank 20 contains liquid nitrogen which is fed to a cold end of heat exchanger 30 via line 22 the liquid nitrogen absorbs heat from boil off gas 12 vaporizes and is then vented 34 to the atmosphere valve 24 can be used to help control the flow rate of the liquid nitrogen additional embodiments can include monitoring of certain conditions for example the following conditions can all be monitored outside temperature temperature within the liquid storage tank pressure within the liquid storage tank liquid level within the liquid storage tank and or heat absorption by the liquid storage tank additionally each of these conditions can then be used to control the flow rates of the boil off gas and or liquid nitrogen fed to the heat exchanger in one embodiment the flow rates can be varied in order to ensure that the amount of refrigeration introduced back to the liquid storage tank exceed the steady state heat gain by the liquid storage tank due to external forces e g ambient air temperatures loading unloading of vessel in an additional embodiment the method can also include adjusting the storage and or operating pressure.