Patent ID: 6672104
Filing Date: 2004-01-06
Classification: F17C,F25J

Abstract:
A method of converting a boil-off stream comprising methane to a liquid having a preselected bubble point temperature, comprising the steps of:(a) pressurizing the boil-off stream; (b) cooling the pressurized boil-off stream of step (a); (c) expanding the cooled, pressurized boil-off stream of step (b), thereby producing pressurized liquid; and (d) obtaining the preselected bubble point temperature of the pressurized liquid by performing at least one of the following steps: i. before, during, or after one or more of steps (a) to (c), removing from the boil-off stream a first predetermined amount of one or more components having a vapor pressure greater than the vapor pressure of methane, and ii. before, during, or after one or more of steps (a) to (c), adding to the boil-off stream a second predetermined amount of one or more additives having a molecular weight heavier than the molecular weight of methane and having a vapor pressure less than the vapor pressure of methane, â€ƒwherein the first predetermined amount of the one or more components removed and the second predetermined amount of the one or more additives added are controlled to obtain the preselected bubble point temperature of the pressurized liquid.