Gas expansion cooling method

摘要

A gas expansion cooling method for reducing hydrocarbon emissions includes feeding a high pressure cooling gas through a valve, decreasing a temperature of the cooling gas by decreasing its pressure; feeding the cooling gas into a heat exchanger; and diverting a hydrocarbon gas into the heat exchanger such that the cooling gas decreases a temperature of the hydrocarbon gas. The cooling gas may be drawn from a preexisting high pressure gas system that serves a purpose other than supplying a coolant for the gas expansion cooling system. A portion of the hydrocarbon gas may be condensed in the heat exchanger to form a hydrocarbon liquid, which may be separated from the hydrocarbon gas in a separation vessel. The hydrocarbon liquid may be recovered, while the hydrocarbon gas may be fed to a ventilation system.

主权项

1. A gas expansion cooling method for reducing hydrocarbon emissions, comprising the steps of:
a) feeding a cooling gas through a valve, wherein the valve decreases a temperature of the cooling gas by decreasing the pressure of the cooling gas; b) feeding the cooling gas into a heat exchanger, wherein the cooling gas is drawn from a preexisting high pressure gas system, and wherein the high pressure gas system serves a purpose other than supplying a coolant to the heat exchanger; c) diverting a hydrocarbon gas into the heat exchanger such that the cooling gas decreases a temperature of the hydrocarbon gas, wherein a portion of the hydrocarbon gas is condensed by the cooling gas to form a hydrocarbon liquid; and d) returning the cooling gas from the heat exchanger into the high pressure gas system.