METHOD OF PRODUCING NITROGEN-DEPLETED GAS, METHOD OF PRODUCING NITROGEN-ENRICHED GAS, METHOD OF NITROGEN SEPARATION, AND SYSTEM OF NITROGEN SEPARATION

摘要

A nitrogen separation system includes a pressurizing apparatus, a temperature regulation apparatus, a nitrogen separation apparatus. The pressurizing apparatus is configured to pressurize a raw material gas to configure a pressurized raw material gas which is in a vapor-liquid equilibrium state with a liquefied gas and contains methane as a principal component and greater than or equal to 1 mol % nitrogen. The nitrogen separation apparatus is configured to separate nitrogen contained in the pressurized raw material gas by use of a nitrogen selective permeation membrane configured from an inorganic material. The pressurization apparatus pressurizes the raw material gas so that a partial pressure of nitrogen in the pressurized raw material gas is greater than or equal to 2 times and less than or equal to 5 times a pressure of the nitrogen-enriched gas.

主权项

1. A method of producing a nitrogen-depleted gas, the method comprising the steps of:
pressurizing a raw material gas to configure a pressurized raw material gas, the raw material gas being in a vapor-liquid equilibrium state with a liquefied gas, the raw material gas containing methane as a principal component and greater than or equal to 1 mol % nitrogen; regulating a temperature so that a temperature of the pressurized raw material gas is regulated to be higher than a temperature of the raw material gas; and separating nitrogen contained in the pressurized raw material gas by use of a nitrogen selective permeation membrane configured from an inorganic material to produce a nitrogen-depleted gas and a nitrogen-enriched gas from the pressurized raw material gas; wherein in the pressurization step, the raw material gas is pressurized so that a partial pressure of nitrogen in the pressurized raw material gas is greater than or equal to 2 times and less than or equal to 5 times a pressure of the nitrogen-enriched gas.