Method for operating gas separation device

A method for recovering a residual gas, the method comprising:

• continuously supplying a mixed gas remaining in a cylinder to a separation membrane module including a gas separation membrane having a molecular sieving action;
• separating the mixed gas into a gas component with a small molecular diameter and a gas component with a large molecular diameter;
• and then,
• recovering both the gas component with a small molecular diameter and the gas component with a large molecular diameter.

A method for recovering a residual gas, the method comprising:

• supplying a mixed gas remaining in a cylinder to a separation membrane module including a gas separation membrane having a molecular sieving action;
• separating the mixed gas into a gas component with a small molecular diameter and a gas component with a large molecular diameter;
• and then,
• recovering both the gas component with a small molecular diameter and the gas component with a large molecular diameter,
• wherein the separation membrane module continuously repeats an operation cycle including:
• a first process in which a gas supply port is opened to supply a mixed gas containing the gas component with a small molecular diameter and the gas component with a large molecular diameter into an airtight container, and fill the airtight container with pressure, in a state where a non-permeated gas discharge port provided so as to communicate with a space on a non-permeation side of the gas separation membranes, of the airtight container in which the gas separation membranes are housed, is closed, and a permeated gas discharge port provided so as to communicate with a space on a permeation side of the gas separation membranes is open;
• a second process in which the gas supply port is closed to stop supply of the mixed gas and retain this state, when a predetermined time has elapsed from a start of supply of the mixed gas or when an inside of the airtight container has reached a predetermined pressure;
• a third process in which the non-permeated gas discharge port is opened to recover the mixed gas containing the gas component with a large molecular diameter from the non-permeated gas discharge port, when a predetermined time has elapsed from a start of the retaining state or when the inside of the airtight container has reached a predetermined pressure;
• and
• a fourth process in which the non-permeated gas discharge port is closed when a predetermined time has elapsed from a start of the recovery or when the inside of the airtight container has reached a predetermined pressure.

A method for recovering a residual gas, the method comprising:

• supplying a mixed gas remaining in a cylinder to a separation membrane module including gas separation membranes having a molecular sieving action;
• separating the mixed gas into a gas component with a small molecular diameter and a gas component with a large molecular diameter;
• and then,
• recovering both the gas component with a small molecular diameter and the gas component with a large molecular diameter,
• wherein the two or more separation membrane modules are connected in parallel,
• wherein one separation membrane module continuously repeats an operation cycle including:
• a first process in which a gas supply port is opened to supply a mixed gas containing the gas component with a small molecular diameter and the gas component with a large molecular diameter into an airtight container, and fill the airtight container with pressure, in a state where a non-permeated gas discharge port provided so as to communicate with a space on a non-permeation side of the gas separation membranes, of the airtight container in which the gas separation membranes are housed, is closed, and a permeated gas discharge port provided so as to communicate with a space on a permeation side of the gas separation membranes is open;
• a second process in which the gas supply port is closed to stop supply of the mixed gas and retain this state, when a predetermined time has elapsed from a start of supply of the mixed gas or when an inside of the airtight container has reached a predetermined pressure;
• a third process in which the non-permeated gas discharge port is opened to recover the mixed gas containing the gas component with a large molecular diameter from the non-permeated gas discharge port, when a predetermined time has elapsed from a start of the retaining state or when the inside of the airtight container has reached a predetermined pressure;
• and
• a fourth process in which the non-permeated gas discharge port is closed when a predetermined time has elapsed from a start of the recovery or when the inside of the airtight container has reached a predetermined pressure, and
• wherein the other separation membrane module is operated in an operation cycle shifted by a predetermined interval with respect to the operation cycle of this one separation membrane module.