Apparatus and system for generating nitrogen gas through dehumidifying and filtering fuel cell exhaust gas

A nitrogen gas generation apparatus comprising:

• a fuel cell configured to operate by taking in air or a gas containing nitrogen and oxygen, and a fuel gas;
• a dehumidification mechanism configured to reduce moisture or water vapor content in an exhaust gas that is extracted from the fuel cell and has a lower oxygen concentration than air;
• a filtering mechanism including a filter using fibers having different degrees of permeation for nitrogen and oxygen and configured to convert the exhaust gas having a reduced moisture or water vapor content into a gas having an increased nitrogen concentration;
• and a gas return flow path in which a filter exhaust gas, which is a gas containing a gas that has permeated the fibers and is a gas different from the nitrogen-enriched gas having an increased nitrogen concentration, is extracted from the filter to which the exhaust gas is applied, and the extracted filter exhaust gas is added to the air or the gas containing nitrogen and oxygen to be supplied to the fuel cell and is used in the fuel cell, and/or is added to the exhaust gas to be supplied to the filtering mechanism and is used in the filtering mechanism.

A nitrogen gas generation system comprising:

• a fuel cell configured to operate by taking in air or a gas containing nitrogen and oxygen, and a fuel gas;
• a gas compressor configured to increase a pressure of the air or the gas containing nitrogen and oxygen, which is applied to the fuel cell;
• a dehumidification mechanism configured to reduce a moisture or water vapor content in an exhaust gas that is extracted from the fuel cell and has a lower oxygen concentration than air;
• a filtering mechanism including a filter using fibers having different degrees of permeation for nitrogen and oxygen and configured to convert the exhaust gas having a reduced moisture or water vapor content into a nitrogen-enriched gas having an increased nitrogen concentration;
• a pressure controller configured to control pressures in a high-pressure combination including a series of the fuel cell, the dehumidification mechanism and the filtering mechanism;
• and
• a total control unit configured to:
• cause the pressure controller to set a pressure of the exhaust gas having a reduced moisture or water vapor content, which is applied to the filtering mechanism, to a value exceeding a filter pressure threshold determined depending on a flow rate and an oxygen concentration of the nitrogen-enriched gas extracted from the filter;
• and
• cause the pressure controller to set a pressure of the air or the gas containing nitrogen and oxygen, which is applied to the fuel cell, to a pressure value determined in conjunction with the value exceeding the pressure threshold,
• wherein the system thus enables to supply the nitrogen-enriched gas having a desired or required low oxygen concentration from the high-pressure combination.