Process for concentrating CO2 from air and dilute CO2 streams using MOF based physisorbents

A method for continuous capturing of CO2 from a gas stream containing approximately 400 ppm to 6% of CO2 using multiple metal organic framework (MOF) based physisorbent CO2 concentrators, comprising:

• pretreating a MOF material under airflow or vacuum, wherein the MOF material is KAUST-7;
• introducing a gas stream into a first CO2 concentrator which comprises the pretreated MOF material;
• capturing, with the first CO2 concentrator, CO2 from the gas stream to generate a CO2-free stream in the first CO2 concentrator;
• discharging the CO2-free stream from the first CO2 concentrator into the atmosphere;
• substituting a second CO2 concentrator comprising pretreated MOF material for the first CO2 concentrator when the pretreated MOF material of the first CO2 concentrator becomes saturated with CO2;
• regenerating the first CO2 concentrator from the saturated MOF material by introducing hot air, hot nitrogen, or a combination thereof, thereby generating a CO2-rich stream, wherein the stream of the hot air or the hot nitrogen or the combination thereof is introduced to the CO2 concentrator at a temperature of approximately 80-150° C., and wherein the hot air, the hot nitrogen, or the combination thereof exit the CO2 concentrator as a part of the CO2-rich gas stream;
• mixing the generated CO2-rich gas stream with a stream of industrial exhaust with similar CO2 concentrations for subsequent purification;
• and
• recycling the regenerated first CO2 concentrator for future capture of CO2.