Production of ultrahigh purity nitrogen

A temperature swing adsorption process for removing carbon monoxide from an air stream which contains carbon monoxide as an impurity comprising the step of passing said air stream through a bed of carbon monoxide-selective adsorbent at a temperature between the dew point of air at the pressure in said bed and about 150.degree. K., thereby producing a substantially carbon monoxide-free air stream.

A temperature swing adsorption process for producing a nitrogen product stream containing not more than 0.5 ppm carbon monoxide from air containing up to about 100 ppm of carbon monoxide as an impurity comprising the steps of:

• (a) cryogenically distilling said air, thereby producing a nitrogen-enriched gaseous stream containing said carbon monoxide;
• (b) adsorbing carbon monoxide from said nitrogen-enriched gaseous stream by passing said nitrogen-enriched gaseous stream through a bed of carbon monoxide-selective adsorbent at a temperature in the range of about 77.degree. to 150.degree. K.

A temperature swing adsorption process for producing a nitrogen product stream containing not more than 0.5 ppm carbon monoxide from an air stream containing up to about 100 ppm of carbon monoxide as an impurity comprising the steps of:

• (a) passing said air stream through a bed of carbon monoxide-selective adsorbent at a temperature in the range of about 90.degree. to 150.degree. K., thereby producing substantially carbon monoxide-free air;
• (b) cryogenically distilling the substantially carbon monoxide-free air, thereby producing a substantially carbon monoxide-free nitrogen-enriched stream.