ADSORPTION OF NITROGEN, CARBON-MONOXIDE, CARBON-DIOXIDE AND NITRIC-OXIDE ON MOLECULAR-SIEVES

Adsorption of N-2, CO, CO2 and NO has been studied on various molecula r sieves using the gas chromatographic method to determine the potenti al for separation of these common atmospheric contaminants from air. T he molecular sieves studied include H-Mordenite, 4A and 5A zeolite, a natural clinoptilolite and an activated carbon. Henry's law constants have been determined over a variety of temperature ranges from 243 to 473 K. Van't Hoff plots are presented for CO on all materials and for NO on all but 4A zeolite. Adsorption of CO2 on the clinoptilolite was too strong to produce an interpretable response peak. Results of CO ad sorption on 4A and 5A zeolites have been compared to and are supported by data available in the literature. Heats of adsorption for CO, NO a nd N-2 were determined. For CO the heats of adsorption decrease in the order of clinoptilolite > 5A zeolite > 4A zeolite > H-Mordenite > act ivated carbon. For adsorption of NO the heats of adsorption decrease i n the order of clinoptilolite > 5A zeolite > activated carbon. Separat ion factors are presented for the CO/N-2 and NO/N-2 systems. The natur al clinoptilolite shows most promise for the separation of CO and NO f rom N-2 at the temperature range 273-398 K. Diffusion coefficients for CO and N-2 on clinoptilolite between 348 and 423 K were also determin ed. Micropore diffusion proved to be the dominant mass transfer mechan ism for both CO and N-2 in clinoptilolite under the conditions examine d.