Experimental study on enrichment of low level NO by means of adsorption

For reducing environmental discharge of NOx below 1 ppm, the authors propos e a minimum NOx emission system comprised of an absorption process that can concentrate low level NOx coupled with a de-NOx process. Adsorption of NO, especially in the range 0.5-20 ppm, for various adsorbents are studied wit h adsorption at ambient temperature and with desorption at 353 K. Phenol re sin based active carbon is found to have excellent adsorption characteristi cs and can achieve almost zero emission of NO. It can reach a maximum adsor ptivity of 2.5 x 10(-3) m(-3) . kg under the presence of O-2 for the initia l gas concentration of 15 ppm NO. When desorbed at 353 K, NO concentration in the desorbed gas is about five times higher than that of the initial gas . It is concluded that the temperature swing adsorption process is quite ap propriate for enrichment of low level NO. Although CO2 has no adverse effec t on the adsorption characteristics, water vapor exerts considerable delete rious effect. Thus it is required to remove water vapor before processing.