CO2 Adsorption and Desorption for CO2 Enrichment at Low-Concentrations Using Zeolite 13X

Abstract

Adsorption of CO2 using zeolite 13X as adsorbent has been studied extensively, but little attention has been paid to CO2 adsorption at very low concentrations such as in the ambient air. Furthermore, there is almost no information on CO2 desorption characteristics. In a carbon enrichment for plant stimulation system, ambient CO2 is enriched from 400 to 1000 ppm to provide an enriched CO2 stream for plant growth in greenhouses. To provide essential design data, systematic performance tests were carried out to evaluate both the adsorption and desorption capacity, enrichment factor, moisture content, and cyclic performance. It was found that the adsorption capacity and CO2 concentration in the enriched air are a function of adsorption temperature and the difference of adsorption and desorption temperatures, for a given adsorbent loading at a properly selected gas flow rate.