Separation of CO2 in a Solid Waste Management Incineration Facility Using Activated Carbon Derived from Pine Sawdust

Resumen

The selective separation of CO₂ from gas mixtures representative of flue gas generated in waste incineration systems is studied on two activated carbons obtained from pine sawdust and compared to a commercial activated carbon. Dynamic adsorption experiments were conducted in a fixed-bed adsorption column using a binary mixture (N₂/CO₂) with a composition representative of incineration streams at temperatures from 30 to 70 °C. The adsorption behavior of humid mixtures (N₂/CO₂/H₂O) was also evaluated in order to assess the influence of water vapor in CO₂ adsorption at different relative humidity in the feed gas: 22% and 60%. Moreover, CO₂ adsorption was studied in less favorable conditions, i.e., departing from a bed initially saturated with H₂O. In addition, the effect of CO₂ on H₂O adsorption was examined. Experimental results showed that the CO₂ adsorption capacity can be reduced significantly by the adsorption of H₂O (up to 60% at high relative humidity conditions). On the other hand, the breakthrough tests over the adsorbent initially saturated with water vapor indicated that H₂O is little affected by CO₂ adsorption. The experimental results pointed out the biomass based carbons as best candidates for CO₂ separation under incineration flue gas conditions.