Preparation And Adsorption Of CO₂of Resorcinol-formaldehyde Resin-Based Spherical Activated Carbon

Xerogel spheres were synthesized by sol-gel polycondensation of resorcinol with formaldehyde in a slightly alkaline aqueous solution. Sphere structures were obtained by inverse suspension polymerization of resorcinol-formaldehyde (RF) sol in paraffin oil. And then, after carbonizing and activating the xerogel spheres, we got activated sphere carbon.During the synthetic process, we have investigated the effects of synthesis parameters including type of the catalysts, resorcinol/formaldehyde(R/F) ratio, resorcinol/catalyst (R/C) ratio, reaction temperature, reactant concentration, pre-polymerization time and the way of mixing on the particle size, distribution of beads and the structures. We found the optimal process route:tri-ethylamine as catalysts; R/F ratio=1:2; reaction temperature range from45℃to65℃; reactant concentration from40%to60%; R/C ratio range from100to500; pre-polymerization time range from0to60min according to the conditions. Xerogel spheres with a good degree of sphericity and dispersion can be obtained. The maximum particle size is about3mm and the minimum size is about476um.During the preparation of activated carbon, therm-ocuring conditions of the xerogel spheres were determined that were72hours at120℃. The effect of carbonization temperature rising rate on surface appearance was investigared and1.5℃/min was more suitable. The sphere activated carbon with steam activation exhibited a high surface area (920m2/g), large total pore volume (0.46cm3/g) with micropore as the main pore types. The activated carbon was applied in the adsorption of CO2and the maximum adsorptive capacity was up to2.46mmol/g.