Preparation Of Phenolic Resin Spheres And Phenolic Resin-based Activated Carbon

Using phenol and formaldehyde as raw materials, the millimeter-sized phenolic resinspheres are prepared by suspension polymerization. The effects of four influencing factors on thesphere diameter and sphericity are investigated, including formaldehyde to phenol ratio （F:P）, theamount of dispersant（PVA）, curing agent（HMTA） and stirring speed. The results show that theoptimum process conditions are as follows: formaldehyde to phenol ratio is0.90, the massfraction of added PVA is8%, HMTA is10%and stirring speed is300r/min. Under this condition,the average sphere diameter of phenolic resin spheres is up to1.04mm and the average sphericityis up to0.97. Industrial analysis and elementary analysis show that phenolic resin spheres are freeof ash and contain74.27%carbon respectively. In addition, the result of thermogravimetricanalysis indicate that the char yield at800℃is up to62%. The self-made phenolic resinspheres are proved to be good activated carbon precursor.The phenolic resin spheres turn to unmelted spheres after the pre-oxidation treatment at180℃for2hours, and then the carbonized phenolic spheres are prepared under the followingoptimum carbonization process conditions: heating rate of15℃/min, carbonization temperatureof600℃and carbonization time of1hour. By this way, the produced carbonized phenolicspheres have dispersed particles and good sphericity, and also, the final char yield is up to59.44%.High surface area activated carbon and micro-porous activated carbon can be prepared byKOH activation. But as a result of strong corrasion of KOH, phenolic resin spheres can’t keepspherical, and the prepared activated carbon contains ash. In the single factor experiment, theinfluence of four factors on the absorbability to iodine and methylene blue of phenolicresin-based activated carbon is analyzed. The fours factors are as follows: the particle size, alkalicharcoal ratio, activation temperature and activation time. The result shows that the bestconditions are as follows: the particle diameter is below0.4mm, alkali charcoal ratio is4:1,activation temperature is800℃, and time is1.5h. In the while, the iodine adsorption value ofthe production is2352mg·g^-1and the methylene blue adsorption value is27mL/0.1g. The N2adsorption shows that the BET surface area is2863m²g^-1.Using steam as activator, the prepared activated carbon can be of high quality, keep veryspherical, and has no ash. In the single factual experiment, the effects of four elements on theprepared activated carbon quality are investigated. The four elements are the particle size ofmaterial particles, activation temperature, activation time, and the quantity of steam flow. Theresult shows that the optimum process conditions are as follows: the diameter of materialparticles is between0.8and1.2mm, the activation temperature is850℃, the time is1.5h, and the quantity of steam flow is1.5mL/min. Under this condition, the adsorption capacity of iodineand methylene blue of the production is1026mg·g^-1and12mL/0.1g respectively. The BETsurface area is1211m²g^-1.