The Preparation Of Resin-basic Spherical Activated Carbon For CO₂Capture

It has become a hot issue of international concerned that global climate is warming. CO2is believed the one of important reasons due to it’s the greenhouse effect. Therefore, it has turned into important issues to development effective technologies for adsorption and separation of CO2, and choose the good performance adsorbents. Spherical activated carbon as a new type of high-performance activated carbon is not only very suitable for removal of CO2in the requirement of large bed, but also is a high-tech, high value-added products, with lower desorption temperature, higher adsorption capacity, high mechanical strength,good adsorption performance and excellent physical and mechanical properties and has attracted widespread attention.In this paper, resin-based spherical activated carbons were prepared from ordinary macroporous adsorption resin as raw material through air pre-oxidation or sulfonation, carbonization and activation treatment. The effect of preparation technology on properties of globular activated carbon was studied and characterized by TG, SEM, and pore structure analysis as characterization methods. The adsorption performance of CO2of globular activated carbon by two different methods has been carried on the simple comparison. Finally globular activated carbon was prepared based on four resin balls with basic functional group, and be compared with ordinary resin ball, all of this,in order to obtain globular activated carbon with high adsorption performance for CO2at high temperature.Spherical activated carbons could be prepared successfully by air pre-oxidation, carbonization, activation. The carbon yield of resin ball after oxidation treatment is higher than that of the original resin ball. Under this experimental condition, the maximum adsorption value (770mg/g) of oxidized spheres could be obtained at280℃for1h with the heating rate of0.25℃/min. The CCl4adsorption value of spherical activated carbons increased with the increase of activation temperature and time. When the activation temperature and activation time were850℃and4h, the CCl4adsorption value of spherical activated carbon was up to the maximum1550mg/g. The CO2adsorption value dropped from0.78mmol/g at30℃to0.05mmol/g at75℃.Spherical activated carbon was prepared successfully by expanding, suffocation, carbonization and activation treatment. Some conclusions could be received.1) the particle size was bigger after expanding and the whole carbonized ball could be got without crack and flaky.2) The char yield of resin balls could be obviously improved after sulfonation.3) single factor experimental study show that the yield of spherical activated carbons kept decreasing, CCl4adsorption value showed a tendencies of decreasing after increasing with the increases of activation temperature, time, steam flow rate. CCl4adsorption value up to2000mg/g could be obtained in the best activation conditions that activation temperature, activation time, steam flow rate were830℃,3h,0.5ml/min through the orthogonal experiment, as well as the process had good reproducibility.4) the CO2adsorption performance of spherical activated carbon prepared by sulfonation is superior to oxidation when adsorption temperature was the same.At the end of the paper, spherical activated carbons prepared from four kinds of basic resin ball by expanding-sulfonated method, were compared with ones from ordinary resin balls. Results show that the CO2adsorption performance of the spherical activated carbons from four kinds of resin balls with basic functional groups is superior to ordinary resins; the strongly basic provided a higher CO2adsorption capacity than the weak alkaline; the CO2adsorption capacity of the spherical activated carbons obtained from strongly basic D201with strongly basic functional groups-N+(CH3)3reached2.57mmol/g. The adsorptive capacities of the spherical activated carbons from ordinary resin ball on CO2decreased relatively faster than the ones from basic resins, and the downward trend of weak alkaline samples declined faster than strongly basic samples; the CO2adsorption capacity of the spherical activated carbons from basic resins showed a better adsorption performance at higher temperatures than ordinary resin. The CO2adsorption capacity of the spherical activated carbons obtained from basic resin balls fall by less than4%, still remained high after ten adsorption cycles, however, the CO2adsorption volume of these prepared from common resin balls kept unchanged basically.