Adsorption And Regeneration Performances Of Activated Coke In Different Regeneration Atmosphere

These technologies which use carbon-based materials as adsorbents have been applied in many industries, because no wastewater or secondary pollutants are produced, and many pollutants such as dust and heavy metals can be removed, and SO2 can be effectively recovered by the reaction of H2SO4 with carbon on the surface when the adsorbents are heated.However, the widespread application of these technologies has been limited, since two problems exist when used carbon-based materials for SO2 and NOx removal. One problem is that the operating cost is high, and the other is that amounts of energy is needed. Based on finding lower carbon-based materials, and improving the De-NOx and De-SO2 performances, and decreasing carbon consumption, and reducing regeneration temperature, this paper explored the application potential of lower-cost semi-coke for SO2 and NO removal, and studied the effects of the adsorption atmosphere and the properties of adsorbents for the De-NOx and De-SO2 performances, and discussed the effects of heating rate, regeneration temperature, concentration and regeneration time for the regeneration performance of activated coke in different regeneration atmospheres.For studying the effects of the adsorption atmosphere and the properties of adsorbents for the De-NOx and De-SO2 performances, four carbon-based materials were used as adsorbents for SO2 and NOx removal in three adsorption atmospheres. The results show that AC-2, AC-3 and AC-4 have better De-NOx performance when without NH3 in the atmosphere, and the AC-1 and AC-4 have better De-NOx performance when with NH3 in the atmosphere, the reason is that AC-2 and AC-3 possess higher special surface area than AC-1 and AC-4, improving De-SO2 efficiency and many ammonium sulfates can generate when with NH3 in the atmosphere, but lots of ammonium sulfates can clog the micropores, depressing SCR reaction.Compared the regeneration performance and carbon consumption of four carbon materials by heated. The results show that the De-SO2 performances of four adsorbents and De-NOx performance of AC-1 are not changed, but De-NOx performances of AC-2, AC-3 and AC-4 are reduced, since the active functional groups of adsorbents are decreased and the pore properties of adsorbents are changed when heated. Carbon consumption of AC-2 is the least among the adsorbents, and SO2 recoveries of AC-2 and AC-4 are better than those of AC-1 and AC-3. Moreover, to depress the decomposition of active functional groups and reduce the carbon consumption, the adsorbents that adsorbed SO2 could be regenerated at lower temperatures, and the SO2 recovery would only slightly decrease.For researching the effects of heating rate, regeneration temperature, concentration and regeneration time for the regeneration performance of regenerated activated coke, activated coke was heated in different atmospheres. The results show that the De-NOx and De-SO2 performances can be improved, and the side reactions can be depressed, decreasing the carbon consumption, but the SO2 recovery is also decreased when with NH3 in the atmosphere; when with H2 O in the atmosphere, the De-NOx and De-SO2 performances are not improved, and carbon consumption increased. Regeneration temperature is important for the De-NOx and De-SO2 performances of regenerated activated coke and SO2 recovery, and with the temperature rises, the De-NOx and DeSO2 performances and SO2 recovery will be increasing, but carbon consumption will be also increasing.