活性炭的催化湿式氧化再生机理及其应用研究

It is well known that different regenerating techniques of activated carbon (AC) require the suitable evaluating methods for regeneration efficiency. In this project, several methods for evaluating the regeneration efficiency of AC by wet air oxidation (WAO) were compared and discussed, which were respectively based on different experimental protocols such as iodine value, molasses color adsorption, breakthrough profile, adsorption isotherm and standard reload experiment. The iodine value, molasses color adsorption and breakthrough profile yielded indefinitely PR values for WAO process, so they could not be applied to evaluate regeneration efficiency. And adsorption isotherm experiment was more correct because it compared isotherm loadings at the same equilibrium liquid phase concentrations, but this more laborious and time-consuming method was difficult to be widely used. The results also showed that the standard reload experiment was consequently picked out, easy to use and had high sensibility alternative to adsorption isotherm experiment. When controlling the WAO parameters at 230°C, 0.6MPa and 1h, the regeneration efficiency arrived to 45% with no catalyst.This project has studied AC regeneration by catalyst wet air oxidation (CWAO) with different catalysts. Three catalysts (homogeneous, CuO/Al2O3 heterogeneous and Cu/AC heterogeneous catalysts) have been studied. Study on AC regeneration by homogeneous CWAO shows the catalysts are in favors of the COD remove in liquid and improvement of AC regeneration. The copper salt has the best effect. Added the copper salt the regeneration efficiency has been improved from 45% to 62% compared to the regeneration no using catalyst, and the regenerating temperature has decreased 20°C. Good reproducibility of five CWAO experiments with copper salt was obtained.The regeneration process of CWAO using CuO/Al2O3 catalyst has been studied in details, and the optimized condition has been obtained. The CuO-Al2O3 and Cu/AC have been analyzed by XRD and their pore diameter distributing has been tested also.Study on AC regeneration CWAO with CuO/Al2O3 heterogeneous has shown the self-made CuO/Al2O3 catalyst has good effect on the regeneration process. And the optimized condition is found, regenerating temperature 210℃, regenerating time 60min, catalyst quantity 25mg (calculated by Cu), regeneration pressure 0.6MPa@25℃, the AC quantity 15g (dry solid), and water 300mL. XRD result of the catalyst shown that the catalyst activated ingredient is CuO. And the steadily process has been found. The regeneration efficiency is about 51%.After the AC was loaded the copper salt, its absorb ability dose not change in evidence. The regeneration efficiency is 65%, and the loss of Cu in Cu/AC decreased. Compare to the regeneration by CuO/Al2O3, it could leave out the separation of catalyst and AC after regeneration..The degradation process of phenol was studied, and degradation products were found. And the regeneration mechanism by Cu/AC wet air oxidation was discussed.

研制以活性炭为载体的新型催化剂，使催化湿式氧化再生活性炭能够在中温（约170℃）和醒梗ǎ?.5MPa）条件下实现，并系统地研究该过程中不同种类活性炭自身表面形态及吸附阅鼙浠媛桑ズ突钚蕴可嫌谢锶コ恚钚蕴吭偕怼⒃偕Ч霸偕倜ズ吞孔试椿峁┮恢指咝У湍芎牡脑偕ひ眨够钚蕴吭谒碇姓嬲玫焦惴河τ谩