活性炭的低温催化氧化再生方法研究

【作者】 朱艳秋；

【导师】 赵大传；

【作者基本信息】 山东大学 ， 环境工程， 2006， 硕士

【摘要】 目前国内外主要采用热再生法进行活性炭再生，但是热再生法需要高温，且炭耗高、烧失现象严重。催化氧化法再生活性炭是在热再生法基础上发展起来的一种新的活性炭再生方法。本文初步研究了吸附苯酚的颗粒状活性炭(GAC)和粉末状活性炭(PAC)的催化氧化再生技术。 实验在查阅文献的基础上，以CuO为催化剂，采用等体积浸渍法负载，通过试验确定最佳焙烧条件。负载了催化剂的活性炭样品的筛选通过吸附等温线实验进行，最终确定负载量为2％CuO的活性炭(重量比)为最佳样品。实验数据表明负载催化剂后，活性炭的吸附性能发生了变化，并且降低了苯酚的氧化温度(Tp)、活性炭的表面氧化温度(Tc)及活性炭的骨架氧化温度(Tg)。Tp和Tc之间的温度，即为活性炭的再生温度范围。Tp、Tc和Tg由热分析实验确定，在此范围内寻求最佳再生条件，最后研究并比较了催化氧化再生GAC、PAC的效果。 再生实验表明，粒状炭在250℃下再生，第一次再生效率达到78％，经6次再生后再生效率达53.2％；粉状炭在240℃下再生，第一次再生效率达到99.9％，再生效率9次后仍能达到99.2％，每次再生时的平均炭耗为2.0％。粉状炭的再生效果要优于粒状炭。 负载了催化剂后的粉状炭的性能评价通过扫描电镜实验、比表面积的测定、XRD实验、ICP实验来进行。催化剂主要负载在中孔和大孔中，使得部分孔堵塞，造成活性炭比表面积下降。在低负载量时，由于催化剂的活性作用，活性炭吸附容量有所增大，而高负载量时，比表面积的下降起控制作用，活性炭吸附容量减小。 综合研究结果表明，催化氧化再生法对吸附苯酚饱和的活性炭的再生是一种有效的再生方法。更多还原

【Abstract】 Thermal regeneration is the main regeneration method of activated carbon (AC) in the world at present, but it need high temperature, and its weight loss and burned loss are seriously. Catalytic oxidative regeneration is an new method debased on thermal regeneration, This paper has studied catalytic oxidative regeneration of granule activated carbon(GAC) and powder activated carbon (PAC) saturated with phenol.CuO was employed as catalyst, and loaded on AC by equal volume impregnation, the optimal burned conditions were determined by experiments. The samples were examined by the adsorption isotherms, and the most promising catalyst was found to be the sample containing 2% CuO (calculated as weight). Experimental data indicated that the adsorption ability was changed, the temperature of phenol oxidation(Tp), temperature of AC surface oxidation(Tc) and skeleton oxidation(Tg) were all reduced at the same time. The range between Tp and Tc was the regeneration temperature of AC which given by the thermal analysis experiments. The optimal regeneration conditions were searched in the range and regeneration effects of GAC and PAC were studied at last.Study on regeneration shows that GAC was regenerated at 250℃, the first regeneration efficiency was 78%, and 53.2% after six repeated regeneration experiments. PAC was regenerated at 240℃, the first regeneration efficiency was 99.9%, and 99.2% after nine repeated regeneration experiments ,and the average weight loss was 2.0%. So the regeneration efficiency of PAC was superior to GAC.Experiments of SEM, surface area, ICP, XRD were done with the PAC samples. The results showed that catalyst could be housed only in the mesopores and macropores, so some pores were blocked up and the surface area was reduced. The adsorption capacity was increased because of the action of catalyst at the low metal weight, while it was reduced because of the reduction of surface area at the high metal weight.更多还原