硝基苯酚和硝酸改性酚醛泡沫脱除烟气中Hg^0

Removal of elemental mercury from flue gas by P-nitrophenol and nitric acid modified phenolic foam

以酚醛泡沫作为基体材料,选择对硝基苯酚和硝酸作为改性剂,制备改性酚醛泡沫PF-12%NO_2和PF-HNO3-5,并研究其对模拟烟气中Hg^0的脱除能力。通过红外和热重表征发现,2种改性剂均可在样品表面引入硝基,且硝酸改性样品PF-HNO_3-5的热解温度更低,可能是由于其表面产生了大量羰基。脱汞实验发现,未改性样品PF-0的汞吸附量仅有0.46μg/g,而PF-12%NO_2的汞吸附量为1.45μg/g,PF-HNO_3-5的汞吸附量为14.63μg/g,表明硝基和羰基确实可以提升吸附剂对烟气中Hg^0的吸附能力。PF-12%NO_2和PF-HNO_3-5的汞吸附曲线均符合颗粒内扩散模型及Bangham模型。

This paper introduces an experimental study on phenolic foams modified by p-nitrophenol and nitric acid,viz. PF-12% NO_2 and PF-HNO_3-5,respectively. We investigated the adsorption capabilities of the modified phenolic foams towards elemental mercury（ Hg^0） in flue gas. The results of Fourier-transform infrared spectrometry and thermogravimetric analysis revealed that nitryl group was brought to the surfaces of both the modified samples. In addition,the thermal decomposition temperature of PF-HNO_3-5 was further lowered,probably due to the ample amount of carbonyl observed on the surfaces of tested samples. In elemental mercury adsorption test,the adsorption capacity of the unmodified foam PF-0 was 0. 46 μg / g; while those of the modified foams,PF-12% NO_2 and PF-HNO_3-5,were 1. 45 μg / g and 14. 63 μg / g,respectively. This demonstrated that nitryl and carbonyl moieties can indeed increase adsorption capacities of phenolic foams towards Hg^0 in flue gas.The Hg^0 adsorption characteristics of both PF-12% NO_2 and PF-HNO_3-5 agree well with the intraparticle diffusion model and the Bangham model.