Hsieh Chu-Chin, Tsai Jyong-Sian, Chang Jen-Ray
Department of Safety, Health and Environmental Engineering, National Yunlin University Science and Technology, Douliu 640301, Taiwan.
Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 621301, Taiwan.
Materials (Basel). 2022 Jan 20;15(3):784. doi: 10.3390/ma15030784.
The performances of reactive adsorbents, HPO/C (activated carbon) and HPO/A (Amberlyst 35), in removing NH from a waste-gas stream were investigated using a breakthrough column. Accelerated aging tests investigated the effects of the water content on the performance of the adsorbents. Results of breakthrough tests show that the adsorption capacity greatly decreased with the drying time of HPO/C preparation. Synchrotron XRPD indicated increased amorphous phosphorus species formation with drying time. Nitrogen adsorption-desorption isotherms results further suggested that the evaporation of water accommodated in macropores decreases adsorption capacity besides the formation of the amorphous species. Introducing water moisture to the NH stream increases the adsorption capacity concomitant with the conversion of some NHHPO to (NH)HPO. Due to the larger pore of cylindrical type and more hydrophilic for acidic porous polymer support, as opposed to slit-type for the activated carbon, the adsorption capacity of HPO/A is about 3.4 times that of HPO/C. XRPD results suggested that NH reacts with aqueous HPO to form NHHPO and no significant macropore-water evaporation was observed when acidic porous polymer support was used, as evidenced by N isotherms characterizing used HPO/A.
使用穿透柱研究了反应性吸附剂HPO/C（活性炭）和HPO/A（Amberlyst 35）从废气流中去除NH的性能。加速老化试验研究了含水量对吸附剂性能的影响。穿透试验结果表明，HPO/C制备过程中的干燥时间会使吸附容量大幅下降。同步加速器XRPD表明，随着干燥时间的增加，无定形磷物种的形成增多。氮吸附-解吸等温线结果进一步表明，大孔中容纳的水分蒸发除了会导致无定形物种的形成外，还会降低吸附容量。向NH气流中引入水分会增加吸附容量，同时一些NHHPO会转化为(NH)HPO。由于圆柱形孔较大且酸性多孔聚合物载体更具亲水性，与活性炭的狭缝型孔相反，HPO/A的吸附容量约为HPO/C的3.4倍。XRPD结果表明，NH与水性HPO反应形成NHHPO，并且使用酸性多孔聚合物载体时未观察到明显的大孔水蒸发，这由表征用过的HPO/A的N等温线证明。
