高温下改性钙基吸附剂固定床反应器从烟气中捕捉二氧化碳(英文)

Four kinds of Ca-based sorbents were prepared by calcination and hydration reactions using different precursors: calcium hydroxide, calcium carbonate, calcium acetate monohydrate and calcium oxide. The CO2 absorption capacity of those sorbents was investigated in a fixed-bed reactor in the temperature range of 350-650℃. It was found that all of those sorbents showed higher capacity for CO2 absorption when the operating temperature higher than 450℃. The CaAc2-CaO sorbent showed the highest CO2 absorption capacity of 299mg·g-1. The morphology of those sorbents was examined by scanning electron microscope (SEM), and the changes of composition before and after carbonation were also determined by X-ray diffraction (XRD). Results indicated that those sorbents have the similar chemical compositions and crystalline phases before carbonation reaction [mainly Ca(OH)2], and CaCO3 is the main component after carbonation reaction. The SEM morphology shows clearly that the sorbent pores were filled with reaction products after carbonation reaction, and became much denser than before. The N2 adsorption-desorption isotherms indicated that the CaAc2-CaO and CaCO3-CaO sorbents have higher specific surface area, larger pore volume and appropriate pore size distribution than that of CaO-CaO and Ca(OH)2-CaO.     

Ce-TiO2/SiO2模拟太阳光下催化降解亚甲基蓝的研究

制备了Ce掺杂的TiO2复合SiO2光催化剂(Ce-TiO2/SiO2),使用该光催化剂在模拟太阳光下催化降解亚甲基蓝水溶液,研究了催化剂用量、亚甲基蓝初始质量浓度、溶液pH、无机阴离子对光催化降解效果的影响。结果表明:n(Ce)∶n(Ti)∶n(Si)=0.002∶1∶1时所制催化剂的光催化活性最好;对于2.5 mg/L、pH为11的亚甲基蓝溶液,投加100 mg/L的光催化剂反应2 h可达到最高降解率(92.6%);NO3-、SO42-、Cl-的存在对光催化降解具有抑制作用。     

CaO/FA吸收剂高温吸收CO2及穿透特性

利用完全煅烧后的CaO和粉煤灰（Fly Ash）为材料制备了CaO/FA吸收剂。在350~650℃温度范围内对其碳酸化反应特性进行了研究。考察了不同质量比的CaO/FA吸收剂吸收CO2的性能。利用XRD、N2吸附等表征手段对吸收剂反应前后产物进行了表征。结果表明：通过水合反应过程,吸收剂比表面积增大,孔径在5~40nm范围内属于中孔,有利于减小CO2向颗粒内部的扩散阻力。CaO/FA吸收剂CO2吸收量随温度的升高而增加。当CaO与粉煤灰的质量比为3:1时制备的吸收剂具有最好的CO2吸收能力,在650℃时其最大CO2吸收量达到了227.13mg/g。通过多次循环试验后,吸附剂仍保持较高的CO2吸收量与稳定吸收性能。失活模型可以很好地预测CaO/FA吸收剂吸收CO2的过程,并得到了理想的吸收速率常数和失活速率常数。