选取天然石灰石和贝壳作为钙基材料,进行CaCO3/CaO循环煅烧/碳酸化反应,原料成本低并且资源丰富。该文在热重分析仪上对不同原料的煅烧动力学特性和CO2循环吸收特性进行研究,对循环前后产物的扫描电镜(scanning electron microscopy,SEM...选取天然石灰石和贝壳作为钙基材料,进行CaCO3/CaO循环煅烧/碳酸化反应,原料成本低并且资源丰富。该文在热重分析仪上对不同原料的煅烧动力学特性和CO2循环吸收特性进行研究,对循环前后产物的扫描电镜(scanning electron microscopy,SEM)形貌及其孔径分布进行分析。结果表明,随着循环次数的增加,二者活性都有所降低,通过多次循环后样品的孔径分布和扫描电镜形貌观察到,石灰石微孔减少,烧结现象严重,而贝壳分布在中孔和大孔之间,钙利用率较低,形貌未发生明显变化。由于二者组分和结构上的差异,使得天然石灰石在CO2循环吸收性能上优于贝壳,而贝壳则具有较好的循环稳定性。展开更多
In the present work,the effect of pre-calcination on carbonation conversion and cyclic stability of modi fied CaObased sorbent was investigated by thermogravimetric analyzer(TGA).The modi fied CaO-based sorbents with ...In the present work,the effect of pre-calcination on carbonation conversion and cyclic stability of modi fied CaObased sorbent was investigated by thermogravimetric analyzer(TGA).The modi fied CaO-based sorbents with CaAc_2 as precursor were respectively doped with different elements(Mg,Al,Ce,Zr and La).The speci fic surface area,pore volume and pore size distribution were tested by N_2 isothermal adsorption measurements.The phase compositions of sorbents were characterized by X-ray diffraction(XRD).The results showed that the cyclic stabilities of the sorbents were improved by pre-calcination.The pre-calcination was conducted at 900°C for 5 h in air by the muf fle furnace.With pre-calcination,the cyclic stabilities of sorbents could be as high as 96% after 22 cycles,such as CaO-Al,CaO-Ce and CaO-La.After contact with air,the carbonation conversions of spent sorbents with pre-calcination suddenly increased by about one-sixth due to the change of channel structure by hydration.Both the cyclic stability of sorbent and the durability of reactivation were related to the structural stability of sample,especially the stability of mesopores between 2 nm and 5.5 nm.The present work also provided an easy and low-cost method for reactivating the spent CaO-based sorbents.展开更多
文摘选取天然石灰石和贝壳作为钙基材料,进行CaCO3/CaO循环煅烧/碳酸化反应,原料成本低并且资源丰富。该文在热重分析仪上对不同原料的煅烧动力学特性和CO2循环吸收特性进行研究,对循环前后产物的扫描电镜(scanning electron microscopy,SEM)形貌及其孔径分布进行分析。结果表明,随着循环次数的增加,二者活性都有所降低,通过多次循环后样品的孔径分布和扫描电镜形貌观察到,石灰石微孔减少,烧结现象严重,而贝壳分布在中孔和大孔之间,钙利用率较低,形貌未发生明显变化。由于二者组分和结构上的差异,使得天然石灰石在CO2循环吸收性能上优于贝壳,而贝壳则具有较好的循环稳定性。
基金Supported by Capture CO2 and Storage Technology Jointly Studied by USA and China(2013DFB60140-04)Key Program of National Natural Science Foundation of China(No.21536009)
文摘In the present work,the effect of pre-calcination on carbonation conversion and cyclic stability of modi fied CaObased sorbent was investigated by thermogravimetric analyzer(TGA).The modi fied CaO-based sorbents with CaAc_2 as precursor were respectively doped with different elements(Mg,Al,Ce,Zr and La).The speci fic surface area,pore volume and pore size distribution were tested by N_2 isothermal adsorption measurements.The phase compositions of sorbents were characterized by X-ray diffraction(XRD).The results showed that the cyclic stabilities of the sorbents were improved by pre-calcination.The pre-calcination was conducted at 900°C for 5 h in air by the muf fle furnace.With pre-calcination,the cyclic stabilities of sorbents could be as high as 96% after 22 cycles,such as CaO-Al,CaO-Ce and CaO-La.After contact with air,the carbonation conversions of spent sorbents with pre-calcination suddenly increased by about one-sixth due to the change of channel structure by hydration.Both the cyclic stability of sorbent and the durability of reactivation were related to the structural stability of sample,especially the stability of mesopores between 2 nm and 5.5 nm.The present work also provided an easy and low-cost method for reactivating the spent CaO-based sorbents.
