A hybrid system combined with a non-contact membrane and bubbling absorption is proposed to capture CO_(2) from flue gas.The non-contact way of membrane and liquid absorbent effectively avoids the reduction of gas dif...A hybrid system combined with a non-contact membrane and bubbling absorption is proposed to capture CO_(2) from flue gas.The non-contact way of membrane and liquid absorbent effectively avoids the reduction of gas diffusion flux through the membrane.High-porosity ceramic membranes in hybrid systems are used for gas-solid separation in fuel gas treatment.Due to the high content of H_(2)O and cement dust in the flue gas of the cement plant,the membrane is hydrophobically modified by polytetrafluoroethylene(PTFE)to improve its anti-water,anti-fouling,and self-cleaning performances.The results show that the diffusion flux of CO_(2) through the membrane is still higher than 7.0×10^(−3) mol/m^(2)s(20%CO_(2) concentration)even under the influence of water and cement dust.In addition,slaked lime selected as the absorbent is cheap and the product after bubbling absorption is nano-scale light calcium carbonate.To sum up,the hybrid system combining non-contact membrane and bubbling absorption is expected to be used to capture carbon dioxide from the flue gas of the cement plant.展开更多
The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H...The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-per fluorooctyltrichlorosilane or 1H,1H,2H,2H-per fluorodecyltriethoxysilane and followed by ultraviolet irradiation.The surface water contact angle was improved from 46° of original ceramic membrane to 159°,which exhibited a stable and excellent superhydrophobic effect.The modi fied membranes showed a high flux of 27.28 kg·m^(-2)·h^(-1) and simultaneously maintained an excellent retention rate of 99.99%,when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl(75 °C) aqueous solution.These results suggested that superhydrophobic modi fication of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance.The superhydrophobically-modi fied ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.展开更多
Al2O3 ceramic powder was applied to modify the large pores defects on the surface of the porous metal Ti support,in situ oxidation method was a convenient method to prepare defect free ceramic/Ti composite membranes o...Al2O3 ceramic powder was applied to modify the large pores defects on the surface of the porous metal Ti support,in situ oxidation method was a convenient method to prepare defect free ceramic/Ti composite membranes on this basis.In situ oxidation conditions experimental results show that the best condition for preparing the TiO2-Al2O3/Ti composite membrane is under 800°C for 2 h,and the microstructure and pore sizes of the TiO2-Al2O3/Ti composite membranes are affected obviously.The thickness and composition of the TiO2/Ti composite membranes are determined by SEM and XRD completely.The pore size distribution of the composite membrane is measured by bubble pressure method,the most probable aperture is about 3.12μm,while the average pore size of defect free TiO2-Al2O3/Ti is about 3.23μm.After ultrasonic treatment,the slight weight change of membranes reveals no observable change,which indicates that TiO2-Al2O3/Ti composite membranes maintain a good stability.展开更多
Al 2O 3-SiO 2-TiO 2-ZrO 2 supported membranes were prepar ed by Sol-Gel method. These composite ceramic membranes are level, even and no macro crack. There exist several crystalline phases such as Al 2O 3, TiO...Al 2O 3-SiO 2-TiO 2-ZrO 2 supported membranes were prepar ed by Sol-Gel method. These composite ceramic membranes are level, even and no macro crack. There exist several crystalline phases such as Al 2O 3, TiO 2(a natase), Al 2SiO 5, and ZrO 2 in these membranes. Changing the molar ratio of Al∶Si∶Ti∶Zr,the kinds and content of crystal phases of composite membranes could be different, which may lead to a variety of microstructure of membranes. The surface nanoscale topography and microstructure of membranes were investiga ted by XRD,SEM,AFM,EPMA. The effects of additives and heat treatments on the sur face nanoscale topography and microstructure of composite ceramic membranes were also analyzed.展开更多
文摘A hybrid system combined with a non-contact membrane and bubbling absorption is proposed to capture CO_(2) from flue gas.The non-contact way of membrane and liquid absorbent effectively avoids the reduction of gas diffusion flux through the membrane.High-porosity ceramic membranes in hybrid systems are used for gas-solid separation in fuel gas treatment.Due to the high content of H_(2)O and cement dust in the flue gas of the cement plant,the membrane is hydrophobically modified by polytetrafluoroethylene(PTFE)to improve its anti-water,anti-fouling,and self-cleaning performances.The results show that the diffusion flux of CO_(2) through the membrane is still higher than 7.0×10^(−3) mol/m^(2)s(20%CO_(2) concentration)even under the influence of water and cement dust.In addition,slaked lime selected as the absorbent is cheap and the product after bubbling absorption is nano-scale light calcium carbonate.To sum up,the hybrid system combining non-contact membrane and bubbling absorption is expected to be used to capture carbon dioxide from the flue gas of the cement plant.
基金Supported by the National Natural Science Foundation of China(51473013)
文摘The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-per fluorooctyltrichlorosilane or 1H,1H,2H,2H-per fluorodecyltriethoxysilane and followed by ultraviolet irradiation.The surface water contact angle was improved from 46° of original ceramic membrane to 159°,which exhibited a stable and excellent superhydrophobic effect.The modi fied membranes showed a high flux of 27.28 kg·m^(-2)·h^(-1) and simultaneously maintained an excellent retention rate of 99.99%,when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl(75 °C) aqueous solution.These results suggested that superhydrophobic modi fication of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance.The superhydrophobically-modi fied ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.
基金Projects(212006065,21666018)supported by the National Natural Science Foundation of China
文摘Al2O3 ceramic powder was applied to modify the large pores defects on the surface of the porous metal Ti support,in situ oxidation method was a convenient method to prepare defect free ceramic/Ti composite membranes on this basis.In situ oxidation conditions experimental results show that the best condition for preparing the TiO2-Al2O3/Ti composite membrane is under 800°C for 2 h,and the microstructure and pore sizes of the TiO2-Al2O3/Ti composite membranes are affected obviously.The thickness and composition of the TiO2/Ti composite membranes are determined by SEM and XRD completely.The pore size distribution of the composite membrane is measured by bubble pressure method,the most probable aperture is about 3.12μm,while the average pore size of defect free TiO2-Al2O3/Ti is about 3.23μm.After ultrasonic treatment,the slight weight change of membranes reveals no observable change,which indicates that TiO2-Al2O3/Ti composite membranes maintain a good stability.
文摘Al 2O 3-SiO 2-TiO 2-ZrO 2 supported membranes were prepar ed by Sol-Gel method. These composite ceramic membranes are level, even and no macro crack. There exist several crystalline phases such as Al 2O 3, TiO 2(a natase), Al 2SiO 5, and ZrO 2 in these membranes. Changing the molar ratio of Al∶Si∶Ti∶Zr,the kinds and content of crystal phases of composite membranes could be different, which may lead to a variety of microstructure of membranes. The surface nanoscale topography and microstructure of membranes were investiga ted by XRD,SEM,AFM,EPMA. The effects of additives and heat treatments on the sur face nanoscale topography and microstructure of composite ceramic membranes were also analyzed.
