[Objective] This study aimed to investigate the adsorption properties of the adsorption tower filled with calcium superphosphate on ammonia volatilized with aer- ation. [Method] Adsorption tower filled with calcium su...[Objective] This study aimed to investigate the adsorption properties of the adsorption tower filled with calcium superphosphate on ammonia volatilized with aer- ation. [Method] Adsorption tower filled with calcium superphosphate was adopted as experimental apparatus, which was constructed by poly vinyl chloride （PVC） circular tubes. With hartshorn as the source of ammonia volatilization, the effect of different ratios of height to diameter of the tower filled with equal amount of calcium super-phosphate on ammonia adsorption was investigated. In addition, adsorption tower with height-diameter ratio of 9.9 was selected to adsorb the ammonia emitted from the composting systems of pig manure and chicken manure with optimized and reg- ulated carbon-nitrogen ratio. [Result] Under certain volatilization rate, calcium super- phosphate particles in the adsorption tower could effectively adsorb the ammonia, and the adsorption efficiency was enhanced with the increase of height-diameter ra-tio, which could reach above 90% with height-diameter ratio of more than 1.1; the ammonia emitted from composting systems of pig manure and chicken manure with optimized and regulated carbon-nitrogen ratio could be completely absorbed using adsorption tower with height-diameter ratio of 9.9 filled with calcium superphosphate accounting for about 8% of the weight of composting materials. [Conclusion] Experi- mental results of this study provided reference for the application of adsorption tower filled with calcium superphosphate in the treatment of waste gas emitted from com- posting materials.展开更多
The adsorption of xenon from air has an interest in the monitoring of nuclear explosion or accident, or in the treatment of nuclear waste gas. In this paper, the pore structure of several series of activated carbon fi...The adsorption of xenon from air has an interest in the monitoring of nuclear explosion or accident, or in the treatment of nuclear waste gas. In this paper, the pore structure of several series of activated carbon fibers has been characterized. The adsorption properties of xenon on these activated carbon fibers under different temperatures have been studied in details. The results show that the xenon adsorption amount on activated carbon fibers do not increase with specific surface area of adsorbents, but are closely related to their pore size distribution. Pores whose radius equal to or narrow than 0.4nm would be more advantageous to the adsorption of xenon.展开更多
Structures of a series of activated carbon fibers were modified by impregnating them with organic and inorganic materials such as Methylene blue(Mb)、p-nitrophenol (PNP)、NaCl or by oxidizing with KMnO4 or HNO3. The i...Structures of a series of activated carbon fibers were modified by impregnating them with organic and inorganic materials such as Methylene blue(Mb)、p-nitrophenol (PNP)、NaCl or by oxidizing with KMnO4 or HNO3. The influence of pore filling or chemical treatment on their xenon adsorption properties was studied. The experimental results show that Mb and PNP filling of activated carbon fibers result in the decrease of xenon adsorption capacities of these treated ACFs, which is due to the decrease of their surface area and micro-pore volume. However, the adsorption capacity increases greatly with oxidizing treatment of activated carbon fibers by 7mol/L HNO3.展开更多
A series of sisal based activated carbon fibers were prepared with steam activation at temperature from 750℃ to 900℃. Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using...A series of sisal based activated carbon fibers were prepared with steam activation at temperature from 750℃ to 900℃. Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using different theories. The results showed that t-plot method and DR-plot method could suitably be used to characterize the mesopore structure and the multi-stage distribution of pore size of activated carbon fibers. It also showed that the pore size widens with the increase of activation temperature.展开更多
During the reaction between calcium sorbents and SO2, calcium sorbents are first calcined and converted into CaO. CaO can be obtained by calcining Ca(OH)2or CaCO3. The porosity of the sorbent is increased because of c...During the reaction between calcium sorbents and SO2, calcium sorbents are first calcined and converted into CaO. CaO can be obtained by calcining Ca(OH)2or CaCO3. The porosity of the sorbent is increased because of calcination and is decreased because of sulfurization. In the calcination process H2O or CO2 is escaped from the particles and pores are formed in particles. The reaction or convert rate of CaO is influenced strongly by the pore structure characters. From Ca(OH)2 to CaO the escape velocity of H2O or its mass transfer is one of the key factors influencing the pore forming. During calcination process different healing velocity, different heating time and temperature were suggested. The temperature rising rate and calcining temperature play important role to the pore structure. The convert rates of CaO obtained through different calcining conditions were investigated experimentally. Some interesting results were showed that the calcium utilization of CaO particles is determined not only by the special surface area and total pore volume, but also by pore-size distribution. The main factor influencing the sulfation is the pore diameter distribution at lower sulfation temperature. For higher reaction temperature specific volume is the important reason. But pore-size distribution is strongly influenced by heat flux and temperature in the calcining process.展开更多
文摘[Objective] This study aimed to investigate the adsorption properties of the adsorption tower filled with calcium superphosphate on ammonia volatilized with aer- ation. [Method] Adsorption tower filled with calcium superphosphate was adopted as experimental apparatus, which was constructed by poly vinyl chloride （PVC） circular tubes. With hartshorn as the source of ammonia volatilization, the effect of different ratios of height to diameter of the tower filled with equal amount of calcium super-phosphate on ammonia adsorption was investigated. In addition, adsorption tower with height-diameter ratio of 9.9 was selected to adsorb the ammonia emitted from the composting systems of pig manure and chicken manure with optimized and reg- ulated carbon-nitrogen ratio. [Result] Under certain volatilization rate, calcium super- phosphate particles in the adsorption tower could effectively adsorb the ammonia, and the adsorption efficiency was enhanced with the increase of height-diameter ra-tio, which could reach above 90% with height-diameter ratio of more than 1.1; the ammonia emitted from composting systems of pig manure and chicken manure with optimized and regulated carbon-nitrogen ratio could be completely absorbed using adsorption tower with height-diameter ratio of 9.9 filled with calcium superphosphate accounting for about 8% of the weight of composting materials. [Conclusion] Experi- mental results of this study provided reference for the application of adsorption tower filled with calcium superphosphate in the treatment of waste gas emitted from com- posting materials.
基金Natural Science Foundation Committee of Chinese government (grant No. 50073029) and by Guangdong Provincial Natural Science Foundation (001276)
文摘The adsorption of xenon from air has an interest in the monitoring of nuclear explosion or accident, or in the treatment of nuclear waste gas. In this paper, the pore structure of several series of activated carbon fibers has been characterized. The adsorption properties of xenon on these activated carbon fibers under different temperatures have been studied in details. The results show that the xenon adsorption amount on activated carbon fibers do not increase with specific surface area of adsorbents, but are closely related to their pore size distribution. Pores whose radius equal to or narrow than 0.4nm would be more advantageous to the adsorption of xenon.
基金National Natural Science Foundation of China (50073029) and Guangdong Provincial Natural Science Foundation (001276)
文摘Structures of a series of activated carbon fibers were modified by impregnating them with organic and inorganic materials such as Methylene blue(Mb)、p-nitrophenol (PNP)、NaCl or by oxidizing with KMnO4 or HNO3. The influence of pore filling or chemical treatment on their xenon adsorption properties was studied. The experimental results show that Mb and PNP filling of activated carbon fibers result in the decrease of xenon adsorption capacities of these treated ACFs, which is due to the decrease of their surface area and micro-pore volume. However, the adsorption capacity increases greatly with oxidizing treatment of activated carbon fibers by 7mol/L HNO3.
基金Natural Science Foundation Committee of Chinese government (grant No. 50073029) and by Guangdong Provincial Natural Science Foundation (001276)
文摘A series of sisal based activated carbon fibers were prepared with steam activation at temperature from 750℃ to 900℃. Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using different theories. The results showed that t-plot method and DR-plot method could suitably be used to characterize the mesopore structure and the multi-stage distribution of pore size of activated carbon fibers. It also showed that the pore size widens with the increase of activation temperature.
文摘During the reaction between calcium sorbents and SO2, calcium sorbents are first calcined and converted into CaO. CaO can be obtained by calcining Ca(OH)2or CaCO3. The porosity of the sorbent is increased because of calcination and is decreased because of sulfurization. In the calcination process H2O or CO2 is escaped from the particles and pores are formed in particles. The reaction or convert rate of CaO is influenced strongly by the pore structure characters. From Ca(OH)2 to CaO the escape velocity of H2O or its mass transfer is one of the key factors influencing the pore forming. During calcination process different healing velocity, different heating time and temperature were suggested. The temperature rising rate and calcining temperature play important role to the pore structure. The convert rates of CaO obtained through different calcining conditions were investigated experimentally. Some interesting results were showed that the calcium utilization of CaO particles is determined not only by the special surface area and total pore volume, but also by pore-size distribution. The main factor influencing the sulfation is the pore diameter distribution at lower sulfation temperature. For higher reaction temperature specific volume is the important reason. But pore-size distribution is strongly influenced by heat flux and temperature in the calcining process.
