ABSTRACT
Objective To prepare the Pt/CeO2/GAC catalyst used to catalyze oxidation of condensate wastewater and to investigate whether the doping of Ce can increase catalytic activity for oxidizing condensate wastewater.Methods Impregnation glycol reduction method was adopted to prepare Pt/CeO2/GAC catalyst,and it was characterized by BET,XPS and XRD.The catalytic activity was determined by batch experiment.Results The experimental results revealed that more than 93.4% of ethanol in the condensate wastewater was oxidized to aldehyde and acetic acid with 13.33 g?L-1 Pt/CeO2/GAC catalyst dose,for 2 h reaction time,at 40 ℃ and normal pressure.In contrast,the oxidation efficiency was only 85.0% with Pt/GAC catalyst without doping Ce in the same reaction condition.Conclusion It is proven that the doping of Ce in Pt/GAC improves the catalytic activity.The characterization of Pt/CeO2/GAC catalyst shows that Ce is presented as Ce4+ that not only increases the content of chemisorbed oxygen on the surface of the catalyst,but also increases the content of Pt greatly.
ABSTRACT
Objective To study the flow fields of electrolysis oxygen generation with micro-flow-channels of small square cylinders and the key structure factors impacting on the uniform distribution of the water flow in the micro-flow-channels.Methods The low Renault k-? model was used to represent the characteristics of the flow field in the micro-flow-channels.And the simulation results of the flow fields by CFD were calibrated by comparing with that of the particle image velocimetry(PIV) experiments,which showed that the low Renault k-? model was suitable to describe the flow field of the micro-flow-channels.Results The flow fields of variable flow were obtained.Conclusion The flow fields of variable flow rates distribute non-uniformly.The velocity magnitude is 10-3m/s,and the inlet structure of the electrolysis oxygen generation is a key factor impacting on the uniform distribution of the water flow.
ABSTRACT
Objective To study a technology for separating water from gas under microgravity in long-term manned space flight.Methods Several kinds of mixture of water and oxygen were separated by a new water/gas separating matrix and the action of gravity on the process was studied.Results The water/gas separator worked well in the range of gas flow below 2 500 mL/min and water flow below 4～6 L/h.A mixture of gas and water was separated into gas containing no water containing less than 1% gas.The phenomenon of a little oxygen existing in the water flow was explained.It was also found that gravity has nothing to do with the separation.Conclusion Hydrophilic porous membrane can be used to separate water from gas,and further works were continue needed to study the process and to resolve a few problems about water/gas separation under microgravity.
ABSTRACT
Preliminary research and partial satellite carrying experiment were firstly carried out,so as to research the technique of environmental control and life support system(ECLSS)of Chinese manned spacecraft.Environmental control and life support sub-system of "Shenzhou" spacecraft were developed subsequently,and the technique of physical/chemical regenerative ECLSS and controlled ecological life support system(CELSS)were also researched gradually.This paper introduced the research and development of ECLSS of Chinese manned spacecraft,and discussed the technical character of ECLSS.