A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic a...A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.展开更多
A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas vel...A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.展开更多
Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase（GPDH） which severel...Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase（GPDH） which severely affected the glycerol productivity. Three osmoregulators such as NaCl, PEG4000 and glycerol were used to investigate their effects on yeast growth, glucose consumption and glycerol production. In order to determine the effect of extracellular glycerol concentration, different amounts of glycerol were initially supplemented as an osmoregulator to increase glycerol production. The maximum glycerol concentration attained 179g·L^-1 with initial glycerol concentration of 80g·L^-1 in medium, compared with 41g·L^-1 in the control experiment. These results were successfully reoroduced for fed-batch orocess in an air-lift reactor.展开更多
基金Project(2009T100100602) supported by the Korea Institute of Energy Technology Evaluation and Planning,Korea
文摘A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.
基金Supported by Liaoning Provincial Natural Science Foundation(No.972050).
文摘A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.
基金Supported by the National Natural Science Foundation of China （No.20576118）.
文摘Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase（GPDH） which severely affected the glycerol productivity. Three osmoregulators such as NaCl, PEG4000 and glycerol were used to investigate their effects on yeast growth, glucose consumption and glycerol production. In order to determine the effect of extracellular glycerol concentration, different amounts of glycerol were initially supplemented as an osmoregulator to increase glycerol production. The maximum glycerol concentration attained 179g·L^-1 with initial glycerol concentration of 80g·L^-1 in medium, compared with 41g·L^-1 in the control experiment. These results were successfully reoroduced for fed-batch orocess in an air-lift reactor.
