Fe2＋ oxidation by Acidithiobacillus ferrooxidans（At.ferrooxidans） under different solid contents by adding inert Al2O3 powder was examined in rotating-drum and stirred-tank reactors.The results show that the bioact...Fe2＋ oxidation by Acidithiobacillus ferrooxidans（At.ferrooxidans） under different solid contents by adding inert Al2O3 powder was examined in rotating-drum and stirred-tank reactors.The results show that the bioactivity of At.ferrooxidans in the stirred-tank is higher than that in the rotating-drum in the absence of Al2O3 powder,but the biooxidation rate of Fe2＋ decreases markedly from 0.23 g/（L·h） to 0.025 g/（L·h） with increasing the content of Al2O3 powder from 0 to 50%（mass fraction） in the stirred-tank probably due to the deactivation of At.ferrooxidans resulting from the collision and friction of solid particles.The increase in Al2O3 content has a little adverse effect on the bioactivity of At.ferrooxidans in the rotating-drum due to different mixing mechanisms of the two reactors.The biooxidation rate of Fe2＋ in the rotating-drum is higher than that in the stirred-tank at the same content of Al2O3 powder,especially at high solid content.The higher bioactivity of At.ferrooxidans can be maintained for allowing high solid content in the rotating-drum reactor,but its application potential still needs to be verified further by the sulfide bioleaching for the property differences of Al2O3 powder and sulfide minerals.展开更多
Six Ni-Mo catalysts with different metal contents were prepared and characterized by N2 adsorption and X-ray diffi＇actometry. The active phase microstructure of these catalysts was examined by the Raman spectroscopy,...Six Ni-Mo catalysts with different metal contents were prepared and characterized by N2 adsorption and X-ray diffi＇actometry. The active phase microstructure of these catalysts was examined by the Raman spectroscopy, temperature- programmed reduction （TPR）, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Hydrodesulfurization （HDS） activity of catalyst samples were analyzed in a flow fixed-bed microreactor. The sulfidation degree of Mo and the length of the MoS2 slab slightly increased with the amount of metal loaded following sulfidation. This small change is attributed to polymolybdate species observed in all the oxidized catalysts. Weak metal-support interactions, as determined by the TPR technique, increased the NiSx sulfidation phase and MoS2 slab stacking. The HDS activity of the catalyst samples increased with the number of active sites. For high metal loading catalysts, their HDS activity was nearly identical because the sulfur atoms cannot easily approach active sites. This change is caused by the large number of stacked layers in the MoS2 slabs as well as the decrease in the specific surface area and pore volume of the catalyst samples with an increasing metal loading.展开更多
基金Project(2010CB630904) supported by the National Basic Research Program of ChinaProject(5102030) supported by the Beijing Natural Science Foundation,China+1 种基金Projects(21076214,21006108) supported by the National Natural Science Foundation of ChinaProject supported by the Open Funding Project of the State Key Laboratory of Bioreactor Engineering,China
文摘Fe2＋ oxidation by Acidithiobacillus ferrooxidans（At.ferrooxidans） under different solid contents by adding inert Al2O3 powder was examined in rotating-drum and stirred-tank reactors.The results show that the bioactivity of At.ferrooxidans in the stirred-tank is higher than that in the rotating-drum in the absence of Al2O3 powder,but the biooxidation rate of Fe2＋ decreases markedly from 0.23 g/（L·h） to 0.025 g/（L·h） with increasing the content of Al2O3 powder from 0 to 50%（mass fraction） in the stirred-tank probably due to the deactivation of At.ferrooxidans resulting from the collision and friction of solid particles.The increase in Al2O3 content has a little adverse effect on the bioactivity of At.ferrooxidans in the rotating-drum due to different mixing mechanisms of the two reactors.The biooxidation rate of Fe2＋ in the rotating-drum is higher than that in the stirred-tank at the same content of Al2O3 powder,especially at high solid content.The higher bioactivity of At.ferrooxidans can be maintained for allowing high solid content in the rotating-drum reactor,but its application potential still needs to be verified further by the sulfide bioleaching for the property differences of Al2O3 powder and sulfide minerals.
基金SINOPEC for its financial support(No.108012/No.108041)
文摘Six Ni-Mo catalysts with different metal contents were prepared and characterized by N2 adsorption and X-ray diffi＇actometry. The active phase microstructure of these catalysts was examined by the Raman spectroscopy, temperature- programmed reduction （TPR）, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Hydrodesulfurization （HDS） activity of catalyst samples were analyzed in a flow fixed-bed microreactor. The sulfidation degree of Mo and the length of the MoS2 slab slightly increased with the amount of metal loaded following sulfidation. This small change is attributed to polymolybdate species observed in all the oxidized catalysts. Weak metal-support interactions, as determined by the TPR technique, increased the NiSx sulfidation phase and MoS2 slab stacking. The HDS activity of the catalyst samples increased with the number of active sites. For high metal loading catalysts, their HDS activity was nearly identical because the sulfur atoms cannot easily approach active sites. This change is caused by the large number of stacked layers in the MoS2 slabs as well as the decrease in the specific surface area and pore volume of the catalyst samples with an increasing metal loading.
