TiO_(2) is a promising photocatalyst,but its practical use is restricted by its low catalytic efficiency caused by the large particle size and uneven size distribution,which arise from the limited contact area of the ...TiO_(2) is a promising photocatalyst,but its practical use is restricted by its low catalytic efficiency caused by the large particle size and uneven size distribution,which arise from the limited contact area of the liquid-liquid interface during synthesis.Impinging stream-rotating packed bed(IS-RPB)reactors,which are used for process intensification,overcome the mixing limitation of traditional stirred-tank reactors and provide a micromixing environment at the molecular scale for the two liquid phases,which can reduce the particle size and distribution range.Cu/N-TiO_(2) nanoparticles were prepared in an IS-RPB reactor by the one-step precipitation method using urea as the nitrogen source,titanyl sulfate as the titanium source,copper chloride as the copper source,and ammonium hydroxide as the precipitant.The particle size of the photocatalyst was about 11.40 nm with a narrow size distribution measured by scanning electron microscopy and transmission electron microscopy.X-ray photoelectron spectroscopy showed that N replaced some O and was uniformly dispersed in the TiO_(2) lattice as interstitial and substitutional N.Cu replaced some Ti and was present as Cu^(2+).The synergistic effects of these two elements formed a new impurity energy level and reduced the band gap energy of the TiO_(2) nanoparticles.The specific surface area of the Cu/N-TiO_(2) nanoparticles was 152.97 m^(2)/g.The effects of the main factors on the degradation rate were studied,and the removal efficiency reached 100%under the optimal operating conditions after 2 h ultraviolet irradiation.The electron paramagnetic resonance measurements showed that the superoxide radical played a main role in the degradation process,whereas the photogenerated holes and hydroxyl radicals had weak effects.展开更多
A new continuous process for preparing methanol-diesel emulsified fuel with an Impinging Stream-Rotating Packed Bed is proposed. The droplet size of dispersed phase(methanol) of the emulsified fuel has a significant e...A new continuous process for preparing methanol-diesel emulsified fuel with an Impinging Stream-Rotating Packed Bed is proposed. The droplet size of dispersed phase(methanol) of the emulsified fuel has a significant effect on the combustion of methanol-diesel emulsified fuel. In this paper, the methanol-diesel emulsified fuel uses diesel as the continuous phase and methanol as the dispersed phase. The Sauter mean diameter of the dispersed phase of methanol-diesel emulsified fuel was characterized with microphotography and arithmetic method. The experimental result showed that the Sauter mean diameter of the dispersed phase, which was decreased with the augmentation of the high gravity factor, liquid flow rate and emulsifier dosage, was inversely proportional to the methanol content. The Sauter mean diameter of the dispersed phase can be controlled and adjusted in the range of 12—40 μm through the change of operating conditions. The correlative expressions of the Sauter mean diameter of emulsified fuel were obtained and the calculated values agreed well with the experimental values.展开更多
基金supported by the Natural Science Foundation of Shanxi Province (201901D211222)the Natural Science Foundation of the Shanxi Province of China (201901D111173)the Scientific and Technological Innovation Programs of Higher Education Institution in Shanxi (2019L0515)
文摘TiO_(2) is a promising photocatalyst,but its practical use is restricted by its low catalytic efficiency caused by the large particle size and uneven size distribution,which arise from the limited contact area of the liquid-liquid interface during synthesis.Impinging stream-rotating packed bed(IS-RPB)reactors,which are used for process intensification,overcome the mixing limitation of traditional stirred-tank reactors and provide a micromixing environment at the molecular scale for the two liquid phases,which can reduce the particle size and distribution range.Cu/N-TiO_(2) nanoparticles were prepared in an IS-RPB reactor by the one-step precipitation method using urea as the nitrogen source,titanyl sulfate as the titanium source,copper chloride as the copper source,and ammonium hydroxide as the precipitant.The particle size of the photocatalyst was about 11.40 nm with a narrow size distribution measured by scanning electron microscopy and transmission electron microscopy.X-ray photoelectron spectroscopy showed that N replaced some O and was uniformly dispersed in the TiO_(2) lattice as interstitial and substitutional N.Cu replaced some Ti and was present as Cu^(2+).The synergistic effects of these two elements formed a new impurity energy level and reduced the band gap energy of the TiO_(2) nanoparticles.The specific surface area of the Cu/N-TiO_(2) nanoparticles was 152.97 m^(2)/g.The effects of the main factors on the degradation rate were studied,and the removal efficiency reached 100%under the optimal operating conditions after 2 h ultraviolet irradiation.The electron paramagnetic resonance measurements showed that the superoxide radical played a main role in the degradation process,whereas the photogenerated holes and hydroxyl radicals had weak effects.
基金financially supported by the Natural Science Foundation of China (No.21206153, 21376229)the Science and Technology Foundation of Province Shanxi of China (No.2010021007-2, 2012011008-2)
文摘A new continuous process for preparing methanol-diesel emulsified fuel with an Impinging Stream-Rotating Packed Bed is proposed. The droplet size of dispersed phase(methanol) of the emulsified fuel has a significant effect on the combustion of methanol-diesel emulsified fuel. In this paper, the methanol-diesel emulsified fuel uses diesel as the continuous phase and methanol as the dispersed phase. The Sauter mean diameter of the dispersed phase of methanol-diesel emulsified fuel was characterized with microphotography and arithmetic method. The experimental result showed that the Sauter mean diameter of the dispersed phase, which was decreased with the augmentation of the high gravity factor, liquid flow rate and emulsifier dosage, was inversely proportional to the methanol content. The Sauter mean diameter of the dispersed phase can be controlled and adjusted in the range of 12—40 μm through the change of operating conditions. The correlative expressions of the Sauter mean diameter of emulsified fuel were obtained and the calculated values agreed well with the experimental values.
