当今社会消耗了大量的化石能源,使得环境和能源问题十分突出。污泥厌氧消化产沼气是解决能源问题一种具有潜力的方法。然而,传统污泥厌氧消化存在效率低以及污泥停留时间长等问题,严重地阻碍了其优势的发挥。探究了添加不同浓度微量元...当今社会消耗了大量的化石能源,使得环境和能源问题十分突出。污泥厌氧消化产沼气是解决能源问题一种具有潜力的方法。然而,传统污泥厌氧消化存在效率低以及污泥停留时间长等问题,严重地阻碍了其优势的发挥。探究了添加不同浓度微量元素Fe和Ni对污泥厌氧消化产气和有机物去除的影响。结果表明,当FeCl_2投加量小于400 mg·L^(-1)时均能促进产气,FeCl_2投加量为25 mg·L^(-1)时,产气率取得最大值414.6 m L·g-1(VSadded),比对照组高28 m L·g-1(VSadded)。当NiCl_2投加量小于5 mg·L^(-1)时均能促进产气,在NiCl_2投加量为5 mg·L^(-1)时,产气率取得最大值389.5 m L·g-1(VSadded)。在最佳投加浓度下,添加Fe对产气的促进效果比添加Ni对产气的促进效果好。对有机物去除而言,当FeCl_2投加浓度为25 mg·L^(-1)时,有机物去除率轻微提升,而后随着FeCl_2添加量的增加整体呈下降趋势,FeCl_2最佳投加浓度为25 mg·L^(-1)。有机物去除率随着NiCl_2添加量的增加整体呈下降趋势。在水解产酸实验中,最优FeCl_2投加条件下(25 mg·L^(-1))能使污泥溶解态化学需氧量和挥发性脂肪酸浓度分别提高15.3%和39.2%,为后续的产气提供了更好的基质条件。展开更多
The hydrogen storage properties and catalytic mechanism of FeCl-doped LiAlHwere investigated in minute details. LiAlH-2 mol% FeClsamples start to release hydrogen at 76 °C, which is 64 °C lower than that of ...The hydrogen storage properties and catalytic mechanism of FeCl-doped LiAlHwere investigated in minute details. LiAlH-2 mol% FeClsamples start to release hydrogen at 76 °C, which is 64 °C lower than that of as-received LiAlH. Isothermal desorption measurements show that the 2 mol% FeCl-doped sample releases 7.0 wt% of hydrogen within 17 min at 250 °C. At lower temperatures of 110 °C and 80 °C, the sample can release 4.4 wt% and 3 wt% of hydrogen, respectively. The apparent activation energy of LiAlH-2 mol% FeClsamples for R2 is 105.02 k J/mol, which is 67 k J/mol lower than that of pure LiAlH. The reaction between LiAlHand FeClduring ball milling was found by analyzing the X-ray diffraction results,and Fe-Al particles formed in-situ from the reaction act as the real catalyst for the dehydrogenation of LiAlH.展开更多
The cyclic voltammetry, current time curve at potential step were used to investigate the electrochemical behavior of Fe(Ⅱ) in DMSO, DMF and CH 3CN solutions on Pt cathode. Experimental results indicate that the el...The cyclic voltammetry, current time curve at potential step were used to investigate the electrochemical behavior of Fe(Ⅱ) in DMSO, DMF and CH 3CN solutions on Pt cathode. Experimental results indicate that the electroreduction of Fe(Ⅱ) to Fe(0) is irreversible in one step on Pt electrode. The diffusion coefficients of Fe(Ⅱ) in DMSO, DMF and CH 3CN solutions at 298 K were determined to be 2.3×10 -6 , 1.32×10 -6 and 2.5×10 -6 cm 2·s -1 , respectively. The transfer coefficients of Fe(Ⅱ)+2e→Fe(0) in DMSO, DMF and CH 3CN solutions were determined to be 0.11, 0.10 and 0.06, respectively.展开更多
The passivation behavior of Fe in the acidic AlCl_3-1-ethyl-3-methyl-imidazolium chloride(AlCl_3-EMIC) ionic liquid was studied by linear sweep voltammetry and chonopotentiometry. Various approaches were used to chara...The passivation behavior of Fe in the acidic AlCl_3-1-ethyl-3-methyl-imidazolium chloride(AlCl_3-EMIC) ionic liquid was studied by linear sweep voltammetry and chonopotentiometry. Various approaches were used to characterize the composition and morphology of passive film formed on the Fe electrode, such as scanning electron microscopy(SEM), Raman spectra and X-ray Photoelectron Spectroscopy(XPS). The results showed that the critical passivation potential of Fe shifted to more negative when the molar ratio of AlCl_3:EMIC changing from 2 to 1.3.A film with a light yellow color was observed on the surface of the Fe electrode after passivation. The composition of the passive film was demonstrated to be FeCl_2. The passive film was composed of particulate FeCl_2 with average diameter of about 500 nm. The formation of FeCl_2 film was attributed to the variation of the electrolyte Lewis acidity from acidic to neutral at the interface during the dissolution process of Fe. The reason caused the variation of the electrolyte acidity was discussed.展开更多
The effect of cosolvent on the palladium catalyst which catalyze alkoxycarbonylation of allyl bromide in supercritical CO2 has been investigated. It was found that a small amount of cosolvent such as ethanol, CH2Cl2 a...The effect of cosolvent on the palladium catalyst which catalyze alkoxycarbonylation of allyl bromide in supercritical CO2 has been investigated. It was found that a small amount of cosolvent such as ethanol, CH2Cl2 and cyclohexane can affect both reaction yields and selectivities largely. Ethanol was the most favorable cosolvent for increasing the total yield of unsaturated esters and the selectivity of 3-butenoic acid ester. Using cosolvent ethanol and cocatalyst FeCl2 Simultaneously can lead to better reaction results.展开更多
文摘当今社会消耗了大量的化石能源,使得环境和能源问题十分突出。污泥厌氧消化产沼气是解决能源问题一种具有潜力的方法。然而,传统污泥厌氧消化存在效率低以及污泥停留时间长等问题,严重地阻碍了其优势的发挥。探究了添加不同浓度微量元素Fe和Ni对污泥厌氧消化产气和有机物去除的影响。结果表明,当FeCl_2投加量小于400 mg·L^(-1)时均能促进产气,FeCl_2投加量为25 mg·L^(-1)时,产气率取得最大值414.6 m L·g-1(VSadded),比对照组高28 m L·g-1(VSadded)。当NiCl_2投加量小于5 mg·L^(-1)时均能促进产气,在NiCl_2投加量为5 mg·L^(-1)时,产气率取得最大值389.5 m L·g-1(VSadded)。在最佳投加浓度下,添加Fe对产气的促进效果比添加Ni对产气的促进效果好。对有机物去除而言,当FeCl_2投加浓度为25 mg·L^(-1)时,有机物去除率轻微提升,而后随着FeCl_2添加量的增加整体呈下降趋势,FeCl_2最佳投加浓度为25 mg·L^(-1)。有机物去除率随着NiCl_2添加量的增加整体呈下降趋势。在水解产酸实验中,最优FeCl_2投加条件下(25 mg·L^(-1))能使污泥溶解态化学需氧量和挥发性脂肪酸浓度分别提高15.3%和39.2%,为后续的产气提供了更好的基质条件。
基金supported by Tianjin Natural Science Foundation 09JCZDJC24800
文摘The hydrogen storage properties and catalytic mechanism of FeCl-doped LiAlHwere investigated in minute details. LiAlH-2 mol% FeClsamples start to release hydrogen at 76 °C, which is 64 °C lower than that of as-received LiAlH. Isothermal desorption measurements show that the 2 mol% FeCl-doped sample releases 7.0 wt% of hydrogen within 17 min at 250 °C. At lower temperatures of 110 °C and 80 °C, the sample can release 4.4 wt% and 3 wt% of hydrogen, respectively. The apparent activation energy of LiAlH-2 mol% FeClsamples for R2 is 105.02 k J/mol, which is 67 k J/mol lower than that of pure LiAlH. The reaction between LiAlHand FeClduring ball milling was found by analyzing the X-ray diffraction results,and Fe-Al particles formed in-situ from the reaction act as the real catalyst for the dehydrogenation of LiAlH.
文摘The cyclic voltammetry, current time curve at potential step were used to investigate the electrochemical behavior of Fe(Ⅱ) in DMSO, DMF and CH 3CN solutions on Pt cathode. Experimental results indicate that the electroreduction of Fe(Ⅱ) to Fe(0) is irreversible in one step on Pt electrode. The diffusion coefficients of Fe(Ⅱ) in DMSO, DMF and CH 3CN solutions at 298 K were determined to be 2.3×10 -6 , 1.32×10 -6 and 2.5×10 -6 cm 2·s -1 , respectively. The transfer coefficients of Fe(Ⅱ)+2e→Fe(0) in DMSO, DMF and CH 3CN solutions were determined to be 0.11, 0.10 and 0.06, respectively.
基金the National Natural Science Foundation of China(No.51271166)
文摘The passivation behavior of Fe in the acidic AlCl_3-1-ethyl-3-methyl-imidazolium chloride(AlCl_3-EMIC) ionic liquid was studied by linear sweep voltammetry and chonopotentiometry. Various approaches were used to characterize the composition and morphology of passive film formed on the Fe electrode, such as scanning electron microscopy(SEM), Raman spectra and X-ray Photoelectron Spectroscopy(XPS). The results showed that the critical passivation potential of Fe shifted to more negative when the molar ratio of AlCl_3:EMIC changing from 2 to 1.3.A film with a light yellow color was observed on the surface of the Fe electrode after passivation. The composition of the passive film was demonstrated to be FeCl_2. The passive film was composed of particulate FeCl_2 with average diameter of about 500 nm. The formation of FeCl_2 film was attributed to the variation of the electrolyte Lewis acidity from acidic to neutral at the interface during the dissolution process of Fe. The reason caused the variation of the electrolyte acidity was discussed.
文摘The effect of cosolvent on the palladium catalyst which catalyze alkoxycarbonylation of allyl bromide in supercritical CO2 has been investigated. It was found that a small amount of cosolvent such as ethanol, CH2Cl2 and cyclohexane can affect both reaction yields and selectivities largely. Ethanol was the most favorable cosolvent for increasing the total yield of unsaturated esters and the selectivity of 3-butenoic acid ester. Using cosolvent ethanol and cocatalyst FeCl2 Simultaneously can lead to better reaction results.
