The occurrences of associated elements and their genetic factors in the No. 30 coal seam in the Zhijin Coalfield were studied using instrumental neutron activation analysis, inductively coupled plasma-atomic emission ...The occurrences of associated elements and their genetic factors in the No. 30 coal seam in the Zhijin Coalfield were studied using instrumental neutron activation analysis, inductively coupled plasma-atomic emission spectroscopy, and a scanning electron microscope equipped with an energy-dispersive X-ray analyzer. And, a microscope photometer system (Leitz MPV-Ⅲ) was used to observe the characteristics of coal petrology. According to the influence degree by the siliceous low-temperature hydrothermal fluids, the organic matter is divided into four types: A, B, C, and D of the hydrothermally-altered organic matter (HAOM). The study shows that the high content of Fe (2.31%) is not from pyrite, but mostly from the siliceous low-temperature hydrothermal fluids. The occurrences of the associated elements in the four organic matter types are different. The contents of Fe, Si, and Al are decreasing, but S and Cu are increasing in the order of the HAOM-A, HAOM-B, HAOM-C, and HAOM-D. The losing rate of sulfur in organic matter is 0.35% and the content of Fe taken from the low-temperature hydrothermal fluids into the organic matter is 0.794% during the siliceous low-temperature hydrothermal fluids invading the coal seam. The above facts indicate that the low-temperature hydrothermal fluids play a crucial role in the re-distributions and occurrences of associated elements in coal.展开更多
To improve microalgae biomass utilization efficiency during biofuel production process,medium-low temperature hydrothermal hydrolysis pretreatment was adopted in this study.The pretreatment kinetic characteristics of ...To improve microalgae biomass utilization efficiency during biofuel production process,medium-low temperature hydrothermal hydrolysis pretreatment was adopted in this study.The pretreatment kinetic characteristics of concentrated wet microalgae Chlorella vulgaris biomass(50 g/L)under medium-low temperature hydrolysis(100°C-200°C)were experimentally investigated.The hydrothermal hydrolysis kinetics describing the coupled effects of temperature,initial pressure and retention time then were proposed using response surface methodology(RSM).The maximum carbohydrate yield reached 327.3 mg/g dried biomass under initial pressure of 4 MPa at reaction temperature of 150°C for 120 min.The maximum protein yield(321.5 mg/g dried biomass)was obtained under initial pressure of 4 MPa at reaction temperature of 200°C for 60 min.Based on the hydrothermal hydrolysis kinetic models,it was confirmed that temperature was the most important factor affecting both carbohydrate and protein release during hydrothermal hydrolysis process.Hydrothermal initial pressure and retention time were significant to carbohydrate release,but not to protein release.While,lipid was mainly distributed in microalgae residual and almost did not exist in supernatant(about 8.03 mg/g).And with assistance of mixed hexane and methanol(the ratio of hexane to methanol was 7:3),67.69%of microalgae lipid was extracted out from hydrothermal hydrolysed microalgae residual(123.3 mg/g dried biomass).展开更多
The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite t...The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied temperature difference grows and over the critical value. The phase relationships of the disturbed velocity,temperature and pressure demonstrate that the traveling wave is driven by the disturbed tem-perature,which is named hydrothermal wave. The hydrothermal wave is so weak that the oscillatory flow field and temperature distribution can hardly be observed in the liquid layer. The exciting mechanism of hydrothermal wave is analyzed and discussed in the present paper.展开更多
基金the National NaturalScience Foundation of China(No.40072054)the Coal Science Foundation of China(No.97Geo-10205).
文摘The occurrences of associated elements and their genetic factors in the No. 30 coal seam in the Zhijin Coalfield were studied using instrumental neutron activation analysis, inductively coupled plasma-atomic emission spectroscopy, and a scanning electron microscope equipped with an energy-dispersive X-ray analyzer. And, a microscope photometer system (Leitz MPV-Ⅲ) was used to observe the characteristics of coal petrology. According to the influence degree by the siliceous low-temperature hydrothermal fluids, the organic matter is divided into four types: A, B, C, and D of the hydrothermally-altered organic matter (HAOM). The study shows that the high content of Fe (2.31%) is not from pyrite, but mostly from the siliceous low-temperature hydrothermal fluids. The occurrences of the associated elements in the four organic matter types are different. The contents of Fe, Si, and Al are decreasing, but S and Cu are increasing in the order of the HAOM-A, HAOM-B, HAOM-C, and HAOM-D. The losing rate of sulfur in organic matter is 0.35% and the content of Fe taken from the low-temperature hydrothermal fluids into the organic matter is 0.794% during the siliceous low-temperature hydrothermal fluids invading the coal seam. The above facts indicate that the low-temperature hydrothermal fluids play a crucial role in the re-distributions and occurrences of associated elements in coal.
基金the International Cooperation and Exchange of the National Natural Science Foundation of China(Grant No.51561145013)the National Science Foundation for Young Scientists of China(Grant No.51606020)the National Key Research and Development Program-China(2016YFB0601002).
文摘To improve microalgae biomass utilization efficiency during biofuel production process,medium-low temperature hydrothermal hydrolysis pretreatment was adopted in this study.The pretreatment kinetic characteristics of concentrated wet microalgae Chlorella vulgaris biomass(50 g/L)under medium-low temperature hydrolysis(100°C-200°C)were experimentally investigated.The hydrothermal hydrolysis kinetics describing the coupled effects of temperature,initial pressure and retention time then were proposed using response surface methodology(RSM).The maximum carbohydrate yield reached 327.3 mg/g dried biomass under initial pressure of 4 MPa at reaction temperature of 150°C for 120 min.The maximum protein yield(321.5 mg/g dried biomass)was obtained under initial pressure of 4 MPa at reaction temperature of 200°C for 60 min.Based on the hydrothermal hydrolysis kinetic models,it was confirmed that temperature was the most important factor affecting both carbohydrate and protein release during hydrothermal hydrolysis process.Hydrothermal initial pressure and retention time were significant to carbohydrate release,but not to protein release.While,lipid was mainly distributed in microalgae residual and almost did not exist in supernatant(about 8.03 mg/g).And with assistance of mixed hexane and methanol(the ratio of hexane to methanol was 7:3),67.69%of microalgae lipid was extracted out from hydrothermal hydrolysed microalgae residual(123.3 mg/g dried biomass).
基金Supported by the National Natural Science Foundation of China (Grant No. 10432060)
文摘The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied temperature difference grows and over the critical value. The phase relationships of the disturbed velocity,temperature and pressure demonstrate that the traveling wave is driven by the disturbed tem-perature,which is named hydrothermal wave. The hydrothermal wave is so weak that the oscillatory flow field and temperature distribution can hardly be observed in the liquid layer. The exciting mechanism of hydrothermal wave is analyzed and discussed in the present paper.
