The paper studies CO2 degassing and controlling factors under the condition of contact metamorphism in the Shuangshan area, southern Tan-Lu fault belt and the method of calculating the amount of CO2 degassing. The res...The paper studies CO2 degassing and controlling factors under the condition of contact metamorphism in the Shuangshan area, southern Tan-Lu fault belt and the method of calculating the amount of CO2 degassing. The results show that the amount of CO2 degassing is controlled by the characteristics of the country rocks, including the thermal conductivity, penetrability, porosity and connectivity. Compositions, size and depth of intrusive rock also have an important influence on CO2 degassing, i.e., they generated numerous cracks in the country rocks, and thus allowed the easy flow and accumulation of fluids. The amount of CO2 flux in contact metamorphism is calculated quantitatively based on the metamorphic reaction and time-integrated fluid flux. The value （0.729- 2.446×10^4 mol/cm^2） of CO2 flux suggests that CO2 was provided mainly by the contact metamorphic reaction. The generation and releasing of CO2 are positively correlated with the degree of metamorphism, and XCO2 in fluids gradually increases from dolomite zone to calcite zone, but in the zone of grossular, fluid flux is the largest and XCO2 sharply decreases due to involvement of magmatic water. This study presents evidence that a large amount of industrial-scale CO2 can be produced during contact metamorphism. On the basis of theoretical and practical studies, a cone model has been proposed to response CO2 degassing for the contact metamorphism, and it can be used to explore CO2 accumulations beyond the oil-gas basins. This model can also be applied to the study of inorganic genesis of CO2 accumulations.展开更多
As significant differences in cellular physiology, metabolic potential and genetics occur among strains with morphological similarity, the screening of appropriate microalgae species for effective CO2 fixation and bio...As significant differences in cellular physiology, metabolic potential and genetics occur among strains with morphological similarity, the screening of appropriate microalgae species for effective CO2 fixation and biodiesel production is extremely critical. In this study, ten strains of Chlorella were cultivated in municipal wastewater influent（MWI） and their tolerance for MWI, CO2 fixation efficiency and lipid productivity were assessed. The results showed that the biomass concentrations of four strains（Chlorella vulgaris, Chlorella64.01, Chlorella regularis var. minima and Chlorella sp.） were significantly higher than other strains. When the cultivation systems were aerated with 10% CO2, Chlorella sp. showed the highest CO2 fixation efficiency（35.51%）, while the highest lipid accumulation（58.48%） was observed with C. vulgaris. Scanning electron microscopy images revealed that the cells of both Chlorella sp. and C. vulgaris kept their normal morphologies after 15 day batch culture.These findings indicated that Chlorella sp. and C. vulgaris have fairly good tolerance for MWI,and moreover, Chlorella sp. was appropriate for CO2 fixation while C. vulgaris represented the highest potential for producing biodiesel.展开更多
基金supported by grants from the Natural Science Foundation of China(grant Nos:40473021 and 40472074)the National Basic Research Program of China(grant No:2003CB214600).
文摘The paper studies CO2 degassing and controlling factors under the condition of contact metamorphism in the Shuangshan area, southern Tan-Lu fault belt and the method of calculating the amount of CO2 degassing. The results show that the amount of CO2 degassing is controlled by the characteristics of the country rocks, including the thermal conductivity, penetrability, porosity and connectivity. Compositions, size and depth of intrusive rock also have an important influence on CO2 degassing, i.e., they generated numerous cracks in the country rocks, and thus allowed the easy flow and accumulation of fluids. The amount of CO2 flux in contact metamorphism is calculated quantitatively based on the metamorphic reaction and time-integrated fluid flux. The value （0.729- 2.446×10^4 mol/cm^2） of CO2 flux suggests that CO2 was provided mainly by the contact metamorphic reaction. The generation and releasing of CO2 are positively correlated with the degree of metamorphism, and XCO2 in fluids gradually increases from dolomite zone to calcite zone, but in the zone of grossular, fluid flux is the largest and XCO2 sharply decreases due to involvement of magmatic water. This study presents evidence that a large amount of industrial-scale CO2 can be produced during contact metamorphism. On the basis of theoretical and practical studies, a cone model has been proposed to response CO2 degassing for the contact metamorphism, and it can be used to explore CO2 accumulations beyond the oil-gas basins. This model can also be applied to the study of inorganic genesis of CO2 accumulations.
文摘As significant differences in cellular physiology, metabolic potential and genetics occur among strains with morphological similarity, the screening of appropriate microalgae species for effective CO2 fixation and biodiesel production is extremely critical. In this study, ten strains of Chlorella were cultivated in municipal wastewater influent（MWI） and their tolerance for MWI, CO2 fixation efficiency and lipid productivity were assessed. The results showed that the biomass concentrations of four strains（Chlorella vulgaris, Chlorella64.01, Chlorella regularis var. minima and Chlorella sp.） were significantly higher than other strains. When the cultivation systems were aerated with 10% CO2, Chlorella sp. showed the highest CO2 fixation efficiency（35.51%）, while the highest lipid accumulation（58.48%） was observed with C. vulgaris. Scanning electron microscopy images revealed that the cells of both Chlorella sp. and C. vulgaris kept their normal morphologies after 15 day batch culture.These findings indicated that Chlorella sp. and C. vulgaris have fairly good tolerance for MWI,and moreover, Chlorella sp. was appropriate for CO2 fixation while C. vulgaris represented the highest potential for producing biodiesel.
