China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption ...China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994-2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China's declining energy intensity.展开更多
The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as ...The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as fly ash, slag in concrete save energy consumption, CO2 emissions and costs. The importance and effectiveness of recycled materials will be statistically evaluated via energy consumption, carbon footprint, ultimate strength and their ratios. Embodied energy to ultimate strength or embodied carbon to ultimate strength ratios may emphasize the effectiveness of a sustainable material. The analyses in this study indicate the utilization of the recycled steel and C50 concrete with 50% fly ash or slag is the most efficient way of using sustainable materials.展开更多
The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate...The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.展开更多
The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as constr...The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as construction （including manufacture of materials and equipment）, renewal （including repair work） and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O （input-output） table in Japan. According to our case study conducted from the construction phase to demolition, the EC （embodied CO2） of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions （CO2e） by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building＇s EC and CO2e by refrigerants was 9%-12% of the building＇s EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.展开更多
Here we utilize input-output tables for 2005 and 2010 to calculate the change in carbon dioxide emission intensity. Results show that total carbon dioxide emissions were 6.79 and 9.30 billion tons, and carbon dioxide ...Here we utilize input-output tables for 2005 and 2010 to calculate the change in carbon dioxide emission intensity. Results show that total carbon dioxide emissions were 6.79 and 9.30 billion tons, and carbon dioxide emission intensity was 0.37 and 0.33 ton per thousand CNY in 2005 and 2010, respectively. Carbon dioxide emission intensity declined 11% over these five years. We used structural decomposition analysis modeling to measure the effect of four factors on this reduction in intensity. We found that the contribution values of energy structure, energy efficiency, economic growth mode and economic structure were -0.001, -0.102, 0.050, and 0.013 ton per thousand CNY, respectively. Changes in energy efficiency and energy structure are major factors promoting decreases in carbon dioxide emission intensity; the effect of the former is more distinct than the latter. Economic growth mode and economic structure are major factors that increase carbon dioxide emission intensity, whereby the effect of the former is more distinct than the latter.展开更多
In this article, we calculate China's Mainland’s CO2 emission of fossil fuel consumption from 1991 to 2010 following the apparent consumption method recommend by IPCC： （i） the scale of CO2 emissions has increa...In this article, we calculate China's Mainland’s CO2 emission of fossil fuel consumption from 1991 to 2010 following the apparent consumption method recommend by IPCC： （i） the scale of CO2 emissions has increased nearly to 4 times as that in 1991; （ii） coal consumption constitutes the highest proportion due to the richness of coal resources in China; （iii） per capita CO2 emission has increased from 1.98 to 5.57 t CO2 ; （iv） carbon emission intensity declined significantly from 6.66 to 1.07 kg CO2 USD -1 , but recently it tends to be stable; and （v） regional develop gaps remain in China's Mainland, for according to the provincial data, in many developing regions economic increase over-reliance on fossil fuel consumption. China has made the promises and already taken actions to deal with the high carbon emission. Comprehensively considering the sustainability of development and the uncertainties remaining in global climate change, healthier structures of industry, intensive usage of fossil fuel, and a more balanced development pattern among the southern, central and western China should be put more emphasis.展开更多
基金funded by National Science Foundation (Grant No.40535027,40871065)program of Enviromental Education Base of Chinese University Students
文摘China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994-2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China's declining energy intensity.
文摘The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as fly ash, slag in concrete save energy consumption, CO2 emissions and costs. The importance and effectiveness of recycled materials will be statistically evaluated via energy consumption, carbon footprint, ultimate strength and their ratios. Embodied energy to ultimate strength or embodied carbon to ultimate strength ratios may emphasize the effectiveness of a sustainable material. The analyses in this study indicate the utilization of the recycled steel and C50 concrete with 50% fly ash or slag is the most efficient way of using sustainable materials.
基金Projects(U1202274,51004033,51204040,50974035)supported by the National Natural Science Foundation of ChinaProjects(2010AA03A405,2012AA062303)supported by the National High Technology Research and Development Program(863 Prograam)of ChinaProject(N100302005)supported by the Fundamental Research Funds for the Central Universities,China
文摘The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.
文摘The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as construction （including manufacture of materials and equipment）, renewal （including repair work） and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O （input-output） table in Japan. According to our case study conducted from the construction phase to demolition, the EC （embodied CO2） of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions （CO2e） by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building＇s EC and CO2e by refrigerants was 9%-12% of the building＇s EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.
基金National Natural Science Fund of China(No.71103012)Humanities and Social Science Project of Beijing University of Technology(No.X5104001201201)
文摘Here we utilize input-output tables for 2005 and 2010 to calculate the change in carbon dioxide emission intensity. Results show that total carbon dioxide emissions were 6.79 and 9.30 billion tons, and carbon dioxide emission intensity was 0.37 and 0.33 ton per thousand CNY in 2005 and 2010, respectively. Carbon dioxide emission intensity declined 11% over these five years. We used structural decomposition analysis modeling to measure the effect of four factors on this reduction in intensity. We found that the contribution values of energy structure, energy efficiency, economic growth mode and economic structure were -0.001, -0.102, 0.050, and 0.013 ton per thousand CNY, respectively. Changes in energy efficiency and energy structure are major factors promoting decreases in carbon dioxide emission intensity; the effect of the former is more distinct than the latter. Economic growth mode and economic structure are major factors that increase carbon dioxide emission intensity, whereby the effect of the former is more distinct than the latter.
基金the National Natural Science Foundation of China (31070384)
文摘In this article, we calculate China's Mainland’s CO2 emission of fossil fuel consumption from 1991 to 2010 following the apparent consumption method recommend by IPCC： （i） the scale of CO2 emissions has increased nearly to 4 times as that in 1991; （ii） coal consumption constitutes the highest proportion due to the richness of coal resources in China; （iii） per capita CO2 emission has increased from 1.98 to 5.57 t CO2 ; （iv） carbon emission intensity declined significantly from 6.66 to 1.07 kg CO2 USD -1 , but recently it tends to be stable; and （v） regional develop gaps remain in China's Mainland, for according to the provincial data, in many developing regions economic increase over-reliance on fossil fuel consumption. China has made the promises and already taken actions to deal with the high carbon emission. Comprehensively considering the sustainability of development and the uncertainties remaining in global climate change, healthier structures of industry, intensive usage of fossil fuel, and a more balanced development pattern among the southern, central and western China should be put more emphasis.
