It is important but challenging to design and fabricate an efficient and cost-effective electrocatalyst for the oxygen evolution reaction(OER). Herein, we report free-standing 3 D nickel arrays with a cross-linked por...It is important but challenging to design and fabricate an efficient and cost-effective electrocatalyst for the oxygen evolution reaction(OER). Herein, we report free-standing 3 D nickel arrays with a cross-linked porous structure as interesting and high-performance electrocatalysts for OER via a facile one-step electrodeposition method. The 3 D nickel arrays are strongly anchored on the substrate, forming self-supported electrocatalysts with reinforced structural stability and high electrical conductivity. Because of their increased active surface area, abundant channels for electron/ion transportation and enhanced electronic conductivity, the designed 3 D nickel arrays exhibit superior electrocatalytic OER performance with a low overpotential(496 mV at 50 mA cm–2) and a small Tafel slope(43 mV dec–1) as well as long-term stability(no decay after 24 h) in alkaline solution. Our proposed rational design strategy may open up a new way to construct other advanced 3 D porous materials for widespread application in electrocatalysis.展开更多
The mathematic model of combined converter with two different flow modes of gas-cooled reactor was established. The effects of gas flow mode in gas-cooled reactor on combined converter was investigated with the yield ...The mathematic model of combined converter with two different flow modes of gas-cooled reactor was established. The effects of gas flow mode in gas-cooled reactor on combined converter was investigated with the yield of methanol was 1 400 kt/a. The results show that if the flow mode of the cooling pipe gas and the catalytic bed gas change from countercurrent to concurrent, the catalytic bed temperature distribution does not fit the most optimum temperature curve of reversible exothermic reaction and the heat duty of heat changer in whole process increased seriously, which means that there is much more equipment investment and more operating cost. The gas flow mode of gas-cooled reactor affects the methanol yield slightly. There- fore, the countercurrent gas flow mode of gas-cooled reactor is more lucrative in the combined converter process.展开更多
Reburning was applied to Polish automatic coal-fired retort boiler (25 kW).The use of bio-syngas reduced NOx emissions from the boiler by over 25%,below the significant level of 200 mg/m3 .Reburning was carried out us...Reburning was applied to Polish automatic coal-fired retort boiler (25 kW).The use of bio-syngas reduced NOx emissions from the boiler by over 25%,below the significant level of 200 mg/m3 .Reburning was carried out using an integrated system consisting of the boiler and a fixed-bed 60 kW (GazEla) gasification reactor.The process gas was continuously introduced above the coal burner of the boiler.The process parameters of the boiler and the gasifier were also measured and compared with the other units.Characteristic NOx emissions from automatic and manually operated boilers were also presented.展开更多
The influence of active metal components of catalyst, additives and catalyst preparation method on the reactivity of catalyst for selective hydrodesulfurization (HDS) of FCC naphtha was investigated, and the RSDS-21 c...The influence of active metal components of catalyst, additives and catalyst preparation method on the reactivity of catalyst for selective hydrodesulfurization (HDS) of FCC naphtha was investigated, and the RSDS-21 catalyst with high HDS performance and the RSDS-22 catalyst with high selectivity were developed by RIPP. The composite loading of a new series of catalysts for selective HDS of FCC gasoline has demonstrated excellent desulfurization activity and selectivity and can under conventional hydrotreating conditions manufacture clean gasoline product meeting the national IV emission standard and the Euro V emission standard with less loss in antiknock index. The finalized new series of FCC catalysts upon being adopted for selective HDS of FCC naphtha have good adaptability to different feedstocks along with good stability.展开更多
The gas-liquid phase equilibrium is used in controlling the nitrosation reaction process. Decomposition of nitrous acid and oxidation side reaction.are suppressed in a closed reaction system. The system pressure is us...The gas-liquid phase equilibrium is used in controlling the nitrosation reaction process. Decomposition of nitrous acid and oxidation side reaction.are suppressed in a closed reaction system. The system pressure is used as the criterion of the end of reaction, avoiding excessive feeding and reducing＇the decomposition＇of nitrous acid. The head space of the reactor is used as the gas buffer, stabilizing the feeding fluctuations and inhibiting the side reaction, decomposition of nitrous acid. Nitrogen oxide concentration is controlled at the minimum level.Thus the zero release ofnitrogen ox!de waste gas can be achieved without using any absorption process.展开更多
In this study, discharge at the outlet of Xijiang River, the biggest sub-basin of the Zhujiang River, was simulated and projected from 1961 to 2099 using the hydrological model HBV-D. The model uses precipitation and ...In this study, discharge at the outlet of Xijiang River, the biggest sub-basin of the Zhujiang River, was simulated and projected from 1961 to 2099 using the hydrological model HBV-D. The model uses precipitation and temperature data from CISRO/MK3 5, MPI/ECHAM5, and NCAR/CCSM3 under three greenhouse gas emission scenarios (SRES A2, A1B, B1). The results in water resources and flood frequency suggest that annual precipitation and annual runoff would increase after 2050 relative to the reference period of 1961-1990. In addition, increasing trends have been projected in area averaged monthly precipitation and runoff from May to October, while decreasing trends in those from December to February. More often and larger floods would occur in future. Potential increase in runoff during the low-flow season could ease the pressure of water demand until 2030, but the increase in runoff in the high-flow season, with more often and larger floods, more pressure on flood control after 2050 is expected.展开更多
In January 2013, a long-lasting episode of severe haze occurred in central and eastern China, and it attracted attention from all sectors of society. The process and evolution of haze pollution episodes were observed ...In January 2013, a long-lasting episode of severe haze occurred in central and eastern China, and it attracted attention from all sectors of society. The process and evolution of haze pollution episodes were observed by the ＂Forming Mechanism and Con- trol Strategies of Haze in China＂ group using an intensive aerosol and trace gases campaign that simultaneously obtained data at 11 ground-based observing sites in the CARE-China network. The characteristics and formation mechanism of haze pollu- tion episodes were discussed. Five haze pollution episodes were identified in the Beijing-Tianjin-Hebei （Jing-Jin-Ji） area; the two most severe episodes occurred during 9-15 January and 25-31 January. During these two haze pollution episodes, the maximum hourly PMz5 mass concentrations in Beijing were 680 and 530 ~tg m-3, respectively. The process and evolution of haze pollution episodes in other major cities in the Jing-Jin-Ji area, such as Shijiazhuang and Tianjin were almost the same as those observed in Beijing. The external cause of the severe haze episodes was the unusual atmospheric circulation, the depres- sion of strong cold air activities and the very unfavorable dispersion due to geographical and meteorological conditions. How- ever, the internal cause was the quick secondary transformation of primary gaseous pollutants to secondary aerosols, which contributed to the ＂explosive growth＂ and ＂sustained growth＂ of PM2.5. Particularly, the abnormally high amount of nitric ox- ide （NOx） in the haze episodes, produced by fossil fuel combustion and vehicle emissions, played a direct or indirect role in the quick secondary transformation of coal-burning sulphur dioxide （SO2） to sulphate aerosols. Furthermore, gaseous pollutants were transformed into secondary aerosols through heterogeneous reactions on the surface of fine particles, which can change the particle＇s size and chemical composition. Consequently, the proportion of secondary inorganic ions, such as sulphate and nitrate, gradually increased, which enhances particle hygroscopicity and thereby accelerating formation of the haze pollution.展开更多
Energy-yielding processes in the N-cycle form important links with the global C-cycle. One example is demonstrated with the supply of nitrogen to soils, initially resulting in lowered CO2 emissions. This well known ef...Energy-yielding processes in the N-cycle form important links with the global C-cycle. One example is demonstrated with the supply of nitrogen to soils, initially resulting in lowered CO2 emissions. This well known effect has mostly been interpreted as hampered or delayed soil respiration. When added in surplus, however, nitrogen supply does not stabilize the minimum emissions initially obtained, but gradually results in increased CO2 emissions. Specific inhibition of the CO2 consuming process nitrification in soils, with surplus ammonium supply or with acetylene, mostly results in additional CO2 emissions. The difference between this disclosed gross heterotrophic respiration （GHR） and the net CO2 emission （NHR） is the result of a within-soil CO2-sink. Soil respiration solely determined as CO2 emitted as NHR （the common situation） therefore may lead to misinterpretations of the function of the soil system, especially in areas with high N-deposition. As a consequence, the interpreted ’acclimation’ of the soil respiration response in a warmer world should be reconsidered. The concept of respiration inhibition by nitrogen supply may also be questioned. Disregard of these processes, including the indicated N-driven within-soil CO2-sink, may prevent adequate measures counteracting climate change.展开更多
Exothermic hydrogenation reaction of acetone is an important part of an IAH-CHP, and the performance of IAH-CHP is affected directly by this reaction. This paper studies the influence of space velocity, temperature, h...Exothermic hydrogenation reaction of acetone is an important part of an IAH-CHP, and the performance of IAH-CHP is affected directly by this reaction. This paper studies the influence of space velocity, temperature, hydrogen flow rate and pressure on conversion and selectivity experimentally. The byproducts are analyzed and classified into three types: hydrogenation product, cracking products and condensation products. Both the conversion and selectivity of this reaction have the same trend with the change of space velocity, temperature and hydrogen flow rate, and has the opposite trend with the change of pressure. As the space velocity increases, the conversion curve is a gradual decline parabola but the selectivity curve is close to a straight line. Hydrogen flow rate has a more obvious influence on conversion than temperature, whereas on selectivity the situation is opposite. High pressure increases the conversion of acetone to all products, but the increment of byproducts is more than that of isopropanol, so the selectivity decreases as pressure increases.展开更多
基金supported by the National Natural Science Foundation of China(51772272,51502263,51728204)the Fundamental Research Funds for the Central Universities(2018QNA4011)+2 种基金Qianjiang Talents Plan of Zhejiang Province(QJD1602029)the Program for Innovative Research Team in University of Ministry of Education of China(IRT13037)the Startup Foundation for Hundred-Talent Program of Zhejiang University~~
文摘It is important but challenging to design and fabricate an efficient and cost-effective electrocatalyst for the oxygen evolution reaction(OER). Herein, we report free-standing 3 D nickel arrays with a cross-linked porous structure as interesting and high-performance electrocatalysts for OER via a facile one-step electrodeposition method. The 3 D nickel arrays are strongly anchored on the substrate, forming self-supported electrocatalysts with reinforced structural stability and high electrical conductivity. Because of their increased active surface area, abundant channels for electron/ion transportation and enhanced electronic conductivity, the designed 3 D nickel arrays exhibit superior electrocatalytic OER performance with a low overpotential(496 mV at 50 mA cm–2) and a small Tafel slope(43 mV dec–1) as well as long-term stability(no decay after 24 h) in alkaline solution. Our proposed rational design strategy may open up a new way to construct other advanced 3 D porous materials for widespread application in electrocatalysis.
文摘The mathematic model of combined converter with two different flow modes of gas-cooled reactor was established. The effects of gas flow mode in gas-cooled reactor on combined converter was investigated with the yield of methanol was 1 400 kt/a. The results show that if the flow mode of the cooling pipe gas and the catalytic bed gas change from countercurrent to concurrent, the catalytic bed temperature distribution does not fit the most optimum temperature curve of reversible exothermic reaction and the heat duty of heat changer in whole process increased seriously, which means that there is much more equipment investment and more operating cost. The gas flow mode of gas-cooled reactor affects the methanol yield slightly. There- fore, the countercurrent gas flow mode of gas-cooled reactor is more lucrative in the combined converter process.
基金Projects(DEC-2011/01/B/ST8/07394,DEC-2011/01/D/ST8/07399)supported by the Polish National Centre for Science(NCN)
文摘Reburning was applied to Polish automatic coal-fired retort boiler (25 kW).The use of bio-syngas reduced NOx emissions from the boiler by over 25%,below the significant level of 200 mg/m3 .Reburning was carried out using an integrated system consisting of the boiler and a fixed-bed 60 kW (GazEla) gasification reactor.The process gas was continuously introduced above the coal burner of the boiler.The process parameters of the boiler and the gasifier were also measured and compared with the other units.Characteristic NOx emissions from automatic and manually operated boilers were also presented.
文摘The influence of active metal components of catalyst, additives and catalyst preparation method on the reactivity of catalyst for selective hydrodesulfurization (HDS) of FCC naphtha was investigated, and the RSDS-21 catalyst with high HDS performance and the RSDS-22 catalyst with high selectivity were developed by RIPP. The composite loading of a new series of catalysts for selective HDS of FCC gasoline has demonstrated excellent desulfurization activity and selectivity and can under conventional hydrotreating conditions manufacture clean gasoline product meeting the national IV emission standard and the Euro V emission standard with less loss in antiknock index. The finalized new series of FCC catalysts upon being adopted for selective HDS of FCC naphtha have good adaptability to different feedstocks along with good stability.
文摘The gas-liquid phase equilibrium is used in controlling the nitrosation reaction process. Decomposition of nitrous acid and oxidation side reaction.are suppressed in a closed reaction system. The system pressure is used as the criterion of the end of reaction, avoiding excessive feeding and reducing＇the decomposition＇of nitrous acid. The head space of the reactor is used as the gas buffer, stabilizing the feeding fluctuations and inhibiting the side reaction, decomposition of nitrous acid. Nitrogen oxide concentration is controlled at the minimum level.Thus the zero release ofnitrogen ox!de waste gas can be achieved without using any absorption process.
基金supported by the National Basic Research Program of China (No. 2010CB428401)
文摘In this study, discharge at the outlet of Xijiang River, the biggest sub-basin of the Zhujiang River, was simulated and projected from 1961 to 2099 using the hydrological model HBV-D. The model uses precipitation and temperature data from CISRO/MK3 5, MPI/ECHAM5, and NCAR/CCSM3 under three greenhouse gas emission scenarios (SRES A2, A1B, B1). The results in water resources and flood frequency suggest that annual precipitation and annual runoff would increase after 2050 relative to the reference period of 1961-1990. In addition, increasing trends have been projected in area averaged monthly precipitation and runoff from May to October, while decreasing trends in those from December to February. More often and larger floods would occur in future. Potential increase in runoff during the low-flow season could ease the pressure of water demand until 2030, but the increase in runoff in the high-flow season, with more often and larger floods, more pressure on flood control after 2050 is expected.
基金supported by the Chinese Academy of Sciences Strategic Priority Research Program(Grant Nos.XDB05020000 and XDA05100100)the National Natural Science Foundation of China(Grant Nos.41230642 and 41021004)
文摘In January 2013, a long-lasting episode of severe haze occurred in central and eastern China, and it attracted attention from all sectors of society. The process and evolution of haze pollution episodes were observed by the ＂Forming Mechanism and Con- trol Strategies of Haze in China＂ group using an intensive aerosol and trace gases campaign that simultaneously obtained data at 11 ground-based observing sites in the CARE-China network. The characteristics and formation mechanism of haze pollu- tion episodes were discussed. Five haze pollution episodes were identified in the Beijing-Tianjin-Hebei （Jing-Jin-Ji） area; the two most severe episodes occurred during 9-15 January and 25-31 January. During these two haze pollution episodes, the maximum hourly PMz5 mass concentrations in Beijing were 680 and 530 ~tg m-3, respectively. The process and evolution of haze pollution episodes in other major cities in the Jing-Jin-Ji area, such as Shijiazhuang and Tianjin were almost the same as those observed in Beijing. The external cause of the severe haze episodes was the unusual atmospheric circulation, the depres- sion of strong cold air activities and the very unfavorable dispersion due to geographical and meteorological conditions. How- ever, the internal cause was the quick secondary transformation of primary gaseous pollutants to secondary aerosols, which contributed to the ＂explosive growth＂ and ＂sustained growth＂ of PM2.5. Particularly, the abnormally high amount of nitric ox- ide （NOx） in the haze episodes, produced by fossil fuel combustion and vehicle emissions, played a direct or indirect role in the quick secondary transformation of coal-burning sulphur dioxide （SO2） to sulphate aerosols. Furthermore, gaseous pollutants were transformed into secondary aerosols through heterogeneous reactions on the surface of fine particles, which can change the particle＇s size and chemical composition. Consequently, the proportion of secondary inorganic ions, such as sulphate and nitrate, gradually increased, which enhances particle hygroscopicity and thereby accelerating formation of the haze pollution.
文摘Energy-yielding processes in the N-cycle form important links with the global C-cycle. One example is demonstrated with the supply of nitrogen to soils, initially resulting in lowered CO2 emissions. This well known effect has mostly been interpreted as hampered or delayed soil respiration. When added in surplus, however, nitrogen supply does not stabilize the minimum emissions initially obtained, but gradually results in increased CO2 emissions. Specific inhibition of the CO2 consuming process nitrification in soils, with surplus ammonium supply or with acetylene, mostly results in additional CO2 emissions. The difference between this disclosed gross heterotrophic respiration （GHR） and the net CO2 emission （NHR） is the result of a within-soil CO2-sink. Soil respiration solely determined as CO2 emitted as NHR （the common situation） therefore may lead to misinterpretations of the function of the soil system, especially in areas with high N-deposition. As a consequence, the interpreted ’acclimation’ of the soil respiration response in a warmer world should be reconsidered. The concept of respiration inhibition by nitrogen supply may also be questioned. Disregard of these processes, including the indicated N-driven within-soil CO2-sink, may prevent adequate measures counteracting climate change.
基金supported by the National Natural Science Foundation of China under Grant No 51276181the National Basic Research Program of China under Grant No 2011CB710705
文摘Exothermic hydrogenation reaction of acetone is an important part of an IAH-CHP, and the performance of IAH-CHP is affected directly by this reaction. This paper studies the influence of space velocity, temperature, hydrogen flow rate and pressure on conversion and selectivity experimentally. The byproducts are analyzed and classified into three types: hydrogenation product, cracking products and condensation products. Both the conversion and selectivity of this reaction have the same trend with the change of space velocity, temperature and hydrogen flow rate, and has the opposite trend with the change of pressure. As the space velocity increases, the conversion curve is a gradual decline parabola but the selectivity curve is close to a straight line. Hydrogen flow rate has a more obvious influence on conversion than temperature, whereas on selectivity the situation is opposite. High pressure increases the conversion of acetone to all products, but the increment of byproducts is more than that of isopropanol, so the selectivity decreases as pressure increases.
