Sulfur hexafluoride(SF_(6))is an extremely severe greenhouse gas.It is an urgently important mission to find excellent candidates for selective adsorption of SF_(6),in order to reduce the emission of SF_(6) facilities...Sulfur hexafluoride(SF_(6))is an extremely severe greenhouse gas.It is an urgently important mission to find excellent candidates for selective adsorption of SF_(6),in order to reduce the emission of SF_(6) facilities.Here,we adopt the molecular simulation method to systematically explore the selective adsorption of SF_(6) in 22 kinds of representative covalent-and metal-organic frameworks.Results indicate that COF-6 is a promising candidate for the SF_(6) adsorption at low pressure P<20 kPa because of its small pore size,while MOF-180 and PAF-302 are excellent candidates at high pressure P=2×10^(3) kPa due to their large Brunauer-Emmett-Teller specific surface area(BET SSA)and pore volumes.For the two cases of the power industry(X_(SF_(6))=0.1)and the semiconductor industry(X_(SF_(6))=0.002)environments,COF-6 and ZIF-8 are fairly promising candidates for selective adsorption of SF_(6) from the SF_(6)/N_(2) mixtures,because they not only present the high selectivity,but also the large adsorption capacity at ambient environment,which can be considered as potential adsorbents for selective adsorption of SF_(6) at ambient conditions.展开更多
We present in-situ measurements of atmospheric sulfur hexafluoride（SF6） conducted by an automated gas chromatograph–electron capture detector system and a gas chromatography/mass spectrometry system at a regional b...We present in-situ measurements of atmospheric sulfur hexafluoride（SF6） conducted by an automated gas chromatograph–electron capture detector system and a gas chromatography/mass spectrometry system at a regional background site, Shangdianzi,in China, from June 2009 to May 2011, using the System for Observation of Greenhouse gases in Europe and Asia and Advanced Global Atmospheric Gases Experiment（AGAGE）techniques. The mean background and polluted mixing ratios for SF6 during the study period were 7.22 × 10-12（mol/mol, hereinafter） and 8.66 × 10-12, respectively. The averaged SF6 background mixing ratios at Shangdianzi were consistent with those obtained at other AGAGE stations located at similar latitudes（Trinidad Head and Mace Head）, but larger than AGAGE stations in the Southern Hemisphere（Cape Grim and Cape Matatula）. SF6 background mixing ratios increased rapidly during our study period, with a positive growth rate at 0.30 × 10-12year-1. The peak to peak amplitude of the seasonal cycle for SF6 background conditions was 0.07 × 10-12, while the seasonal fluctuation of polluted conditions was 2.16 × 10-12. During the study period, peak values of SF6 mixing ratios occurred in autumn when local surface horizontal winds originated from W/WSW/SW/SWS/S sectors, while lower levels of SF6 mixing ratios appeared as winds originated from N/NNE/NE/ENE/E sectors.展开更多
基金We are greatly thankful to the support from the Open Fund of the State Key Laboratory of Laser Interaction with Matter(SKLLIM1710).
文摘Sulfur hexafluoride(SF_(6))is an extremely severe greenhouse gas.It is an urgently important mission to find excellent candidates for selective adsorption of SF_(6),in order to reduce the emission of SF_(6) facilities.Here,we adopt the molecular simulation method to systematically explore the selective adsorption of SF_(6) in 22 kinds of representative covalent-and metal-organic frameworks.Results indicate that COF-6 is a promising candidate for the SF_(6) adsorption at low pressure P<20 kPa because of its small pore size,while MOF-180 and PAF-302 are excellent candidates at high pressure P=2×10^(3) kPa due to their large Brunauer-Emmett-Teller specific surface area(BET SSA)and pore volumes.For the two cases of the power industry(X_(SF_(6))=0.1)and the semiconductor industry(X_(SF_(6))=0.002)environments,COF-6 and ZIF-8 are fairly promising candidates for selective adsorption of SF_(6) from the SF_(6)/N_(2) mixtures,because they not only present the high selectivity,but also the large adsorption capacity at ambient environment,which can be considered as potential adsorbents for selective adsorption of SF_(6) at ambient conditions.
基金supported by the Natural Science Foundation of China(Nos.41030107,41205094)the National Basic Research Program of China"973"(No.2010CB950601)the CAMS Fundamental Research Funds(No.2014Z004)
文摘We present in-situ measurements of atmospheric sulfur hexafluoride（SF6） conducted by an automated gas chromatograph–electron capture detector system and a gas chromatography/mass spectrometry system at a regional background site, Shangdianzi,in China, from June 2009 to May 2011, using the System for Observation of Greenhouse gases in Europe and Asia and Advanced Global Atmospheric Gases Experiment（AGAGE）techniques. The mean background and polluted mixing ratios for SF6 during the study period were 7.22 × 10-12（mol/mol, hereinafter） and 8.66 × 10-12, respectively. The averaged SF6 background mixing ratios at Shangdianzi were consistent with those obtained at other AGAGE stations located at similar latitudes（Trinidad Head and Mace Head）, but larger than AGAGE stations in the Southern Hemisphere（Cape Grim and Cape Matatula）. SF6 background mixing ratios increased rapidly during our study period, with a positive growth rate at 0.30 × 10-12year-1. The peak to peak amplitude of the seasonal cycle for SF6 background conditions was 0.07 × 10-12, while the seasonal fluctuation of polluted conditions was 2.16 × 10-12. During the study period, peak values of SF6 mixing ratios occurred in autumn when local surface horizontal winds originated from W/WSW/SW/SWS/S sectors, while lower levels of SF6 mixing ratios appeared as winds originated from N/NNE/NE/ENE/E sectors.
