Hydrate formation rate and separation effect on the capture of CO2 from binary mixture via forming hydrate with 5 wt% tetra-n-butyl ammonium bromide （TBAB） solution were studied. The results showed that the inductio...Hydrate formation rate and separation effect on the capture of CO2 from binary mixture via forming hydrate with 5 wt% tetra-n-butyl ammonium bromide （TBAB） solution were studied. The results showed that the induction time was 5 min, and the hydrate formation process finished in 1 h at 4.5 ℃ and 4.01 MPa. The hydrate formation rate constant reached the maximum of 1.84× 10^-7 molZ/（s.J） with the feed pressure of 7.30 MPa. The CO2 recovery was about 45 % in the feed pressure range from 4.30 to 7.30 MPa. Under the feed pressure of 4.30 MPa, the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 mol%, respectively. The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.展开更多
Semiclathrate hydrates of tetra-n-butyl ammonium bromide （TBAB） offer potential solution for gas storage, transportation, separation of flue gases and CO2 sequestration. Models for phase equilibria for these systems...Semiclathrate hydrates of tetra-n-butyl ammonium bromide （TBAB） offer potential solution for gas storage, transportation, separation of flue gases and CO2 sequestration. Models for phase equilibria for these systems have not yet been developed in open literatures and thus require urgent attention. In this work, the first attempt has been made to model phase equilibria of semiclathrate hydrates of CH4, CO2 and N2 in aqueous solution of TBAB. A thermodynamic model for gas hydrate system as proposed by Chen and Guo has been extended for semiclathrate hydrates of gases in aqueous solution of TBAB. A correlation for the activity of water relating to the system temperature, concentration of TBAB in the system and the nature of guest gas molecule has been proposed. The model results have been validated against available experimental data on phase equilibria of semiclathrate hydrate systems of aqueous TBAB with different gases as guest molecule. The extended Chen and Guo＇s model is found to be suitable to explain the promotion effect of TBAB for the studied gaseous system such as, methane, carbon dioxide and nitrogen as a guest molecule. Additionally, a correlation for the increase in equilibrium formation temperature （hydrate promotion temperature, ATp） of semiclathrate hydrate system with respect to pure gas hydrate system has been developed and applied to semiclathrate hydrate of TBAB with several gases as guest molecules. The developed correlation is found to predict the promotion effect satisfactorily for the system studied.展开更多
利用离子速度影象技术研究了正-溴丁烷（n-C4H9Br）在231-267nm波段的光解，得出了如下结论：正-溴丁烷（n-C4H9Br）在231-267nm波段的吸收源于基态到三个最低激发态的跃迁，这三个激发态标识为1A″、2A′和3A′；发生在这三个排斥态的...利用离子速度影象技术研究了正-溴丁烷（n-C4H9Br）在231-267nm波段的光解，得出了如下结论：正-溴丁烷（n-C4H9Br）在231-267nm波段的吸收源于基态到三个最低激发态的跃迁，这三个激发态标识为1A″、2A′和3A′；发生在这三个排斥态的势能面（PES）上的光解最终导致C4H9＋Br（^2P3/2）或C4H9＋Br^＊（^2P1／2）的产生；2A′和3A′态之间存在避免交叉（Avoided crossing）会影响最终的光解产物；从基态1A′到激发态1A″的跃迁矩垂直于对称面，也就垂直于C-Br键；从基态1A′到激发态3A′的跃迁矩平行于对称面，同时平行于C—Br键；从基态1A′到激发态2A′的跃迁矩在对称面内，且与C—Br键成53．1^＊夹角．我们也讨论了正-溴丁烷（n—C4H9Br）在234nm和267nm附近光解时的避免交叉几率（Avoided crossing probability），以及它对单通道相对产额（Relative fraction of the individual pathways）的影响．展开更多
文摘Hydrate formation rate and separation effect on the capture of CO2 from binary mixture via forming hydrate with 5 wt% tetra-n-butyl ammonium bromide （TBAB） solution were studied. The results showed that the induction time was 5 min, and the hydrate formation process finished in 1 h at 4.5 ℃ and 4.01 MPa. The hydrate formation rate constant reached the maximum of 1.84× 10^-7 molZ/（s.J） with the feed pressure of 7.30 MPa. The CO2 recovery was about 45 % in the feed pressure range from 4.30 to 7.30 MPa. Under the feed pressure of 4.30 MPa, the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 mol%, respectively. The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.
基金supported by the the Industrial Consultancy and Sponsored Research (ICSR),Indian Institute of Technology Madras,Chennai (Project Number OEC/10 11/530/NFSC/JITE)the National Institute of Ocean Technology (NIOT),Chennai,India (Project Number OEC/10-11/105/NIOT/JITE)
文摘Semiclathrate hydrates of tetra-n-butyl ammonium bromide （TBAB） offer potential solution for gas storage, transportation, separation of flue gases and CO2 sequestration. Models for phase equilibria for these systems have not yet been developed in open literatures and thus require urgent attention. In this work, the first attempt has been made to model phase equilibria of semiclathrate hydrates of CH4, CO2 and N2 in aqueous solution of TBAB. A thermodynamic model for gas hydrate system as proposed by Chen and Guo has been extended for semiclathrate hydrates of gases in aqueous solution of TBAB. A correlation for the activity of water relating to the system temperature, concentration of TBAB in the system and the nature of guest gas molecule has been proposed. The model results have been validated against available experimental data on phase equilibria of semiclathrate hydrate systems of aqueous TBAB with different gases as guest molecule. The extended Chen and Guo＇s model is found to be suitable to explain the promotion effect of TBAB for the studied gaseous system such as, methane, carbon dioxide and nitrogen as a guest molecule. Additionally, a correlation for the increase in equilibrium formation temperature （hydrate promotion temperature, ATp） of semiclathrate hydrate system with respect to pure gas hydrate system has been developed and applied to semiclathrate hydrate of TBAB with several gases as guest molecules. The developed correlation is found to predict the promotion effect satisfactorily for the system studied.
文摘利用离子速度影象技术研究了正-溴丁烷（n-C4H9Br）在231-267nm波段的光解，得出了如下结论：正-溴丁烷（n-C4H9Br）在231-267nm波段的吸收源于基态到三个最低激发态的跃迁，这三个激发态标识为1A″、2A′和3A′；发生在这三个排斥态的势能面（PES）上的光解最终导致C4H9＋Br（^2P3/2）或C4H9＋Br^＊（^2P1／2）的产生；2A′和3A′态之间存在避免交叉（Avoided crossing）会影响最终的光解产物；从基态1A′到激发态1A″的跃迁矩垂直于对称面，也就垂直于C-Br键；从基态1A′到激发态3A′的跃迁矩平行于对称面，同时平行于C—Br键；从基态1A′到激发态2A′的跃迁矩在对称面内，且与C—Br键成53．1^＊夹角．我们也讨论了正-溴丁烷（n—C4H9Br）在234nm和267nm附近光解时的避免交叉几率（Avoided crossing probability），以及它对单通道相对产额（Relative fraction of the individual pathways）的影响．
文摘设计了1-溴正丁烷与金属镁反应制备格氏试剂,并将其与环己嗣反应合成1-正丁基环己醇的实验室合成方案,探讨了金属镁预处理、格氏试剂与环已嗣反应时间等实验条件对产率的影响.实验结果表明:金属镁预处理与否对产率的影响不大,格氏试剂与环已酮反应时间需50 min,产率约为50.0%,完成整个实验约需5 h.
