The separation of ethylene glycol(EG)and 1,2-butanediol(1,2-BDO)azeotrope in the synthesis process of EG via coal and biomass is becoming of increasing commercial and environmental importance.Selective adsorption is d...The separation of ethylene glycol(EG)and 1,2-butanediol(1,2-BDO)azeotrope in the synthesis process of EG via coal and biomass is becoming of increasing commercial and environmental importance.Selective adsorption is deemed as the most promising methods because of energy saving and environment favorable.In this paper,NaY zeolite was used to separate 1,2-BDO from EG,and its adsorption properties was then investigated.The isotherms of EG and 1,2-BDO in vapor and liquid phases from 298 to 328 K indicated that they fitted Langmuir model quite well,and the NaY zeolite absorbent favored EG more than 1,2-BDO.The Grand Canonical Monte Carlo(GCMC)and molecular dynamics(MD)simulation techniques were conducted to investigate the competition adsorption and diffusion characteristics in different adsorption regions.It was observed that EG and 1,2-BDO molecules all have the most probable locations of the center of the 12-membered ring near the Na cations.The diffusivities of EG are lower than those of 1,2-BDO at the same adsorption concentration.At last,the breakthrough curves of the binary mixture regressed from the empirical Dose–Response model in fixed-bed column showed that the adsorption selectivity of EG could reach to as high as 2.43,verified that the NaY zeolite could effectively separate EG from 1,2-BDO.This work is also helpful for further separation of other dihydric alcohol mixtures from coal and biomass fermentation.展开更多
The kinetics of the oxidation of 1,2-butanediol or mephenesin by ditelluratocuprate（Ⅲ）（DTC） was investigated spectrophotometrically at temperatures between 283.2―303.2 K in alkaline media. The reaction rate show...The kinetics of the oxidation of 1,2-butanediol or mephenesin by ditelluratocuprate（Ⅲ）（DTC） was investigated spectrophotometrically at temperatures between 283.2―303.2 K in alkaline media. The reaction rate showed first order dependence in DTC and fractional order in 1,2-butanediol or mephenesin. It was shown that the pseudo- first-order rate constant kobs increased with an increase in concentration of OH– and a decrease in concentration of TeO42–. The reaction has a negative salt effect. A plausible mechanism of reaction involving a pre-equilibrium of adduct formation between the complex and 1,2-butanediol or mephenesin was proposed. The rate equations derived from the mechanism can explain all the experimental phenomena. The activation parameters for the rate-determining step were also calculated.展开更多
基金the National Natural Science Foundation of China(21576272)“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of Chinese Academy of Sciences,Grant No.XDA 21030600,Science and Technology Service Network Initiative,Chinese Academy of Sciences(KFJ-STS-QYZD-138).
文摘The separation of ethylene glycol(EG)and 1,2-butanediol(1,2-BDO)azeotrope in the synthesis process of EG via coal and biomass is becoming of increasing commercial and environmental importance.Selective adsorption is deemed as the most promising methods because of energy saving and environment favorable.In this paper,NaY zeolite was used to separate 1,2-BDO from EG,and its adsorption properties was then investigated.The isotherms of EG and 1,2-BDO in vapor and liquid phases from 298 to 328 K indicated that they fitted Langmuir model quite well,and the NaY zeolite absorbent favored EG more than 1,2-BDO.The Grand Canonical Monte Carlo(GCMC)and molecular dynamics(MD)simulation techniques were conducted to investigate the competition adsorption and diffusion characteristics in different adsorption regions.It was observed that EG and 1,2-BDO molecules all have the most probable locations of the center of the 12-membered ring near the Na cations.The diffusivities of EG are lower than those of 1,2-BDO at the same adsorption concentration.At last,the breakthrough curves of the binary mixture regressed from the empirical Dose–Response model in fixed-bed column showed that the adsorption selectivity of EG could reach to as high as 2.43,verified that the NaY zeolite could effectively separate EG from 1,2-BDO.This work is also helpful for further separation of other dihydric alcohol mixtures from coal and biomass fermentation.
基金Supported by the Natural Science Foundation of Hebei Province,China(No.295066)
文摘The kinetics of the oxidation of 1,2-butanediol or mephenesin by ditelluratocuprate（Ⅲ）（DTC） was investigated spectrophotometrically at temperatures between 283.2―303.2 K in alkaline media. The reaction rate showed first order dependence in DTC and fractional order in 1,2-butanediol or mephenesin. It was shown that the pseudo- first-order rate constant kobs increased with an increase in concentration of OH– and a decrease in concentration of TeO42–. The reaction has a negative salt effect. A plausible mechanism of reaction involving a pre-equilibrium of adduct formation between the complex and 1,2-butanediol or mephenesin was proposed. The rate equations derived from the mechanism can explain all the experimental phenomena. The activation parameters for the rate-determining step were also calculated.
