This report aims to reduce the benzene in a mixture of benzene and toluene as a model reaction using catalytic hydrogenation. In this research, we developed a series of catalysts with different supports such as Ni/HMS...This report aims to reduce the benzene in a mixture of benzene and toluene as a model reaction using catalytic hydrogenation. In this research, we developed a series of catalysts with different supports such as Ni/HMS, Ni/HZSM-5, Ni/HZSM5-HMS, Ni/Al2O3 and Ni/SiO2. Kinetic of this reaction was investigated under various hydrogen and benzene pressures. For more study, two kinetic models have also been selected and tested to describe the kinetics for this reaction. Both used models, the power law and Langmuir-Hinshelwood, provided a good fit toward the experimental data and allowed to determine the kinetic parameters. Among these catalysts, Ni/Al2O3 showed the maximum benzene conversion （99.19%） at 130℃ for benzene hydrogenation. The lowest toluene conversion was observed for Ni/SiO2. Furthermore, this catalyst presented high selectivity to benzene （75.26%） at 130℃. The catalytic performance （activity, selectivity and stability） and kinetics evaluations were shown that the Ni/SiO2 is an effective catalyst to hydrogenate benzene. It seems that the surface properties particularly pore size are effective parameter compared to other factors such as acidity and metal dispersion in this process.展开更多
In a tokamak plasma, shear Alfvén waves （SAWs） are generally characterized by a continuous spectrum with gaps, due topoloidal symmetry breaking. For low frequencies, ｜ω｜〈〈｜ωA｜=νA/qR, it has been shown ...In a tokamak plasma, shear Alfvén waves （SAWs） are generally characterized by a continuous spectrum with gaps, due topoloidal symmetry breaking. For low frequencies, ｜ω｜〈〈｜ωA｜=νA/qR, it has been shown that the SAW continuum can becomeunstable due to finite ion temperature gradient. Here, νA is the Alfvén speed, q and R are the safety factor and the major radius of the flux surface, respectively. Recently, it has been shown, with the multiple scale asymptotic technique, that discrete modes may exist in an unstable shear Alfvén continuous spectrum, due to finite ion Larmor radius （FLR） and finite drift-orbit width （FOW） effects in tokamak plasmas which are stable with respect to ideal magnetohydrodynamic （MHD） instabilities .展开更多
文摘This report aims to reduce the benzene in a mixture of benzene and toluene as a model reaction using catalytic hydrogenation. In this research, we developed a series of catalysts with different supports such as Ni/HMS, Ni/HZSM-5, Ni/HZSM5-HMS, Ni/Al2O3 and Ni/SiO2. Kinetic of this reaction was investigated under various hydrogen and benzene pressures. For more study, two kinetic models have also been selected and tested to describe the kinetics for this reaction. Both used models, the power law and Langmuir-Hinshelwood, provided a good fit toward the experimental data and allowed to determine the kinetic parameters. Among these catalysts, Ni/Al2O3 showed the maximum benzene conversion （99.19%） at 130℃ for benzene hydrogenation. The lowest toluene conversion was observed for Ni/SiO2. Furthermore, this catalyst presented high selectivity to benzene （75.26%） at 130℃. The catalytic performance （activity, selectivity and stability） and kinetics evaluations were shown that the Ni/SiO2 is an effective catalyst to hydrogenate benzene. It seems that the surface properties particularly pore size are effective parameter compared to other factors such as acidity and metal dispersion in this process.
基金Supported by the National Natural Science Foundation of China（10135020）
文摘In a tokamak plasma, shear Alfvén waves （SAWs） are generally characterized by a continuous spectrum with gaps, due topoloidal symmetry breaking. For low frequencies, ｜ω｜〈〈｜ωA｜=νA/qR, it has been shown that the SAW continuum can becomeunstable due to finite ion temperature gradient. Here, νA is the Alfvén speed, q and R are the safety factor and the major radius of the flux surface, respectively. Recently, it has been shown, with the multiple scale asymptotic technique, that discrete modes may exist in an unstable shear Alfvén continuous spectrum, due to finite ion Larmor radius （FLR） and finite drift-orbit width （FOW） effects in tokamak plasmas which are stable with respect to ideal magnetohydrodynamic （MHD） instabilities .
