In the present study,a series of Ru/ZSM-5 catalysts with different pore-size distributions were prepared and investigated for NH3 synthesis.Our studies indicate that Ru/ZSM-5-Mic with micropore structure exhibits supe...In the present study,a series of Ru/ZSM-5 catalysts with different pore-size distributions were prepared and investigated for NH3 synthesis.Our studies indicate that Ru/ZSM-5-Mic with micropore structure exhibits superior NH3 synthesis rate,which is much higher than those of Ru/ZSM-5-Mac(with macroporous structure)and Ru/ZSM-5-Mes(with mesoporous structure)catalysts.A series of TPD experiments demonstrate that pore-size distributions play an important role in N2 adsorption and activation over Ru/ZSM-5.Moreover,the addition of La significantly promotes the NH3 synthesis performance over Ru/ZSM-5-Mic.Additionally,in situ DRIFTS studies indicate that the main intermediate species over Ru/ZSM-5-Mic are-NH2,and most of the surface hydrogen species desorb following the H2O-formation pathway.展开更多
Fractal pore-size distribution K(x) is given based on J(x) function proposed by Jaronic. Activated carbon fibers (ACF) with different surface areas are characterized by using two functions mentioned above. The present...Fractal pore-size distribution K(x) is given based on J(x) function proposed by Jaronic. Activated carbon fibers (ACF) with different surface areas are characterized by using two functions mentioned above. The present work studies the fractal pore-size distribution of ACF and adsorption isotherms of nonpolar benzene vapor on ACF, and thereby reveals the correlation between them.展开更多
Research on the Gangxi III area in the Dagang Oilfield shows that there was still a significant amount of oil remaining in oil reservoirs after many years of polymer flooding.This is a potential target for enhanced oi...Research on the Gangxi III area in the Dagang Oilfield shows that there was still a significant amount of oil remaining in oil reservoirs after many years of polymer flooding.This is a potential target for enhanced oil recovery（EOR）.Surfactant–polymer（SP） flooding is an effective chemical EOR method for mobilizing residual oil and improving displacement efficiency macroscopically,but the microscopic oil displacement efficiency in pores of different sizes is unclear.Nuclear magnetic resonance（NMR） is an efficient method for quantifying oil saturation in the rock matrix and analyzing pore structures.In this paper,the threshold values of different pore sizes were established from the relationship between mercury injection curves and NMR T2 spectrums.The distribution and migration of residual oil in different flooding processes was evaluated by quantitatively analyzing the change of the relaxation time.The oil displaced from pores of different sizes after the water flood,polymer flood,and the SP flood was calculated,respectively.Experimental results indicate that（1） the residual oil in medium pores contributed the most to the incremental oil recovery for the SP flood,ranging from 40 % to 49 %,and small pores usually contributed ／30 %;（2） the residual oil after the SP flood was mainly distributed in small and medium pores;the residual oil in medium pores accounted for 47.3 %–54.7 %,while that trapped in small pores was 25.7 %–42.5 %.The residual oil in small and medium pores was the main target for EOR after the SP flood in oilfields.展开更多
基金Project supported by the National Natural Science Foundation of China(21972019)。
文摘In the present study,a series of Ru/ZSM-5 catalysts with different pore-size distributions were prepared and investigated for NH3 synthesis.Our studies indicate that Ru/ZSM-5-Mic with micropore structure exhibits superior NH3 synthesis rate,which is much higher than those of Ru/ZSM-5-Mac(with macroporous structure)and Ru/ZSM-5-Mes(with mesoporous structure)catalysts.A series of TPD experiments demonstrate that pore-size distributions play an important role in N2 adsorption and activation over Ru/ZSM-5.Moreover,the addition of La significantly promotes the NH3 synthesis performance over Ru/ZSM-5-Mic.Additionally,in situ DRIFTS studies indicate that the main intermediate species over Ru/ZSM-5-Mic are-NH2,and most of the surface hydrogen species desorb following the H2O-formation pathway.
文摘Fractal pore-size distribution K(x) is given based on J(x) function proposed by Jaronic. Activated carbon fibers (ACF) with different surface areas are characterized by using two functions mentioned above. The present work studies the fractal pore-size distribution of ACF and adsorption isotherms of nonpolar benzene vapor on ACF, and thereby reveals the correlation between them.
基金Scientific Research Foundation of China University of Petroleum,Beijing (No.2462013YJRC033) and (No.01JB0177)
文摘Research on the Gangxi III area in the Dagang Oilfield shows that there was still a significant amount of oil remaining in oil reservoirs after many years of polymer flooding.This is a potential target for enhanced oil recovery（EOR）.Surfactant–polymer（SP） flooding is an effective chemical EOR method for mobilizing residual oil and improving displacement efficiency macroscopically,but the microscopic oil displacement efficiency in pores of different sizes is unclear.Nuclear magnetic resonance（NMR） is an efficient method for quantifying oil saturation in the rock matrix and analyzing pore structures.In this paper,the threshold values of different pore sizes were established from the relationship between mercury injection curves and NMR T2 spectrums.The distribution and migration of residual oil in different flooding processes was evaluated by quantitatively analyzing the change of the relaxation time.The oil displaced from pores of different sizes after the water flood,polymer flood,and the SP flood was calculated,respectively.Experimental results indicate that（1） the residual oil in medium pores contributed the most to the incremental oil recovery for the SP flood,ranging from 40 % to 49 %,and small pores usually contributed ／30 %;（2） the residual oil after the SP flood was mainly distributed in small and medium pores;the residual oil in medium pores accounted for 47.3 %–54.7 %,while that trapped in small pores was 25.7 %–42.5 %.The residual oil in small and medium pores was the main target for EOR after the SP flood in oilfields.
