The partial oxidation of hydrocarbons is an important technical route to produce acetylene for chemical industry.The partial oxidation reactor is the key to high acetylene yields.This work is an experimental and numer...The partial oxidation of hydrocarbons is an important technical route to produce acetylene for chemical industry.The partial oxidation reactor is the key to high acetylene yields.This work is an experimental and numerical study on the use of a methane flame to produce acetylene.A lab scale partial oxidation reactor was used to produce ultra fuel-rich premixed jet flames.The axial temperature and species concentration profiles were measured for different equivalence ratios and preheating temperatures,and these were compared to numerical results from Computational Fluid Dynamics(CFD)simulations that used the Reynolds Averaged Navier-Stokes Probability Density Function(RANS-PDF)approach coupled with detailed chemical mechanisms.The Leeds 1.5,GRI 3.0 and San Diego mechanisms were used to investigate the effect of the detailed chemical mechanisms.The effects of equivalence ratio and preheating temperature on acetylene production were experimentally and numerically studied.The experimental validations indicated that the present numerical simulation provided reliable prediction on the partial oxidation of methane.Using this simulation method the optimal equivalence ratio for acetylene production was determined to be 3.6.Increasing preheating temperature improved acetylene production and shortened greatly the ignition delay time.So the increase of preheating temperature had to be limited to avoid uncontrolled ignition in the mixing chamber and the pyrolysis of methane in the preheater.展开更多
Rhodium(III)-catalyzed coupling between ketoximes and alkynes via C–H activation and annulation typically followed the[4+2]selectivity to afford isoquinolines.By designing alkynes bearing a highly electron-withdrawin...Rhodium(III)-catalyzed coupling between ketoximes and alkynes via C–H activation and annulation typically followed the[4+2]selectivity to afford isoquinolines.By designing alkynes bearing a highly electron-withdrawing group and under substrate control,we have successfully switched the selectivity of the coupling between oximes and alkynes to the alternative[3+2]annulation,leading to the efficient synthesis of indenamines.This process features good regioselectivity for both substrates,high efficiency,broad substrate scope,and excellent functional group tolerance.展开更多
基金Supported by the National Natural Science Foundation of China(20976090)the Foundation for the Author of National Excellent Doctoral Dissertation of China(200757)
文摘The partial oxidation of hydrocarbons is an important technical route to produce acetylene for chemical industry.The partial oxidation reactor is the key to high acetylene yields.This work is an experimental and numerical study on the use of a methane flame to produce acetylene.A lab scale partial oxidation reactor was used to produce ultra fuel-rich premixed jet flames.The axial temperature and species concentration profiles were measured for different equivalence ratios and preheating temperatures,and these were compared to numerical results from Computational Fluid Dynamics(CFD)simulations that used the Reynolds Averaged Navier-Stokes Probability Density Function(RANS-PDF)approach coupled with detailed chemical mechanisms.The Leeds 1.5,GRI 3.0 and San Diego mechanisms were used to investigate the effect of the detailed chemical mechanisms.The effects of equivalence ratio and preheating temperature on acetylene production were experimentally and numerically studied.The experimental validations indicated that the present numerical simulation provided reliable prediction on the partial oxidation of methane.Using this simulation method the optimal equivalence ratio for acetylene production was determined to be 3.6.Increasing preheating temperature improved acetylene production and shortened greatly the ignition delay time.So the increase of preheating temperature had to be limited to avoid uncontrolled ignition in the mixing chamber and the pyrolysis of methane in the preheater.
基金supported by the Dalian Institute of Chemical Physics,Chinese Academy of Sciencesthe National Natural Science Foundation of China(21472186,21272231)
文摘Rhodium(III)-catalyzed coupling between ketoximes and alkynes via C–H activation and annulation typically followed the[4+2]selectivity to afford isoquinolines.By designing alkynes bearing a highly electron-withdrawing group and under substrate control,we have successfully switched the selectivity of the coupling between oximes and alkynes to the alternative[3+2]annulation,leading to the efficient synthesis of indenamines.This process features good regioselectivity for both substrates,high efficiency,broad substrate scope,and excellent functional group tolerance.
