Hydrogenation of 2-ethylanthraquinone is a key step in the industrial production of hydrogen peroxide via anthraquinone. This reaction on palladium-supported catalysts is normally carried out in trickle-bed reactors. ...Hydrogenation of 2-ethylanthraquinone is a key step in the industrial production of hydrogen peroxide via anthraquinone. This reaction on palladium-supported catalysts is normally carried out in trickle-bed reactors. A numerical model for simulation of a gas-liquid-solid hydrogenation trickle-bed reactor is presented. The model is based on the film theory and takes into account the axial dispersion effect on the performance of the reactor. Comparison of calculated values with data from pilot plant and industrial reactor shows that the agreement is quite satisfactory and the maximum variance is less than 5%. Gas-liquid and liquid-solid mass-transfer coefficients are determined by semi-empirical correlations available in the literature. The palladium-supported catalyst is extremely active and the reaction is always controlled by gas-liquid mass-transfer, and the overall effectiveness factor is always very low in agreement with the high catalytic activity of the palladium-supported catalyst.The overall effectiveness factor increases with decreasing catalyst hold-up. Therefore, it is feasible to improve the productivity of unit catalyst by decreasing the catalyst hold-up in a commercial plant with the hydrodynamic characters kept unchange.展开更多
Anthraquinone working solutions used in hydrogen peroxide manufacture were selected as the test system to investigate the flow pattern transition behavior of foaming system in the trickle bed reactor (TBR) with the me...Anthraquinone working solutions used in hydrogen peroxide manufacture were selected as the test system to investigate the flow pattern transition behavior of foaming system in the trickle bed reactor (TBR) with the method of measurement and analysis of the instantaneous pressure drop fluctuations. The boundaries and the corresponding flow map for the foaming system were established for TBR packed with different size particles. It was found that the size of particles shows significant effect on the flow regime distributions. A theoretical model proposed by Cheng and Yuan and an empirical correlation by Bartelmus and Janecki were used to predict boundaries of the flow pattern transition for anthraquinone working solutions. Comparison between estimation and experimental results showed that the predicted boundaries of Cheng and Yuan theoretical model are consistent with the observations in the present work.展开更多
For the gas and liquid superficial velocity ranging from 0.07—0.36?m·s -1 and 0.008—0.016?m·s -1 respectively,the significance of operating conditions on the macro-characteristic properties,such as liquid ...For the gas and liquid superficial velocity ranging from 0.07—0.36?m·s -1 and 0.008—0.016?m·s -1 respectively,the significance of operating conditions on the macro-characteristic properties,such as liquid holdup,pressure drop,pulsing velocity and pulsing frequency etc ,are investigated through experiments.Based on the 130 dynamic liquid holdup data a new correlation is proposed for the dynamic liquid holdup as: β d=1.324· γ·Re l 0.057 ·Re g -0.332 ,and correlation of the pressure drop is shown as: Δ p Δ L=∑iA i(1-ε) 2a 2 vε 3μ iu i+B i(1-ε)a vε 3ρ iu 2 i ,where A l=3.84×10 -3 ,A g =9.33×10 -3 ,B l=7.0×10 -5 ,B g =1.59×10 -4 .A new type of corcentric ring conductance probe was used to measure the conductance fluctuation in the trickle bed reactor packed with 4—5?mm glass beads.The pulse velocity and frequency are calculated based on the time series data.Correlations of the pulse velocity and pulse frequency were obtained as V p =1.575u g 1.98 1-0.0864u g 12.01 (1-17.668U l)and f= -2.505 +5.113U g +2.04×10 2U l,respectively.All the correlations have high accuracy in predicting the parameters.展开更多
基金国家重点基础研究发展规划项目 (No 2 0 0 0 0 480 0 5 )国家自然科学基金项目 (No 2 0 10 60 11)化学工程国家重点实验室资助~~
文摘Hydrogenation of 2-ethylanthraquinone is a key step in the industrial production of hydrogen peroxide via anthraquinone. This reaction on palladium-supported catalysts is normally carried out in trickle-bed reactors. A numerical model for simulation of a gas-liquid-solid hydrogenation trickle-bed reactor is presented. The model is based on the film theory and takes into account the axial dispersion effect on the performance of the reactor. Comparison of calculated values with data from pilot plant and industrial reactor shows that the agreement is quite satisfactory and the maximum variance is less than 5%. Gas-liquid and liquid-solid mass-transfer coefficients are determined by semi-empirical correlations available in the literature. The palladium-supported catalyst is extremely active and the reaction is always controlled by gas-liquid mass-transfer, and the overall effectiveness factor is always very low in agreement with the high catalytic activity of the palladium-supported catalyst.The overall effectiveness factor increases with decreasing catalyst hold-up. Therefore, it is feasible to improve the productivity of unit catalyst by decreasing the catalyst hold-up in a commercial plant with the hydrodynamic characters kept unchange.
文摘Anthraquinone working solutions used in hydrogen peroxide manufacture were selected as the test system to investigate the flow pattern transition behavior of foaming system in the trickle bed reactor (TBR) with the method of measurement and analysis of the instantaneous pressure drop fluctuations. The boundaries and the corresponding flow map for the foaming system were established for TBR packed with different size particles. It was found that the size of particles shows significant effect on the flow regime distributions. A theoretical model proposed by Cheng and Yuan and an empirical correlation by Bartelmus and Janecki were used to predict boundaries of the flow pattern transition for anthraquinone working solutions. Comparison between estimation and experimental results showed that the predicted boundaries of Cheng and Yuan theoretical model are consistent with the observations in the present work.
文摘For the gas and liquid superficial velocity ranging from 0.07—0.36?m·s -1 and 0.008—0.016?m·s -1 respectively,the significance of operating conditions on the macro-characteristic properties,such as liquid holdup,pressure drop,pulsing velocity and pulsing frequency etc ,are investigated through experiments.Based on the 130 dynamic liquid holdup data a new correlation is proposed for the dynamic liquid holdup as: β d=1.324· γ·Re l 0.057 ·Re g -0.332 ,and correlation of the pressure drop is shown as: Δ p Δ L=∑iA i(1-ε) 2a 2 vε 3μ iu i+B i(1-ε)a vε 3ρ iu 2 i ,where A l=3.84×10 -3 ,A g =9.33×10 -3 ,B l=7.0×10 -5 ,B g =1.59×10 -4 .A new type of corcentric ring conductance probe was used to measure the conductance fluctuation in the trickle bed reactor packed with 4—5?mm glass beads.The pulse velocity and frequency are calculated based on the time series data.Correlations of the pulse velocity and pulse frequency were obtained as V p =1.575u g 1.98 1-0.0864u g 12.01 (1-17.668U l)and f= -2.505 +5.113U g +2.04×10 2U l,respectively.All the correlations have high accuracy in predicting the parameters.
