It is generally admitted that experimental data obtained in“laboratory-scale”bubble columns are representative of“industrial-scale”reactors if the well-known three“Wilkinson et al.scale-up criteria”are satisfied...It is generally admitted that experimental data obtained in“laboratory-scale”bubble columns are representative of“industrial-scale”reactors if the well-known three“Wilkinson et al.scale-up criteria”are satisfied:(a)the diameter of the bubble column is larger than 0.15 m,(b)the sparger openings are larger than 1e2mm and(c)the aspect ratio is larger than 5.The aim of this communication is to contribute to the existing discussion.To this end,this communication collects relevant experimental investigation and include new experimental data:in particular,we have experimentally studied the combined effect of the aspect ratio(within the range of 1e15)and the sparger design(considering both“coarse”and“fine”spargers)on the gas holdup in a large-diameter and large-scale gas-liquid bubble column.The bubble column has been operated both in the batch mode and in the counter-current mode.Filtered air has been used as the gaseous phase in all the experiments,while the liquid phase has included deionized water and different aqueous solutions of organic(i.e.,ethanol)and inorganic(i.e.,sodium chloride,NaCl)active agents.It is found that the“Wilkinson et al.scale-up criteria”are valid for the air-water case in the batch mode for“very-coarse”spargers.Conversely,they are no more valid when considering different liquid velocity,and/or aqueous solutions of active agents,and other sparger openings.展开更多
The increasing concentration of CO_(2) in atmosphere is deemed the main reason of global warming.Therefore,efficiently capturing CO_(2) from various sources with energy conservation is of great significance.Herein,a s...The increasing concentration of CO_(2) in atmosphere is deemed the main reason of global warming.Therefore,efficiently capturing CO_(2) from various sources with energy conservation is of great significance.Herein,a series of experiments were carried out to successfully test the slurry-based ab-adsorption method for continuously capturing CO_(2) in the large-scale cycled separation unit with cost-effect taking into account the scale-up criteria.A bubble column(with height 4900 mm and inner diameter 376 mm)and a desorption tank(with volume 310 L)are the essential components of the separation unit.The novel slurry used in this study was formed with zeolitic imidazolate framework-8 and 2-methylimidazole-water solution.The influence of operation conditions was investigated systematically.The results show that increasing sorption pressure and slurry height level,decreasing gas volume flow and sorption temperature are beneficial for separation processes.The volume fraction of CO_(2) in the feed gas was also studied.Although the scale-up effect had been observed and it was found that it exerted a negative effect on CO_(2) capture,depending on experimental conditions,CO_(2) removal efficiency could still reach 85%-95%and the maximum CO_(2) loading in the recycled slurry could be up to0.007 mol·L-1·kPa-1.Furthermore,the slurry-based method could be operated well even under very moderate regeneration conditions(333 K and 0.05 MPa),which means that the novel approach shows greater energy conservation than traditional amine absorption methods.展开更多
实验测量了两种塔径( 200 和 500 mm)和两种操作模式(气体单独喷射和气液同轴喷射)下喷射环流反应器内的全塔平均气含率、局部气含率及轴向液速径向分布、循环液速,归纳出全塔平均气含率的关联式。实验发现,喷射环流反应器具有十分显著...实验测量了两种塔径( 200 和 500 mm)和两种操作模式(气体单独喷射和气液同轴喷射)下喷射环流反应器内的全塔平均气含率、局部气含率及轴向液速径向分布、循环液速,归纳出全塔平均气含率的关联式。实验发现,喷射环流反应器具有十分显著的放大效应。小塔( 200)与大塔( 500)中的全塔平均气含率存在很大差异:小塔的全塔平均气含率~气速关系曲线比大塔陡峭,低气速下小塔气含率低于大塔、较高气速下高于大塔。根据漂移通量法分析得到小塔中流型转变点在表观气速 0.1 m s 1左右,在实验气速范围内只存在拟均匀鼓泡流;大塔中流型转变点在表观气速 0.04 m s 1左右,随气速增大从拟均匀鼓泡流转变为湍动鼓泡流。喷射环流反应器比气升式环流反应器、一般鼓泡塔全塔平均气含率略低,但循环液速更大,适用于强化固体悬浮与混合的气液固三相反应过程。展开更多
It is known that the performances of multi-phase reactors depend on the operating parameters(the temperature and the pressure of the system),the phase properties,and the design parameters(the aspect ratio(AR),the bubb...It is known that the performances of multi-phase reactors depend on the operating parameters(the temperature and the pressure of the system),the phase properties,and the design parameters(the aspect ratio(AR),the bubble column diameter,and the gas sparger design).Hence,the precise design and the correct operation of multi-phase reactors depends on the understanding and prediction of the fluid dynamics parameters.This paper contributes to the existing discussion on the effect of operating and design parameter on multi-phase reactors and,in particular,it considers an industrial process(e.g.,the LOPROX(low pressure oxidation)case study,which is typical example of two-phase bubble columns).Based on a previously-validated set of correlations,the influence of operating and design parameter on system performances is studied and critically analyzed.First,we studied the effects of the design parameter on the liquid–gas interfacial area,by keeping constant the fluid physical–chemical properties as well as the operating conditions;subsequently,we discussed for a fixed system design,the influence of the liquid phase properties and the operating pressure.In conclusion,this paper is intended to provide guidelines for the design and scale-up of multi-phase reactors.展开更多
基于 Rheinpreussen-Koppers 示范装置和 Sasol 的浆态床 Fischer-Tropsch(FT)合成反应器工程放大实践,指出针对目前使用的 Fe 催化剂而言,浆态床 FT 合成的总包反应过程以反应控制为主,为浆态床 FT 合成反应器的放大提供了有利因数。...基于 Rheinpreussen-Koppers 示范装置和 Sasol 的浆态床 Fischer-Tropsch(FT)合成反应器工程放大实践,指出针对目前使用的 Fe 催化剂而言,浆态床 FT 合成的总包反应过程以反应控制为主,为浆态床 FT 合成反应器的放大提供了有利因数。当量直径放大概念在 Rheinpreussen-Koppers 示范装置的成功应用,为浆态床 FT 合成反应器的放大和生产能力的扩大提供了实践的基础。Sasol 浆态床 FT 合成反应器的工程放大成功是以其雄厚的固定流化床 FT 合成反应器的技术为基础的。简介了国内浆态床 FT 合成技术的工业化研究进展。展开更多
文摘It is generally admitted that experimental data obtained in“laboratory-scale”bubble columns are representative of“industrial-scale”reactors if the well-known three“Wilkinson et al.scale-up criteria”are satisfied:(a)the diameter of the bubble column is larger than 0.15 m,(b)the sparger openings are larger than 1e2mm and(c)the aspect ratio is larger than 5.The aim of this communication is to contribute to the existing discussion.To this end,this communication collects relevant experimental investigation and include new experimental data:in particular,we have experimentally studied the combined effect of the aspect ratio(within the range of 1e15)and the sparger design(considering both“coarse”and“fine”spargers)on the gas holdup in a large-diameter and large-scale gas-liquid bubble column.The bubble column has been operated both in the batch mode and in the counter-current mode.Filtered air has been used as the gaseous phase in all the experiments,while the liquid phase has included deionized water and different aqueous solutions of organic(i.e.,ethanol)and inorganic(i.e.,sodium chloride,NaCl)active agents.It is found that the“Wilkinson et al.scale-up criteria”are valid for the air-water case in the batch mode for“very-coarse”spargers.Conversely,they are no more valid when considering different liquid velocity,and/or aqueous solutions of active agents,and other sparger openings.
基金The authors gratefully acknowledge the financial supports received from the National Natural Science Foundation of China(21776301,21636009)the Science Foundation of China University of Petroleum,Beijing(2462018BJC004).
文摘The increasing concentration of CO_(2) in atmosphere is deemed the main reason of global warming.Therefore,efficiently capturing CO_(2) from various sources with energy conservation is of great significance.Herein,a series of experiments were carried out to successfully test the slurry-based ab-adsorption method for continuously capturing CO_(2) in the large-scale cycled separation unit with cost-effect taking into account the scale-up criteria.A bubble column(with height 4900 mm and inner diameter 376 mm)and a desorption tank(with volume 310 L)are the essential components of the separation unit.The novel slurry used in this study was formed with zeolitic imidazolate framework-8 and 2-methylimidazole-water solution.The influence of operation conditions was investigated systematically.The results show that increasing sorption pressure and slurry height level,decreasing gas volume flow and sorption temperature are beneficial for separation processes.The volume fraction of CO_(2) in the feed gas was also studied.Although the scale-up effect had been observed and it was found that it exerted a negative effect on CO_(2) capture,depending on experimental conditions,CO_(2) removal efficiency could still reach 85%-95%and the maximum CO_(2) loading in the recycled slurry could be up to0.007 mol·L-1·kPa-1.Furthermore,the slurry-based method could be operated well even under very moderate regeneration conditions(333 K and 0.05 MPa),which means that the novel approach shows greater energy conservation than traditional amine absorption methods.
文摘实验测量了两种塔径( 200 和 500 mm)和两种操作模式(气体单独喷射和气液同轴喷射)下喷射环流反应器内的全塔平均气含率、局部气含率及轴向液速径向分布、循环液速,归纳出全塔平均气含率的关联式。实验发现,喷射环流反应器具有十分显著的放大效应。小塔( 200)与大塔( 500)中的全塔平均气含率存在很大差异:小塔的全塔平均气含率~气速关系曲线比大塔陡峭,低气速下小塔气含率低于大塔、较高气速下高于大塔。根据漂移通量法分析得到小塔中流型转变点在表观气速 0.1 m s 1左右,在实验气速范围内只存在拟均匀鼓泡流;大塔中流型转变点在表观气速 0.04 m s 1左右,随气速增大从拟均匀鼓泡流转变为湍动鼓泡流。喷射环流反应器比气升式环流反应器、一般鼓泡塔全塔平均气含率略低,但循环液速更大,适用于强化固体悬浮与混合的气液固三相反应过程。
文摘It is known that the performances of multi-phase reactors depend on the operating parameters(the temperature and the pressure of the system),the phase properties,and the design parameters(the aspect ratio(AR),the bubble column diameter,and the gas sparger design).Hence,the precise design and the correct operation of multi-phase reactors depends on the understanding and prediction of the fluid dynamics parameters.This paper contributes to the existing discussion on the effect of operating and design parameter on multi-phase reactors and,in particular,it considers an industrial process(e.g.,the LOPROX(low pressure oxidation)case study,which is typical example of two-phase bubble columns).Based on a previously-validated set of correlations,the influence of operating and design parameter on system performances is studied and critically analyzed.First,we studied the effects of the design parameter on the liquid–gas interfacial area,by keeping constant the fluid physical–chemical properties as well as the operating conditions;subsequently,we discussed for a fixed system design,the influence of the liquid phase properties and the operating pressure.In conclusion,this paper is intended to provide guidelines for the design and scale-up of multi-phase reactors.
文摘基于 Rheinpreussen-Koppers 示范装置和 Sasol 的浆态床 Fischer-Tropsch(FT)合成反应器工程放大实践,指出针对目前使用的 Fe 催化剂而言,浆态床 FT 合成的总包反应过程以反应控制为主,为浆态床 FT 合成反应器的放大提供了有利因数。当量直径放大概念在 Rheinpreussen-Koppers 示范装置的成功应用,为浆态床 FT 合成反应器的放大和生产能力的扩大提供了实践的基础。Sasol 浆态床 FT 合成反应器的工程放大成功是以其雄厚的固定流化床 FT 合成反应器的技术为基础的。简介了国内浆态床 FT 合成技术的工业化研究进展。
