共查询到19条相似文献,搜索用时 156 毫秒
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在气升式搅拌反应器中,利用水对微溶气体CO2(常压和室温条件)的物理吸收过程,考察加入辛醇(有机分散相)对传质过程中体积传质系数和增强因子的影响。研究辛醇加入体积分数(1%—5%)、搅拌速率(200—700 r/min)、气体流速(350—700 L/min)变化对吸收效果的影响,用插值函数微商法确定体积传质系数。结果表明,向水体系中加入少量辛醇可以明显改善吸收效果,体积传质系数随辛醇加入体积分数的增加呈现先增加后减小的趋势,当辛醇加入的体积分数为4%左右时吸收效果最好。增强因子与CO2分配系数、扩散系数有关,与吸收效果呈线性关系,最大增强因子为2.76。 相似文献
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气泡细化过程中气含率的实验研究 总被引:1,自引:0,他引:1
应用压差法测定局部气含率,用膨胀法测定平均气含率.分别讨论了中心和偏心搅拌模式下气体流量、搅拌转速等因素对局部气含率和平均气含率的影响,以及局部气含率沿径向的变化规律.结果表明,中心双向搅拌和偏心单向搅拌均可显著提高气含率,且后者更有效;在筒内壁附近的气含率无论何种搅拌方式均随着气体流量的增大而增大;中心搅拌下的气含率随着径向距离的增大而下降,但偏心搅拌则在不同的位置气含率沿径向的变化表现出不同的变化趋势:平均气含率无论中心和偏心搅拌均随流量增加,但随转速的增加中心搅拌模式下气含率变小而偏心搅拌模式下的则增大. 相似文献
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用Kenlcs静态混合器,对碳酸钠水溶液吸收二氧化碳过程进行强化作了研究,测定了总体积传质系数,分析了静态混合元件强化气体吸收的机理。实验表明,传质系数随气体质量流量、流体质量流量和元件数的增加而增加。根据实验数据,得出了传质系数和吸收效率的关联式。 相似文献
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为研究CO2驱油田分离器内泡沫层产生及消除机理,设计了一套高压溶气原油泡沫测试系统,采用降压法研究了CO2-原油体系的发泡特性。利用高速摄像机对泡沫产生至衰变的演变过程进行了记录,总结分析了不同降压阶段的气泡行为,研究了降压速率和搅拌速率对原油发泡特性的影响规律。研究发现,随压力降低,稳定存在气泡的直径增大,气泡位置上移,发泡行为更加剧烈;降压速率增加对降压阶段的发泡行为无明显影响,但会加剧稳定工作压力下的发泡行为;在转速小于等于120 r/min的条件下,搅拌速率增加会加剧降压阶段的发泡行为,但会加速稳定工作压力下的泡沫衰变。 相似文献
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设计了以离子液体[APMIM]Br水溶液吸收-生成水合物捕获CO2工艺流程,并利用CO2在该离子水溶液中的溶解度数据和在其中生成CO2水合物的相平衡实验数据进行物料衡算. 考察了水含量、压力和液气流量比对气体吸收-水合物生成的CO2双重捕获效果的影响,对比了气体水合物与离子液体水溶液捕获CO2的能力. 结果表明,在较高压力和水含量条件下,水合物捕获CO2的效应强于离子液体溶液;较低压力下离子液体溶液吸收CO2起主要作用. 与纯水合物法相比,双捕获工艺具有一定优势,且突破了单纯水合物脱碳的压力和CO2含量要求高的局限性. 当原料气中CO2低于65%(j)时,系统的脱碳效率低于40%,对于CO2含量较低的气体,其CO2的脱除性能回归至单纯离子液体溶液体系. 相似文献
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Yuan-Kun Lee S. John Pirt 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1984,34(1):28-32
In a CO2-limited algal culture, grown in a tubular loop photobioreactor, the maximum rate of CO2 absorption increased about 1.5-fold when the culture pH value was increased from 6.5 to 7.5 with a fixed initial PCO2. The mean volumetric CO2 transfer coefficient (KLa) increased about 1.8-fold. The bicarbonate ion concentration would be increased 10-fold by the pH increase. The effect of pH on the absorption rate is attributed to changes in either the CO2 diffusivity, the gas bubble size, or the CO2 reaction kinetics at the gas/liquid boundary. 相似文献
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To investigate the mechanism of gas absorption from a bubble containing soluble and insoluble components, a gaseous mixture of ammonia and nitrogen was bubbled into water. The growth curve, volume, surface area and shape of the growing bubbles were measured with parameters such as inlet gas composition, gas flow rate and gas chamber volume. The bubble volume decreased with the increasing composition of ammonia in a bubble, decreasing gas chamber volume and decreasing gas flow rate.To reasonably express the mass transfer from the bulk of a gas in a bubble to the bulk of a liquid, the overall mass transfer resistance was evaluated by the mass transfers in the gas phase, interface and liquid phase.The non-spherical bubble formation model combined with the overall mass transfer resistance estimated well experimental bubble shape, bubble volume at its detachment from an orifice, growth rate and mass transfer rate.Moreover, the change of concentration with bubble growth time and the fractional absorption during bubble formation were simulated. 相似文献
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气化粗合成气主要成分为CO、CO2、H2,经过变换和重整后在催化剂作用下可以合成不同的化学品。熔融盐可吸收粗合成气中的CO2,并实现H2/CO在1.5~2.9之间调整。熔融盐合成气成份调整过程是一个传质与化学反应同时进行的非平衡、耦合过程。从球体扰流方程和反应动力学方程出发,通过量纲分析推导出合成气组分与操作条件的关系,对固定床内熔融盐对合成气成份调整过程进行了分析。熔融盐合成气成份调整的限制过程为气体从气泡表面向熔融盐内部的传质过程。温度升高、气泡直径减小、停留时间增加有利于合成气中H2百分比增加;然后对模型进行了实验验证,实验结果与理论结果吻合良好。 相似文献
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A continuous bubble‐column scrubber, capturing CO2 gas by monoethanolamine (MEA) solution in a pH‐stat operation, is used to search for optimum process parameters by means of the Taguchi method. The process variables are the pH of the solution, gas flow rate, concentration of CO2 gas, and temperature. From the measured outlet CO2 gas concentrations, the absorption rate and overall mass transfer coefficient can be determined with the support of a steady‐state material balance equation as well as a two‐film model. According to the signal‐to‐noise ratio, the significance sequence influencing the parameters and optimum conditions can be determined. CO2 concentration and pH value proved to be decisive parameters, while temperature and gas flow rate were minor. Five sets of optimum conditions were obtained and could be further verified by empirical equations. 相似文献
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Absorption of SO2 from a SO2/air mixture with sodium citrate buffer solution was investigated using a rotating packed bed(RPB) in laboratory scale.The effects of operating parameters,such as the rotation speed of RPB,liquid-gas ratio,inlet gas flow rate,inlet concentration of SO2 in flue gas,sodium citrate buffer concentration and initial pH of absorption solution,on the SO2 concentration in the absorption solution or removal efficiency of SO2 were examined.Incremental rate of sulfate radical ions in the absorption solution was also examined.Experimental results indicate that the efficiency of this regenerative process will be improved by using RPB under appropriate operating conditions,and the generation of SO2-4 will be restrained in the process in RPB. 相似文献
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The effect of different surfactants (n-octyltrimethylammonium bromide (OTABr), sodium dodecyl benzene sulfonate (SDBS) and Tween 80) with different critical micelle concentrations (CMC) on the CO2 absorption into aqueous solutions in a bubble column is analyzed in the present work. The presence of these surfactants in-creased the gas–liquid interfacial area, and decreased the liquid phase mass transfer coefficient, but with signif-icant different extent. The results indicated that the CMC can be a key parameter affecting the mass transfer of CO2 absorption into a dilute aqueous solution of a surfactant. Sardeing's model was used to fit the experimental data successfully by re-correlating the parameters. 相似文献