超重力技术在脱硫液再生中的探索性研究

用超重力旋转填充床替代再生槽。进行了超重力法再生脱硫液的研究。实验证明，用一台7L的超重力旋转填充床替代原有的320L再生槽。可以达到更好的再生效果。经超重力旋转填充床再生的脱硫液可提高脱硫效率、减少脱硫液的再生时间。且脱硫后出口净化气的硫化氢质量浓度均低于20mg／m^3．满足了天然气运输的要求。     

铁基脱硫剂超重力法脱除硫化氢

用N₂和H₂S的混合气模拟含硫天然气, 以铁基脱硫剂为脱硫液, 采用超重力旋转填充床(RPB)进行脱除H₂S的集约化实验研究, 考察了原料气H₂S质量浓度、含硫原料气流量、脱硫液流量、温度及RPB转子转速对H₂S脱除率的影响。实验结果表明, 铁基脱硫剂超重力法脱除H₂S的较佳工艺条件为原料气H₂S含量14g/m³, 原料气流量0.45m³/h, 脱硫液流量13.5L/h, 脱硫液温度40℃, RPB转子转速1000r/min。在此条件下, H₂S脱除率稳定在99.98%以上, 脱硫后净化气H₂S含量小于2mg/m³。另外, 舍弃再生用RPB, 采用直接向脱硫富液储槽鼓空气的方法, 脱硫剂氧化再生良好, 脱硫效果保持不变, 且可长时间稳定运行。因此, 铁基脱硫剂超重力法脱硫工艺简单、效率高、设备体积小, 可实现海洋油气平台天然气或石油伴生气脱硫的集约化, 工业化应用前景广阔。     

并流超重力旋转床在烟气除尘脱硫工艺中的应用

超重力旋转床是超重力除尘脱硫工艺中的主要设备之一。针对超重力除尘脱硫工艺中存在的问题,构建了基于并流超重力旋转床的烟气除尘脱硫工艺装备。论述了并流超重力旋转床的结构特征和主要参数的确定。结果表明,并流超重力旋转床除尘脱硫效率高,对优化中小型燃煤锅炉和垃圾焚烧烟气除尘脱硫工艺装备有一定的意义。     

旋转填料床/柠檬酸盐法脱除烟气中SO2的实验研究

提出采用旋转填料床结合柠檬酸盐法脱除烟气中SO2的方法,考察了旋转填料床转子转数、液气比、pH值等因素对脱硫率的影响.结果表明采用超重力法柠檬酸盐溶液初始浓度为1.5mol/L、液气比为71/m3、超重机转子转速为1000r/min,吸收液的pH值为5.0,脱硫率达到98％以上.     

超重力旋转填充床氧解吸过程的数值模拟

基于旋转填充床流体流动的可视化结果,建立了超重力旋转填充床气液传质过程的数学模型,模拟氮气解吸水中溶解氧的传质过程。模拟结果表明,缩短液相停留时间、提高液相扩散系数都能增大液相传质分系数k_L;总体积传质系数K_La随超重力因子的增加而增大、随温度的上升而增大、随气相流率的增加略有下降、随液相流率的增加明显增大;空腔区传质贡献率随空腔区的增大而增大,随超重力因子的增大而减小;且短暂的停留时间是超重力旋转填充床对传质过程强化的本质原因。模型较好地符合文献的实验数据,误差在±16%以内。     

超重力旋转填充床氧解吸过程的数值模拟

基于旋转填充床流体流动的可视化结果,建立了超重力旋转填充床气液传质过程的数学模型,模拟氮气解吸水中溶解氧的传质过程。模拟结果表明,缩短液相停留时间、提高液相扩散系数都能增大液相传质分系数kL;总体积传质系数KLa随超重力因子的增加而增大、随温度的上升而增大、随气相流率的增加略有下降、随液相流率的增加明显增大;空腔区传质贡献率随空腔区的增大而增大,随超重力因子的增大而减小;且短暂的停留时间是超重力旋转填充床对传质过程强化的本质原因。模型较好地符合文献的实验数据,误差在±16%以内。     

超重力法脱除气体中硫化氢

采用超重力设备--旋转填料床替代传统湿法脱硫工艺中的脱硫塔,以PDS为脱硫催化剂,对工业过程中产生的含硫化氢气体进行了脱硫实验研究,考察了气液比、转速、碱废、温度、PDS含量等对脱硫率的影响规律.在适宜的条件下,获得了99.0%以上的脱硫率.与塔式脱硫技术相比,该技术具有脱硫效率高、液气比小、脱硫设备体积小等优点.     

超重力烟气脱硫的试验研究

该试验在超重力条件下以乙二胺为吸收剂进行SO_2吸收的研究。试验研究了转速、气液比、吸收液温度对SO_2吸收效率的影响。研究结果表明:旋转填充床合适的操作条件为转速1 000r/min、吸收液温度45℃,随着气液比的减小,SO_2吸收效率增加,脱硫率可达到95%以上。     

不同填料错流旋转填料床气液传质特性研究

为了探索不同填料错流旋转填料床的传质性能,以Na2CO3水溶液吸收空气中硫化氢为实验体系,对装有不锈钢丝网、塑料波纹孔板和θ环填料的错流旋转填料床的气液传质性能进行研究。实验确定的适宜操作条件为:超重力因子7.8,气体流量2 m3/h,液气比20 L/m3,碳酸钠质量浓度12 g/L;在此条件下,3种填料的脱硫率均可达到90%以上。在相同操作条件下,不锈钢丝网填料的脱硫率及气相总体积传质系数大于塑料孔板填料大于θ环填料;错流旋转填料床中,规整填料的气液传质效果优于乱堆填料。文中的研究结果为错流旋转填料床填料的选取及在脱硫方面的应用提供了依据。     

同心圈式超重力旋转床液泛模型

同心圈式超重力旋转床是一种新型超重力旋转床。液泛是超重力旋转床流体力学的重要特征。同心圈式超重力旋转床液体分布器和转子内缘之间的环形空间内的液滴被气体夹带,液滴受到离心力和气体曳力的作用,通过建立微分方程可获得液滴径向速度为零时的液滴运动径向距离。当该径向距离小于环形空间的径向距离,此时产生雾沫夹带液泛。由此建立同心圈式超重力旋转床雾沫夹带液泛模型。实验以空气和水为物系,测定了转子直径为1000 mm、高度为100 mm的同心圈式超重力旋转床在不同转速和表观液速下气体进口和出口之间的气相压降随表观气速的变化。气相压降随表观气速的增大先缓慢增大后快速增大。用表观气速对气相压降求导和目测旋转床中心气体出口处出现大量液体被气体夹带来确定液泛点气速。通过液泛点气速求得雾沫夹带液泛模型的系数k,并对该系数k进行关联。该雾沫夹带液泛模型的计算值和实验值吻合很好,平均偏差为3.1%。该模型优于Sherwood液泛模型,对同心圈式超重力旋转床的工业应用提供了必要的设计依据。     

翅片导流板填料应用于旋转填料床的特性

For an alcohol/water system and with fin baffle packing, continuous distillation experiments were carried out in a rotating packed bed (RPB) system at atmospheric pressure. The effects of the average high gravity factor (β), liquid reflux ratio (R) and feedstock flux (F) on the momentum transfer and mass transfer were investigated. The gas phase pressure drop of RPB increased with the average high gravity factor, liquid reflux ratio and feedstock flux, which was 13.55-64.37 Pa at β of 2.01-51.49, R of 1.0-2.5, and F of 8-24 L&;#8226;h－1 for a theoretical tray in the RPB with fin baffle packing. The investigation on the mass transfer in the RPB with different packings showed that the number of transfer units of RPB with a packing also increased with the average high gravity factor, reflux ratio and feedstock flux. It is found that the fin baffle packing (packing III) presents the best mass transfer performance and lowest pressure drop for the height equivalent to a theoretical plate (HETP), which is 6.59-9.84 mm.     

Hydrogen sulfide removal by catalytic oxidative absorption method using rotating packed bed reactor

Using catalytic oxidative absorption for H_2S removal is of great interest due to its distinct advantages. However,traditional scrubbing process faces a great limitation in the confined space. Therefore, there is an urgent demand to develop high-efficiency process intensification technology for such a system. In this article, H_2S absorption experimental research was conducted in a rotating packed bed(RPB) reactor with ferric chelate absorbent and a mixture of N_2 and H_2S, which was used to simulate natural gas. The effects of absorbent p H value, gas–liquid ratio, gravity level of RPB, absorption temperature and character of the packing on the desulfurization efficiency were investigated. The results showed that H_2S removal efficiency could reach above 99.6% under the most of the experimental condition and above 99.9% under the optimal condition. A long-time continuous experiment was conducted to investigate the stability of the whole process combining absorption and regeneration. The result showed that the process could well realize simultaneous desulfurization and absorbent regeneration, and the H_2S removal efficiency kept relatively stable in the whole duration of 72 h. It can be clearly seen that high gravity technology desulfurization process, which is simple, high-efficiency, and space intensive, has a good prospect for industrial application of H_2S removal in confined space.     

新型旋转填料床的气相传质特性

以CO2-NaOH体系化学吸收测定不同超重力因子、液量和气液比(体积流量比)条件下的有效传质比表面积a,在相同操作条件下,以氨-空气-水体系进行空气吹脱含氨富液测定不同超重力因子、液量和气液比条件下的气相体积传质系数kya,从而得到气相传质系数ky,对其气相传质特性进行了研究. 结果表明,a随超重力因子、液量和气液比增大而增大,kya和ky均随超重力因子和气液比增大而增大,随液量增大而减小. 通过对比可知,在相近操作条件下新型旋转填料床的气相体积传质系数比文献折流旋转填料床的提高36%. 对实验数据进行回归,拟合出a, kya和ky分别与气相雷诺数ReG、液相韦伯数WeL和伽利略数Ga之间的关联式.     

Micromixing efficiency of rotating packed bed with premixed liquid distributor

Rotating packed bed (RPB), in which high gravity is simulated by a centrifugal force, plays an important role in process intensification of fluid mixing and mass transfer. However, uneven initial liquid distribution in RPB leads to poor micromixing efficiency in local areas of the packing. Therefore, a premixed liquid distributor is proposed in this work to improve the liquid distribution in RPB. Micromixing efficiency of RPB with the premixed liquid distributor was studied by adopting the iodide–iodate reaction as working system and show better micromixing efficiency compared to that of RPB with non-premixed liquid distributor. Also, the effects of operating conditions (e.g. rotational speed, acid concentration, volumetric flow rate) and geometries using the premixed liquid distributor on micromixing efficiency (characterized by segregation index X_S) were investigated. The results show that segregation index X_S decreases with the increase of rotational speed, and the decrease of acid concentration and volumetric flow rate.     

多级雾化旋转填料床的传质性能

以两级雾化超重力旋转床为例,用化学吸收法考察了超重力因子β、液体流量、气体流量等对体积传质系数kyα的影响。结果表明:多级雾化超重力旋转床的体积传质系数随气液流量的增加而增加,在β较小时,实验曲线的斜率较大,kyα随β的增加急剧增加;但是当β超过100后,曲线的斜率减小,kyα随β的增加缓慢增大。     

Modeling and experimental studies on absorption of CO2 by Benfield solution in rotating packed bed

This work presents the modeling and experimental investigation on absorption of CO₂ by Benfield solution in rotating packed bed (RPB). A model was established to illustrate the mechanism of gas–liquid mass transfer with reactions in RPB at higher gravity level. Experiments were carried out at various rotating speeds, liquid flow rates, gas flow rates and temperatures in RPB, with Benfield solution as the absorbent. The validity of this model was demonstrated by the fact that most of the predicted y_o (mole fraction of CO₂ in outlet gas) agreed well with the experimental data with a deviation within 10%. The presented profile of K_Ga (gas-phase volumetric mass transfer coefficient) along the radial direction of the packing could reasonably explain the end effect in RPB. As a result, this model is reliable in describing the removal of CO₂ by Benfield solution in RPB at higher gravity level.     

Ozonation of CI Reactive Black 5 using rotating packed bed and stirred tank reactor

This study investigates the ozonation of CI Reactive Black 5 (RB5) by using the rotating packed bed (RPB) and completely stirred tank reactor (CSTR) as ozone contactors. The RPB, which provides high gravitational force by adjusting the rotational speed, was employed as a novel ozone contactor. The same ozone dosage was separately introduced into either the RPB or the CSTR for the investigation, while the experimental solution was continuously circulated within the apparatus consisting of the RPB and CSTR. The decolorization and mineralization efficiencies of RB5 in the course of ozonation are compared for these two methods. Moreover, the dissolved and off‐gas ozone concentrations were simultaneously monitored for the further analysis. As a result, the ozone mass transfer rate per unit volume of the RPB was significantly higher because of its higher mass transfer coefficient and gas–liquid concentration driving force. Furthermore, ozonation kinetics was found to be independent of the gravitational magnitude of an ozone gas–liquid contactor. Therefore, the results suggest employing RPBs as ozone‐contacting devices with the advantage of volume reduction. The experimental results, which can be used for further modeling of the ozonation process in the RPB, also show the requirement of correct design for the RPB. Consequently, the present study is useful for the understanding of practical application of RPBs. Copyright © 2004 Society of Chemical Industry     

超重力强化臭氧高级氧化技术的研究进展

臭氧高级氧化技术因其绿色高效、适用性广、操作简便等优势，成为当前水处理领域前沿技术之一，但臭氧在传统反应器内普遍存在吸收效果差，臭氧利用率低等缺陷。旋转填料床（RPB）利用高速旋转的填料产生超重力场，将液体剪切破碎为细小的液膜、液丝或液滴，其较高的相界面积、不断更新的界面以及内部流体的强制湍动，加快了臭氧的传质与分解，该技术对于传质受限的臭氧高级氧化过程的强化有着突出的优势。本文简述了超重力强化臭氧氧化过程的原理，介绍了RPB与O₃、O₃/H₂O₂、O₃/Fenton、O₃/PS（过硫酸盐）、催化臭氧氧化等高级氧化法耦合应用处理有机废水的研究现状，并对超重力技术的优势及技术突破进行了述评，总结了超重力应用臭氧高级氧化技术的潜在经济效益和环境效益，提出功能化填料及大型RPB的开发需求，以期为超重力技术在废水处理领域的拓展应用提供理论基础和技术参考。