大孔吸附树脂HZ816对红霉素的固定床吸附过程研究

在上柱质量浓度为2.31—6.56 mg/mL、流量为14.33—42.80 mL/h的范围内研究了固定床吸附柱中大孔吸附树脂HZ816对红霉素的动态吸附过程,考察了原料液质量浓度和进口流量等操作参数对穿透曲线的影响。并采用基于液膜及孔内扩散模型的动力学模型,同时考虑吸附树脂颗粒内外扩散阻力及轴向扩散的影响,研究了固定床上红霉素在大孔吸附树脂中的吸附动力学,并从穿透曲线回归得到液膜传质系数孔内扩散系数。结果表明,在实验范围内,该模型能较好地描述红霉素在HZ816树脂上的吸附过程,由模型拟合得到的液膜传质系数随着原料液质量浓度减小而增大,随着流量升高而增大;孔内扩散系数随着原料液质量浓度增大而减小,随着流量升高而减小。为采用大孔吸附树脂HZ816吸附技术分离纯化红霉素工艺提供了实验和理论基础。     

油茶果壳活性炭对铜离子的动态吸附

利用油茶果壳活性炭填料柱对水中铜离子进行动态吸附。探讨了pH值、初始质量浓度、床层高度等因素对穿透曲线的影响。结果表明,油茶果壳活性炭能有效去除水中的铜离子,随着床层高度的增高、pH的增大和初始浓度的减小,油茶果壳活性炭填料柱对水中铜离子的吸附穿透曲线位点向右移。通过数学模型得到的速率常数、相关系数、平衡吸附量和动力学参数,能较好地描述油茶果壳活性炭填料柱吸附铜离子的吸附动力学。     

微通道内离子液体/乙醇混合溶液吸收CO2的传质特性

采用高速摄像仪对微通道内离子液体/乙醇混合溶液吸收CO₂的传质行为进行了实验研究。考察了弹状流型下气液两相流量比和离子液体浓度对液侧体积传质系数k_La和液侧传质系数k_L的影响。当离子液体浓度不变时,k_La、k_L均随气液流量比的升高而增大并逐渐趋于恒定。当液相流量不变时,对于不同浓度的离子液体溶液,液侧体积传质系数k_La和液侧传质系数k_L随气液流量比的变化曲线出现了交叉点。在交叉点之前,k_La和k_L均随着离子液体浓度的增大而减小;在交叉点之后,k_La和k_L均随着离子液体浓度的增大而增大。提出了用于预测液侧体积传质系数k_La的新的量纲1经验关联式,预测效果良好。     

活性炭填充床脱除水中苯酚及填充床的再生

实验研究了活性炭填充床脱除水中苯酚的吸附性能,探讨其饱和吸附填充床的再生方法,结果表明当平衡浓度范围为0－0．8kg/m^3时,活性炭对水中苯酚的吸附能力达230kg/kg（吸附剂）,吸附等温线符合Langmuir型,填充床的穿透曲线和穿透时间强烈依赖于实验条件,较高的进料浓度,较大的进料速度,以及较短的床层长度都将使填充床穿透较快;用热的NaOH稀溶液可再生被苯酚饱和的活性炭纤维填充床,再生效率达90％以上。     

微通道内离子液体/乙醇混合溶液吸收CO_2的传质特性

采用高速摄像仪对微通道内离子液体/乙醇混合溶液吸收CO_2的传质行为进行了实验研究。考察了弹状流型下气液两相流量比和离子液体浓度对液侧体积传质系数kLa和液侧传质系数kL的影响。当离子液体浓度不变时,kLa、kL均随气液流量比的升高而增大并逐渐趋于恒定。当液相流量不变时,对于不同浓度的离子液体溶液,液侧体积传质系数kLa和液侧传质系数kL随气液流量比的变化曲线出现了交叉点。在交叉点之前,kLa和kL均随着离子液体浓度的增大而减小;在交叉点之后,kLa和kL均随着离子液体浓度的增大而增大。提出了用于预测液侧体积传质系数kLa的新的量纲1经验关联式,预测效果良好。     

乙醇-水体系在马铃薯粉吸附剂上的气相吸附过程研究

利用固定床吸附柱(φ25 mm×900 mm)对乙醇-水体系在马铃薯粉吸附剂中的气相吸附过程进行了研究,研究了不同条件下乙醇-水体系在马铃薯粉中吸附的透过曲线。结果表明,在本试验条件下,生产能力和透过时间随温度降低、粒径变小、进料流量降低和床层高度增加而增大。在乙醇-水体系进料流量为3 mL/min左右、床层温度80℃、吸附剂粒径245～350μm、床层高度700 mm和进料乙醇体积分数94.5%条件下,每1 000 g马铃薯粉吸附剂可脱水得到无水乙醇205.1 g。马铃薯粉吸附性能良好,再生容易,具备作为生物质吸附剂制备无水乙醇的潜力。     

结构化5A分子筛吸附床结构及工艺参数对N2/H2吸附性能的影响

利用吸附等温线获得动力学参数,建立了CFD模型,模拟了氢气/氮气在结构化5A分子筛吸附床中的吸附过程,研究了吸附剂层片间距、吸附剂厚度等结构参数和吸附压力、进气流量等工艺参数对混合气吸附效果的影响。结果表明：减小层片间距和吸附剂厚度可显著提高传质系数和床层利用率。增大吸附压力可提高床层利用率,但会减小传质系数。进气流量对传质系数的影响不明显,但当流量较大时,吸附容量和床层利用率均呈减小趋势。结构化5A分子筛吸附剂吸附性能良好。     

AB-8大孔树脂对葡萄籽原花青素的吸附过程

研究葡萄籽原花青素粗提液在AB-8大孔树脂上的吸附过程,建立了AB-8大孔树脂吸附原花青素的相平衡方程和动态吸附模型,计算了不同流速、不同进料浓度下的总传质系数、传质区长度及穿透时间。实验结果表明,原花青素静态吸附符合Langmuir吸附等温方程式;AB-8树脂对原花青素的动态吸附属于外扩散控制过程;穿透时间计算值与实验值一致。建立的数学模型可用于指导实际生产操作,为吸附柱的设计提供参考。     

连续环状色谱柱分离性能的模拟

连续环状色谱柱是有机物稀溶液及生物制品纯化的重要制备手段,为深入认识连续环状色谱柱的性能,开展了连续环状色谱柱分离性能模拟计算的研究。提出了二维空间网格差分的模拟计算方法,并采用文献报道的木糖-山梨糖分离的实验结果进行验证,模拟计算结果与实验数据基本吻合,证明了模拟计算方法的可行性。同时考察了单组分体系下进料流量、床层旋转速度、相间总传质系数、吸附平衡常数对流出曲线的影响;以木糖为分离关键组分,以木糖的收率和纯度为目标函数,对双组分体系下进料流量、床层旋转速度、床层高度、选择性系数对分离效果的影响进行了计算和讨论,结果表明,选择性系数是决定性因素,适当提高床层旋转速度或床层高度可以增大木糖的纯度。     

模拟移动床离子交换树脂矿浆吸附过程的传质模型

首次将模拟移动床用于离子交换树脂矿浆过程,使吸附、淋洗、再生等步骤在同一设备中进行,简化了工艺流程和操作.应用总传质系数的概念,推导出吸附段各级搅拌吸附槽中浆相的离子浓度分布曲线,单级和4级连续吸附的实验结果与计算结果吻合得很好.经过分析计算,得到了不同操作条件下的总传质系数.进料流量和离子浓度对单级和4级连续吸附操作的浓度分布曲线均有不同程度的影响.     

Vacuum pressure swing adsorption process for coalbed methane enrichment

The enrichment of low concentration coalbed methane using adsorption process with activated carbon adsorbent was studied in this work.Adsorption isotherms of methane,nitrogen and carbon dioxide on activated carbon were measured by volumetric method,meanwhile a series of breakthrough tests with single component,binary components and three components feed mixture has been performed for exploring dynamic adsorption behaviors.Moreover,a rigorous mathematical model of adsorption bed containing mass,energy,and momentum conservation equation as well as dual-site Langmuir model with the Linear driving force model for gas-solid phase mass transfer has been proposed for numerical modeling and simulation of fixed bed breakthrough process and vacuum pressure swing adsorption process.Furthermore,the lumped mass transfer coefficient of methane,nitrogen and carbon dioxide on activated carbon adsorbent has been determined to be 0.3 s~(-1),1.0 s~(-1) and 0.06 s~(-1) by fitting the breakthrough curves using numerical calculation.Additionally,a six bed VPSA process with twelve step cycle sequence has been proposed and investigated for low concentration coalbed methane enrichment.Results demonstrated that the methane molar fraction in feed mixture ranged from 10% to 50% could be enriched to 32.15% to 88.75% methane in heavy product gas with a methane recovery higher than 83%under the adsorption pressure of 3 bar(1 bar=10~5 Pa) and desorption pressure of 0.1 bar.Energy consumption of this VPSA process was varied from 0.165 kW·h·m~(-3) CH_4 to 0.649 kW·h·m~(-3) CH_4.Finally,a dual-stage VPSA process has been successfully developed to upgrade a low concentration coalbed methane containing 20% methane to a target product gas with methane purity higher than 90%,meanwhile the total methane recovery was up to 98.71% with a total energy consumption of 0.504 kW·h·m~(-3) CH_4.     

气体中醋酸甲酯在活性炭上的动态吸附

研究了Calgon活性炭对醋酸甲酯的动态吸附行为,从穿透时间、穿透吸附量以及穿透曲线的形状等方面,考察了初始浓度、气速和温度等因素对活性炭吸附性能的影响。另外选择3种不同产地的国产活性炭在相接近的吸附条件下与Calgon活性炭进行对比,结果显示活性炭的微孔分布是与其吸附性能相关性较大的因素。     

对二甲苯在活性炭固定床上的吸附动力学

研究了对二甲苯在活性炭固定床上的吸附动力学。考察了初始浓度、气体流量、床层长度等因素对吸附透过曲线的影响。同时,采用Yoon—Nelson模型对吸附透过曲线进行线性回归分析。实验结果表明,随着初始浓度的增大,透过时间缩短,吸附量增大：气体流最对透过曲线的形状影响不大：床层长度基本不影响透过曲线;Yoon-Nelson模型可以较好的模拟固定床吸附过程。     

Nonuniform channels in adsorbent monoliths

A model is introduced to account for nonuniform channel geometries in monolithic adsorbents. Based on nonisothermal operation, fully developed parabolic flow and the full three‐dimensional convection‐diffusion equation, the model is applied to the adsorption of dichloromethane from an air stream flowing through a binder‐less activated carbon monolith. The equilibrium parameters and the effective diffusion coefficient for adsorption are obtained independently from gravimetric adsorption experiments. The nonuniform channel model is capable of predicting breakthrough curves as a function of feed gas flow rates up to dimensionless breakthrough concentrations of about 0.4–0.6, depending on the feed flow rate. Even though the variation of effective diffusion coefficient with both concentration and temperature has been tested, successful prediction over the whole range of concentration may require the incorporation of further aspects relating to the anisotropic nature of the carbon. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

固定床动力学模型在离子交换过程中的应用

为了掌握所选的Thomas模型,Yoon-Nelson模型和Adams-Bohart模型在固定床米格列醇离子交换过程中的应用情况,实验借助对不同质量浓度的米格列醇溶液在定量树脂和固定流速下研究其在固定床中离子交换过程,并通过对透过曲线实验数据分析来验证相关固定床动力学模型在此过程中的有效性。结果表明:固定床上样液质量浓度增大,达到平衡饱和点的时间将缩短,传质区长度增大,吸附率变小,上样液质量浓度在8 mg/mL时吸附量达到最大;用动力学模型拟合透过曲线的过程参数,结果表明Thomas模型和Yoon-Nelson模型具有较好的相关系数,Thomas模型的速率常数和最大吸附量值随着上样液质量浓度的降低而增大,Yoon-Nelson模型的速率常数随着上样液质量浓度的降低而减小,且在Yoon-Nelson模型中计算得到的透过曲线中出口质量浓度与上样质量浓度比值为1/2时所对应的计算值和实验值相差很小,Thomas模型和Yoon-Nelson模型可用于该过程的离子交换性研究。     

吸附法处理低质量浓度N,N-二甲基甲酰胺废水的研究

采用活性炭对经六级逆流萃取后含低质量浓度N,N-二甲基甲酰胺(DMF)的萃余液废水进行吸附处理,研究了活性炭吸附等温线、活性炭投加量对吸附过程的影响,流速和活性炭种类对动态吸附的影响。实验结果表明:流速为2 mL/min左右,活性炭粒径为1—2 mm时,动态吸附性能较好。此时,动态吸附穿透点为180 min,活性炭对DMF饱和吸附量为53.50 mg/g。萃余液经过吸附处理后,废水中DMF的质量浓度可降至9 mg/L以下,达到了国家一级排放标准。     

水合焦油废水的废弃活性炭吸附法处理工艺

为了实现高原电解铝碳阳极生产中沥青烟气净化水合焦油的综合处理利用,采用活性炭吸附法处理水合焦油废水。考察了活性炭静态吸附和动态吸附焦油废水过程中主要影响参数,如吸附剂用量、反应时间、停留时间、pH、进水流速、活性炭的类型、吸附层的高度及焦油废水浓度等,绘制了吸附等温线和穿透曲线。扩大试验进一步论证了活性炭吸附焦油废水的可行性。     

A Reynolds mass flux model for gas separation process simulation:II. Application to adsorption on activated carbon in a packed column☆

Simulations of adsorption process using the Reynolds mass flux model described in Part I of these serial articles are presented. The object of the simulation is the methylene chloride adsorption in a packed column (0.041 m id, packed with spherical activated carbon up to a length of 0.2 m). With the Reynolds mass flux model, breakthrough/regeneration curves, concentration and temperature as well as the velocity distributions can be obtained. The simulated results are compared with the experimental data reported in the literature and satisfactory agreement is found both in breakthrough/regeneration curves and temperature curves. Moreover, the anisotropic turbulent mass diffusion is characterized and discussed.     

GOLD ADSORPTION ON ACTIVATED CARBON AND THE EFFECT OF SUSPENDED SOLIDS AND DISSOLVED SILICON DIOXIDE

The use of gold adsorption by activated carbon has recently become widespread on South African gold mines. This has caused a great deal of interest in the kinetics of gold adsorption onto activated carbon. However, almost all previous work has been done using clear solutions. In practice the gold adsorption occurs from a slurry containing fine ground rock particles and possibly a number of other metals in solution as well as organics which may poison the carbon. As the next step in the understanding of the gold adsorption process, this work assesses the impact of a fine solid suspension on the gold adsorption kinetics. This is found to significantly reduce the adsorption rate of gold cyanide (Au(CN)2¯) by G210 activated carbon in completely mixed batch adsorbers. The relative effects of solid particle size and mixing intensity on the adsorption rate are investigated. Batch adsorption rate experiments are performed with clear solutions, and with solutions containing 20% (m/m) fine suspended solid material, agitated at impeller speeds of 200 and 300 r.p.m. with an initial gold cyanide concentration of = 10 p.p.m. Equilibrium isotherms for gold cyanide, gold cyanide/glass particles and dissolved silicon on G210 activated carbon were determined. The batch adsorption kinetics of gold cyanide from clear solutions were successfully modelled using the Homogeneous Surface Diffusion Model of Crittenden & Weber (1978). The adsorption of gold cyanide from clear solutions was found to be characterized by intra-particle diffusion rate control, limited by a finite film mass transfer rate at low gold loadings. When fine suspended solids are present it is shown that blinding of the carbon macropores is the likely cause of the reduced adsorption rate. Although the solids used were artificial in the sense that these would not be present in this form in an industrial operation, it was felt that using solids from an operating mine would introduce complications in addition to the specific effects this paper addresses.