Determination and correlation of VLE data for ethylene glycol and 1,2-butanedioi system

为解决合成气经由草酸酯制乙二醇反应过程中产生的副产物1,2-丁二醇与乙二醇的分离问题,利用改进的Ellis汽液平衡釜测定了乙二醇-1,2丁二醇二元体系常压下汽液平衡数据,并通过Herington规则验证了实验结果符合热力学一致性.分别用Wilson和NRTL模型对实验数据进行热力学关联,得到了相关的模型参数并计算了该二元体系不同摩尔分数2种组分的活度系数值,预测了该二元体系的共沸点组成(摩尔分数)为乙二醇47.0％,1,2-丁二醇53.0％,共沸点温度为465.91K.汽相组成的计算值与实验值平均相对偏差均小于0.2％,说明2种模型均适用于该二元体系,为工业分离工艺的设计提供了参考.     

乙二醇-1,2-丁二醇二元体系汽液平衡数据的测定及关联

为解决合成气经由草酸酯制乙二醇反应过程中产生的副产物1,2-丁二醇与乙二醇的分离问题,利用改进的Ellis汽液平衡釜测定了乙二醇-1,2丁二醇二元体系常压下汽液平衡数据,并通过Herington规则验证了实验结果符合热力学一致性。分别用Wilson和NRTL模型对实验数据进行热力学关联,得到了相关的模型参数并计算了该二元体系不同摩尔分数2种组分的活度系数值,预测了该二元体系的共沸点组成(摩尔分数)为乙二醇47.0%,1,2-丁二醇53.0%,共沸点温度为465.91 K。汽相组成的计算值与实验值平均相对偏差均小于0.2%,说明2种模型均适用于该二元体系,为工业分离工艺的设计提供了参考。     

分子筛吸附脱除N,N-二甲基乙酰胺中微量水分的研究

测定了N,N-二甲基乙酰胺中微量水分在3A、4A和5A分子筛上的吸附平衡数据、以及不同温度下3A分子筛的吸附等温曲线,并采用Langmuir方程进行拟合,研究了不同流量和初始水含量下3A分子筛的吸附穿透曲线,并采用Yoon-Nelson模型进行拟合。结果表明,3A分子筛的吸附脱水效果最好,Langmuir方程对吸附等温曲线的拟合效果较好,Yoon-Nelson模型对吸附穿透曲线的拟合效果较好。研究结果为N,N-二甲基乙酰胺吸附脱水工艺的设计提供了依据。     

分子筛吸附脱除2-甲基四氢呋喃中水的研究

为实现2-甲基四氢呋喃(2-MeTHF)循环利用,采用一系列吸附剂(3A、4A和5A分子筛)对2-MeTHF脱水进行研究.考察了分子筛种类、投入量对脱水效果的影响;研究了该过程的热力学和动力学;并通过固定床吸附实验测得其穿透曲线.结果表明,水分去除率随吸附剂投料量的增加而升高,且3A和5A分子筛的性能较好,其投料量均为...     

化学循环分离煤基乙二醇联产碳酸丁烯酯工艺研究

为解决酯交换法合成五元环状碳酸丁烯酯的原料短缺以及煤制乙二醇产品精制过程中乙二醇与1,2-丁二醇共沸物难以分离的瓶颈问题,基于化学循环分离技术与反应精馏技术提出了耦合集成工艺,将碳酸-1,2-丁烯酯的合成与乙二醇/1,2-丁二醇的分离过程耦合集成于同一工艺中同时完成,在此基础上建立了集成工艺的全流程模拟模型,并通过灵敏度分析对该耦合工艺的设计与操作参数进行优化,研究结果为煤基乙二醇生产过程分离高纯度乙二醇同时联产碳酸1,2-丁烯酯耦合工艺的开发奠定了基础。     

RHO分子筛空分性能评价

RHO分子筛由于独特的孔道结构在O₂/N₂分离方面表现出其特有的性质。采用水热合成法合成Na,Cs-RHO分子筛,进行碱金属离子交换改性,然后利用XRD和SEM对样品进行表征。通过单组分气体吸附实验、Aspen Adsorption软件模拟混合组分穿透曲线实验和双塔PSA空分实验对吸附剂性能进行评价。结果表明:Li-RHO是一种容易通过阳离子调控骨架扭曲程度的分子筛,O₂/N₂平衡分离性能参数最大。穿透曲线实验结果表明,弱吸附组分(N₂)首先穿透吸附床,O₂因强吸附而后穿出,Li-RHO的动力学分离因子很高。Aspen Adsorption模拟结果表明,Li-RHO制得的N₂纯度和回收率最高,可能是一种具有良好应用前景的空分吸附剂。     

乙二醇与1,2-丁二醇的分离方法研究进展

综述了乙二醇与1,2-丁二醇分离方法的研究进展,介绍了不同分离纯化技术,主要包括共沸精馏、萃取精馏、萃取与共沸精馏联用、反应精馏、吸附分离等。分析了每种方法的优缺点,指出共沸精馏、共沸精馏与萃取联用的分离技术分离乙二醇与1,2-丁二醇可用于工业规模化生产,吸附分离可用于小规模生产,反应精馏可以作为未来乙二醇纯化技术的发展方向。     

乙二醇和1,2-丁二醇二元气液平衡体系的研究及模型预测

为了研究乙二醇-1,2-丁二醇在不同真空度下共沸组成的变化规律及差压精馏分离的可行性，使用改进的Othmer气液平衡釜测定了1～100 kPa下乙二醇-1,2-丁二醇二元体系的气液平衡数据，均通过了热力学一致性检验。分别采用Wilson、NRTL和UNIQUAC方程对不同压力下的气液平衡数据进行整体关联，结果表明，UNIQUAC方程计算精度更高，可适用于1～100kPa下的相平衡计算。采用UNIQUAC方程计算了不同压力下乙二醇-1,2-丁二醇的共沸组成，共沸组成中乙二醇的摩尔分数随压力的降低呈非线性增加。操作压力由100降低至1kPa时，共沸组成中乙二醇的摩尔分数的变化可达到12%，推断乙二醇-1,2-丁二醇具有差压精馏分离的可行性。     

改性分子筛吸附2,2-二甲基丁烷的运行参数研究

M-13X分子筛是13X分子筛经过改性后得到的,具有更好的吸附效果,基于静态吸附试验装置,通过单因素实验得到M-13X吸附2,2-二甲基丁烷时的最佳运行参数为70℃、60%填充率、0.2 MPa、吸附30 min;通过动态吸附,得到了M-13X分子筛的吸附穿透曲线和饱和吸附量;研究通过改变环境温度,得到了M-13X分子筛的吸附等温线。这些研究结果为吸附法处理有机废气的工艺设计提供了参考。     

载金属离子的13X分子筛吸附噻吩的动态特性

采用13X分子筛及负载Cu2 、Zn2 、Ni2 、Ag 的13X分子筛等五种吸附剂,对噻吩进行动态吸附特性研究.在φ10.5 mm×200 mm的吸附柱测定了五种吸附剂吸附正己烷溶液中的噻吩的穿透曲线.采用加热法对Zn2 -13X、Ni2 -13X、Ag -13X三种吸附剂进行再生,测定了再生后吸附剂的穿透曲线,对吸附剂再生前后的吸附性能进行了比较.结果表明Ag -13X吸附性能优于其它吸附剂,其对噻吩的吸附容量为60.20 mg·g-1.再生后的Ag -13X对噻吩仍有很好的吸附能力,吸附容量相比新鲜吸附剂的仅下降了5%.穿透点以前出口噻吩含量为0.这些结果为工业吸附装置的设计提供了必要的吸附数据.     

Numerical simulation of low-concentration CO2 adsorption on fixed bed using finite element analysis

Accurately predicting distributions of concentration and temperature field in fixed-bed column is essential for designing adsorption processes.In this study,a two-dimensional (2D),axisymmetric,nonisothermal,dynamic adsorption model was established by coupling equations of mass,momentum and energy balance,and solved by finite element analysis.The simulation breakthrough curves fit well with the low-concentration CO2 adsorp-tion experimental data,indicating the reliability of the established model.The distributions of concentration and temperature field in the column for CO2 adsorption and separation from CO2/N2 were obtained.The sensitivity analysis of the adsorption conditions shows that the operation parameters such as feed flow rate,feed concentra-tion,pellet size,and column height-to-diameter ratio produce a significant effect on the dynamic adsorption performance.The multi-physics coupled 2D axisymmetric model could provide a theoretical foundation and guidance for designing CO2 fixed-bed adsorption and separation processes,which could be extended to other mixed gases as well.     

Use of Clinoptilolite in Ethanol Dehydration

Abstract

Clinoptilolite-type natural zeolite, which exists in various regions of Turkey, has been experimentally studied. For the ethanol-water-local clinoptilolite system, uptake and breakthrough curves were determined under a nitrogen gas atmosphere. In adsorption kinetics and adsorption equilibrium studies, the effects of particle size, temperature and, amount of zeolite on the uptake rate have been investigated. The breakthrough curves for four different flow rates of ethanol and three different bed heights were determined in dynamic column studies. The results of the experiments show that intraparticle diffusion is the main resistance. The local clinoptilolite is a promising adsorbent for water adsorption from aqueous ethanol.     

锰氧化物负载沸石固定床离子交换柱去除铀(VI)的研究

The adsorption of uranium (VI) on the manganese oxide coated zeolite (MOCZ) from aqueous solution was investigated in a fixed-bed column. The experiments were conducted to investigate the effects of bed height, flow rate, particle size, initial concentration of uranium (VI), initial pH, presence of salt and competitive ions. The U-uptake by MOCZ increased with initial uranium (VI) concentration and bed height, but decreased as the flow rate and particle size increased. In the presence of salt and competitive ions, the breakthrough time was shorter. The ad-sorption capacity reached a maximum at pH of 6.3. The Thomas model was applied to the experimental data to de-termine the characteristic parameters of the column for process design using linear regression. The breakthrough curves calculated from the model were in good agreement with the experimental data. The BDST model was used to study the influence of bed height on the adsorption of uranium (VI). Desorption of uranium (VI) in the MOCZ column was investigated. The column could be used for at least four adsorption-desorption cycles using 0.1 mol•L－1 NaHCO3 solution as the elution. After desorption and regeneration with deionized water, MOCZ could be reused to adsorb uranium (VI) at a comparable capacity. Compared to raw zeolite, MOCZ showed better capacity for uranium (VI) removal.     

沸石ZSM-5吸附回收低浓度煤层气中CH4

利用高硅疏水性沸石ZSM-5吸附回收低浓度煤层气中的甲烷,对其吸附平衡、吸附动力学以及真空变压吸附分离过程进行了理论和实验研究。通过重量法和穿透曲线法测定了CH₄/N₂单组分及双组分的竞争吸附平衡数据,并采用Multisite Langmuir吸附等温线模型对其进行拟合。结合CH₄和N₂稀释穿透曲线实验数据和等温无动量损失的双分散二级孔结构扩散模型,获得CH₄和N₂在沸石ZSM-5上的微孔扩散系数。建立并求解包含质量、动量及能量传递的固定床吸附分离模型方程,预测了CH₄和N₂在沸石ZSM-5上的竞争吸附穿透曲线。进一步采用ZSM-5吸附剂填充床单柱四步真空变压吸附实验考察了进料浓度、进料流速、进料时间以及吹扫比对分离效果的影响。结果发现沸石ZSM-5对CH₄具有较好的选择性,沸石晶粒内的微孔扩散为吸附速率控制步骤,真空变压吸附工艺可将模拟煤层气中20%的CH₄提纯至31%～41%,回收率为93%～98%。     

Breakthrough analysis of carbon dioxide adsorption on zeolite synthesized from fly ash

Zeolite (FAZ) was synthesized by the fusion method using coal fly ash to adsorb carbon dioxide. The experimental adsorption was operated batchwise in a laboratory-scale packed-bed adsorber to obtain the breakthrough curves of CO₂ under conditions such as adsorption temperatures (20–80 °C), flow rates of gaseous mixture of carbon dioxide and nitrogen (40–100 cm³/min), and concentration of CO₂ (3000–10000 ppmv) at atmospheric pressure of 101.3 kPa. The influence of the experimental conditions, such as the gas flow rate, concentration of CO₂ and adsorption temperature on adsorption behavior, was discussed. The deactivation model, combined the adsorption with the deactivation of adsorbent, was used to analyze the physicochemical properties, such as the adsorption kinetics, capacity and heat of adsorption, by fitting the experimental data of the breakthrough curves to this model. The adsorptive activity and capacity of FAZ were as almost same as those of the commercial zeolite of Wako 4A.     

D301树脂动态吸附溴离子过程探究及模型拟合

研究了用D301树脂吸附岩盐矿提钾母液中溴离子的可能性,考察了吸附柱动态吸附过程中原料液溴离子初始浓度、床层高度及进料流速等因素的影响。结果表明,增加原料液溴离子初始浓度或降低进料流速能提高树脂单位饱和吸附量。当原料液溴离子初始浓度从1000 mg/L升至4000 mg/L时,树脂单位饱和吸附量从1.8 mg/L增至6.4 mg/mL。增加床层高度或降低进料流速会延长动态吸附突破时间及饱和时间,而原料液溴离子初始浓度对其没有影响。应用了Bed Depth Service Time(BDST), Thomas, Yoon-Nelson, Wolborska及Modified dose response(MDR)等五种吸附模型对动态吸附过程进行拟合,其中MDR模型的拟合效果最佳。D301树脂可用于从含有高浓度氯离子的提钾母液中提取溴离子。     

Column breakthrough studies for the removal and recovery of phosphate by lime-iron sludge: Modeling and optimization using artificial neural network and adaptive neuro-fuzzy inference system

Increases in the treatment of water to meet the growing water demand ultimately result in unmanageable quantities of residuals, the handling, and disposal of which is a major environmental issue. Consequently, research into beneficial reuse of water treatment residuals continues unabated. This study investigated the applicability of lime-iron sludge for phosphate adsorption by fixed-bed column adsorption. Laboratory-scale experiments were conducted at varying flow rates and bed depths. Fundamental and empirical models(Thomas, Yan,Bohart-Adams, Yoon-Nelson, and Wolboroska) as well as artificial intelligence techniques(Artificial neural network(ANN) and Adaptive neuro-fuzzy inference system(ANFIS)) were used to simulate experimental breakthrough curves and predict column dynamics. Increase in flow rate resulted in reduced adsorption capacity.However, adsorption capacity was not affected by bed depth. ANN was superior in predicting breakthrough curves and predicted breakthrough times with high accuracy(R~20.9962). Na OH(0.5 mol·L~(-1)) was successfully used to regenerate the adsorption bed. After nine cyclic adsorption/desorption runs, only a marginal decrease in adsorption and desorption efficiencies of 10% and 8% respectively was observed. The same regenerate Na OH solution was reused for all desorption cycles. After nine cycles the eluent desorbed a total of 1550 mg phosphate exhibiting potential for further reuse.     

固定床不同床深下的米格列醇离子交换性研究

为考察米格列醇在固定床树脂不同堆积高度下的离子交换吸附行为,采用称量不同量的D001树脂装入离子交换柱中,通过固定床堆积高度的改变,在上样液流速和浓度固定前提下研究米格列醇溶液与树脂间的离子交换规律性,并结合床深服务时间(BDST)模型对此条件下固定床透过曲线进行分析评价。结果表明:固定床堆积高度的增加,提高了树脂与米格列醇溶液间的接触时间和树脂总的可交换离子数,有利于离子交换过程的进行,树脂的吸附质量和吸附率都得到了相应提高,堆积高度的增加使饱和点时间变长,吸附效率变小;对固定床透过曲线进行BDST模型拟合分析,结果表明:该模型与实验值间具有很高的相关系数,计算的相关参数间差异很小,对于该离子交换体系,表明BDST模型能很好地应用于该体系的离子交换吸附过程。     

Fixed‐Bed Adsorption Study for Fumaric Acid Removal from Aqueous Solutions by Amberlite IRA‐400 Resin

A fixed‐bed adsorption study was carried out by using a strong base anion‐exchange resin (Amberlite IRA‐400) for the removal of fumaric acid from aqueous solutions. The breakthrough curves were obtained as a function of flow rate, temperature, feed pH, and inlet fumaric acid concentration. The total adsorption capacity and the percent fumaric acid removal of the resin were calculated. The Yoon‐Nelson model was applied to the experimental data to predict the breakthrough curves and to determine the characteristic column parameters required for process design. The breakthrough curves fit the model predictions well.     

酒精中甲醇,水在NaA沸石上吸附性能的研究

本文测定了酒精中甲醇、水单组分及二元组分的吸附等温线,并用Langmuir方程进行了拟合。在固定床动态吸附研究申测定了酒精中甲醇、水单组分及双组分吸附穿透曲线;着重考察了流速、温度、不同甲醇和水含量对双组分吸附性能的影响。对二个组分的传质机理及置换关系进行了分析探讨。