真空变压吸附分离氮气甲烷模拟与实验研究

采用椰壳活性炭为吸附剂,进行了三床真空变压吸附（VPSA）氮气甲烷分离过程的研究。在吸附和置换压力为0.5 MPa,解吸压力为-0.08 MPa条件下,将体积分数（下同）为30%的甲烷,浓缩至80%～98%,甲烷的回收率达到65%～96%,并研究了吸附和置换步骤下塔顶出口流量对于产品气纯度和收率的影响。运用Aspen Adsorption软件建立上述模型,模拟结果与实验结果基本一致;模拟可以为甲烷富集的工业装置建立提供基本设计参数。     

Separation of Hydrogen-Lean Mixtures for a High-Purity Hydrogen by Vacuum Swing Adsorption

Abstract

High-purity hydrogen is commercially produced by pressure swing adsorption from hydrogen-rich mixtures. In this work, a vacuum pressure swing adsorption cycle is used to produce high purity hydrogen from a hydrogen-lean binary mixture (20/80 H₂/CO) using zeolite 5A as the sorbent. The effects of different process variables on separation performance have been studied. The purity of hydrogen product increases at low throughput, high feed pressure, high end pressure of cocurrent depressurization, low end pressure of countercurrent evacuation, and short cycle time. Also, it was found that for a H₂-lean mixture, the separation is improved at higher ambient temperature. In addition, a new “vacuum purge” step was found to improve the separation and is therefore a promising step for commercial application.     

气体分离用变压吸附剂的研究进展

介绍了在应用变压吸附生产N2、O2和CO2的生产过程中,沸石分子筛和碳分子筛的吸附分离机理及它们的改性研究,并讨论了国内外目前使用的沸石分子筛和碳分子筛的优缺点,评述了现阶段国内外变压吸附剂的研究现状,进而展望了变压吸附剂的研究和发展趋势。     

Concentration-Thermal Swing Adsorption Process for Separation of Bulk Liquid Mixtures

Abstract

A novel concentration-thermal swing adsorption process is described for separation of bulk binary liquid mixtures. The process is designed to produce essentially two pure products with high recoveries of both components. It is particularly suited for separation of azeotropic or close-boiling liquid mixtures which are difficult to separate by distillation. An example of the performance of the new process for separation of an azeotropic water-methyl acetate mixture is given. Experimental binary surface excess equilibrium isotherms, adsorptive mass transfer coefficients, and column dynamics for adsorption of water-methyl acetate mixtures on NaX zeolite are reported.     

Vacuum Swing Adsorption Process for Oxygen Production–-A Historical Perspective

Abstract

Adsorbent and cycle developments for the last 25 years have resulted in the advancement of vacuum swing adsorption processes for the production of oxygen from air, and in this review are traced and critically examined. The key criteria in the past developments and for future improvements are identified.     

Predictive Dynamic Model of Air Separation by Pressure Swing Adsorption

A general dynamic model is developed for separation of air over a carbon molecular sieve and a zeolite adsorbent for production of nitrogen and oxygen. The proposed model is validated using experimental data from working laboratory scale N₂–PSA and laboratory scale O₂–PSA systems. Simulations studies are performed to investigate the effect of changing various process variables, such as the duration of PSA steps, bed length and feed inlet velocity.     

变压吸附空分制氧的技术进展

介绍了近年来变压吸附空分制氧的技术进展情况,分别从空分制氧的工艺和吸附剂的改进状况进行了详细论述,并简单的描述了空分制氧的发展前景。     

变压吸附方法分离五元气体混合物

本文研究了用变压吸附从五元气体混合物分离H_2及操作条件对分离的影响.提出了简化的双孔扩散模型模拟变压吸附过程,计算结果和实验数据符合良好.     

A Pressure Swing Adsorption Process for Production of 23–50% Oxygen-Enriched Air

Abstract

A simple pressure swing adsorption process for direct production of low to medium purity (23–50%) O₂-enriched gas from ambient air is described. The process provides a high O₂ production capacity per unit amount of the adsorbent and a high O₂ recovery combined with a very low energy requirement for the separation. The performance of the process using three different air separation adsorbents is described.     

Vacuum Pressure Swing Adsorption to Produce Polymer-Grade Propylene

We have evaluated the Vacuum Pressure Swing Adsorption (VPSA) technology to separate propane–propylene streams to produce polymer-grade propylene. Zeolite 4A is used as kinetic adsorbent since propylene diffuses much faster than propane. A single VPSA process is able to produce propylene with purity higher than 99.6%. However, propylene recovery is only 67% and therefore a second stage is used. In this VPSA unit, zeolite 4A with smaller crystal radius is employed to reduce kinetic limitations. The second VPSA (tail unit) produces purified propane and recovers propylene that is recycled to the feed of the first VPSA (front unit). Linking these two VPSA units allows us to produce polymer-grade propylene (PGP) recovering 95.9% of the propylene. Comparing the performance of this process with distillation, there is a significant decrease in the separation volume. However, further efforts are necessary to reduce the power consumption of VPSA which is still slightly higher than for distillation.     

变压吸附分离技术的研究进展

简述了变压吸附技术在分离净化方面的应用,及其在分离提纯高沸点组分中的研究进展,寻求进一步拓展变压吸附技术的应用领域,开发新型工业装置的途径     

介绍一种新的制氮方法——变压吸附制氮

本文介绍了可以代替深冷法的新的制氮方法—变压吸附法,该法适合于70t/d以下规模。该法启动快,可根据需要随意开停车。产品氮气的纯度可达99.5％以上。     

膜分离技术与变压吸附技术结合制取高浓度氧的研究

针对膜分离(MS)技术与变压吸附(PSA)技术在以空气为原料制氧方面各自存在的优缺点,尝试将二者相结合用于制取高浓度(体积分数》99.5%)氧气.通过实验证明了采用MS-PSA流程用于制取高浓度氧是行不通的.而通过PSA-MS流程可得到体积分数为99.51%的氧气.结合实验数据进行模拟计算,得出了PSA-MS制高浓度氧最佳结合点.     

变压吸附气体分离技术应用及展望窥探

为了深入探究变压吸附气体分离技术,分析了技术工作原理,依据此原理,研究此项技术在H_2、CO_2、C0、氯乙烯精馏尾气的回收与提取中的应用方法,并探究参数指标变化下气体回收与提取纯度的影响。基于变压吸附技术应用现状,气体吸附提取纯度仍有上升空间,具有较高的研发应用前景。     

Separation of a Five-Component Gas Mixture by Pressure Swing Adsorption

Abstract

Bulk separation of a five-component mixture simulating coal gasification products was performed by pressure swing adsorption (PSA) using activated carbon. The PSA cycle consisted of four commercially used steps: (I) pressurization with H₂, (II) adsorption, (III) blowdown, and (IV) evacuation. Using this cycle, four products were obtained with a single PSA unit: H₂ (over 99.7% purity), CO, CH₄, and acid gas (CO₂ + H₂S). The first three products contained less than 0.001% H₂S, and the acid gas was suitable for sulfur recovery. A mathematical model incorporating equilibrium adsorption of mixture and mass transfer resistance (of CO₂) was found capable of simulating all steps of the PSA cycle. The model simulation results were in fair agreement with the experimental data. A fundamental understanding of the dynamics of the cyclic process was gained through the model.     

Effects of Adsorbent Characteristics on Adiabatic Vacuum Swing Adsorption Processes for Solvent Vapor Recovery

The effects of the adsorbent characteristics on the performance parameters and periodic state behavior of the vacuum swing adsorption (VSA) solvent vapor recovery (SVR) processes are examined and optimized. The adsorbent characteristics studied were the adsorbent particle's porosity, density, radius and heat capacity, the packed bed void fraction, the isosteric heat of adsorption, the monolayer saturation limit of the solvent molecules on the adsorbent, the adsorbent's affinity to adsorb the solvent molecules and the mass transfer coefficient for the adsorption of the solvent molecules. It was found that the best VSA‐SVR process performances can be obtained using adsorbents characterized by the minimum possible packed bed void fraction and particle porosity, with the maximum possible adsorbent heat capacity and density, adsorption monolayer saturation capacity and mass transfer coefficient, and at intermediate adsorption affinity and isosteric heat of adsorption of the solvent molecules.     

变压精馏分离异丙醇-二异丙醚工艺模拟

在分析异丙醇-二异丙醚二元物系性质的基础上,提出了,采用变压精馏分离该二元混合物系的工艺。利用ASPENPLUS模拟软件．选择NRTL物性模型对该物系的分离工艺进行模拟与参数优化,得到了分离该二元物系的最佳工艺参数。研究表明,采用变压精馏的工艺完全能够达到分离该共沸物的要求,变压精馏是分离提纯该二元共沸物的一种可行方法...     

变压吸附技术在气体分离提纯中的应用

介绍了变压吸附技术的基本原理、发展概况及基本工作过程,并阐述了该技术在氢气的分离与提纯、二氧化碳的分离与提纯、一氧化碳的分离、空气分离制氧、空气分离制氮、碳的脱除等工业过程中的应用,对变压吸附技术今后的发展提出了展望。     

变压吸附分离提纯CO_2技术的应用

本文叙述了变压吸附提纯ＣＯ２技术的基本原理和工艺过程，介绍了我国ＰＳＡ－ＣＯ２的开发过程及发展前景，对已开发的ＰＳＡ－ＣＯ２工业装置的生产成本和经济性进行了分析     

Separation of Methane and Carbon Dioxide Gas Mixtures by Pressure Swing Adsorption

Abstract

Two pressure swing adsorption processes for separation of methane and carbon dioxide gas mixtures are described. One process simultaneously produces a high purity CH₄ and a high purity CO₂ product with high recoveries of both components from the feed gas. The other process only produces a high purity CH₄ product with high recovery. Test data for these processes are reported and their relative advantages are discussed.