回收丁辛醇装置驰放气中丙烯和丙烷的工艺设计

本文采用压缩/冷凝/有机蒸汽膜(CCM)技术回收丁辛醇装置驰放气中的丙烯和丙烷,根据本文的工艺技术及设备选型已实际建成回收丁辛醇装置驰放气中丙烯和丙烷的装置,并已开车成功。     

膜法丙烯单体回收技术在呼石化小本体聚丙烯装置中的应用

阐述了应用膜法丙烯单体回收技术回收不凝气中丙烯的基本原理及运行情况，结果表明，膜系统操作简单，占地少，经济效益明显。     

气体膜分离技术在尾气丙烯回收中的应用

对于间歇式液相本体法聚丙烯生产中产生的含大量丙烯、氮、氧的尾气 ,在常用的冷凝法回收的基础上提出了一种新的分离法 ,即以气体膜分离法进一步回收尾气中的丙烯。该法以膜两侧气体的压差为推动力 ,通过溶解、扩散、脱附等过程 ,利用其中产生的各组分传递速率的差异来实现尾气中丙烯气体的充分回收。     

膜法回收小本体聚丙烯生产中的尾气

简要阐述了膜法有机蒸汽回收的基本原理,介绍了压缩冷凝膜系统在小本体聚丙烯尾气回收中的应用效果。     

膜分离技术在聚丙烯尾气回收中的应用

介绍了应用膜分离技术从聚丙烯尾气回收装置释放的不凝气中回收丙烯的情况。不凝气中丙烯的平均体积分数约68.67%,用膜分离系统从不凝气中回收丙烯,丙烯回收率可达90%。膜分离系统操作简单,占地少,经济效益明显。     

膜分离技术在不凝气中回收丙烯的应用

应用膜分离技术。回收聚丙烯装置排空不凝气中的丙烯，回收率在85%以上。在原有丙烯回收的基础上，只需增加膜分离回收系统，每天可多回收2-4t丙烯，可以在短期内收回投资。     

蒸气渗透膜法回收有机蒸气

蒸气渗透过程属于气体膜分离技术,是回收分离有权蒸气很有效的方法.简要论述了蒸气渗透过程的分离权理-溶解扩散机理,以及其膜的选择-一般采同橡胶态膜,并且列举了应用蒸气渗透技术回收几种有机蒸气的工业化应用,如氯氟烃、丙烯、丁烯等.最后展望了蒸气渗透技术的发展前景.     

膜技术在丙烯回收系统中的应用

通过对排放到低压瓦斯管网的不凝气中丙烯含量进行分析，从经济角度，探讨了这部分丙烯的回收价值，采用膜分离装置回收后，可年创效益132．539万元。     

具有回收丙烯氮气双功能的膜技术在聚丙烯尾气回收系统中的应用

本文对小本体聚丙烯装置原尾气回收系统存在的问题进行了分析,通过具有回收丙烯及N2双功能膜分离技术与压缩/冷凝液化回收技术的组合,回收聚丙烯装置尾气中的丙烯及N2,效果显著。     

不凝气中丙烯回收的工艺方法

通过对小本体聚丙烯装置丙烯尾气回收系统不凝气排放所造成的丙烯损耗进行理论分析和计算，说明加强不凝气中丙烯回收，对降低聚丙烯生产成本的重要意义，并提出了回收不凝气中丙烯的工艺方法。     

膜分离技术在丙烯尾气回收中的应用

分析了聚丙烯生产过程中压缩 /冷凝法丙烯尾气回收的不足 ,介绍了压缩 /冷凝 /有机蒸汽膜法在丙烯尾气回收中的应用     

Facilitated Transport Membrane Hybrid Systems for Olefin Purification

Abstract

A new membrane system has been developed by BP for refinery and chemical plant olefin purification and recovery. This facilitated transport system, coupled with distillation, offers lower capital and operating costs than conventional distillation alone. Initial results on lab scale hollow fiber devices indicate membrane flux ranging from 8.75×10^?6 to 8×10^?5 m³/m²/sec (2.5 to 23 scfd/ft²) and selectivities from 150 to 300. Pilot plant experiments on propylene/propane and ethylene purge gas recovery over three to six months duration show membrane stability and product purity of 98.5% or greater using refinery grade propylene feed. Hybrid system optimization data for membranes and distillation indicate that using a side draw from the distillation tower provides advantages in terms of membrane area, purity of feed to the membrane, and low per-pass recovery coupled with high overall propylene recovery. Membrane performance data under various conditions will also be presented. In addition to performance data, economic evaluation and energy savings will be discussed.     

Modelling and process development for gaseous separation with silicone‐coated polymeric membranes

This paper proposes a permeance equation for vapour–permanent gas mixtures in a silicone‐coated polymeric membrane. The equation was derived from the Arrhenius relationship by combining an apparent activation energy and interaction parameter. Accurate values of transmembrane flux were obtained by incorporating this proposed equation, which was dependent on temperature and feed composition. The equation parameters were correlated with the experimental data of eight mixtures consisting of hydrocarbons such as ethylene, ethane, propylene and propane with nitrogen covering a broad range of temperature and concentration. A numerical integration scheme was used for developing a crossflow model utilizing the above equation, which allowed the estimation of product properties including the membrane plasticization cases. The study also reports examples of implementation of this approach in potential industrial applications for the recovery of ethylene and propylene from nitrogen.     

Recovery of pyridine from water by pervaporation using filled and crosslinked EPDM membranes

Organoselective membrane was prepared from ethylene propylene diene monomer (EPDM) rubber. Crosslinked EPDM rubber was filled with 2, 4 and 6 wt% N330 carbon black filler to produce three different filled membranes designated as EPDMCV2, EPDMCV4 and EPDMCV6, respectively. These filled rubber membranes were used for pervaporative recovery of low concentration of pyridine from water. These filled membranes were characterized by crosslink density, SEM, XRD and mechanical properties. Sorption thermodynamics were discussed. Partial permeability, intrinsic membrane selectivity and diffusion coefficients of solvents were also determined. The filled membranes showed much higher pyridine selectivity than most of the membranes reported for similar system.     

Pure Hydrogen and Propylene Coproduction in Catalytic Membrane Reactor-Assisted Propane Dehydrogenation

Propane dehydrogenation on a commercial Pt-Sn/Al₂O₃ catalyst in a Pd-Ag membrane reactor is considered. A mathematical model is developed to evaluate the performance of the catalytic membrane reactor for the process of propane dehydrogenation. Design and operating conditions are systematically evaluated for key performance metrics such as propane conversion, propylene selectivity, hydrogen selectivity, and hydrogen recovery under different operating conditions. The results confirm that the high performance of the membrane reactor is related to the continuous removal of hydrogen from the reaction zone to shift the reaction equilibrium towards the formation of more propylene and hydrogen.     

Supported liquid membrane separation of propylene-propane mixtures using a metal ion carrier

Experimental results for the separation of propylene from a propylene/propane mixture using facilitated transport membrane system with silver nitrate as carrier are presented. The equilibrium constant of the reaction between propylene and silver ion (Ag⁺) at different operating conditions was determined, experimentally. For a 50:50 (vol.%) propylene-propane mixture, at feed pressure of 50-120 kPa, the separation performance of a facilitated transport membrane system was evaluated. It was observed that increasing carrier concentration and trans-membrane pressure, separation factor was increased. At feed pressure of 120 kPa and the carrier concentration of 20 wt.%, a separation factor of 270 was obtained.     

Membranes of triphenylsilyl substituted polyphenylene oxide in the permeation of propylene and propane gases

Poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) was chemically modified by the attachment of a bulky triphenylsilyl (TPS) group substituent (～30 mol %) to study its impact on hydrocarbon gas permeation. A membrane of the modified PPO (TPS–PPO) was tested for the permeation of pure propylene and propane gas and that of their 55:45 binary mixture at 30 ± 2°C. Gravimetric single‐gas equilibrium sorption studies were carried out to determine the gas solubility coefficients and diffusion coefficients to assess their role in the gas permeation mechanism of the membranes. Characterization studies were done to determine the interrelationship between the transport properties and the polymer structure. The studies included density, fractional free volume, Fourier transform infrared spectroscopy, ¹H‐NMR, differential scanning calorimetry, wide‐angle X‐ray diffraction, tensile testing, and scanning electron microscopy. The TPS–PPO membrane was found to be 3 times more permeable to propylene and 3.8 times more permeable to propane with a small decrease in the propylene/propane ideal permselectivity (3.37) when compared to that of unmodified PPO (4.25). TPS–PPO could be a potential membrane material for the efficient recovery of propylene and propane from mixtures with permanent gases such as those found in refinery off‐gas. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013