剪切技术强化膜分离过程的研究进展

为了降低浓差极化和膜污染,剪切强化膜分离技术成为当前膜技术方面的研究热点。剪切强化膜分离技术主要包括旋转管式剪切膜分离技术、旋转盘式剪切膜分离技术和振动剪切膜分离技术。旋转管式和旋转盘式剪切膜分离技术都是通过旋转使膜表面产生剪切力来减少膜表面的污染物。振动剪切膜分离是通过扭转弹簧将偏心块产生的振动传递到过滤膜盘,振动产生的剪切力使污染物不易沉积。旋转管式和旋转盘式剪切膜分离技术因设备旋转耗能较大,从而限制了其实际应用的广泛性。振动剪切膜分离技术能耗较低,且可以浓缩浓度较高的液体,但其核心技术被垄断而限制了推广。因此,振动剪切膜分离技术的研究和设备的开发将是未来研究的重点。     

精馏-膜分离技术集成过程研究进展

精馏-膜分离集成过程与传统精馏工艺相比,因其具有明显节能降耗的经济性优势,故工业应用日渐增多,所以对其进行全面研究更有理论和实际意义。本文介绍了膜分离的机理模型,根据膜的亲水性和亲有机性对膜材料进行分类,总结了精馏-膜分离集成过程的理论研究方法,并分别从脱水和脱有机物两方面介绍了精馏-膜分离集成过程的主要实验研究及工业应用研究进展。通过对现有研究分析发现,目前该集成过程在膜材料和集成优化理论研究方面存在一定局限性,使其未能在工业上得以广泛推广应用。基于上述全面分析,提出了一定改进思路。     

面向CO2分离的膜-深冷耦合过程优化

二氧化碳的分离与纯化是当前的研究热点,而随着环保要求的提高,传统单一的分离手段难以满足行业要求,多种分离方法的集成逐渐得到研究者的重视。以整体煤气化联合循环发电系统（IGCC）流程中二氧化碳的分离与回收环节为例,在流程模拟的基础上,拟合出该体系状态方程的多项式形式。进一步,构建耦合膜-闪蒸超结构数学模型,在设定最低产物纯度和回收率的情况下,以最小化年度费用为目标,筛选出最优的分离序列。     

A pressure swing membrane separation process

A new pressure swing membrane permeation process that can achieve significant improvement in the selectivity of a membrane possessing opposite diffusivity and solubility characteristics toward a gas pair is proposed. By operating a membrane permeator under an unsteady state, the opposite mobility and solubility selectivities of the membrane can work synergistically to accomplish a degree of separation beyond the steady-state membrane permselectivity in the following manner: along the flow direction in the feed channel, the gas mixture is separated by the selective absorption of gases into the membrane; and simultaneously across the membrane, the gas mixture is separated by the diffusivity selectivity of the membrane. The viability of the new process is supported by the results of a theoretical and experimental study on the transient responses of a membrane permeator with a silicone rubber membrane separating a helium-methane mixture. Two different operating schemes are identified in carrying out the proposed process, depending on the mobilities and solubilities of the gas species to be separated.     

膜分离法精馏尾气回收装置的运行总结

介绍了膜法回收精馏尾气装置的运行状况和存在问题，对比分析了膜法与活性炭吸附法的运行数据，总结出膜法回收精馏尾气的优越性和不足点，并提出了相应的解决办法。     

压缩冷凝膜分离回收丙烯工艺中膜系统对其他系统的影响研究

针对聚丙烯装置中丙烯同收过程,通过卵论推导和HYSYS模拟,探讨了压缩冷凝膜分离(CCM)工艺中膜分离系统对原有压缩冷凝(CC)工艺中的气柜系统、压缩系统和冷凝系统的影响.通过气柜中丙烯质量衡算确定了气柜内丙烯浓度随气柜内气体体积减少而降低,在此基础上,确定了膜分离系统循环渗透气对压缩和冷凝系统的影响.针对膜系统对其他系统的影响,提出了调节控制CCM工艺的措施,并对实际生产中遇到的季节变化、膜性能变化、不凝气累积等问题提出了解决方案.     

A total solution for simultaneous organic degradation and particle separation using photocatalytic oxidation and submerged microfiltration membrane hybrid process

Advanced oxidation process (AOP) with reactor capacity of 150 L, using ultraviolet (UV) radiation and titanium dioxide (TiO₂) photocatalyst, was evaluated for the destruction of toxic organic chemical, bisphenol A (BPA). TiO₂ in the form of powder, was suspended as slurry in the water, as against the commonly adopted practice of immobilizing it onto a carrier material such as glass, concrete or ceramics. Adsorption of BPA by TiO₂ was evaluated and was performed as a pretreatment to AOP. The combined effect of ozone with the AOP process was also studied. Applying ozone along with UV/TiO₂, brought about a synergistic effect on BPA degradation. Within three hours, entire 10 ppm of BPA and the intermediate organic compounds were completely removed. The highlight of this study was the simultaneous degradation of BPA and separation of TiO₂ particles from water after photocatalysis, in order to obtain reusable quality water. Separation of TiO₂ particles was carried out by a unique two stage coagulation and settling process followed by submerged hollow fiber microfiltration membrane technique. With initial turbidity of 4,000 NTU, the turbidity of the final permeate water was well below 0.1 NTU. Almost complete removal of TiO₂ particles was achieved. Some of the main advantages of this hybrid treatment system include, large scale treatment, complete and efficient BPA and its organic intermediates degradation; easy separation of TiO₂ after treatment and reuse as it is free from chemical coagulant contaminants; reusable quality water, and the potential for continuous operation with simple process modifications.     

膜分离技术在炼油厂氢气膜回收装置中的应用

介绍了膜分离技术及其在中国石油吉林石化分公司炼油厂柴油加氢车间氢气膜回收装置中的应用。重点介绍了该装置的工艺特点,针对生产中常出现的问题做了分析,并提出了处理措施,对生产过程进行了优化调整。采用气体膜分离技术回收含氢尾气中的氢气,氢气回收率为74.45%,渗透气中氢气体积分数为90%,提高了炼厂氢气资源的利用效率,经济效益显著。     

耦合膜分离的新型CO2低温捕集系统性能优化

CO₂捕集作为温室气体排放控制的有效手段已成为重要研究课题。作为新兴捕集技术之一,低温CO₂捕集因产品纯度高、无附加污染等优势受到关注。然而,该技术能耗和捕集率对于气体中CO₂浓度十分敏感,对于高CO₂浓度气体可获得较高的CO₂捕集率和较低能耗水平。基于此,本文提出了耦合膜分离的新型CO₂低温捕集系统,通过膜材料选择渗透性实现待捕集气体CO₂浓度主动调控,并在最优浓度下进行CO₂低温捕集。首先基于不同传统低温捕集系统特点,对比分析了不同耦合系统模式,从而确定了最优耦合系统结构。针对最优耦合系统进行了运行参数优化,并分别基于实现系统捕集能耗最低与捕集率最高的目标,获得了膜渗透侧CO₂浓度与进气CO₂浓度间的关系式,为该耦合系统中膜组件选型提供指导。研究表明,本文提出的耦合系统捕集能耗为1.92MJ/kgCO₂,相比于传统单一低温系统捕集能耗可降低16.5%。     

乙醇连续发酵与膜超滤耦合过程研究

采用ＣＡ－Ｔｉ复合管式膜组件与发酵耦合操作，用啤酒酵母从葡萄糖连续发酵乙醇是一个从不稳态到稳态的过程。其稳态的最佳操作参数为：初始葡萄糖浓度１４０ｇ／Ｌ，稀释率０．３ｈ~（－１），轴出比０．６３８，相应的细胞浓度２×１０~９ｃｅｌｌ／ｍＬ，葡萄糖利用率９２％，生产率２２ｇ／（Ｌ·ｈ）。当细胞浓度增加到一定程度时，乙醇生产率和酵母比生长速率的增长减缓。反应器中细胞的浓度由稀释率和轴出比决定。     

提高发酵过程乙醇分离效率的新型反应器

设计了一种新型的带侧臂循环的气升式反应器,该反应器可以有效地把真空闪蒸发酵和汽提发酵2项技术结合起来。实验结果表明,与单独的汽提和闪蒸过程相比,利用此反应器进行同步汽提闪蒸操作,大大提高了乙醇的移出效率,从而进一步提高了发酵强度。     

A green separation process for recovery of healthy oil from pumpkin seed

In this study, pumpkin seeds, called as “Ürgüp Sivrisi” and grown in Cappadocia region, were used as plant materials because of high aroma contents. In the supercritical fluid extraction of pumpkin seed oil, the effect of main process parameters as the particle size (250-2360 μm), the volumetric flow rate of supercritical solvent (0.06-0.30 L/h), the operating pressure (20-50 MPa), the operating temperature (40-70 °C), the type of entrainer (ethanol and n-hexane) and those concentrations (0-10 vol.%) on the extraction yield, the oil solubility and the initial extraction rate were investigated. A cross-over effect for the extraction of pumpkin seed oil using supercritical CO₂ was determined at the operating pressure of 20-30 MPa. The maximum extraction yield obtained with entrainer free was reached 0.50 g oil/g dry seed at 600-1180 μm, 0.12 L/h, 50 MPa and 70 °C for the operation time of 5 h. The maximum extraction yield obtained with ethanol as an entrainer in the experiments was reached 0.54 g oil/g dry seed at the conditions of 600-1180 μm, 0.12 L/h, 30 MPa, 40 °C and 8 vol.% for the operating time of 2 h. The oil compositions were determined by gas chromatography analysis and the results showed that the compositions of pumpkin seed oil which were obtained by means of organic solvent extraction and supercritical fluid extraction were similar. The average oil compositions determined as 9.3 (±0.43)% palmitic acid, 7.5 (±0.6)% stearic acid, 32.3 (±0.6)% oleic acid, 48.1 (±0.6)% linoleic acid and 0.7 (±0.3)% linolenic acid. The morphological changes in the seeds were determined by the scanning electron microscopy analysis.     

氨氮回收复合分离流程及装备

开发了全填料结构的"吸收 精馏 压缩冷凝"新型复合分离流程及装备,用于精细化工厂氨氮废气(水)的处理,在获得高收率、高纯度的液氨产品同时,基本实现了气、液无污染排放。     

Diafiltration and water recovery of Reactive Brilliant Blue KN-R solution by two-stage membrane separation process

The conventional process of Reactive Brilliant Blue KN-R production is low purity, labor intensive, inconsistent in the production quality and also causes pollution. The improved process based on membrane technology still generates large volume of effluent though with low pollutants. In this paper, a two-stage membrane separation process is introduced to resolve these shortcomings, in which the first stage is used for diafiltration and concentration of dye solution, and the second is to recover the dye and salt water from the produced permeate. Comparing results from one ultrafiltration (UF) membrane (GH) and four nanofiltration (NF) membranes (AFC40, DL, CA865 and MPT-31), UF membrane ES404 showed the same dye rejection, higher permeate flux and lower sodium sulfate rejection. In the diafiltration and concentration stage, pre-concentration and constant volume diafiltration had the best salt permeability as compared to constant volume diafiltration and post-concentration in addition to variable volume diafiltration. In the dye and salt water recovery, membrane ES404 had the same dye rejection, but higher permeate flux and lower sodium sulfate rejection as compared to membrane GH. The proposed two-stage membrane separation process offers the advantages of high-purity, less labor intensive, consistent in production quality and less pollution.     

面向烟气NOx净化与回收的新型吸附工艺

合理高效的吸附工艺是决定吸附法净化和回收烟气中NO_x工业可行性的关键工艺环节。提出一种通过外部补充气体实现固定床循环体空间内多次循环解吸NO_x的新型吸附工艺（GVTSA）。基于该工艺,采用Na-ZSM-5分子筛作为吸附剂,以某钢厂烧结机脱硫后烟气为原料（组分）进行了NO_x吸附回收实验研究。结果表明,GVTSA工艺相较传统吸附工艺（TSA工艺、VSA工艺）可获取更高的NO_x回收量,在优选条件下（220℃,-50 kPa）,NO_x回收率达到90%,解吸气中NO₂浓度由原料气的36 mg·m^-3提升到2%以上,NO_x循环吸附量可达0.10 mmol·g^-1,16次吸脱附循环稳定。研究结果可为烟气NO_x治理与资源化工业应用提供参考。     

A fine match between the stereoselective ligands and membrane pore size for enhanced chiral separation

A D,L -tryptophan separation factor of 12–15 and D -tryptophan yield of >95% have been successfully achieved through using human serum albumin (HSA) as the stereoselective ligand in an affinity ultrafiltration (UF) system. The obtained separation factor in this work is even higher than the intrinsic value of 8.5 of HSA. This synergism may arise from the fact that a fine match between the regular crystalline structure of HSA molecules and suitable pore size of membranes makes some HSA molecules be retained within the membrane cross-section, thus offering a second-stage binding opportunity for L -tryptophan molecules. Therefore, a simultaneous enhancement in separation factor and D -tryptophan yield has been fulfilled in this work. The feasibility of HSA regeneration after D ,L -tryptophan separation has also been demonstrated through a series of pH adjustment experiments. This study reveals the applicability of HSA in affinity UF systems for chiral separation due to economization of material costs. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

A new regenerable process for the recovery of SO2

Increasing demand for regenerable processes with SO₂ recovery is to be expected. Advantages and limitations of the earlier developed citrate and adipate absorption/ steam stripping process are compared with those of the Wellman-Lord (sulphite) process. On the basis of comprehensive laboratory studies, a new process is proposed which supplements the citrate and adipate process. In this new process, the absorbent is a concentrated sodium phosphate buffer and the loaded buffer is regenerated by evaporation. The main buffer component is Na₂HPO₄, but NaH₂PO₄ is added in order to obtain a more complete stripping of SO₂ during regeneration. The new process promises excellent absorption properties for SO₂ with extremely low oxidation losses, regeneration with few incrustation problems and appreciable energy savings.     

膜分离技术用于废水中金属的分离和回收

废水中的金属元素是污染环境的主要因素之一,对废水中的金属元素进行分离回收可以充分利用资源,减少污染。通过膜分离技术进行二次金属资源的回收和水的回用处理已有大量研究,并在工程实践中获得效益。综述了几种常见的膜分离技术,分析了各种技术在金属分离及回收中的适用条件和局限性,并对膜分离技术在金属废水资源化中的应用前景及发展进行了展望。     

旋流器分离过程随机特性的物理描述

对旋流器中固液两相流运动的随机特性进行了分析,从旋流器内流场的湍动特性、特殊流动形式、颗粒的运动、颗粒在旋流器中的位置、操作条件等几个方面对其进行了随机性物理描述,提出采用随机理论描述旋流器内的真实分离行为的必要性。     

亚磷酸二甲酯尾气的分离回收工艺

介绍了亚磷酸二甲酯生产中尾气回收的工艺原理,对尾气中氯化氢及氯甲烷的分离回收过程进行了分析;提出了采用吸收剂分段循环和降温相结合的回收工艺,将此工艺应用于3万t/a的亚磷酸二甲酯生产装置的尾气回收上,可使氯化氢的回收率达99.9%,氯甲烷的回收率达93%以上,盐酸质量分数大于30%,尾气中氯甲烷的质量分数小于5%。