微孔中空纤维膜接触器烟气脱硫性能的研究

对中空纤维膜接触器用于烟气脱硫的工艺进行了实验研究并建立了脱硫率计算模型。采用疏水性聚丙烯中空纤维膜组装膜组件,用SO2钢瓶气与空气配制模拟烟气,气相走中空纤维膜内侧,以Na2SO3溶液为吸收剂进行脱硫实验研究。实验结果表明,该脱硫工艺脱硫率高且稳定。当Na2SO3吸收液浓度大于5%,液相阻力可以忽略;脱硫率随气速的增大而减小,而随膜组件有效长度、膜传质系数的增大而增大。忽略液相传质阻力,用传质速率与物料衡算方法及传质经验关联式,建立微孔中空纤维膜接触器烟气脱硫率计算模型,模型计算值与实验值误差小于9.5%,模型能比较可靠地模拟烟气脱硫过程,通过该模型可以快捷计算脱硫率。     

边界层传质速率对气体膜分离器分离性能的影响

运用并实验验证了描述气体膜分离速率的串联阻力模型.该模型表明，膜两侧传质阻力总是使膜分离器的实际分离系数小于膜的理想分离系数.对于渗透速率较高的膜,为提高膜分离器的实际分离系数，应尽量增大膜两侧（特别是高压侧）的传质速率.     

中空纤维膜渗透汽化过程中Dean涡强化传质的CFD模拟

建立了一个三维的弯管式中空纤维膜渗透汽化传质CFD模型,研究Dean涡对渗透汽化过程传质的影响,描述了膜内侧的浓度和速率变化情况,该模型与Leveque传质关联式具有良好的一致性。研究结果显示：弯管膜中Dean涡的存在能降低边界层传质阻力,总传质系数比直管膜提高了4倍;在不同的入口速率和浓度条件下,弯管膜内侧的壁面剪应力均大于直管膜。在膜阻力远小于边界层阻力的情况下,入口速率0.275 m·s^-1,水浓度10%（质量）时,弯管膜的渗透通量为12636 g·m^-2·h^-1,是直管膜的5倍。可见,弯管式中空纤维膜在渗透汽化过程中具有显著的强化传质效果。     

中空纤维膜渗透汽化过程中Dean涡强化传质的CFD模拟

建立了一个三维的弯管式中空纤维膜渗透汽化传质CFD模型,研究Dean涡对渗透汽化过程传质的影响,描述了膜内侧的浓度和速率变化情况,该模型与Leveque传质关联式具有良好的一致性。研究结果显示:弯管膜中Dean涡的存在能降低边界层传质阻力,总传质系数比直管膜提高了4倍;在不同的入口速率和浓度条件下,弯管膜内侧的壁面剪应力均大于直管膜。在膜阻力远小于边界层阻力的情况下,入口速率0.275 m·s~(-1),水浓度10%(质量)时,弯管膜的渗透通量为12636 g·m~(-2)·h~(-1),是直管膜的5倍。可见,弯管式中空纤维膜在渗透汽化过程中具有显著的强化传质效果。     

渗透蒸发与化学反应耦合过程的研究进展

渗透蒸发膜分离过程往往不是单独应用 ,而是与其它的分离或反应过程进行耦合的。着重介绍了渗透蒸发膜分离过程与精馏和反应耦合过程的研究现状 ,以及讨论了渗透蒸发膜分离过程与化学反应耦合过程的数学模型和常用的渗透蒸发膜材料。     

优先透水渗透汽化膜的研究

本文将聚乙烯醇和壳聚糖混合物涂到聚丙烯腈中空纤维内表面制备用于渗透汽化过程的中空纤维复合膜，研究不同的聚乙烯醇和壳聚糖共混组成对膜分离性能的影响，通过适当交联，使膜性能稳定，用于渗透汽化过程分离乙醇－水混合液时，进料乙醇浓度０．９５，温度４８℃，膜分离因子１００～２００，渗透通量４０～７０ｇ／ｍ＾２．ｈ。     

超声场强化直接接触式膜蒸馏研究

为了解决膜蒸馏分离过程中聚四氟乙烯(PTFE)膜通量低的问题,构建了超声场强化膜蒸馏反应器,并对膜分离工艺进行了研究。结果表明,当原水流经中空纤维膜壳程时,诸如空化、声冲流等超声效应能有效增大传质驱动力、减缓含量极化现象并提高膜蒸馏通量,其传质过程得到强化,实验范围内的PTFE膜通量可提高30%以上;原水流经中空纤维膜管程时,由于冷侧声能量高过热侧,故造成传质推动力下降,进而导致膜通量有一定程度的下降,相对通量降低了3.2%。低频高功率超声场、低温与低流速浓盐水比较有利于提高超声场强化传质效果。     

中空纤维膜组件分离酸性气体

研究了气体膜分离与溶剂吸收相结合的分离技术.以NaOH水溶液为吸收剂,在中空纤维膜组件中实现二氧化硫气体的选择性吸收.研究了在三种不同结构的疏水性聚丙烯中空纤维膜组件中,吸收剂浓度、液速、气速、气液两相在膜组件内的流程、膜结构等对分离过程的影响;根据膜结构的实际参数确定了多孔膜的曲率因子,总传质系数的计算值与实验值相符.     

中空纤维PVA/PAN复合膜填料的乙醇水溶液精馏性能

以乙醇/水溶液为分离对象,中空纤维PVA/PAN复合膜作为精馏填料,考察了不同膜组件的传质分离效率。实验结果表明:各种组件的分离效率均随塔釜加热功率的增加而减小;和大多数中空纤维膜接触器一样,其总传质系数Ky随中空纤维膜组件填充密度φ的增加而减少;相比于传统精馏填料而言,用中空纤维膜做精馏填料分离乙醇水溶液的分离效果更好,可以在常规填料不能操作的液泛线以上进行操作。当塔釜加热功率为120 W,45根中空纤维膜封装在内径为1.6 cm玻璃管中的传质单元高度(HTU)为5.64 cm。     

中空纤维纳滤膜的应用性能

研究了中空纤维纳滤膜的长期稳定性,以及操作压力、进料液浓度对膜分离性能的影响。结果表明:中空纤维纳滤膜在长时间运行过程中分离性能稳定;随着操作压力的上升,膜的纯水通量增加,截留率提高;随着进料液浓度的增加,膜的渗透通量基本不变,截留率下降。     

用于CO2捕集的新型酒石酸钠交联海藻酸钠膜的制备（英文）

The membrane-based CO2 separation process has an advantage compared to traditional CO2 separation technologies. The membrane is the key of the membrane separation process. In this paper, preparation, characteriza-tion and laboratory testing of the membrane, which was prepared from sodium alginate, hydrogen bond cross-linked with sodium tartrate and used for CO2/N2 separation, were reported. The resistance to SO2 of the membrane was also investigated. The experimental results demonstrate that the membrane possesses a high resistance to SO2. Finally, based on experimental results, the economic feasibility of the membrane used for CO2/N2 separation was evaluated, indicating the two-stage membrane process can compete with the traditional chemical absorption method.     

电石废水在锅炉烟气脱硫中的应用

电石废水脱硫过程是二氧化硫与氢氧化钠发生化学反应生成亚硫酸钠。含亚硫酸钠的脱硫循环水与投加的氢氧化钙反应生成氢氧化钠和亚硫酸钙。通过沉淀分离将难溶的亚硫酸钙从循环水中清除,氢氧化钠溶于水循环使用,脱硫过程只消耗氢氧化钙。采用电石废水脱硫,脱硫效率高,运行费用低又达到综合利用的目的。     

二氧化碳驱伴生气分离技术综述

对CO2驱油田伴生气成分复杂、二氧化碳浓度高等特点进行了分析,详细介绍了几种当前热门的伴生气分离提纯技术,包括化学吸收法、膜分离法、变压吸附法、低温分馏法等,并对各类方法的原理、优缺点进行了深入解析。对伴生气CO2分离技术及复配方法进行了综合对比,得出膜分离+化学吸收法、低温分馏+化学吸收、膜分离+变压吸附更适用于分离CO2驱油田伴生气中的CO2。     

超临界二氧化碳技术与绿色化工过程

介绍了超临界二氧化碳的有关知识,说明了它在萃取分离、反应分离、多相反应以及清除环境污染物中的重要作用。指出了其目前存在的问题并对其应用前景进行了展望。     

三种气体分离技术应用于电厂烟气二氧化碳捕集经济性的比较(英文)

Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three technologies are analyzed and compared.The cost for chemical absorption is mainly from $30 to $60 per ton(based on CO2 avoided),while the minimum value is $10 per ton(based on CO2 avoided).As for membrane separation and pressure swing adsorption,the costs are $50 to $78 and $40 to $63 per ton(based on CO2 avoided),respectively.Measures are proposed to reduce the cost of the three technologies.For CO2 capture and storage process,the CO2 recovery and purity should be greater than 90%.Based on the cost,recovery,and purity,it seems that chemical absorption is currently the most cost-effective technology for CO2 capture from flue gas from power plants.However,membrane gas separation is the most promising alternative approach in the future,provided that membrane performance is further improved.     

二氧化硅膜的制备及分离CH4/CO2气体的研究

以正硅酸乙酯为前驱体,通过溶胶-凝胶法,采用多分离层镀膜工艺制备了用于分离CH4/CO2气体二氧化硅无机膜。通过TG-DSC、粒度分析仪及SEM对二氧化硅膜进行表征,结果表明分别利用HNO3、EtOH及DMF作为催化剂、助溶剂及添加剂可制备出表面性能较好的二氧化硅膜;利用多分离层镀膜工艺制备的二氧化硅膜,在0.025MPa下,对CH4/CO2气体的分离因子高达1.73,其效果明显高于利用单一溶胶涂膜的分离因子1.6,有效的提高了二氧化硅膜对气体的分离能力。     

Recent progress in selective CO removal in a H2-rich stream

In this review, recent works related to the selective CO removal in a H₂-rich stream for the application of the low-temperature fuel cell are discussed. The membrane separation, the selective CO hydrogenation, and the preferential CO oxidation (PROX) have been generally studied to meet the requirement for the polymer electrolyte membrane fuel cell (PEMFC) where the CO concentration should be controlled to be less than 10 ppm not to degrade the electrochemical performance of Pt anode. For the membrane separation, the thin layer of Pd-based alloy metal on the porous ceramic material coupled with the catalytic purification is the most advanced method at present. For PROX catalysts, supported Ru catalysts and Pt-based alloy catalysts have been successfully developed so far. The combination of highly selective PROX catalysts and the CO methanation catalyst can provide the extended temperature range to achieve the acceptable CO removal. Because each method has presently its own weak points, the further advance is still in need. The non-noble metal-based membrane requiring smaller pressure differentials is highly plausible in the membrane separation. The highly selective catalyst for CO methanation in the presence of excess CO₂ and H₂O can simplify the CO removal step. The PROX catalyst should be operative over a wide reaction temperature as well as at low temperatures not to cause the reverse water–gas shift reaction. During the development of these catalysts, the progress on the high-temperature PEM fuel cell or the CO-tolerant anode should be carefully evaluated.     

基于海水淡化中试的超滤膜清洗工艺及机理

为了对海水淡化过程中的超滤膜进行清洗,利用超滤中试设备研究了反洗水和清洗药剂对超滤膜清洗的效果。分别研究了不同的反洗用水对于跨膜压差的影响,结果表明,清洗效果：淡水（自来水）>超滤产水>反渗透浓水。另选用不同的酸性清洗剂与碱性清洗剂进行清洗,结果表明,清洗效果：柠檬酸>草酸>盐酸>次氯酸钠>氢氧化钠,柠檬酸清洗效果最好,纯水透过速率可从283.24 L/(m²·h)恢复至571.56 L/(m²·h)。此外,实验证明碱洗+酸洗效果优于单独清洗效果,先用氢氧化钠清洗,再用柠檬酸清洗,纯水透过速率可从283.24 L/(m²·h)恢复至818.81 L/(m²·h)。本研究成果对于海水淡化过程中超滤膜的维护具有较好的应用前景。     

Ultrafiltration membrane cleaning technology and mechanism based on seawater desalination pilot equipment

In order to clean the ultrafiltration membrane in the process of seawater desalination, this paper studied the cleaning effects of backwash water and chemical agents on the ultrafiltration membrane by using the ultrafiltration pilot equipment. Effects of different backwash water on the transmembrane pressure difference were studied. The results showed that the cleaning effect was in the order of fresh water (tap water) > ultrafiltration water > reverse osmosis concentrated water. In addition, cleaning effect was as follows: citric acid > oxalate > hydrochloric acid > sodium hypochlorite > sodium hydroxide. Citric acid had the best cleaning effect, and the pure water penetration rate could be restored from 283.24 L/(m²·h) to 571.56 L/(m²·h). Moreover, the effect of alkali washing and acid washing together is better than that of cleaning alone. After cleaning with sodium hydroxide and then citric acid, the pure water transmission rate can recover from 283.24 L/(m²·h) to 818.81 L/(m²·h). The results of this study have a good application prospect for the maintenance of ultrafiltration membrane in seawater desalination.     

PVDF中空纤维膜接触器分离烟气CO2

以水（H2O）、氢氧化钠（NaOH）、氨基乙酸钾（GLY）、氨基乙酸钾-哌嗪（GLY-PZ）水溶液为吸收剂,研究了疏水性聚偏氟乙烯（PVDF）中空纤维膜接触器分离CO2/N2模拟烟气中CO2的技术,具体考察了流动方式、气液流率、吸收液浓度和温度、原料气CO2浓度、填充密度等对膜接触器吸收效率的影响。结果表明,气液逆流的腔流程模式具有较高的分离效率。不同吸收剂的分离性能为：NaOH > GLY-PZ > GLY > H2O。温度对各种吸收剂的影响随其种类不同而有所差异。膜接触器对烟气CO2的分离效率随填充密度、吸收液浓度和流率的提高而增大,随气体流率及其中CO2浓度的增大而减小。