聚酯切片干燥除湿系统

对聚酯切片干燥除湿系统及其典型设备如冷冻式除湿机 ,转轮式除湿机和分子筛除湿机进行了介绍和分析。指出冷冻式除湿与分子筛吸附相结合是切片干燥除湿系统的优选配置。     

改性5A分子筛对水中As(Ⅴ)的吸附作用研究

改性5A分子筛是一种高效吸附材料。实验用5A分子筛作为载体,制备了该吸附剂,并表征了其基本性质。结果表明,改性5A分子筛对As(Ⅴ)具有很高的吸附率和选择性;室温下,pH=7时,改性5A分子筛吸附As(Ⅴ)的吸附等温线符合Langmuir型和Freundlich型。     

焦化苯脱硫用吸附剂研究进展

焦化苯的选择吸附脱硫(SARS)技术以脱硫精度高、操作简单、设备投资小等优点而被看好。综述了焦化苯脱硫用分子筛吸附剂、金属氧化物吸附剂、活性炭吸附剂的研究进展,其中,分子筛吸附剂主要介绍了微孔吸附材料、介孔吸附材料和碳分子筛吸附材料,通过分析可知,吸附剂的孔道结构对硫化物吸附选择性的作用明显,Y型分子筛和ZSM-5分子筛是比较理想的吸附剂。并指出,要获得脱硫精度好、硫容高的焦化苯脱硫吸附剂,先制备孔径孔容较大、性质稳定、活性位丰富的多孔材料,然后对其进行酸性改性或金属离子改性是一条较好的途径。     

复合改性5A分子筛对水中Cr~(3+)的吸附研究

对复合改性5A分子筛去除水中Cr⁽³⁺⁾的效果进行了研究。采用氢氧化钠和硝酸铁为改性试剂对5A分子筛进行复合改性,考察分子筛用量、溶液pH值、Cr(3+)的效果进行了研究。采用氢氧化钠和硝酸铁为改性试剂对5A分子筛进行复合改性,考察分子筛用量、溶液pH值、Cr⁽³⁺⁾溶液初始浓度、吸附时间对Cr(3+)溶液初始浓度、吸附时间对Cr⁽³⁺⁾去除率的影响。用Langmuir和Freundlich等温吸附模型对分子筛吸附Cr(3+)去除率的影响。用Langmuir和Freundlich等温吸附模型对分子筛吸附Cr⁽³⁺⁾的吸附过程进行拟合,并探讨分子筛吸附Cr(3+)的吸附过程进行拟合,并探讨分子筛吸附Cr⁽³⁺⁾过程的吸附动力学模型。结果表明,经0.4 mol/L氢氧化钠,6 mmol/L硝酸铁复合改性后效果最好,较未改性的5A分子筛的吸附容量提升了176%,改性前后分子筛的吸附均符合Langmuir吸附等温模型,吸附速率符合Lagergren准二级速率方程。     

沸石转轮技术涂料行业VOCs治理应用实例

相对于活性炭吸附工艺,沸石转轮技术具有再生性能好、安全性高、使用寿命久的优点。针对涂料行业特征污染物,验证了由ZSM-5及Y型分子筛负载于陶瓷纤维制成的沸石转轮吸附材料的吸附效果,其净化效率均在95%以上。将沸石转轮+RCO工艺应用于涂料行业,净化效率高、系统安全性高、运行维护成本低,对于该行业废气治理具有一定参考价值。     

介孔分子筛改性及在吸附脱硫中的应用

介孔分子筛由于具有较大的比表面积、孔容、孔径等优点使得其在吸附分离等领域得到了广泛的应用。本文综述了介孔分子筛改性的不同方法,包括嵌入法、负载法,以及有机-无机杂化介孔材料的制备等。对介孔分子筛在吸附脱硫方面的最新研究进展进行了总结,包括对燃料油、天然气、煤气中硫化物的吸附脱除,以及H2S、SO2等大气污染物的吸附脱除。同时对介孔分子筛的改性及发展前景进行了展望,合成新型有机-无机杂化介孔材料并将其应用于吸附等领域是未来发展的主要趋势。     

沸石分子筛对苯系物的吸附脱除研究进展

阐述了沸石分子筛对苯系物的吸附脱除原理，并探讨了沸石分子筛对苯系物吸附脱除性能的改进方法，包括沸石分子筛结构优化、减弱亲水性、阳离子补偿、孔道多极化及复合分子筛等。在流量大、压降高时，分子筛转轮吸附技术对苯系物吸附脱除效率高，此技术在工业领域应用广泛。目前沸石分子筛对苯系物的吸附脱除需要解决的问题还有如何提升疏水性、稳定性以及选择性。     

疏水改性MCM-41材料对邻苯二甲酸二丁酯的吸附

基于介孔分子筛亲水性强、对疏水性有机污染物吸附效果不佳的问题,采用3,3,3-三氟丙基三甲氧基硅烷作为改性剂对MCM-41分子筛进行表面修饰,制得疏水性的MCM-41。利用XRD、FT-IR等表征方法对材料进行表征,以邻苯二甲酸二丁酯为目标污染物,考察材料的吸附性能。结果表明,所制备的改性MCM-41材料结构性能良好,改性基团成功接枝到分子筛表面;3,3,3-三氟丙基接枝的TFP-MCM-41材料疏水性强于丙基接枝的P-MCM-41和未改性的MCM-41,相应地,其对邻苯二甲酸二丁酯的吸附效果也高于后两者。中性及酸性条件下p H的变化对DBP吸附影响很小,碱性条件不利于DBP吸附。     

基于吸附法的氨气试验处理研究

针对室内检测中氨气给人体带来的危害,提出一种基于沸石分子筛改性的室内氨气吸附处理方法。为验证沸石分子筛改性的可行性,利用氨气与金属氯化物容易形成络化物的原理,对13X沸石分子筛进行改性,得到经氯化铜和氯化镍改性后的吸附效果更佳;以改性后的13X沸石分子筛作为原材料,分析不同吸附颗粒大小、浸渍液浓度、吸附压力等对吸附效果的影响;最后根据上述的实验结果,找到最佳的试验处理方法,以此提升对空气中氨气吸附的效果。     

5A分子筛的改性制备及其对汞的吸附研究

以5A分子筛为原料,Ce(NO3)3.6H2O为改性试剂,通过一步浸渍法并结合干燥、焙烧与研磨过程,制备CeO2/5A分子筛吸附剂,研究了5A分子筛在改性前后及不同温度下对汞的吸附性能,由表征和吸附热力学分析的结果可知:改性后的5A分子筛与改性前相比,吸附能力提高将近一倍,穿透时间延长;CeO2/5A分子筛对汞的最佳去除温度是175℃,去除率为90％,吸附量是6.25 μg/g;改性后的5A分子筛孔径增大,比表面积减小,有利于对汞的吸附;TG结果表明CeO2成功的负载到5A分子筛上,使5A分子筛对汞的吸附能力增强;热力学研究发现Langmuir吸附模型的拟合结果比Freundlich模型要好;CeO2/5A分子筛对汞的吸附过程是一个多层吸附过程.     

沸石材料的改性及其对水体污染物的吸附性能

吸附法以其选择性强、操作简易、二次污染少等优势逐步成为污水处理的重要方法。天然沸石材料具有孔腔结构丰富、吸附成本低廉以及吸附性能高等优势,但存在选择吸附性差、与水相分离困难、再生成本偏高等问题。通过改性,可以为沸石吸附剂对阴离子污染物的吸附提供更多吸附活性位点。本文基于沸石材料改性制备的国内外最新研究进展,总结了不同改性材料制备复合吸附材料的研究工作,重点介绍了沸石材料改性方法及其应用,进一步回顾了改性沸石材料对水中污染物的吸附性能和影响因素。通过改性提高沸石材料的选择吸附性能及吸附后的绿色再生将是推动沸石吸附材料规模化应用发展的核心。     

天然沸石颗粒吸附剂对Cr3+的吸附性能及再生研究

将天然沸石粉与易燃微粉按一定比例混合,挤压造粒,灼烧成多孔质天然沸石颗粒吸附剂,然后用于吸附Cr3 .试验了溶液pH、Cr3 初始质量浓度和吸附时间等因素对吸附性能的影响,绘制的吸附等温线近似符合Freundlich吸附等温方程.     

Effectiveness of modified zeolites as adsorbent materials for frying oils

Natural zeolite was modified by four different techniques namely using Tween80, β‐cyclodextrine and olive mill waste water at RT and hydrochloric acid at 110°C, and then modified zeolites were used as adsorbent materials in six consecutive days dough frying with refined hazelnut oil. Some parameters in the oil samples of control and experimental groups were measured and the ranges were determined as following; total polar materials (TPM)‐chromatography (4.09–70.22%), free acidity (0.16–1.19%), smoke point (221.50–184.00°C), conjugated dienoic acids (0.36–2.19%), L value (35.65–52.15), a* value (?0.18–5.98), b* value (?3.73–10.40), turbidity (0.70–10.40 NTU), viscosity (67.67–825.50 cP), and oil absorbed by the dough (5.10–8.85%). The results of this study have shown that both natural zeolite and modified zeolites have different level of activities as frying oil adsorbent materials. The best results were achieved with Tween80 modified zeolite for the TPMs, free acidity, instrumental color values, smoke point, and conjugated dienoic acid measurements. Similarly better result for turbidity was with olive mill waste water modified zeolite and for viscosity was with hydrochloric acid modified zeolite. It was determined that adsorbent treatment did not affect fat absorption level of fried dough. Practical applications : The results of this study have shown that natural zeolite modification with different techniques can improve its adsorption capacity significantly. In this respect, utilization of modified zeolite for frying oil recovery applications can be an industrially sound practice since natural zeolite is a very cheap and easily found material.     

Zeolite filled siloxane composite foams: Compression property

In this article, mechanical behavior under compression loads of an innovative adsorbent material, based on silicone composite foams filled with SAPO 34 zeolite, is presented. The innovative composite foams were obtained profiting by the dehydrogenative coupling of siloxane constituents. These new adsorbent systems have been proposed to overcome to the low mechanical stability of conventional SAPO‐34 coating for adsorption chiller. In this concern, static and cyclic compressive tests at room temperature have been carried out. Samples at increasing content of SAPO 34 zeolite were tested to evaluate the influence of the filler content on the mechanical behavior of the composite foam. The results showed that the presence of zeolite reduces the elastic limit of the foam and increases the strength. The foams evidenced also acceptable mechanical stability to cyclic compressive loads. The encouraging results confirm the possible use of these new composite foams as adsorbent materials for cyclic adsorption heat pumps. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46145.     

改性沸石氨氮吸附剂的制备及其在生活污水处理中的应用

针对部分地区污水厂常规处理工艺排水氨氮超标的问题,通过制备改性沸石氨氮吸附剂,结合吸附试验、表征分析和中试试验对改性沸石去除城市生活污水中氨氮的性能进行深入研究,考察了改性沸石氨氮吸附剂最佳的制备工艺与氨氮去除特性。结果表明:改性沸石氨氮吸附剂有着更多的钠型沸石与孔道;在NaCl浓度为1.5 mol/L,搅拌时间为3 h,加热温度为75 ℃时,平均氨氮去除率与吸附量分别达到83.51%和0.840 mg/g;中试试验结果显示,经改性沸石氨氮吸附剂过滤后的水中氨氮含量稳定在2.0 mg/L以下,且吸附剂可再生后重复使用。该研究可为城市生活污水氨氮处理提供理论依据。     

Characterization of adsorbent materials supported on polyurethane foams by nitrogen and toluene adsorption

Different composite adsorbent materials were obtained by supporting three activated carbons, one zeolite and one pillared clay, in a polyurethane foam. Adsorption isotherms of nitrogen and toluene were determined to evaluate the influence of the supporting process in the adsorption capacity of the different adsorbent materials. The results indicate that the activated carbons in form of pellets presented the best results with a decrease of about 20% in the nitrogen adsorption capacity but maintaining the same toluene adsorption capacity. The inorganic adsorbents presented a decrease of about 73% for the zeolite and 97% for the pillared clay in the nitrogen adsorption capacity and also a pronounced decrease in the toluene adsorption capacity. Two materials, one activated carbon and one zeolite, with different particle sizes were supported in the polyurethane foam. The decrease in the adsorption capacity of nitrogen and toluene was more pronounced when solids with smaller particles were used. This was an indication that the decrease in the adsorption capacity is related to the impregnation of the surface of the solid particles by the polyurethane during the synthesis of the composite material, which was observed by scanning electron microscopy. Nevertheless, the supporting method, in a one step procedure, presented itself with good possibilities for applications with activated carbons in the form of pellets.     

人造沸石吸附水中金属铜离子研究

研究了人造沸石对水中金属铜离子的吸附。结果表明,人造沸石对金属铜离子有吸附效果。pH值是影响吸附的主要因素,另外时间、人造沸石用量和溶液中金属铜离子浓度都会影响吸附容量。通过红外光谱比较人造沸石和天然沸石的异同,分析人造沸石的优劣势。     

Morphological and functional aspects of zeolite filled siloxane composite foams

One of the main objectives of the recent research and development activities on adsorption heat pumps is the improvement of the volume‐specific power while maintaining a reasonable thermodynamic efficiency. In this sense, a potentially effective approach is the development of adsorbent materials with high zeolite/support mass ratio such as zeolites‐based foam adsorbent composites. In this work, the influence of the morphological aspects on adsorption performances of innovative SAPO‐34 silicone composite foams has been investigated by varying zeolite filler content. The composite foam evidenced a mixed open/closed‐cell structure, depending on zeolite amount. At low zeolite content (20%), a mainly open cell structure was obtained, while at large zeolite content foams (up to 70 wt %), a mainly closed‐cell structure was obtained. Adsorption tests evidenced that SAPO‐34 zeolite foams have a high adsorption efficiency when compared with pure zeolite highlighting the active behavior of siloxane matrix during water vapor diffusion. Based on the morphological and physical properties of the foam, a simplified model for vapor diffusion flow process in composite foams was proposed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45683.     

氧化铈改性沸石脱氮的研究

用浸渍焙烧法制备稀土吸附剂,用于静态脱氮实验。结果表明,氧化铈改性的稀土吸附剂吸附性能优于氧化镧和氧化镧-氧化铈复合改性的稀土吸附剂;当吸附剂用量为2 g/L,进水pH为4~6,吸附时间为2.5 h,氧化铈改性稀土吸附剂对模拟废水氨氮浓度为20 mg/L的吸附率达到80.23%;吸附剂再生6次后氨氮的去除率下降不到7%,说明吸附剂具有较好的稳定性。     

Formation of coke from propene over 5A adsorbents – influence of the binder on the coke composition, location and removal

Coke formation from propene was investigated at 623 K and P_propene=100 kPa on a pure 5A zeolite and an industrial adsorbent (5A zeolite 80 wt.%–binder 20 wt.%). The composition and location of coke molecules were determined as a function of time on stream. Coking on the pure zeolite was faster than on the industrial adsorbent. This result is mainly due to the trapping of coke precursors by the binder, and consequently a significant decrease in the amount of coke on the zeolite present in the adsorbent. While the coke deposited on the binder is very polyaromatic, the carbonaceous compounds formed on the zeolite and on the adsorbent are constituted at low coke content by mono-, bi-, tri- and tetra-alkyl aromatic components, and these compounds are sterically blocked in the -cages of the 5A zeolite. At high coke content, very heavy polyaromatic compounds appear and are certainly located on the external surface of the zeolite crystallites. Adsorption measurements of both samples show that coke is heterogeneously distributed in the zeolite pores. Whatever be the adsorbent, the partial oxidation of coke on highly coked samples caused an increase in the adsorption capacity. The first few steps of regeneration of coked samples remove the heavy polyaromatic molecules responsible for the pore blockage and thus liberate the pores which are not occupied by coke molecules.