活性炭纤维吸附挥发性有机化合物的研究进展

简述了挥发性有机化合物、活性炭纤维以及活性炭纤维吸附挥发性有机化合物的机理及其优点,重点介绍国内外关于活性炭纤维吸附挥发性有机化合物的研究进展。活性炭纤维凭着自身显著的优点,在吸附挥发性有机化合物方面具有很大的潜力。     

活性炭对挥发性有机化合物的吸附回收研究进展

介绍了挥发性有机化合物(VOCs)的来源、种类、危害、回收意义以及常见的回收技术。VOCs是指除CO、CO₂、H₂CO₃、金属碳化物、金属碳酸盐和碳酸铵外,所有参加大气光化学反应的碳化合物,主要来源于以石化产品为主要燃料的交通工具产生的尾气和工业生产过程中产生的废气等,会对环境造成严重危害。目前主要的处理技术有破坏技术和回收技术,其中活性炭吸附技术已经成为环保领域研究的热点。重点介绍了活性炭对芳香烃、脂肪烃、卤代烃、醇类、醛类、酮类、醚类和酯类这几种主要的VOCs的吸附回收技术及研究进展。     

活性炭对挥发性有机化合物的吸附回收研究进展北大核心

介绍了挥发性有机化合物(VOCs)的来源、种类、危害、回收意义以及常见的回收技术。VOCs是指除CO、CO_2、H_2CO_3、金属碳化物、金属碳酸盐和碳酸铵外,所有参加大气光化学反应的碳化合物,主要来源于以石化产品为主要燃料的交通工具产生的尾气和工业生产过程中产生的废气等,会对环境造成严重危害。目前主要的处理技术有破坏技术和回收技术,其中活性炭吸附技术已经成为环保领域研究的热点。重点介绍了活性炭对芳香烃、脂肪烃、卤代烃、醇类、醛类、酮类、醚类和酯类这几种主要的VOCs的吸附回收技术及研究进展。     

活性炭吸附挥发性有机物的影响因素研究进展

从挥发性有机物(VOCs)的基本概念出发,介绍了其主要来源、危害及其污染控制技术,并在此基础上具体地介绍了活性炭吸附法。综述了影响活性炭吸附性能的的因素如活性炭的孔结构、表面化学结构、活化技术、VOCs的入口浓度、VOCs的物化性质、多组分VOCs吸附、吸附柱填充密度等。     

介孔分子筛在挥发性有机化合物吸附中的研究进展

挥发性有机化合物(VOCs)是破坏生态环境质量的重要污染物,近年来发现介孔分子筛对VOCs有较好的吸附效果.综述了近年来介孔分子筛在VOCs吸附中的研究进展,详细讨论了VOCs在介孔分子筛吸附剂上的吸附过程,并对以后介孔分子筛吸附剂的研究提出了建议.     

可挥发性有机化合物废气治理新进展

本文介绍了近年国内外在治理可挥发有机化合物的研究进展,并对应用较多的治理技术及其新进展进行了较全面的综述。     

低浓度挥发性有机废气的吸附净化

吸附净化是处理低浓度挥发性有机废气(≤1000 mg/m3)的有效方法之一。整体式蜂窝状活性炭由于其开孔道结构,压降小,是比较理想的吸附剂。考察了甲苯浓度、空速、吸附-脱附循环次数和表面改性等对整体式蜂窝状活性炭吸附性能的影响,取得了较好的净化效果。结果表明,当吸附温度为25°C,气体空速为10000 h-1,甲苯浓度为500 mg/m3时,对甲苯的吸附率为6.5wt%,当脱附温度为250°C时,甲苯基本脱附完全。     

吸附挥发性有机化合物树脂的高效微波再生过程

主要研究应用微波辐射再生高聚物吸附树脂.论述了微波加热的优点和微波脱附的原理,以乙醇为吸附质研究了吸附和微波辐射再生吸附剂过程.进行了正流微波辐射脱附和逆流微波辐射脱附实验,测定了微波脱附流出曲线和床层的温升曲线,并与传统的热脱附流出曲线和在不同加热速率下得到的床层温升曲线进行比较.实验结果表明：微波脱附比热脱附脱附速度更快,效率更高;高聚物吸附树脂类吸附剂对微波是半透明的,它对微波的吸收能力随着温度的升高而下降,因此,在微波辐射下,吸附剂床层吸收微波的能力也随着床层温度的升高和吸附质的脱附而减弱,床层最终温度不超过84℃,可使吸附剂的结构和性能不会被破坏和受影响,这有利于吸附剂的循环使用.微波在脱附和吸附剂再生中有很好的应用前景.     

挥发性有机化合物处理技术

本文主要介绍了脱除工业废气中挥发性有机污染物的各种方法,并阐述了各种方法的特点和影响因素。     

活性炭吸附回收VOCs技术的研究进展

详细介绍了活性炭吸附回收VOCs的技术研究过程以及研究进展,分析了吸附剂的制备与改性、吸附过程的影响因素及数学模型、脱附方法等内容,并指出了存在的问题。在总结现有研究进展的基础上,对活性炭吸附回收VOCs技术的研究重点进行了预测和展望。     

Synthesis and characterisation of organo-silica hydrophobic clay heterostructures for volatile organic compounds removal

Mesostructured materials belonging to a new class of solid acids known as porous clay heterostructures (PCHs) have been prepared by chemical modification of a natural clay, by using a cationic surfactant, a neutral amine, and an equimolar mixture of bis(triethoxysilyl)benzene (BTEB) and tetraethyl orthosilicate (TEOS). The effect of different polymerisation times of the silica sources and of the hydrocarbon chain length of the neutral amine was studied. The materials retained their layered structure after the formation of stable pillars by the polymerisation of hydrolysed TEOS and BTEB. All materials were characterised by low temperature nitrogen adsorption isotherms, ¹³C CP MAS, ²⁹Si MAS and CP MAS NMR spectroscopy, thermal analyses and infrared spectroscopy. The specific surface BET areas of the materials were in the range 550–800 m² g⁻¹ and the corresponding microporous volume were near 0.2–0.3 cm³ g⁻¹. The reduction of the reaction time from 12 to 4 h avoids the extra-gallery polymerisation, contributing for a larger specific surface area. The increase of two carbon atoms in the neutral amine chain does not show much effect on the available surface area.

These materials were very effective as adsorbents of volatile organic compounds (VOCs), according to tests on methanol, methyl ethyl ketone, toluene and trichloroethylene. The water adsorption isotherms proved the hydrophobicity of the materials, suggesting their capabilities for VOC adsorption in the presence of water.     

沸石分子筛用于VOCs吸附脱除的应用研究进展

挥发性有机化合物（volatile organic compounds,VOCs）作为空气中有机污染物的主要成分,对环境与人类健康造成了严重的危害。吸附法可有效富集低浓度VOCs气体,成本低、易操作,是末端治理去除VOCs的主要技术。沸石分子筛具有高度有序、孔径可调的微孔孔道,可实现VOCs分子的选择性吸附,且热稳定性极佳,易于脱附再生,是一种优良的VOCs气体吸附剂。本文分别从沸石分子筛的结构性质、复合型分子筛吸附剂以及整体式分子筛吸附剂三方面详细介绍了沸石分子筛用于VOCs吸附脱除的研究进展。结果表明,变换骨架拓扑结构以及补偿阳离子类型,可实现对VOCs分子进行选择性吸附;提高结构疏水性可有效降低高湿度条件下水分子对VOCs的竞争吸附,增强分子筛吸附剂的环境适应性;通过孔道多级化或与其他介/大孔构建复合型吸附剂,可提高分子筛吸附剂的比表面积和孔容,增大对VOCs的吸附容量;沸石分子筛可构建为整体式吸附剂,相较于颗粒型吸附剂,其机械强度更高,应用性更强。文章还指出,作为整体式分子筛吸附剂的典型代表,分子筛转轮吸附技术在高通量、高压降等吸附工况条件下均表现出极佳的VOCs吸附脱除效率,已广泛应用于工业排放VOCs的有效治理。     

Preparation of hollow fibers for the removal of volatile organic compounds from air

Hollow-fiber membranes were prepared to remove volatile organic vapors (VOCs) from a nitrogen or air stream. Conditions were found to spin hollow fibers of high performance for the removal of VOCs. The effect of temperature on the permeation of nitrogen gas and acetone vapor was studied. It was found that nitrogen permeation was governed by diffusion while vapor permeation was governed by sorption. There were two distinct mechanisms for vapor permeation, depending on temperature. Performance data for hollow fibers with and without a silicone rubber coating at the internal surface were compared. The effect of the presence of water vapor in the feed was also studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 371–379, 1998     

燃烧处理挥发性有机污染物的研究进展

随着环境问题的日益严重,治理作为PM_2.5前体的挥发性有机物（VOCs）越来越受到重视,燃烧法是目前常用的处理VOCs污染物技术之一。本文从燃烧的机理出发综述了燃烧法处理VOCs的研究进展,将燃烧法分为两大类,即非催化燃烧法和催化燃烧法。非催化燃烧法中从燃烧方式出发,总结了直接燃烧法、蓄热式热力燃烧法、多孔介质燃烧法的研究进展,并对燃烧影响因素进行了综述。在催化燃烧法中阐述了贵金属催化剂、非贵金属催化剂和复合金属氧化物催化剂的研究进展,探讨了催化剂的失活问题,分析了每种催化剂的优势与不足。贵金属催化剂活性高,但是价格昂贵、稳定性差;非贵金属催化剂价格低廉、寿命长,但是起燃温度高;复合金属氧化物催化剂活性高、抗毒性强,但是制备工艺复杂。最后基于目前的研究现状和不足,展望了未来燃烧法处理VOCs的研究方向为：结合实际应用的工艺条件和催化燃烧的机理,制备出活性高、价格低廉、抗毒性强和寿命长的催化剂用于蓄热式催化燃烧技术;将催化燃烧和多孔介质燃烧相结合,开发出高效、稳定、经济的燃烧技术处理VOCs污染物。     

Effective combination of non-thermal plasma and catalyst for removal of volatile organic compounds and NOx

A plasma/catalyst hybrid reactor was designed to overcome the limits of plasma and catalyst technologies. A two-plasma/catalyst hybrid system was used to decompose VOCs (toluene) and NOx at temperature lower than 150 °C. The single-stage type (Plasma-driven catalyst process) is the system in which catalysts are installed in a non-thermal plasma reactor. And the two-stage type (Plasma-enhanced process) is the system in which a plasma and a catalyst reactor are connected in series. The catalysts prepared in this experiment were Pt/TiO₂ and Pt/Al₂O₃ of powder type and Pd/ZrO₂, Pt/ZrO₂ and Pt/Al₂O₃ which were catalysts of honeycomb type. When a plasma-driven catalyst reactor with Pt/Al₂O₃ decomposed only toluene, it removed just more 20% than the only plasma reactor but the selectivity of CO₂ was remarkably elevated as compared with only the plasma reactor. In case of decomposing VOCs (toluene) and NOx using plasma-enhanced catalyst reactor with Pt/ZrO₂ or Pt/Al₂O₃, the conversion of toluene to CO₂ was nearly 100% and about 80% of NOx was removed. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

低浓度挥发性有机物吸附浓缩材料的研究进展

由于挥发性有机物（VOCs）会对环境造成严重的危害,因此VOCs的处理一直备受人们的关注,但发展高效的VOCs处理技术仍然存在严峻的挑战。本文针对大风量、低浓度VOCs的处理展开了综述,重点围绕吸附、催化燃烧处理展开讨论。对于大风量的低浓度VOCs,虽然浓度较低但VOCs排放量非常巨大。通过VOCs浓缩技术,提高浓度减少风量成为降低VOCs处理成本的有效途径。其中,发展高性能VOCs吸附材料是VOCs浓缩技术的关键。阐明了活性炭、分子筛等重要吸附材料的性质及其吸附VOCs的原理,并对吸附材料性质和VOCs种类对吸附效果的影响进行了探讨。展望了活性炭浓缩-催化燃烧技术和分子筛转轮浓缩-催化燃烧技术在大风量的低浓度VOCs处理中的应用前景。     

Optimum operating conditions for the removal of volatile organic compounds in a compost-packed biofilter

Biofiltration was performed for 101 days in a compost-packed biofilter (I.D. 5.0 cmxheight 62 cm) for the removal of nine volatile organic compounds (benzene, toluene,m-xylene,o-xylene, styrene, chloroform, trichloroethylene, isoprene, and dimethyl sulfide). Removal efficiency of the volatile organic compounds (VOCs) was dependent upon the column temperature, gas flow rate, and incoming concentrations of VOCs. At an empty bed residence time (EBRT) of 3 min and the incoming gas concentration of 66 g m^-3 overall removal and efficiency increased up to 92.1 and 86.4% at 25 °C and 45 °C, respectively. Upon further increase of the incoming gas concentration to 83 g m⁻³, the removal efficiency was 93.7% at 25 °C, but dropped to 73.1% at 45 °C. At incoming gas concentration of 92 g m^-3 and EBRT of 1.5 min, the removal efficiency at 25 °C (91.6%) was comparable to 32 °C (95.5%). However, for 1 min of EBRT removal efficiency was better (86.6%) at 32 °C as compared to at 25 °C (73.6%). The maximum removal rates of VOCs were 3,561, 4,196, and 1,150 g m^-3 h^-1 at 25, 32, and 45 °C, respectively. At an EBRT of 1.5 min and 32 °C the removal efficiency of individual component was highest for toluene (98.9%) andm-xylene (97.6%), and lowest for TCE (86.1%) and chloroform (89.4%). Aromatic compounds (benzene, toluene, and xylene) were removed by 97.1–98.9%. After 101 days of operation profiles of pH and moisture content from the top to the bottom of the column were 7.2–6.3 and 53.8–67.2%, respectively, at 32 °C column, and 67% of the incoming VOCs was removed in the first quarter of the column. After 36 days of operation the cell concentration increased 108-fold from its initial value at 25 °C, and reached a maximum of 1.08x108 cells·(g of dry compost)^-1.     

Adsorption and desorption of small molecule volatile organic compounds over carbide-derived carbon

Carbide-derived carbon (CDC) was prepared by selective extraction of titanium from titanium carbide in a flow of freshly prepared chlorine. The dynamic adsorption and desorption performance of CDC of small molecule volatile organic compounds (VOCs) including methanol, acetaldehyde and acetone, was investigated and compared with that of two types of commercial activated carbons. The physicochemical properties of carbons were characterized by nitrogen adsorption, temperature programmed desorption, Raman spectroscopy and transmission electron microscopy. It was observed that the CDC could adsorb much more VOCs than commercial activated carbons (especially for the less polar methanol). The desorption behavior of VOCs from the saturated CDC was similar to that of commercial activated carbons, with adsorbed VOCs desorbed in the maximum degree at 110–150 °C, which indicated that the adsorption sites for the VOCs on the three carbon adsorbents were similar and the saturated CDC could be effectively regenerated by simple heat treatment just like commercial activated carbons. Based on the characterizations, the large adsorption capacity of CDC was attributed to its larger micropore volume, narrower pore distributions (0.7–1.5 nm), as well as higher specific surface area than those of two commercial activated carbons.     

Activated carbon cloth adsorption-cryogenic system to recover toxic volatile organic compounds

There is an emergent need to reduce the emissions of toxic volatile organic compounds (VOCs) to the atmosphere. One strategy to reduce the emissions of VOCs from point sources is to use air pollution control devices on the sources' discharge streams. This paper describes the development of a new activated carbon cloth (ACC) adsorption system that is integrated with cryogenic vapor recovery to reduce the amount of VOCs emitted to the atmosphere from point sources and provide for reuse of the VOCs that are recovered. Electrical current is used to regenerate the ACC. ACC adsorption followed by electrothermal regeneration results in formation of a concentrated organic vapor which is cryogenically condensed from the gas phase. Electrothermal desorption allows for careful control of the desorption time and the concentration profile of the desorbed VOC to allow minimal use of cryogen. Adsorption, followed by cryogenic treatment enables VOC sources to meet air quality control regulations while providing a high quality liquid VOC product for reuse.