脱除低浓度硫化氢的改性活性炭纤维的再生研究

用改性的活性炭纤维（ACF）脱除低浓度的H2S是一种十分有效的方法,但脱硫后的改性ACF容易达到脱硫饱和而失活。用溶剂再生和气体热再生的方法可以对失活后的改性ACF进行再生。在固定床反应器上考察了再生后ACF的脱硫性能。实验结果表明,与溶剂再生相比,气体热再生是更有效的再生方法。不同再生方法的效果的不同,是由ACF脱除H2S的反应机理的不同和再生机理的不同造成的。     

用活性炭纤维同时脱除二氧化碳中COS与H_2S的研究

采用固定床动态吸附实验考察了用NaOH、KOH、Na2CO3、K2CO3和Fe3+、CO2+等对活性炭纤维(ACF)进行改性,并分别对其脱除氧硫化碳(COS)和硫化氢(H2S)的性能进行了测试。重点是以N2和CO2为稀释气,对改性离子的种类、含量、反应气氛和反应温度等的脱硫性能进行研究,还考察了在COS和H2S同时存在的情况下,ACF脱除COS和H2S的性能。结果表明,碱改性ACF比空白ACF脱除效果好,金属离子改性ACF与碱改性ACF相比可以有效地提高活性炭纤维的硫容量。其中,用CO2+改性ACF能同时提高脱除COS和H2S的效果。     

改性活性炭纤维吸附二甲胺水溶液的研究

采用气相氧化法制备改性ACF,以二甲胺水溶液为吸附对象,在静态吸附条件下研究了吸附时间、温度、ACF用量对吸附效果的影响,获得了吸附等温线;在动态吸附条件下测定了动态穿透曲线,并研究了ACF的再生方法。在ACF优化用量0.6g/100mL溶液条件下,对初始浓度256mg/L二甲胺溶液的吸附率为85%;吸附饱和的ACF用5%盐酸溶液进行再生时,再生率接近100%。     

活性炭纤维电吸附重金属及磺胺甲恶唑性能研究

使用盐酸对吸附剂活性炭纤维（activated carbon fiber,ACF）进行改性,通过SEM、BET和FTIR对改性前后的ACF形貌及结构进行系统表征发现,改性后ACF较改性前表面杂质减少且沟壑更加明显,比表面积提高22%,微孔体积增加5%,含氧官能团（C-O和C=O）明显增多. 以水中重金属离子（Zn(II)及Cr(VI)）和抗生素磺胺甲恶唑（Sulfamethoxazole,SMX）为目标污染物,研究改性后ACF对目标污染物的吸附（静吸附和电吸附）性能,考察了浓度、pH、外加电压对吸附的影响. 结果表明,ACF用量为5 g,电压为1.2 V,Zn(II)、Cr(VI)及SMX浓度均为10 mg·L^-1,Zn(II)溶液pH为5时,ACF吸附水中Zn(II)的最大吸附量为9.25 mg·g^-1,是静吸附条件的2.15倍;Cr(VI)溶液pH为4时,ACF吸附Cr(VI)的最大吸附量为8.86 mg·g^-1,是静吸附条件的1.96倍;SMX溶液pH为6时,ACF吸附SMX的最大吸附量为8.32 mg·g^-1,是静吸附条件的1.84倍. ACF吸附Zn(II)、Cr(VI)及SMX的动力学曲线均符合准二级动力学模型,吸附过程为化学吸附. Freundlich等温模型能更好地描述ACF对Zn(II)、Cr(VI)及SMX的吸附特性,其吸附形式为多分子层吸附. ACF通过电极反接方式进行循环再生,脱附速率快且脱附效果明显,经4次循环再生后,ACF对Zn(II)、Cr(VI)及SMX的去除率均在90%以上.     

改性活性炭纤维可见光催化联合脱硫脱硝的研究

利用水合肼还原法制备的TiO₂/Cu₂O复合光催化剂对活性炭纤维(ACF)进行改性,利用SEM、XPS、BET以及XRD对其进行表征,研究改性后ACF的性质及其脱硫脱硝效果。研究表明,TiO₂/Cu₂O同时改性后的ACF表面孔径减小,但表面石墨碳和羰基(C=O)官能团增加,增强了ACF对NO和SO₂的吸附能力,从而提高了脱硫脱硝的效率,该催化剂在40℃、可见光的催化下脱硫效率达90%,脱硝效率达60%。     

Effect of SO2 and NO on removal of VOC from simulated flue gas by activated carbon fibers at low temperature

采用H2O2浸渍的方法对活性炭纤维(ACF)进行改性,并利用氮吸附等温线和XPS(X-ray photoelectron spectroscopy)的方法对ACF样品进行表征.通过实验测定改性前后ACF脱除VOC(甲苯作为VOC的代表物)的效果,同时考察二氧化硫( SO2)和一氧化氮(NO)对ACF脱除甲苯的影响.研究发现,双氧水浸渍改性对ACF的BET表面积和孔容没有影响,但使得ACF样品表面的含氧官能团含量大量增加.实验数据也表明,SO2和NO对VOC在ACF上的吸附具有抑制作用,且随着两者浓度的增加,抑制作用也增强.研究还发现,SO2和NO同时存在比单一的SO2或NO对VOC在ACF上吸附的抑制作用更为明显.     

SO2和NO对ACF低温脱除模拟燃煤烟气中VOC的影响

采用H₂O₂浸渍的方法对活性炭纤维(ACF)进行改性,并利用氮吸附等温线和XPS(X-ray photoelectron spectroscopy)的方法对ACF样品进行表征。通过实验测定改性前后ACF脱除VOC(甲苯作为VOC的代表物)的效果,同时考察二氧化硫(SO₂)和一氧化氮(NO)对ACF脱除甲苯的影响。研究发现,双氧水浸渍改性对ACF的BET表面积和孔容没有影响,但使得ACF样品表面的含氧官能团含量大量增加。实验数据也表明,SO₂和NO对VOC在ACF上的吸附具有抑制作用,且随着两者浓度的增加,抑制作用也增强。 研究还发现,SO₂和NO同时存在比单一的SO₂或NO对VOC在ACF上吸附的抑制作用更为明显。     

活性炭纤维吸附脱除硫化氢研究进展

从活性炭纤维(ACF)的结构特点、未改性ACF吸附H2S和改性ACF吸附H2S三方面综述了国内外对ACF吸附H2S的研究进展。归纳了ACF的改性方法、ACF吸附H2S的反应机理和动力学研究。总结了相对湿度、原料气组成、生成物和改性方法等工艺条件对ACF吸附H2S性能的影响。展望了改性ACF吸附脱除H2S的研究前景。     

低温NH_3-SCR催化剂MnO_x-CeO_x/ACF的SO_2中毒机理(英文)

在二氧化硫(SO2)气氛下,对Fe、Cu和V改性的催化剂MnOx-CeOx/ACF(活性碳纤维)的氨选择性催化还原(NH3-SCR)一氧化氮的低温活性进行研究.实验结果表明:以Cu和V改性催化剂未提高MnOx-CeOx/ACF的低温抗SO2性能;Fe改性MnOx-CeOx/ACF在初始6h内提高了催化剂的抗SO2性能,但较长时间仍然失活.以N2吸附、X射线光电子能谱(XPS)、傅里叶变换红外(FT-IR)光谱以及热重分析(TGA)等手段对中毒催化剂进行分析.在SO2存在下,催化剂中毒归因于两个方面:一是覆盖于催化剂表面的铵盐类物质,二是SO2与催化剂中的金属氧化物反应生成的金属硫酸盐及亚硫酸盐.在中毒催化剂中硫元素主要以金属硫酸盐及亚硫酸盐的形式存在,其在中毒的MnOx-CeOx/ACF、Fe-MnOx-CeOx/ACF、Cu-MnOx-CeOx/ACF和V-MnOx-CeOx/ACF催化剂中所占比例分别为70.4%、68.9%、86.3%和71.4%(w).进一步揭示了MnOx-CeOx/ACF催化剂在低温SCR条件下的SO2中毒机理.     

活性炭纤维电极生成羟基自由基降解酸性红B

分别采用具有吸附催化性能的活性炭纤维(ACF)作为阳极和阴极对水中偶氮染料酸性红B (ARB)的电化学降解情况进行了系统研究. 研究表明两种体系均可较好降解ARB, 可达到色度完全去除, 但ACF作为阴极电芬顿对有机物的矿化程度远远高于以ACF作为阳极时的矿化程度, 其TOC去除率达到70%, 高于阳极体系的30% TOC去除率. 通过电子自旋捕集技术(ESR)检测两种反应体系中产生的活性中间体, 发现在两种体系中均有高活性的羟基自由基生成, ACF阴极体系中产生的羟基自由基的量远远高于阳极体系产生量, 这是阴极体系有机物矿化效果较好的根本原因. 还对电流强度和初始pH的影响进行了研究, 并对两个体系反应机理进行了讨论.     

A novel process for CO2/CH4 gas separation on activated carbon fibers--electric swing adsorption

Equilibrium and breakthrough adsorptions on activated carbon fibers (ACF) were conducted for CO2 and CH4 gas mixtures and the selective separation of CO2 was demonstrated. An electric swing adsorption process (ESA) was exploited to effect the rapid desorption of adsorbed gas at atmospheric pressure. Also, the relationship between the electrical behavior and desorption characteristics of ACF is discussed. In a single component adsorption experiment, the amount of adsorbed CO2 reached up to 40 mg/g-ACF, twice as much as that of adsorbed CH4. Therefore, the separation factor, defined as the ratio of adsorbed CO2 to adsorbed CH4, was 2.0. Multicomponent experiments showed a higher separation factor of 5.2, owing to a roll-up phenomenon. The temperature increase is not linearly proportionate to the power input, while the passage of higher electrical voltage (30 V) caused the ACF temperature to exceed 200 degrees C within 30 s. CO2 desorption at low voltage was well accomplished by heating the ACF to temperatures <60 degrees C. An ACF adsorption bed regenerated with ESA showed a constant regeneration efficiency of over 85% with a regular breakthrough curve. The ESA method increased desorption efficiency by over 20%, compared with the vacuum method.     

脱硫化氢活性炭的再生方法研究

采用了溶剂再生法和气体再生法对脱硫化氢失活后的活性炭进行再生,溶剂再生时所用的溶剂为H2O2溶液、HNO3溶液以及NaOH溶液。结果表明,NaOH溶液不能使活性炭得到再生,而H2O2溶液、HNO3溶液能够通过氧化的方法使活性炭得到再生。气体再生时所用的气体分别为高纯N2,含20%O2的N2,H2,它们再生的原理分别是热再生,通过氧化单质硫再生和通过还原单质硫再生。再生效果最好的是30%的HNO3溶液和H2,它们能将活性炭孔道内的单质硫分别脱出69.8%和81.2%,再生后的活性炭中硫容量能达到原来的70%以上。再生后活性炭的比表面积和pH值是再生性能的两个重要指标。     

共溶剂存在下N-烯丙基吡啶氯盐离子液体对纤维素的溶解性能研究

采用一步法合成N-烯丙基吡啶氯盐离子液体([APy]Cl),考察其对纤维素的溶解性能.结果发现,在120℃下对棉浆粕(聚合度(DP)=556)的溶解度可高达19.71%,但再生后聚合度为223,热降解严重.通过添加不同种类共溶剂的方法克服此缺点.结果表明,有机溶液(DMSO,DMAc,DMF或吡啶)作为[APy]Cl的共溶剂时,[APy]Cl/DMAc复合溶剂对棉浆粕的溶解效果最佳,100℃下溶解度为15.03%,再生后聚合度为403.此外降低了溶剂成本.但70℃下,溶解度仅为1.36%,溶解能力较弱.继续探讨了[AMIM]Cl作为[APy]Cl的共溶剂时对纤维素的溶解性能,结果表明,70℃下,[APy]Cl/[AMIM]Cl复合溶剂对棉浆粕的溶解度为8.78%,再生后聚合度为516.可知添加上述2种共溶剂均使[APy]Cl在低于自身熔点下形成液体并能够溶解一定量纤维素,拓宽了溶解温度区间及应用平台.对FTIR,XRD和TGA谱图分析,结果表明上述为纤维素的直接溶剂,可将其晶型由Ⅰ型转变成Ⅱ型,再生后热稳定性稍有降低.通过照片和SEM表明再生膜无色透明,结构致密.     

F-T合成沉淀铁系催化剂的原位再生(英文)

Ｆ－Ｔ合成沉淀铁系催化剂在３ ０００小时工业单管模试反应器中进行了三次原位再生试验。用自产的Ｃ６—Ｃ１１馏分油在接近其临界点的条件下对催化剂进行处理,然后用Ｈ２或合成气还原。经过上述再生处理,催化剂床层压降从１．０ ＭＰａ降至０．１ＭＰａ,催化剂反应性能同时得到恢复。还讨论了导致催化剂失活和催化剂床层压降增加的原因。     

Study on ionic liquids based novel method for separation and purification of silkworm pupa protein

Silkworm pupa protein (SPP) that obtained by traditional method usually had a high fat content, which would impose restrictions on the further use of SPP. Herein, various functionalized ionic liquids (ILs) were used to extract SPP from silkworm pupae, the structure-performance relationship of ILs with their SPP separation performance were explored at the same time. The research showed that the maximum extraction yield of SPP was up to 62.6% with less than 0.5% low fat content by using 1-ethyl-3-methylimidazolium chloride ([Emim]Cl), when the dissolution experiment was conducted at 90 °C for 24 h with ethanol bath as the regeneration solvent. Comparing with the structure of raw material, the regenerated SPP maintained the native protein backbone. Meanwhile, all regenerated SPP showed a decreased crystallinity, which also exhibited decreased fraction of the α-helix comparing to that β-sheet united with coil random structures.     

Making a Case for Regenerating GC Liners in Industrial Wastewater Screening

An environmental laboratory can save on GC inlet liners by regenerating the discarded ones after use in industrial wastewater extracts analysis. In this study, a simple regeneration method for used liners is described, and the results from those liners are compared with results obtained using new liners. The two types of liners were found to be interchangeable: the difference between the new and the regenerated liners data pairs plotted against their means had no unexpected outliers for 61 test organic pollutants. The results also show that the regenerated liners gave more precise measurements. Only the boxplots from regenerated liners had equal variance at 40 and at 80 μg L^?1, the two common spiking levels for the 61 test organic pollutants. Surprisingly, the independence of new liners on the GC instruments was revealed when the relative percent deviations (RPD) were plotted against recoveries of the 61 test organic pollutants. In the plot, all 183 data points acquired using three different GC instruments fell on the same regression line: RPD = ?1.07 [%Recovery] + 107. The same plot for regenerated liners produced a slope less in value than that of the new liners. The latter simply restates the better precision observed with regenerated liners.     

Physicochemical properties of maize cob cellulose powders reconstituted from ionic liquid solution

Suitable α-cellulose and cellulose II powders for use in the pharmaceutical industry can be derived from maize cob. α-Cellulose was extracted from an agricultural residue (maize cobs) using a non-dissolving method based on inorganic substances. Modification of this α-cellulose was carried out by its dissolution in the ionic liquid 1-butyl-3-methylimidazolium chloride ([C₄mim]Cl), and subsequent regeneration by addition of either water or acetone at room temperature, or of boiling water. X-ray diffraction and infrared spectroscopy results showed that the regenerated celluloses had lower crystallinity, and proved that the treatment with [C₄mim]Cl led to the conversion of the crystalline structure of α-cellulose from cellulose I to cellulose II. Thermogravimetric analysis and differential scanning calorimetry data showed quite similar thermal behavior for all cellulose samples, although with somewhat lower stability for the regenerated celluloses, as expected. The comparison of physicochemical properties of the regenerated celluloses and the native cellulose mainly suggests that the regenerated ones might have better flow properties. For some of the characterizations carried out, it was generally observed that the sample regenerated with boiling water had more similar characteristics to the α-cellulose sample, evidencing an influence of the regeneration strategy on the resulting powder after the ionic liquid treatment.     

Use of Adsorbents for Recovery of Acetic Acid from Aqueous Solutions Part III—Solvent Regeneration

Solvent leaching was investigated as a method of regeneration for activated carbons and polymer sorbents loaded with acetic acid by contact with aqueous solutions. Both batch-equilibration and fixed-bed experiments were employed. Methanol, methyl acetate, and acetone are suitable regeneration solvents for most activated carbons. Amoco GX-031 is an exception, giving incomplete regeneration. Methanol provides still more efficient regeneration for macroreticular styrene-divinylbenzenes adsorbents. Among basic sorbents, amine resins give incomplete regeneration by solvent leaching, as does a poly N oxide. Polybenzimidazole, a weaker base, gives higher recoveries of acetic acid when leached by solvents. Poly(4-vinylpyridine) is regenerated completely and efficiently by methanol, methyl acetate, and acetone in a fixed-bed geometry. It thus appears that an intermediate degree of basicity is desirable in a synthetic sorbent for acetic acid – strong enough to give the uptake benefits of acid-base interactions, but weak enough to be regenerable.