Ti-MWW催化氧化脱除轻油中苯并噻吩和二苯并噻吩

 以Ti-MWW为催化剂,研究了轻油中的有机硫模型化合物苯并噻吩和二苯并噻吩的氧化脱除. 结果表明,在343 K和乙腈为溶剂的条件下,苯并噻吩的转化率可达100%, 二苯并噻吩的转化率可达95%以上. 溶剂对苯并噻吩的氧化有很大影响,在相同的反应条件下,三种溶剂中苯并噻吩的转化率为乙腈＞甲醇＞水. 讨论了Ti-MWW催化氧化苯并噻吩的反应历程和溶剂效应.     

四氟硼酸改性活性炭的制备及其吸附脱除二苯并噻吩性能

采用浸渍法制备了四氟硼酸(HBF₄)改性活性炭,并研究了其对模拟油中二苯并噻吩(DBT)的吸附脱除性能。利用傅里叶红外光谱(FT-IR)、差示热分析仪(TG-DTA)、X射线光电子能谱(XPS)以及N₂吸附技术对吸附剂的表面态和孔结构进行了表征,考察了四氟硼酸浓度、热处理温度以及模拟油中DBT浓度对吸附脱硫效果的影响。结果表明,经质量分数0.5%的HBF₄溶液浸渍、140 ℃热处理后,在剂油比1:100条件下,活性炭的吸附容量为352 mg/g,较未改性活性炭提高了72.5%。     

活性炭负载TiO2光催化氧化二苯并噻吩的研究

以活性炭负载的TiO2为光催化剂,H2O2为氧化剂,30W紫外灯为光源,对含二苯并噻吩（DBT）的模型硫化物进行光催化氧化脱硫研究。考察了TiO2的煅烧温度、负载量、催化剂用量、H2O2用量和光照时间对DBT去除率的影响。实验结果表明,用溶胶 凝胶法制备的TiO2 /活性炭催化剂对DBT具有很好的光催化效果。最佳反应条件为,催化剂煅烧温度400℃,TiO2的负载量为32％,催化剂用量0.7g/100mL, H2O2最佳用量为10mL,即O/S（摩尔比）为14。在最佳反应条件下,光照时间8h,DBT去除率为90％, 此反应为一级动力学反应。     

过氧化环己酮对二苯并噻吩的氧化脱硫研究

二苯并噻吩（dibenzothiophene DBT）及其衍生物是重油、减压馏分油及渣油中的主要硫化物。在通常的加氢脱硫中,二苯并噻吩系列是较难脱除的一类有机硫。近年来,以二苯并噻吩系列为模型的深度脱硫研究发展迅速。李建源等对二苯并噻吩及其衍生物为模型的氧化脱硫（Oxidative desulfurization ODS）、加氢脱硫、吸附脱硫及生物脱硫等作了较为详尽的报道。     

羧基功能化离子液体催化二苯并噻吩氧化脱硫

以羧基功能化离子液体1-甲基-3-羧甲基咪唑四氟硼酸盐([cmmim]BF₄)为催化剂和萃取剂,过氧化氢为氧化剂,催化氧化二苯并噻吩(DBT)。结果表明,当反应温度为60 ℃,O/S摩尔比为6,反应时间80 min时,DBT的转化率可以达到100%。离子液体回收重复使用四次,催化活性无明显下降。     

双核金属酞菁的制备及其对二苯并噻吩的催化氧化性能

采用微波法合成了双核酞菁钴,并采用红外光谱、紫外可见光谱、热重分析对其进行表征。以二苯并噻吩(DBT)为反应底物,考察双核酞菁钴对DBT催化氧化性能,筛选出较优催化剂,并进行脱硫反应工艺条件优化。结果表明,双核酞菁钴具有较好的催化性能,在室温下、双核酞菁钴用量为0.01 g(cat)/5 m L、空气流量为80 m L/min、反应温度为40℃、反应1 h,DBT脱硫率达到97.17%。催化剂重复使用5次,催化效果无明显下降。氧化产物经红外光谱、质谱分析为DBTO2。对芳香烃及烯烃进行了催化氧化实验,发现该工艺对油品的质量基本无影响。     

活性炭催化氧化脱除单质汞的研究

模拟煤气的气氛,在硫化氢（H₂S）和氧气（O₂）存在条件下,对活性炭催化氧化吸附单质汞（Hg⁰）的性能进行了研究。结果表明,H₂S和O₂存在条件下,活性炭对Hg⁰的吸附能力明显提高。在180min内,H₂S和O₂共存气氛下,脱汞效率约为78%;只有H₂S存在下,脱汞效率约为69%;没有H₂S和O₂气氛下活性炭脱汞效率快速下降为28%。随着吸附温度的升高,入口汞浓度的提高和吸附剂粒径的增大,活性炭的脱汞效率会随着下降。通过XRD表征表明,Hg⁰的吸附反应机理是Hg⁰在活性炭催化氧化下与H₂S形成硫化汞（HgS）,从而实现了Hg⁰的稳定化脱除。     

过氧化叔戊醇对二苯并噻吩的氧化脱硫研究

二苯并噻吩（DBT）及其衍生物是重油、减压馏分油及渣油中的主要硫化物。其性质稳定,在通常的加氢脱硫中,二苯并噻吩系列是较难脱除的一类有机硫。李建源等对二苯并噻吩及其衍生物为模型物的氧化脱硫（ODS）、加氢脱硫、吸附脱硫及生物脱硫等作了较为详细的综述。     

分子氧为氧化剂磷钒酸盐为催化剂超深度氧化脱除柴油中的二苯并噻吩

一种“双帽Keggin型”磷钒酸盐在温和的反应条件下以分子氧为氧化剂氧化二苯并噻吩至二苯并噻吩砜的反应中表现出很高的催化活性. 用溶剂萃取或者选择吸附等方法可轻易地将反应产生的二苯并噻吩砜从油品中除去. 这提供了一种新型的分子氧为氧化剂的超深度氧化脱硫方法.     

酸性离子液体萃取/催化二苯并噻吩氧化脱硫反应的优化

ö以Brönsted酸性离子液体N-甲基-2-吡咯烷酮磷酸二氢盐(\[Hnmp\]H₂PO₄)为萃取剂和催化剂,双氧水为氧化剂,二苯并噻吩(DBT)溶于正辛烷为模型油,利用正交实验法优化了DBT氧化脱硫反应工艺。所优化的反应条件为：反应温度60℃,模型油与离子液体体积比为1∶1,氧/硫摩尔比为16, 氧化时间5h;在此条件下模型油脱硫率达99.8%,实际柴油脱硫率为64.3%。由正交实验极差可知,各因素对DBT脱硫率影响的大小依次为：反应温度＞反应时间＞氧/硫摩尔比＞剂油比;离子液体循环利用6次,脱硫率下降不明显。     

Effect of activated carbon support on CS_2 removal over coupling catalysts

Supported coupling catalysts for CS2 removal were prepared with different activated carbons originated from wood,coconut shell and coal as supports,and their catalytic activities for CS2 removal were tested at ambient temperature.The textural and surface properties of the activated carbons were characterized by nitrogen adsorption,temperature-programmed desorption(TPD)and Boehm titration.The activated carbon support with meso-and macropores,and oxygen-functional groups performs higher CS2 removal ability at ambient temperature.The effects of flow rate,CS2 inlet concentration,temperature and relative humidity on CS2 removal were also investigated.High efficient removal is obtained at temperature of 50-C,space velocity of 2000 h-1,inlet CS2 concentration of 500 mgS/m3 and relative humidity of 20%with the breakthrough sulfur capacity up to 4.3 gS/gCat and working sulfur capacity up to 7 gS/gCat.     

Textural characteristics, surface chemistry and oxidation of activated carbon

Numerous researches were reviewed and interpreted to depict a comprehensive illustration of activated carbon and its behavior towards oxidation. Activated carbon as one of the most important adsorbents is tried to be described in this review paper by terms of its "Textural Characteristics" and "Surface Chemistry". These two terms, coupled with each other, are responsible for behavior of activated carbon in adsorption processes and in catalytic applications. Although as-prepared activated carbons are usually non-selective and their surfaces suffer from lack of enough reactive groups, their different aspects may be improved and developed by diverse types of modifications. Oxidation is one of the most conventional modifications used for activated carbons. It may be used as a final modification or as a pre-modification followed by further treatment. In this paper, methods of oxidation of activated carbon and other graphene-layer carbon materials are introduced and wet oxidation as an extensively-used category of oxidation is discussed in more detail.     

处理方法对活性炭在流化床反应器内甲烷催化裂解制氢活性的影响

在流化床反应器内,初步研究了处理方法对活性炭在甲烷裂解制氢过程中催化活性的影响。结果表明,浓硝酸处理后,活性炭表面会生成大量的含氧基团,未处理的活性炭上,850℃和900℃时甲烷的初始转化率在8%和11%左右,浓硝酸处理后,850℃和900℃时初始转化率分别上升到12%和16%,稳定性也明显改善。离子交换法负载微量金属的活性炭比采用浸渍法负载的有更好的活性和稳定性。     

Zinc polyoxometalate on activated carbon: an efficient catalyst for selective oxidation of alcohols with hydrogen peroxide

[PW₁₁ZnO₃₉]^5? was immobilized on activated carbon and characterized using Fourier transform infrared, X‐ray diffraction, Brunauer–Emmett–Teller and elemental analysis techniques. Effective oxidation of various alcohols with hydrogen peroxide was performed in the presence of this catalyst. Easy separation of the catalyst from the reaction mixture, cheapness, high activity and selectivity, stability as well as retained activity in subsequent catalytic cycles make this supported catalyst suitable for small‐scale synthesis. Copyright © 2015 John Wiley & Sons, Ltd.     

Effect of agitation on removal of acetic acid from pretreated hydrolysate by activated carbon

The effect of agitation on the adsorption of acetic acid by activated carbon was tested utilizing an external mass transfer-diffusion model. Simulated pretreated biomass was contacted with activated carbon under prescribed conditions of temperature and agitation. Adsorption isotherm studies are presented as well as batch kinetic rate studies. Use of these data enabled the determination of isotherm constants, an external mass transfer coefficient, and an effective diffusivity for each agitation rate studied. The external film coefficient results ranged from 33.62 μm/s to a complete absence of external mass transfer resistance, and the diffusivity results ranged from 0.8625 to 10.70 μm²/s. The optimum combination of no external film resistance, and highest diffusivity, 10.70 μm²/s, occurred at 250 rpm and 25°C. The results of these models and the experimental parameters suggested an efficacious method and conditions for the removal of this undesirable chemical.     

Oxidation using activated carbon and molecular oxygen system

This paper describes the utility of an activated carbon–molecular oxygen system, not only in the oxidation of benzylic and allylic alcohols, but also in the direct carbonylation at the benzylic position. The preparation of a variety of heteroaromatic and aromatic compounds, including substituted pyridines, pyrazoles, benzoxazoles, benzimidazoles, benzothiazoles, 2‐substituted imidazoles, indoles, pyrimidin‐2(1H)‐ones, and anthracenes, by oxidative aromatization using the activated carbon–molecular oxygen system is also discussed. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 252–267; 2008: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20152     

Nitrogen adsorption on fluorinated activated carbon fiber

Nitrogen adsorption isotherms for fluorinated activated carbon fiber (F-ACF) and fluorinated carbon black (F-CB) were measured at 77 K. Surface structures of F-ACF and F-CB were examined by _s -plot analysis using the adsorption data on the nonporous carbon black (CB) and F-CB. The surface energy of F-ACF was lower than that of ACF. The micropore structure of ACF was preserved even after fluorination, although the limiting adsorption amount and the micropore width decreased with fluorination.     

活性炭的表面化学改性及其对有机硫化物的吸附性能的研究

活性炭; 表面化学改性; 有机硫化物; 吸附性     

金属助剂对蜂窝状MnO_x-CeO_2/ACH催化剂低温脱硝行为的影响

考察了铁、锡助剂对蜂窝状活性炭担载MnOx-CeO2(MnOx-CeO2/ACH)催化剂的低温脱硝活性及抗硫性能的影响。结果表明,添加FeOx助剂,有利于改善MnOx和CeO2在ACH载体表面的分散性,使得催化剂的脱硝活性在80~200℃随反应温度的升高而增加,且抗SO2毒化性能提高;SnOx助剂的添加,使得催化剂在较高温区仍具有较高脱硝活性,并表现出良好的抗SO2毒化性能,在250℃时NO转化率由无SO2条件下的98.6%略降至SO2存在时(700min)的87.8%。