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1.
传统的加氢脱硫(HDS)过程可以除去燃料油中的大部分含硫有机化合物,但汽油的深度加氢脱硫会引起烯烃大量饱和,导致辛烷值显著降低,因此,除了改进现有的加氢脱硫过程外,还需要开发非加氢脱硫的方法以满足生产清洁汽油的迫切需求.吸附脱硫方法具有操作简便、易与原料分离等特点,因此在烟气脱硫方面已有研究和应用;  相似文献   

2.
概述了未来炼油厂主要任务中关键技术的特点和使用效果. (1)提高轻质油收率, 关键在于重油的高效转化, 关键技术包括渣油加氢技术、重油加氢与催化裂化双向组合技术、多产轻质油的催化裂化蜡油选择性加氢工艺与选择性催化裂化工艺集成技术、浅度溶剂脱沥青-脱沥青油加氢处理-催化裂化技术; (2)生产清洁燃料, 主要是生产要求越来越高的清洁汽油和柴油, 关键技术有汽油选择性加氢脱硫技术、柴油超深度加氢脱硫技术、柴油超深度加氢脱硫催化剂; (3)生产优质化工原料, 关键技术主要是催化丙烯技术.  相似文献   

3.
通过硝酸钴与硅酸钠共沉淀、辅以正丁醇干燥技术制备了具有原子分散度的Co-O-Si复合氧化物(Co/Si原子比 ≈ 0.65),该催化剂具有较大的比表面积(562 m2/g)和较强表面酸性. 在硫化处理后,能够形成高度分散的硫化物活性组分,在模型汽油加氢处理反应中显示了较高的催化活性,在573 K时,噻吩的加氢脱硫活性可达99.4%,同时,1-己烯的骨架异构收率达到了35%. 该催化剂虽然不含Mo,其加氢脱硫活性可与工业催化剂Co-Mo/γ-Al2O3相当. 而在汽油深度加氢脱硫过程中,直链烯烃往往被加氢饱和,造成辛烷值损失. 该催化剂则可使部分直链烯烃发生骨架异构而生成异构烷烃,可减少深度加氢脱硫过程中的辛烷值损失.  相似文献   

4.
多酸基深度加氢脱硫催化剂的原位表征和反应性能   总被引:4,自引:4,他引:0  
采用浸渍法合成了镍盐复合的磷钨酸(HPW)/纳米晶HZSM-5固体酸催化剂,其在催化裂化(FCC)汽油加氢改质反应中显示出了良好地深度加氢脱硫活性。原位电子自旋共振和原位吡啶吸附红外光谱表征手段的研究结果表明,纳米晶HZSM-5沸石上Ni(Ⅱ)结合3电子还原态的HPW(Ⅲ)是FCC汽油深度加氢脱硫反应的活性中心。探讨了多酸基催化剂在FCC汽油深度加氢脱硫反应中活性改善的原因。  相似文献   

5.
载铜5A分子筛在汽油模拟体系中脱硫性能的研究   总被引:11,自引:4,他引:7  
近年,美国环保局计划将汽油中硫的质量分数从当前的300×10-6降到2006年的30×10-6,欧盟也已经通过了新的汽油硫质量分数标准为30×10-6~50×10-6,德国甚至提出计划使用无硫汽油[1]。中国汽油硫的质量分数高达800×10-6以上,与世界汽油品质距离甚远。因此汽油中硫化物的脱除成为当务之急。目前,脱硫技术主要有催化裂化脱硫、催化加氢脱硫、水蒸气脱硫、生物催化脱硫、吸附精制脱硫、氧化脱硫等[2~5]。吸附精制法具有净化度高、能耗低、易于操作等优点,高效的脱硫吸附剂制备是过程开发的关键。负载金属离子的活性纤维是脱除汽油中硫醇的一种…  相似文献   

6.
轻质油品非加氢脱硫技术   总被引:5,自引:0,他引:5  
日益严格的环保法规,对生产低硫、超低硫清洁油品技术提出了更高的要求。传统的加氢脱硫技术存在投资大、运行成本高等问题,因此开发成本低、操作条件温和的非加氢脱硫技术成为一种趋势。本文综述了目前轻质油品非加氢脱硫的相关技术,主要包括氧化脱硫、吸附脱硫和生物脱硫等技术的研究进展;简要介绍了萃取脱硫、络合脱硫、催化裂化脱硫、烷基化脱硫、膜分离脱硫及离子液体脱硫等技术;同时对轻质油品非加氢脱硫技术的应用前景进行了展望。  相似文献   

7.
介孔碳担载的 Co-Mo 和 Ni-Mo 加氢脱硫催化剂   总被引:4,自引:0,他引:4  
 自制介孔碳 (CMC) 具有比传统活性碳 (AC) 更大的比表面积、孔径和孔体积, 以其为载体, 在浸渍液中加入螯合剂, 采用等量浸渍法制备了 Co-Mo/CMC 和 Ni-Mo/CMC 催化剂, 分别用于模型汽油和柴油加氢脱硫反应. 结果表明, Co-Mo/CMC 和 Ni-Mo/CMC 催化剂具有比 Co-Mo/AC 催化剂更好的织构性质和加氢脱硫活性. 在模型汽油的加氢脱硫反应中, Co-Mo/CMC 催化剂活性比工业催化剂 Co-Mo/Al2O3 高得多; 而在模型柴油的加氢脱硫反应中, Ni-Mo/CMC 催化剂活性也比工业催化剂 FH-98 高得多.  相似文献   

8.
以硝酸镁和硝酸铝为原料,用氨水溶液作为pH调节剂,采用共沉淀法制备了镁铝复合氧化物载体,研究了制备过程中镁铝比、pH调节剂种类、水解过程pH值的大小、反应温度、焙烧温度及回流晶化温度对复合氧化物载体理化性质的影响。并以RFCC汽油加氢脱硫为探针反应,考察了以镁铝复合氧化物为载体的催化剂选择性加氢脱硫性能。实验结果表明,在镁铝分子比为10、反应温度为80℃、pH值为9.5条件下制备的镁铝复合氧化物载体具有适宜的比表面积和均匀的孔分布,且晶型较完整,结晶度高。以该复合氧化物为载体制备的催化剂具有良好的RFCC汽油选择性加氢脱硫反应性能。  相似文献   

9.
以脱硫选择性不同的2组催化裂化汽油加氢脱硫催化剂为研究对象,采用CO吸附原位红外光谱表征了2组催化剂的活性相特征,并通过分子模拟计算方法比较了助剂Co加入前后噻吩和1-己烯在催化剂表面的电荷分布、吸附能及其加氢反应的活化能等,探讨了助剂Co的加入对选择性加氢脱硫催化剂脱硫选择性的作用机理.结果表明,加氢脱硫催化剂CoMoS活性相的增加有利于提高催化剂的加氢脱硫/加氢降烯烃(HDS/HYD)选择性.与1-己烯加氢位相比,Co的加入显著提高了噻吩分子加氢位的缺电子性,噻吩在催化剂表面的吸附度增强,显著降低噻吩加氢反应的能垒,从而使噻吩加氢反应更易进行.这也表明CoMoS为高HDS活性、高HDS/HYD选择性的活性相.  相似文献   

10.
柴油脱硫的机理研究以及反应中的溶剂效应   总被引:2,自引:0,他引:2  
王雪松 《广州化学》2007,32(1):62-67
柴油的脱硫技术分为加氢脱硫和非加氢脱硫。在非加氢脱硫的研究中,氧化脱硫技术具有反应条件温和、不使用昂贵的氢气、投资和操作费用低等优点日益受到重视。文章介绍了柴油的脱硫技术的机理方面的研究进展。其中包括加氢脱硫的反应网络;以及氧化脱硫研究中,光化学氧化体系和有机过氧化物氧化体系中DBT的氧化机理。在不同的反应体系中,溶剂对含硫化合物的脱除也有很大的影响.  相似文献   

11.
以不同焙烧温度和Ce负载量的CeY分子筛为研究对象,运用XRD及N_2吸附表征其织构性质;运用吡啶吸附红外光谱法剖析了分子筛中活性位的化学属性;采用固定床评价其对噻吩模拟油的吸附脱硫性能及芳烃和烯烃对噻吩脱除的影响;并结合红外光谱和GC-SCD技术分析了其脱硫机制。结果表明,CeY样品经150℃焙烧后,其超笼中具备高含量的B酸和Ce羟基化物种活性位,两者协同增强了噻吩低聚反应能力,进而提高了其吸附穿透硫容量(18.45 mg (S)/g);而提升焙烧温度和Ce负载量会严重降低其有效活性位的数量,削弱了噻吩低聚反应能力,其吸附穿透硫容量显著减小(4.03 mg (S)/g)。当加入烯烃和芳烃后,CeY-12.3-150吸附剂对含低浓度(质量分数)1-己烯(1.0%)和苯(0.1%)的噻吩模拟油依旧保持较高吸附穿透硫容量;但随两者含量的持续增加,其硫容量急剧下降。其主要分别归因于噻吩烷基化反应的发生及“S-H”键的作用模式。  相似文献   

12.
活性炭的表面处理对二苯并噻吩催化氧化脱除的影响   总被引:4,自引:1,他引:3  
将一种木质活性炭经过三种表面处理,即高锰酸钾稀硫酸溶液液相氧化、浓硝酸液相氧化和350℃低温气相氧化处理。实验所选活性炭及相应的表面改性炭使用氮气吸附和Boehm滴定分别进行了结构性质和表面化学表征。研究了所选活性炭和相应的表面改性炭催化过氧化氢氧化脱除二苯并噻吩(DBT)。实验结果表明,活性炭表面化学对二苯并噻吩的氧化脱除影响很大;炭表面化学对DBT吸附脱除的影响不同于对DBT氧化脱除的影响,表面酸性越强越有利于DBT的吸附;表面羰基能加速过氧化氢产生自由基,表面羰基量的增加明显有利于DBT的氧化脱除。活性炭经过热处理后,在二苯并噻吩的氧化脱除中催化活性明显增加,正辛烷溶液中硫的体积质量从0.556g·L-1降到0.009g·L-1。  相似文献   

13.
Steam activated carbons from oil-palm shells were prepared and used in the adsorption of phenol. The activated carbon had a well-developed mesopore structure which accounted for 45% of the total pore volume. The BET surface area of the activated carbon was 1183 m2/g and a total pore volume of 0.69 cm3/g using N2 adsorption at 77 K. The adsorption capacity of the activated carbon for phenol was 319 mg/g of adsorbent at 298 K. The adsorption isotherms could be described by both the Langmuir-Freundlich and the Langmuir equations. The adsorption kinetics consisted of a rapid initial uptake phase, followed by a slow approach to equilibrium. A new multipore model is proposed that takes into account of a concentration dependent surface diffusion coefficient within the particle. This model is an improvement to the traditional branched pore model. The theoretical concentration versus time curve generated by the proposed model fitted the experimental data for phenol adsorption reasonably well. Phenol adsorption tests were also carried out on a commercial activated carbon known as Calgon OLC Plus 12×30 and the agreement between these adsorption data and the proposed model was equally good.  相似文献   

14.
Two different types of modification of activated carbon, by treatment with concentrated solution of HNO3 and outgassing treatment at high temperature, were studied in order to obtain the most effective adsorption of chromium(VI) ions from water solution. The basic parameters affecting the adsorption capacity of Cr(VI) ions on modified activated carbons were studied in details and the effect of modifications of activated carbons has been determined by studying the initial runs of adsorption isotherms. The obtained Cr(VI) adsorption isotherms were well fitted in the Freundlich equation. The reduction of Cr(VI) to Cr(III) and further ion exchange mechanism of adsorption onto oxidizing activated carbon and surface precipitation to Cr(OH)3 in case of outgassing activated carbon were found as the main adsorption mechanisms of Cr(VI) ions onto modified activated carbons. Presence of chlorides and nitrates in studied adsorption system strongly decreased the adsorption ability of Cr(VI) onto outgassing activated carbon and mechanism of this behavior is proposed.  相似文献   

15.
Fir wood was first carbonized for 1.5 h at 450 degrees C, then soaked in a KOH solution KOH/char ratio of 1, and last activated for 1 h at 780 degrees C. During the last hour CO2 was poured in for further activation for 0, 15, 30, and 60 min, respectively. Carbonaceous adsorbents with controllable surface area and pore structure were chemically activated from carbonized fir wood (i.e., char) by KOH etching and CO2 gasification. The pore properties, including the BET surface area, pore volume, pore size distribution, and pore diameter, of these activated carbons were first characterized by the t-plot method based on N2 adsorption isotherms. Fir-wood carbon activated with CO2 gasification from 0 to 60 min exhibited a BET surface area ranging from 1371 to 2821 m2 g(-1), with a pore volume significantly increased from 0.81 to 1.73 m2 g(-1). Scanning electron microscopic (SEM) results showed that the surfaces of honeycombed holes in these carbons were significantly different from those of carbons without CO2 gasification. The adsorption of methylene blue, basic brown 1, acid blue 74, p-nitrophenol, p-chlorophenol, p-cresol, and phenol from water on all the carbons studied was examined to check their chemical characteristics. Adsorption kinetics was in agreement with the Elovich equation, and all equilibrium isotherms were in agreement with the Langmuir equation. These results were used to compare the Elovich parameter (1/b) and the adsorption quantity of the unit area (q(mon)/Sp) of activated carbons with different CO2 gasification durations. This work facilitated the preparation of activated carbon by effectively controlling pore structures and the adsorption performance of the activated carbon on adsorbates of different molecular forms.  相似文献   

16.
In this paper, we present the results of the prediction of the high-pressure adsorption equilibrium of supercritical gases (Ar, N2, CH4, and CO2) on various activated carbons (BPL, PCB, and Norit R1 extra) at various temperatures using a density-functional-theory-based finite wall thickness (FWT) model. Pore size distribution results of the carbons are taken from our recent previous work,(1,2) using this approach for characterization. To validate the model, isotherms calculated from the density functional theory (DFT) approach are comprehensively verified against those determined by grand canonical Monte Carlo (GCMC) simulation, before the theoretical adsorption isotherms of these investigated carbons calculated by the model are compared with the experimental adsorption measurements of the carbons. We illustrate the accuracy and consistency of the FWT model for the prediction of adsorption isotherms of the all investigated gases. The pore network connectivity problem occurring in the examined carbons is also discussed, and on the basis of the success of the predictions assuming a similar pore size distribution for accessible and inaccessible regions, it is suggested that this is largely related to the disordered nature of the carbon.  相似文献   

17.
We use a fast density functional theory (a "slab-DFT") and the polydisperse independent ideal slit-pore model to predict gas mixture adsorption in active carbons. The DFT is parametrized by fitting to pure gas isotherms generated by Monte Carlo simulation of adsorption in model graphitic slit-pores. Accurate gas molecular models are used in our Monte Carlo simulations with gas-surface interactions calibrated to a high surface area carbon, rather than a low surface area carbon as in all previous work of this type, as described in part 1 of this work. We predict the adsorption of binary mixtures of carbon dioxide, methane, and nitrogen on two active carbons up to about 30 bar at near-ambient temperatures. We compare two sets of results; one set obtained using only the pure carbon dioxide adsorption isotherm as input to our pore characterization process, and the other obtained using both pure gas isotherms as input. We also compare these results with ideal adsorbed solution theory (IAST). We find that our methods are at least as accurate as IAST for these relatively simple gas mixtures and have the advantage of much greater versatility. We expect similar results for other active carbons and further performance gains for less ideal mixtures.  相似文献   

18.
19.
A new method for the determination of the micropore volume distribution function of activated carbons is presented. It is based on the treatment of pure gas adsorption isotherms by a theoretical model derived from the Hill-de Boer theory. Adsorption data (isotherms and heat curves) for carbon dioxide, ethane and ethylene on activated carbon (F30/470 CHEMVIRON CARBON) have been provided by a thermobalance coupled to a calorimeter (TG-DSC 111 SETARAM) at different temperatures (233, 273, 303 and 323 K) for pressures up to 100 kPa. Adsorption isotherms of carbon dioxide and ethane at 303 and 323 K have been used for the determination of the micropore volume distribution function of the activated carbon of interest. The knowledge of its structure has then allowed the simulation of adsorption isotherms and heats for the same adsorbates at the same temperatures as those experimentally studied. Similar calculations have been conducted for ethylene. Whatever the adsorbate (carbon dioxide and ethane used for the determination of the micropore volume distribution function or ethylene), the mean deviation between experimental and calculated isotherms does not exceed 4% at quasicritical and supercritical temperatures (303 and 323 K). In the same temperature conditions, discrepancies between calculation and experiment reach about 10% for adsorption heats. For both isotherms and heats, large discrepancies appear at low temperature (233 and 273 K). This method allows the determination of the micropore volume distribution function of activated carbons. The validity of the results is insured using several isotherms of several adsorbates and taking into account the calorimetric effect of the phenomenon. That is the reason why this method can also be seen as a new possible model for pure gas adsorption data prediction. This paper also presents a brief summary of the state of the art in this field.  相似文献   

20.
以木屑为原料,在低温条件下一步法制得活性炭基吸附剂,考察了吸附剂制备条件和液-固、气-固吸附条件对吸附剂脱硫性能的影响。结果表明,吸附剂的最佳制备条件为,浸渍液与木屑质量比为1:1,浸渍液中硝酸质量分率为30%、吸附剂表面NiO负载量为5%,常温下浸渍24 h,400℃焙烧3 h。该吸附剂在0.2 g吸附剂/10 mL模拟油、温度为40℃及时间为5 h的液-固吸附脱硫的条件下,脱硫率为28.36%,吸附四次后饱和吸附硫容量可达2.34 mgS/g;在气-固吸附温度为250℃、空速为6.3 h-1的条件下,饱和吸附硫容量为2.37 mgS/g;高温气-固吸附脱硫对吸附剂的影响表明,与脱硫前相比,吸附剂在比表面积、总孔体积、微孔体积均有明显提高,这说明气-固吸附脱硫过程同时实现了活性炭的扩孔活化。甲苯溶剂再生实验表明,经五次再生后吸附剂的再生性能均可达90%以上。  相似文献   

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