Ultra-deep catalytic adsorptive desulfurization of diesel fuel using Ti-silica gel adsorbent at low Ti-loading

In this work, the effective ultra-deep catalytic adsorptive desulfurization (CADS) using titanium-silica gel (Ti-SG) adsorbent at low Ti loading (<1 wt.%) was investigated. The superior CADS capacity (37.3 mg-S/g-A) and high TOF value (432 h⁻¹) for dibenzothiophene (DBT) of Ti-SG adsorbent were achieved at Ti loading of 0.6% with high dispersion and low titanium coordination. The rate equation of catalytic DBT oxidation was described as , where the TiOOR was determined as the intermediate to enable the DBT oxidation to form the corresponding sulfone (DBTO₂). The effectiveness of CADS using Ti-SG adsorbents was verified in real diesels with varied sulfur concentrations and O/S ratios in the dynamic adsorption and multicycle regeneration. This work provides insights on using low-cost bifunctional catalytic adsorbents at low Ti loadings for effective CADS to realize ultra-deep desulfurization of transportation fuels.     

活性炭担载金属氧化物用于热煤气脱硫

以热煤气脱硫并回收单质硫为目的,考察了活性炭担载金属氧化物(M/AC)在中温范围150—250℃内,催化氧化硫化氢生成单质硫的研究。担载量1%(质量分数)的M/AC通过等体积浸渍法制得,在固定床上评价了其脱硫活性,并考察了温度、反应气氛等工艺条件对脱硫效果的影响。M/AC脱硫的活性顺序为:Mn/ACCu/ACCe/ACFe/ACCo/ACV/AC。通过DTG分析,硫化氢选择性氧化的主要产物是单质硫。M/AC上金属氧化物起主要的催化作用,催化硫化氢和氧气反应生成单质硫,生成的单质硫被吸附在活性炭的孔道中。     

A novel approach for ultra‐deep adsorptive desulfurization of diesel fuel over TiO2–CeO2/MCM‐48 under ambient conditions

A novel approach for ultra‐deep desulfurization of diesel fuel was proposed, in which the original fuel was treated by light irradiation before adsorptive desulfurization (ADS) over the TiO₂–CeO₂/MCM‐48 adsorbent under ambient conditions. A superior capacity of 95 cm³‐fuel/g‐adsorbent (32 times higher than that of the original fuel) was achieved. The promoting effect of light irradiation was likely through in situ peroxides generation in fuel under visible light/sunlight, which may oxidize organosulfur to form strongly adsorbed sulfones over the adsorbent.     

Dynamic catalytic adsorptive desulfurization of real diesel over ultra‐stable and low‐cost silica gel‐supported TiO2

To develop dynamic ultra‐deep catalytic adsorptive desulfurization (CADS) of real diesel using ultra‐stable and low‐cost silica gel‐supported TiO₂ is the aim of the work. A two‐stage dynamic breakthrough model was built to describe the CADS process, varied with H/R ratio and O/S ratio. The desulfurization capacity reached 1.3 mg‐S/g‐A at the breakthrough concentration of 5 ppm‐S. Various types of silica gel were screened as the substrate for TiO₂, and the textural/acidic properties and CADS capacity were correlated in high relevancy. The effectiveness of diverse oxidants on CADS and the oxidation path were elucidated via combined experiment/simulation. Adsorption enthalpy derived from fitted isotherm data was calculated as 33.4 kJ/mol. The TiO₂/silica gel‐based sorbent demonstrated remarkable recyclability/stability in 10 cycles. An effective and economic route to eliminate the trace amount of stubborn sulfur compounds in low‐sulfur diesel is provided, which can be potentially implemented as the final polishing step for ultra‐clean diesel production. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2146–2159, 2018     

活性半焦在FCC柴油吸附脱硫中的应用研究

利用活性半焦对FCC柴油进行固定床吸附脱硫实验。按正交设计方法考察床层高径比、固定床温度、空速、催化剂种类和金属氧化物焙烧温度对脱硫率的影响。结果表明,各因素对脱硫率影响的大小顺序及最佳工艺条件为：空速（2 h^-1）＞床层高径比（7.5）＞固定床温度（120 ℃）＞催化剂种类（负载CuO）＞焙烧温度（350　℃）。考察了最佳工艺条件下活性半焦的脱硫性能,并对其600 ℃进行热再生三次。结果表明,最佳工艺条件下,脱硫剂脱硫率达55.95％,随脱硫时间的延长,脱硫剂新鲜样和再生样脱硫率均下降,随再生次数的增加,脱硫率降低,但降低缓慢。经新鲜样和再生样脱硫后,柴油产品收率均在81％以上,而油品总收率在93％以上。     

氧化法脱除重油催化裂化柴油中的硫化物

采用双氧水-甲酸对重油催化裂化柴油进行氧化,然后使用N,N-二甲基甲酰胺萃取剂萃取脱硫。研究了在反应体系中氧化时间、氧化温度以及双氧水与甲酸的加入量对氧化脱硫率的影响,并考察了加入分散剂Span-80的效果。最终得到双氧水-甲酸-Span-80体系最佳氧化条件：分散剂Span-80为2.0%,双氧水为36%,甲酸为32%,氧化温度为60 ℃,氧化时间为50 min。分散剂Span-80的加入可以大大提高双氧水-甲酸体系对重油催化裂化柴油的氧化脱硫能力。在双氧水-甲酸体系最佳条件下氧化萃取脱硫率为85.58%,双氧水-甲酸-Span-80体系脱硫率高达98.27%,重油催化裂化柴油的硫含量由12 500 mg/L降至216 mg/L。气相色谱结果显示,氧化脱硫后重油催化裂化柴油中的噻吩、苯并噻吩及其衍生物基本被脱除,有少量二苯并噻吩及其衍生物需要进一步脱除。     

负载型吸附剂用于柴油吸附脱硫的研究

考察了改变吸附压力、温度、空速、剂油比、氧气流量等条件对吸附脱硫效果的影响。测试结果表明：负载型吸附剂的吸附脱硫性能和载体种类、负载活性组分的种类、含量及分散均匀度相关，载体对硫化物的吸附以物理吸附为主。     

碱处理Beta分子筛吸附脱硫动力学

当吸附质尺寸与分子筛的孔结构尺寸相当时才能进入分子筛的内部,分子筛的孔道尺寸是影响吸附性能的重要因素之一,NaOH溶液处理可实现分子筛孔径的调变,以改善分子筛对吸附质的选择性和扩散传质能力。通过对碱处理后的Beta分子筛进行BET、TEM、FT-IR、XRD和NH₃-TPD表征,以考察碱处理对Beta分子筛晶体结构、表面酸性和孔结构参数的影响。碱处理Beta分子筛吸附脱硫的结果显示,碱处理后Beta分子筛吸附量和吸附速率明显增加,尤其动力学尺寸较大的二苯并噻吩吸附量达到了5.06 mg·g^-1。吸附动力学研究显示,该吸附过程符合准二级动力学方程,碱处理后分子筛吸附速率常数和粒子内扩散速率常数明显增大,有效地改善了硫化合物在孔道内扩散传质性能,脱硫效率增加。     

金属-有机骨架材料吸附脱硫的研究进展

金属-有机骨架材料(MOFs)是一种新型多孔材料,近年来在吸附脱硫中的应用使其在清洁汽油生产中成为最有潜力的材料。综述MOFs吸附脱硫的研究进展及主要机理,并对MOFs的发展前景和方向进行展望。     

低温等离子体催化氧化柴油脱硫工艺的研究

利用浸渍法制备了Cu~(2+)/Al_2O_3、Ni-Mn为主要组分的催化剂,并用其为催化剂、市售0~#柴油为对象探讨了等离子体催化氧化-萃取脱硫上艺.结果表明该催化剂的催化效果优于其他催化剂.当电极两端电压为17 kV、驱动频率为15 kHz、催化剂用量为5%质量分数、氧化时间为20 min、萃取剂为甲醇、剂/油体积比为1:1、萃取时间为15 min时,一级脱硫率可达到73.8%.     

V-Mo based catalysts for oxidative desulfurization of diesel fuel

Catalytic oxidative desulfurization (ODS) of a Mexican diesel fuel on a spent HDS catalyst, deactivated by metal deposits, was carried out during several reactive-batch cycles in order to study the catalytic performance to obtain low sulfur diesel. To explain catalytic activity results, Mo and/or V oxides supported on alumina pellets were prepared and evaluated in the ODS of a model diesel using tert-butyl hydroperoxide (TBHP) or H₂O₂ as oxidant. The catalytic results show that V-Mo based catalysts are more active during several ODS cycles using TBHP. The performance of the catalysts was discussed in terms of reduced species of vanadium oxide, prevailing on the catalysts, which increase the sulfone yield of refractory HDS compounds (DBT, 4-MDBT and 4,6-DMDBT).     

柴油脱硫技术的研究进展

对目前清洁燃料油的生产技术进行了概述.随着世界清洁柴油中含硫标准的提高,降低柴油中硫含量已成为全球性关注的问题.近几年,出现了许多新的脱硫技术,其中柴油非加氢脱硫技术的研究进展较快.介绍了氧化脱硫和非氧化脱硫技术的理论基础,重点概述了这方面取得的最新成果,并从清洁生产的角度出发,对柴油脱琉技术的发展进行了辰望.     

金属改性分子筛吸附脱硫研究新进展

从分子筛金属改性的方式、吸附脱硫机理、吸附剂再生等方面综述了近几年国内外关于金属改性的微、介孔分子筛在燃料油液相吸附脱硫中的应用,分析了微、介孔分子筛作为脱硫吸附剂的优势和存在的问题,指出如何提高吸附剂的硫容量和选择性仍是未来研究的主要方向。     

复合金属氧化物催化丙烷选择氧化制丙烯酸

采用溶液法制备Mo-V-Te-Nb-O催化剂,研究了焙烧次数对催化剂性能的影响,考察催化剂在普通密封条件下储存时间和连续反应过程中的稳定性。结果表明,二次焙烧制备的催化剂中M1和M2相增强,对丙烯酸生成有利,且晶相形态不随焙烧次数的增加而改变,而烧结现象逐渐增加。催化剂可在普通密封条件下储存24个月,性能不发生变化,催化剂活性和选择性随反应进行不断震荡升高,丙烯酸初期收率为24.7%,反应180 h左右达31.8%,随后催化剂迅速失活。XRD、BET表征及催化剂再生实验表明,其失活的主要原因是Te流失。     

燃料油吸附脱硫的研究进展

与传统的加氢脱硫技术相比,吸附脱硫技术在超低硫燃料油生产方面具有明显优势,近年来得到了迅速发展。综述了吸附法脱除燃料油中有机硫化物的研究进展,重点介绍了反应吸附脱硫和选择性吸附脱硫两种类型的吸附脱硫方法以及分子筛基吸附剂、金属氧化物基吸附剂、活性炭基吸附剂和粘土基吸附剂在吸附脱硫方面的应用。指出选择性吸附脱硫技术是近期最有希望实现零硫目标的脱硫技术。     

柴油氧化脱硫技术研究进展

介绍了近年来柴油氧化脱硫技术研究的进展情况,主要包括:H2O2均相、非均相催化氧化脱硫,超声波氧化脱硫,光催化氧化脱硫和分子氧直接氧化脱硫等。认为分子氧直接氧化脱硫技术克服了H2O2价格较高、稳定性差等缺点,并且该法具有操作条件缓和,反应时间短等优点,将成为柴油氧化脱硫的主要研究方向。     

Fluoride ions adsorption from water by CaCO3 enhanced Mn–Fe mixed metal oxides

Novel CaCO₃-enhanced Mn–Fe mixed metal oxides (CMFC) were successfully prepared for the first time by a simple-green hydrothermal strategy without any surfactant or template combined with calcination process. These oxides were then employed as an adsorbent for adsorptive removal of excess fluoride ions. The adsorbent was characterized by SEM, XPS, XRD, FTIR, and BET analysis techniques. The adsorption property of CMFC toward fluoride ion was analyzed by batch experiments. In fact, CMFC exhibited adsorption capacity of 227.3 mg∙g^‒1 toward fluoride ion. Results showed that ion exchange, electrostatic attraction and chemical adsorption were the main mechanism for the adhesion of large amount of fluoride ion on the CMFC surface, and the high adsorption capacity responded to the low pH of the adsorption system. When the fluoride ion concentration was increased from 20 to 200 mg∙L^‒1, Langmuir model was more in line with experimental results. The change of fluoride ion adsorption with respect to time was accurately described by pseudo-second-order kinetics. After five cycles of use, the adsorbent still maintains a performance of 70.6% of efficiency, compared to the fresh adsorbent. Therefore, this material may act as a potential candidate for adsorbent with broad range of application prospects.     

催化裂化汽油吸附脱硫工艺研究

在固定床吸附装置上对催化裂化汽油进行吸附脱硫实验,考察了吸附脱硫工艺条件对催化裂化汽油硫质量分数、辛烷值及吸附剂单程寿命的影响。实验结果表明,吸附脱硫适宜的工艺条件为:吸附温度360℃,吸附压力0.3 MPa,氢气流量300 mL/m in,体积空速1.0 h-1。通过对吸附脱硫实验过程中的尾气分析,对催化裂化汽油吸附脱硫的机理进行了探讨。     

车用燃料油固体脱硫吸附剂的研究进展

吸附脱硫的优势是投资成本低、操作条件温和,其技术关键在于研发吸附硫容量大、选择性高和再生性能好的固体吸附剂。本文综述了车用燃料油固体脱硫吸附剂的研究进展,包括常规的分子筛、活性炭、金属氧化物吸附剂以及一种新型金属-有机骨架（MOFs）材料脱硫吸附剂。从吸附机理、制备方法、脱硫效果等方面分析了上述吸附剂的优缺点和改进方向。提出今后的固体脱硫吸附剂可从吸附机理出发在分子尺度上设计和组装新材料的观点。