Polyoxometalate as effective catalyst for the deep desulfurization of diesel oil

Aiming at the deep desulfurization of the diesel oil, a comparison of the catalytic effects of several Keggin type POMs, including H₃PW_xMo_12?xO₄₀ (x = 1, 3, 6), Cs_2.5H_0.5PW₁₂O₄₀, and H₃PW₁₂O₄₀, was made, using the solution of DBT in normal octane as simulated diesel oil, H₂O₂ as oxidant, and acetonitrile as extractant. H₃PW₆Mo₆O₄₀ was found to be the best catalyst, with a desulfurization efficiency of 99.79% or higher. Hence, it is promising for the deep desulfurization of actual ODS process. The role of the main factors affecting the process including temperature, O/S molar ratio, initial sulfur concentration, and catalyst dosage, was investigated, whereby the favourable operating conditions were recommended as T = 60 °C, O/S = 15, and a catalyst dosage of 6.93 g (H₃PW₆Mo₆O₄₀)/L (simulated diesel). With the aid of GC–MS analysis, sulfone species was confirmed to be the only product after reaction for 150 min. Furthermore, macro-kinetics of the process catalyzed by H₃PW₆Mo₆O₄₀ was studied, from which the reaction orders were found to be 1.02 to DBT and 0.38 to H₂O₂, and the activation energy of the reaction was found to be 43.3 kJ/mol. Moreover, the catalyst recovered demonstrated almost the same activity as the fresh.     

High performance sorbents for diesel oil desulfurization

Sorbents with different Ni loading supported on silica–alumina (SiAl) and activated carbon (AC) were synthesized and tested for removal of sulfur compounds from a model diesel oil, containing nearly 250 ppmw S as benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). A state-of-art Commercial Ni-based sorbent and two Norit activated carbons were also tested for comparison. Moreover, the influence on sorbents uptake capacity of the presence of aromatics in amounts representative of real diesel oils was studied. Both commercial and home-made materials performed worse in presence of aromatic compounds. Probably, the latter competed with the refractory sulfur compounds (DBT and 4,6-DMDBT) in the adsorption on active sites. As a first important result of the investigation the sorbents carrying 45% and 30% of Ni on SiAl showed a breakthrough uptake capacity of nearly, respectively, 2 and 2.6 times higher than Commercial sorbent as a consequence of their higher Ni dispersion and surface area. Moreover, activated carbons and the sample with 28%Ni on AC showed an even higher breakthrough uptake capacities. In particular, the deposition of nickel on activated carbon is an innovative approach which takes advantage of the selectivity of Ni towards S-species and the high adsorptive capacity of AC support.     

Study of diesel fuel desulfurization by adsorption

Removal of sulfur from diesel fuel by adsorption on a commercial activated carbon and 13X type zeolite was studied in a batch adsorber. Kinetic characterization of the adsorption process was performed applying Lagergren's pseudo-first order, pseudo-second order and intraparticle diffusion models using data collected during experiments carried out to determine the sulfur adsorption dependency on time. The experiments investigating adsorption efficiency regarding initial sulfur concentration were also performed and the results were fitted to Langmuir and Freundlich isotherms, respectively. Activated carbon Norit SXRO PLUS was found to have much better adsorption characteristics. The process of sulfur adsorption on the fore mentioned activated carbon was further studied by statistically analyzing data collected during experiments which were carried out according to three-factor two-level factorial design. Statistical analysis involved the calculation of effects of individual parameters and their interactions on sulfur adsorption and the development of statistical models of the process.     

柴油氧化脱硫技术新进展

柴油低硫化及其含硫标准的日趋严格,是世界各国柴油产品质量与标准的发展趋势。加氢脱硫技术生产低硫柴油,存在投资大、操作费用高和操作条件苛刻的缺点,导致柴油成本大幅攀升,柴油氧化脱硫技术已成为研究热点。综述了国内外柴油氧化脱硫技术的研究进展,认为柴油氧化脱硫技术将成为今后生产超低硫清洁柴油的主要工艺之一。     

Role of phosphorus in carbon matrix in desulfurization of diesel fuel using adsorption process

Adsorptive removal of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel with 20 ppmw total concentration of sulfur was investigated on polymer-derived carbons with incorporated heteroatoms of oxygen, sulfur and phosphorus. The materials before and after exposure to model diesel fuel were characterized using adsorption of nitrogen, thermal analysis, potentiometric titration, XPS and elemental analysis. The selectivities for DBT and DMDBT adsorption were calculated with reference to naphthalene. The results indicated that the presence of phosphorus, especially in the form of pyrophosphates and P₂O₅, increases the capacity and selectivity for removal of dibenzothiophenes. It also affects the adsorption mechanism. Phosphorus suppresses oxidation reactions of DBT and DMDBT. Owing to a possible location of bulky phosphorus groups in pore with sizes between 1 and 3 nm thiophenic molecules are strongly adsorbed there via dispersive forces. Acidic environment also enhances adsorption via acid–base interactions. Physical adsorption mechanism and stability of surface make these carbons attractive candidates for thermal regeneration.     

微波辐射柴油脱硫实验研究

采用微波辅助氧化反应的方法对辽河常二线柴油配制油样进行了脱硫实验，过氧化氢作氧化剂，可以把柴油中的含硫化合物有选择性地氧化成相应的具有很强极性的砜，根据相似相溶原理，这些砜因溶于剂相而从柴油中除去，从而降低了硫含量。实验过程中分别考察了氧化荆用量、剂油比、反应体系压力、氧化时间、微波功率等对柴油硫含量的影响。确定了实验室适宜的操作条件：剂油体积比为0．25：1，微波辐射压力为0．05MPa，微波功率为375w，辐射时间为6min，柴油的脱硫率为60％．而在无微波辐射的条件下，脱硫率仅为12％。     

吸附法深度脱除燃料油中硫化物的研究进展

综述了吸附法深度脱除燃料油中硫化物的吸附机理及技术进展,主要包括物理吸附脱硫、反应吸附脱硫和选择性吸附脱硫的研究进展。物理吸附脱硫技术对硫化物的选择性较差且很难实现深度脱硫,而反应吸附脱硫在高温下才能有较好的吸附性能,吸附剂的再生温度较高。选择性吸附脱硫技术最具发展前景,操作条件温和,投资和操作费用低,能深度脱硫,是近期最有希望实现零硫目标的脱硫技术,但吸附剂对含硫化合物的选择性和硫含量还有待进一步提高。     

加氢柴油超深度氧化脱硫研究

采用KMnO4/HCl体系氧化大庆炼化公司加氢柴油,考察了反应温度、氧化时间、HCl溶液的pH值、氧化剂用量等对氧化脱硫效果的影响,最佳反应条件下柴油的脱硫率可达92.3%。在氧化过程中,采用红外光照射可使反应时间由30 min缩短到20 min,直接水洗氧化产物即可使柴油的脱硫率达到90%以上。与未使用红外光照射的氧化-萃取过程相比,省去了萃取剂及其回收费用,简化了操作流程,降低了超低硫柴油的生产成本。     

Acylation desulfurization of oil via reactive adsorption

Excellent desulfurization is achieved via reactive adsorption using Friedel‐Crafts acylation materials, that is, acylating reagents and Lewis acids, such as acetyl chloride (AC) and AlCl₃, being named as acylation desulfurization (ACDS). For model oil, thiophenic compounds, namely, dibenzothiophene, benzothiophene, and thiophene, are removed completely by AC–AlCl₃ within 30 min at room temperature. In this process, thiophenic compounds are acylated by AC under the catalysis of AlCl₃, and the acylated derivatives are stronger base than original ones due to incorporation of O‐containing carbonyl group (C?O) and, thus, adsorbed more easily by AlCl₃ via Lewis acid–base complexation. Further, ACDS mechanism is identified by acylated product characterization and quantum chemistry calculation. Satisfactorily, ACDS is still effective for toluene‐rich and real oils, and real oil quality is improved with desulfurization proceeding. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2966–2976, 2013     

甲基叔丁基醚生产深度脱硫工艺的选择

根据国家第五阶段车用汽油标准对汽油硫含量的要求,提出了满足该标准的汽油添加剂甲基叔丁基醚（MTBE）中硫含量的控制指标。分析了MTBE中硫化物的组成、来源及富集效应产生的原因,提出了富集系数的准确的计算方法。计算结果表明,当原料液化气中异丁烯质量分数为15%～30%时,富集系数最高可达4.44。在比较其他引起MTBE中硫含量升高因素的基础上,认为富集效应是导致其含硫量较原料液化气大幅升高以致超标的重要原因。同时研究了液化石油气精脱硫及MTBE蒸馏脱硫两种深度脱硫工艺,通过全面对比分析,认为MTBE双塔脱硫工艺在设备投资、能耗、吸附剂使用等方面均具有优势,并且可以将MTBE中的硫含量稳定地控制在3mg/kg以下。低于10mg/kg的控制指标要求,更适合于国家第五阶段车用汽油标准的添加剂的生产。     

活性炭用于柴油深度脱硫研究进展

综述了活性炭作为吸附剂和催化剂在柴油深度脱硫方面应用的新进展。通过表面热氧化和负载金属离子对活性炭表面进行化学性能改性,有效提高对柴油中噻吩类硫化物的吸附性能。活性炭作为催化剂,能有效催化过氧化氢和氧化柴油中的噻吩类硫化物而达到催化氧化脱硫。活性炭在柴油深度脱硫方面具有广阔的应用前景,但要真正实现其在脱硫上的工业化应用,尚需加强其表面化学性能改性、再生、吸附和催化氧化机理等方面的研究。     

燃料油中硫化物的选择性吸附研究进展

综述了不同吸附剂脱硫和选择性吸附两方面的机理及研究进展。在燃料油选择性吸附脱硫研究的吸附剂中,使用最多的是金属阳离子改性的Y型分子筛,以Cu、Ni和Ce改性的Y型分子筛最为成熟。其吸附脱硫机理主要包括π-络合吸附和金属S—M键作用。燃料油（以汽油和柴油为主）组成复杂,含大量烯烃、芳烃、烷烃及少量的氮化物、氧化物、水及胶质,影响吸附剂的吸附脱硫效果,而烯烃和芳烃严重影响吸附剂的选择性吸附脱硫性能。各种吸附剂对富含烯烃或芳烃的燃料油中的硫化物选择性和硫容量不同,但都不高。研究吸附剂与燃料中的硫化物的选择性吸附机理,对研发具有高选择性和高吸附容量的吸附剂起推动作用。     

连续式FCC柴油萃取-光催化氧化深度脱硫

尽快降低燃料油中的硫含量是整个炼油业都无法回避的重大问题,炼油工业发达的国家已提出生产超低硫清洁燃料 （硫含量低于10 μg•g^-1）的目标。本文通过连续式FCC柴油萃取-光催化深度脱硫工艺,对FCC柴油进行精制,精制油中硫含量采用硫氮荧光分析仪测定,硫含量为45 μg•g^-1。实验结果表明：萃取操作的适宜条件为常压,萃取温度40℃,剂油比1.5∶1;反应操作的适宜条件为反应温度40℃,反应时间1 h,氧化剂用量为4%。在以上操作条件下,精制油中的硫含量为达到欧Ⅳ标准,精制油总收率超过96%。     

柴油氧化吸附脱硫工艺的研究

以过氧化氢为氧化剂,甲酸为催化剂,Al2O3为吸附剂,研究柴油氧化吸附脱硫工艺条件。实验结果表明,在n（氧）∶n（硫）=10.0,氧化时间为40min,氧化温度为70℃,V（吸附剂）∶V（油）=1∶5.5,吸附时间为30min,吸附温度为40℃时,吸附柴油的脱硫率为97.32%,柴油w（硫）=20.5μg/g,达到欧洲Ⅳ柴油标准：w（总硫）〈50μg/g。     

柴油空气催化氧化脱硫的探索研究

为克服柴油加氢脱硫技术投资大、操作条件苛刻及污染严重等问题,提出一种空气催化氧化脱硫方法。考察了催化剂种类及其用量、催化氧化温度、时间、空气流速等因素对脱硫效果的影响。实验结果表明,选用粉状白土作脱硫催化剂,在空气流量为1600 ml/min和160 ℃下反应30 min,可将原料油中硫的质量分数从1033×10^－6降到381×10^－6,脱硫率达63.12%。     

Ultra‐deep desulfurization adsorbents for hydrotreated diesel with magnetic mesoporous aluminosilicates

Magnetic mesoporous aluminosilicates (MMAS) were synthesized by hydrothermal method and applied as ultra‐deep desulfurization adsorbents for hydrotreated diesel. The size of oleic‐coated magnetic Fe₃O₄ nanoparticles prepared by coprecipitation method was about 20 nm. MMAS shows better desulfurization properties for removal of sulfur compounds than NaY and MCM‐41. The amount of Fe₃O₄ nanoparticles has significant effects on specific surface area/pore volume and acidic properties, thus, can affect the desulfurization properties of MMAS. Desulfurization properties of MMAS can be improved with the increase of temperature from 30–70°C and decrease the oil to adsorbent ratio. With the increase of Fe₃O₄ content, adsorption capacity first increased and then decreased. The sulfur adsorption of MMAS was due to the synergetic effect of strong molecular affinity of the magnetite to the sulfur compound and large surface area/pore volume of the mesoporous aluminosilicates. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

炼油厂产品深度脱硫工艺的研究进展

综述了国内外开发和应用的脱硫技术,通过一系列实例阐述了近年来催化加氢脱硫及非加氢脱硫的工艺进展。该技术主要有催化加氢脱硫（改进催化剂的合成、先进的反应器设计、蒸馏与加氢脱硫组合等）及非加氢脱硫技术（烷基化脱硫、溶剂萃取脱硫、沉淀脱硫、吸附脱硫、氧化脱硫和膜分离脱硫等）;评述了催化加氢脱硫、烷基化脱硫、吸附脱硫和氧化脱硫等脱硫技术的特点和研究应用前景。     

轻质油品脱硫技术研究进展

介绍目前国际上正在应用或开发的轻质油品脱硫新技术，阐述这些技术工艺的原理、特点及脱硫性能，并综合进行比较得出吸附法脱除油品中的含硫化合物具有操作简单、投资少、适合于深度脱硫、无污染等优点，是一项具有工业应用前景的汽油脱硫新技术。     

轻质燃料油萃取/萃取精馏深度脱硫

为弥补加氢深度脱硫技术的不足,轻质燃料油的非加氢深度脱硫技术已成为目前的研究热点。本文介绍了萃取/萃取精馏深度脱硫技术的进展情况,包括技术优势,研究进展,工业应用,以及在应用中高效萃取剂的选取。     

微波辐射催化裂化柴油脱硫工艺研究

介绍了以过氧化氢-甲酸为氧化剂对催化裂化(FCC)柴油进行微波辐射氧化脱硫,采用正交设计和单因素方法分别考察了微波辐射压力、辐射功率、恒压时间、萃取剂与油的体积比以及复合剂油的体积比对氧化脱硫反应的影响。得出最佳的实验条件:辐射压力0.4 MPa,恒压时间6 min,辐射功率412.5 W,复合溶剂用量为柴油用量的0.08倍,萃取剂油体积比1.5。在此条件下,硫的质量分数由5538.2μg/g降至825.2μg/g,回收率达到95%以上。