离子液体在汽油烷基化脱硫中的研究

制备了一种带－SO3 H官能团的Brφnsted酸性离子液体[ SO3 H－Bmim] HSO4,应用于模拟汽油烷基化脱硫的研究。结果表明：在反应温度45℃,反应时间120 min的条件下,离子液体复合催化剂对噻吩有较好的脱除效果,脱硫率可达75．1％;单烯烃能与噻吩发生烷基化反应而使脱硫率有所升高;芳烃的存在会导致脱硫率降低。     

Desulfurization of Diesel Fuel by Extraction with Lewis-Acidic Ionic Liquid

Abstract

Ionic liquids were found to be highly selective for the extractive removal of aromatic sulfur compounds from fuels at room temperature. The efficiency of ionic liquids for the removal of aromatic sulfur compounds is dependent on the properties and structure of the ionic liquids. In this work, the Lewis-acidic ionic liquid 1-butyl-3-methylimidazolium tetrahalogenoferrate(III) ([BMIM] [FeCl₄]) was synthesized and demonstrated to be more effective for the removal of aromatic sulfur compounds from diesel over ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] [BF₄]) because of its Lewis-acidic property. The ionic liquids favorably extracted organic compounds with a higher density of aromatic π-electrons. [BMIM][FeCl₄] ionic liquid can be regenerated through reextraction by hexane, and could be used in multiple steps for the removal of sulfur compounds from diesel.     

离子液体用于汽油脱硫的研究进展

离子液体可通过萃取分离、催化作用和电化学聚合等方法降低汽油中的硫含量。对离子液体用于汽油脱硫的研究进展及离子液体脱硫产业化应用存在的问题进行了综述,并对未来的研究方向提出了建议。     

Desulfurization of Real Fuel Oils by Extraction with Ionic Liquids

Aromatic 1-butyl-3-methylimidazolium dicyanamide ([C₄mim][N(CN)₂]) and 1-ethyl-3-methylimidazolium dicyanamide ([C₂mim][N(CN)₂]) ionic liquids are tested for their performance in the extractive desulfurization of real FCC gasoline and diesel fuel. [C₄mim][N(CN)₂] has proven to be more effective than [C₂mim][N(CN)₂] in removing sulfur from fuels and was thus selected to undergo a series of further tests. A competitive desulfurization efficiency of nearly 40% and 30% was realized with [C₄mim][N(CN)₂] for diesel fuel and gasoline, respectively, in a single extraction at <1 h, 25°C, and 1:1(w/w)IL:fuel. The influence of IL:fuel mass ratio, temperature, and multiple extractions on S-extraction efficiency is investigated, and the result tends to favor large-scale industrial application. This high efficiency obtained at low temperature, together with the insensitivity of the Nernst partition coefficient on desulfurization efficiency, is industrially favorable because not much energy and cost are required. The influence of mass ratios is not obvious, but to some degree, the Nernst partition coefficients depend on the mass ratio, suggesting that this extraction is not a completely physically-determined extraction. This work offers a significant contribution to the production of clean oils by extraction with ionic liquids.     

离子液体在萃取脱硫研究中的应用进展

论述了离子液体应用于燃料油萃取脱硫的发展历程,通过对比萃取脱硫、萃取耦合化学氧化脱硫、萃取联合催化氧化脱硫三种不同体系的脱硫机理与技术优势,探究了离子液体的萃取性、催化性、氧化性及其再生问题。阐述了离子液体在燃料油脱硫领域的发展趋势。     

离子液体应用于燃油脱硫技术的研究进展

综述了离子液体在燃油脱硫中的研究情况;重点介绍了离子液体萃取脱硫法以及离子液体萃取结合氧化法在燃油脱硫中的应用,总结了其脱硫效果及影响因素,并对上述两类方法进行了对比;指出离子液体结合氧化脱硫技术具有良好的应用前景。     

Extractive Desulfurization of Fuel Oils with Thiazolium-Based Ionic Liquids

A new class of green solvents, known as ionic liquids (ILs), has recently been the subject of intensive research on the extractive desulfurization of fuel oils because of the limitation of the traditional hydrodesulfurization method in catalytically removing thiophenic sulfur compounds. In this work, four thiazolium-based ILs, that is, 3-butyl-4-methylthiazolium dicyanamide ([BMTH][DCA]), 3-butyl-4-methylthiazolium thiocyanate ([BMTH][SCN]), 3-butyl-4-methylthiazolium hexafluorophosphate ([BMTH][PF₆]), and 3-butyl-4-methylthiazolium tetrafluoroborate ([BMTH][BF₄]), are synthesized. The extractive capability of these ILs in removing thiophene (TS) and dibenzothiophene (DBT) from model fuel oils is investigated. [BMTH][DCA] and [BMTH][SCN] present better extractive desulfurization capability than [BMTH][BF₄] and [BMTH][PF₆], which may be ascribed to the additional π?π interaction between –C≡N (in [BMTH][DCA] and [BMTH][SCN]) and thiophenic ring (in TS and DBT); DBT in diesel fuel is more efficiently extracted than TS in gasoline. [BMTH][DCA] offers the best desulfurization results, where 64% and 45% sulfur removal are obtained for DBT and TS, respectively, at IL:oil mass ratio of 1:1, 25°C, 20 min. [BMTH][DCA] is thus selected to systematically investigate the effects of temperature, IL:oil mass ratio, initial sulfur content, multiple-extraction, and IL regeneration on desulfurization. The mutual solubility of [BMTH][DCA] with fuel oil is also determined. It is observed that the desulfurization capability is not too sensitive to temperature and initial sulfur content, which is desired in industrial application; the sulfur contents in gasoline and diesel fuel are reduced from 558 ppm to 20 ppm (after 5 cycles) and from 547 ppm to 8 ppm (after 4 cycles), respectively. This work may show a new option for deep desulfurization of fuel oils.     

Extractive Desulfurization of Fuel Oils with Dicyano(nitroso)methanide-based Ionic Liquids

The inability of traditional hydrodesulfurization (HDS) to effectively remove aromatic sulfur compounds such as thiophene (TS) and dibenzothiophene (DBT) has called for alternative methods to be studied, among which extractive desulfurization using ionic liquids (ILs) has attracted increasing interest. In this work, we prepared a new IL, 1-butyl-3-methylimidazolium dicyano(nitroso)methanide ([C₄mim][dcnm]), and investigated its extractive desulfurization for both model oils and real FCC gasoline, where model diesel fuel was composed of n-hexane and droplets of DBT and model gasoline was composed of n-hexane, toluene and droplets of TS. Other three [dcnm]-based ILs, 1-ethyl-3-methylimidazolium dicyano(nitroso)methanide ([C₂min][dcnm]), N-ethyl-N-methylpyrrolidinium dicyano(nitroso)methanide ([C₂mpyr][dcnm]), and N-butyl-N-methylpyrrolidinium dicyano(nitroso)methanide ([C₄mpyr][dcnm]), were also comparatively investigated. These [dcnm]-based ILs have low viscosity which favors the mass transfer and reduces the extractive equilibrium time, also are fluorine-free which avoids the corrosion by hydrogen fluoride from anion decomposition that occurs generally in fluorine-containing ILs. The desulfurization ability follows the order [C₄min][dcnm] > [C₄mpyr][dcnm] > [C₂min][dcnm] > [C₂mpyr][dcnm]. Typically, [C₄min][dcnm] is capable of removing 66% DBT and 53% TS from their respective model oils after one cycle (initial 500 ppm S, 25°C, 15 min, mass ratio of IL:oil 1:1), and < 10 ppm S-content can be obtained after 4 cycles. It was observed interestingly that the S-content in real FCC gasoline can be reduced from initial 250 ppm to < 30 ppm after 6 cycles using [C₄min][dcnm] as extractive reagent, which is better than some previous results for real feedstocks. Mutual solubility, extractive temperature, IL:oil mass ratio, multiple extraction, initial S-content, and regeneration were also studied. These dcnm-based ILs are competitive extractive reagents compared with some other ILs to remove those aromatic S-compounds from fuel oils.     

汽油萃取脱硫技术研究进展

随着汽车保有量的增加和环保要求越来越严格,石油燃烧产生的硫化物污染问题备受关注,石油脱硫技术成为研究热点。从有机溶剂和离子液体两种萃取剂的研究现状出发,阐述了反应温度、萃取时间、剂油比以及稀释剂对汽油脱硫效果的影响,展望了汽油萃取脱硫技术的发展趋势。     

基于离子液体的燃料油萃取脱硫过程

以咪唑类离子液体作为萃取脱硫剂,在正戊烷和甲苯的混合溶液中加入少量的噻吩构成油品模拟体系. 采用正交实验,系统考察了单级萃取中温度、时间、剂油比以及离子液体碳数对脱硫效率的影响,得到了较优的脱硫条件：温度约40℃,反应时间约50 min,剂油比为1:1,侧链碳数为10. 回归得到了模拟油品中脱除噻吩的萃取动力学方程. 该研究为基于离子液体的燃料油脱硫工艺提供了重要的基础.     

Highly Efficient Oxidative Desulfurization of Fuels by Lewis Acidic Ionic Liquids Based on Iron Chloride

Acidic ionic liquids (ILs) have been employed as extractant and catalyst in the oxidative desulfurization (ODS) process of fuels in recent years. Several Lewis acidic ionic liquids [C₆³MPy]Cl/nFeCl₃ (molar fraction n = 0.5, 1, 2, 3) and [C₆MIM]Cl/FeCl₃ were prepared and used to remove the aromatic sulfur compounds dibenzothiophene and benzothiophene from fuels. In the ODS process, the used ILs acted as both extractant and catalyst with 30 wt % hydrogen peroxide aqueous solution as oxidant. The effects of Lewis acidity of ILs, IL's cation structure, molar ratio of O/S, reaction temperature, and different sulfur compounds on the sulfur removal of model oil were investigated. The results indicated that the sulfur removal for dibenzothiophene was affected by Lewis acidity of ILs and nearly reached 100 % by [C₆³MPy]Cl/FeCl₃ at conditions of 298 K, IL/oil mass ratio of 1/3, O/S molar ratio of 4/1, in 20 min. The sulfur removal of real gasoline reached 99.7 % after seven ODS runs in the [C₆³MPy]Cl/FeCl₃‐H₂O₂ system.     

汽柴油深度脱硫的技术研究进展

结合汽油柴油中含硫化合物的存在形式和结构特点,说明了催化加氢脱硫的局限性。对几种汽柴油深度脱硫方法如吸附法、溶剂萃取法、化学氧化法、烷基化脱硫法等进行了综述和讨论,并提出了一些深度脱硫的技术策略。     

四氟硼酸盐类离子液体对典型柴油的萃取脱硫研究

The extractive removal of sulfur compounds （S-compounds） from Dongying and Liaohe diesel fuels with [BF4]^--based ionic liquids were systematically investigated. The results show that the absorption capacity of an ionic liquid for the S-compounds in diesel fuels relies on its structure and its size. In the case of the two examined diesel fuels, both elongating the cation tail length and increasing the mass ratio of ionic liquid/diesel fuel promote the desulfurization ability of the examined ionic liquids. The results also show that imidazolium-based ionic liquids display higher extraction efficiencies than pyridinium-based ionic liquids, presumably owing to the fact that the rings of the S-compounds are similar to the imidazolium head ring. With the 1 ： 1 mass ratio of ionic liquid/diesel fuel, the rates of the first desulfurization of Dongying and Liaohe diesel fuels using [C8mim][BF4] amount to 29.96% and 39.76%, suggesting that [C8mim][BF4] is a promising extractant for desulfurization of these diesel fuels.     

汽油吸附脱硫研究现状

综述了汽油吸附剂以及吸附脱硫技术的研究成果,重点介绍了分子筛基吸附剂,金属氧化物基吸附剂和活性炭基吸附剂的研究情况,指出实现汽油吸附脱硫工业化的关键是提高吸附剂的硫容、选择性和再生性能,并对未来吸附剂的研究方向进行了预测.     

功能型离子液体萃取氧化脱硫研究

合成了一系列含有不同阴离子的1-烷基-3-甲基咪唑型离子液体,以35%H2O2以及冰醋酸为氧化剂,分别考察了不同条件下离子液体对模拟油品和实际油品的脱硫效果。结果表明,离子液体阴离子的酸性以及阳离子烷基碳链的长度对脱硫效果具有显著影响,其中具有较长碳链的强酸性硫酸氢盐类离子液体在剂︰油︰氧化剂=1︰25︰1,30℃条件下对模拟油品与实际油品均具有较高的脱硫率,对模拟油品一次脱硫率在90%以上,对抚顺石化公司石油二厂汽油、柴油一次脱硫率在80%以上,其中汽油含硫量降至10 mg/kg左右,达到欧V标准,显示了非常好的工业应用前景。     

汽油脱硫吸附剂的研究

开发了在无机促进剂作用下担载多金属改性硅胶基的选择吸附脱硫剂,在室温条件下用于汽油的模型化合物和直馏汽油的吸附脱硫。结果表明,本文研制的担载过渡金属吸附荆对硫化物的选择吸附有效,在常压、室温的低投资和操作费用下能有效脱除硫醇、硫醚、噻吩类硫化合物。     

轻质油品萃取脱硫研究进展

综述了目前轻质油品脱硫的技术,并进行了对比分析和效果评价。重点讲述了近年来国内外利用有机溶剂、离子液体进行萃取脱硫技术的研究,阐述了离子液体萃取脱硫的原理,分析了影响脱硫效率的因素。通过分析评价可得:(1)离子液体稳定性好、可循环使用、适合深度脱硫等优点,具有广阔的发展前景;(2)萃取和氧化技术相结合能够进一步提高离子液体的脱硫率,将是未来萃取脱硫技术发展的一个重要方向。     

汽柴油深度脱硫方法及发展现状

介绍了目前对汽柴油中硫含量的要求以及汽柴油中的硫化物的特点,结合这些特点,叙述了吸附脱硫、萃取脱硫、膜分离、生物技术脱硫、络合沉淀法和催化氧化法等几种深度脱硫方法,并且提出了对未来在汽柴油深度脱硫方面的建议。     

离子液体在萃取分离中的应用

室温离子液体是由正负离子组成的室温为液体的熔融盐,因其具有极低的蒸汽压、可设计性和特殊的选择溶解能力等独特的性质,使得其在萃取分离有机物及金属离子、液相微萃取和汽油柴油中脱硫及碱性氮化物等领域都有着广泛应用。综述了离子液体在萃取分离上的应用进展。