Deep desulfurization by selective adsorption on a heteroatoms zeolite prepared by secondary synthesis

Gallium atoms have been introduced into the framework of Y zeolite by treating the zeolite with an aqueous solution of ammonium hexafluoro gallate. Desulfurization of various model fuels containing about 500 μg/g sulfur were studied over the synthesized Y zeolite ([Ga]AlY) with a liquid hourly space velocity of 7.2 h^− 1 at ambient conditions. The sulfur adsorption capacity was 7.0, 14.5, and 17.4 mg(S)/g adsorbent for thiophene, 4,6-dimethyldibenzothiophene (4,6-DMDBT), and tetrahydrothiophene (THT), respectively. The charges on S atom in thiophene, 4,6-DMDBT and THT, calculated by using density functional theory (DFT), are − 0.159, − 0.214 and − 0.298, respectively, implying that the S–M bond between the adsorption sites and thiophene is much weaker than that between the adsorption sites and THT or 4,6-DMDBT.     

Effect of Sulfur on the Fischer-Tropsch Synthesis

One of the principalcauses of present concern is the current unavailability of alternative sources of fuels for transporation. Other fuel imensive sectors, such as electric power generation, can depend on coal or nuclear fuel to provide the energy if petroleum-based fuels become scare. The transporation sector, on the other hand, is projected to need liquid fuels. Due to the relevant abundance of coal in the United States, it isimperative to find ways of converting coal to liquid fuels. Products from coal liquefaction processes contain a high aromatic content. Though this is a desirable comporent isgasoline, it is a very undersirable one in jet and diesel fuels (Table 1). In even higher boiling materials such as gas oils, the high aromatic content makes it quite difficult to produce gasoline by normal rednery processess. Fischer-Tropsch (FT)synthesis, in which carbon produces mainly straight chain aliphatic hydrogen obtained from coal gastfication are reacted over a caralyst, is the only develped coal-derived process which produces mainly straight chain aliphatic hydrocarbons. Although such aliphatic hydrocarbons are not very desirable on motor gasolines due to their low octare number, diesel and jet fuels containing such aliphatic, hydrocarbons are considered high quality materials. In addition, the higher boiling gas oil traction from the FT process is easily converted to gasoline and diesel fuel by conventional refining technology     

Dual‐Layer Hollow Fibers for Sulfur Removal from Fuels

Emission of sulfur compounds to the atmosphere is universally recognized as one key target to be reduced. For membrane pervaporation which is considered as a potential purification process of fuels, dual‐layer polyurethane (PU)/polyethersulfone hollow‐fiber membranes were prepared. A novel fabrication technique is proposed using a quadruple spinneret to produce the fiber with such morphology by simultaneous spinning of two polymer solutions in the presence of two corresponding precipitation media. Activated carbon was added into the PU solution to improve the transport properties of the selective layer. Resulting hollow‐fiber membranes showed very good adhesion between the selective layer and its support, in addition to an effective removal of a sulfur compound such as 2‐methyl thiophene from a typical model fuel, an indication of good prospects for both the fabrication technique and for sulfur removal by pervaporation of fuels.     

煤基燃料油品特性与煤制油产业发展分析

基于最新汽油、柴油和航煤质量标准,结合我国市场对成品油需求走向,本文探讨了煤直接液化油、煤间接液化油、加氢煤焦油、煤油共炼产品、甲醇制汽油（MTG汽油）和聚甲氧基二甲醚（DMM_n）等煤基油品的馏分结构与性质,分析了它们对煤制油产业发展的影响。文章指出国家绿色可持续发展需要低硫、低烯烃、低芳烃和高抗爆性能的交通运输燃料,需要降低柴汽比,增产航空煤油。煤基油品的硫氮等有害物质含量低、清洁性很好。除了MTG汽油外,煤基油品的柴汽比过高,需要与石油产品协同发展以满足我国未来的成品油市场需求。费托合成工艺能够直接生产优质柴油和航空喷气燃料油组分,是煤制油产业发展的主要技术路线;煤直接液化工艺所产汽煤柴油馏分性质均不理想,需要持续改进提高;煤油共炼工艺在成品油质量方面弥补了煤直接液化工艺的不足,可作为一条新的煤制油途径。煤焦油加氢可以生产出质量指标达到或接近国Ⅵ标准的车用柴油调和组分,是一条高效利用煤炭加工过程副产品的煤制油技术路线。MTG汽油和DMM_n是优质汽油和柴油组分,能改善炼油企业成品油的柴汽比结构和交通运输燃料产品质量,应加大低成本工艺技术研发、扩大产能。     

An overview of new approaches to deep desulfurization for ultra-clean gasoline, diesel fuel and jet fuel

This review discusses the problems of sulfur reduction in highway and non-road fuels and presents an overview of new approaches and emerging technologies for ultra-deep desulfurization of refinery streams for ultra-clean (ultra-low-sulfur) gasoline, diesel fuels and jet fuels. The issues of gasoline and diesel deep desulfurization are becoming more serious because the crude oils refined in the US are getting higher in sulfur contents and heavier in density, while the regulated sulfur limits are becoming lower and lower. Current gasoline desulfurization problem is dominated by the issues of sulfur removal from FCC naphtha, which contributes about 35% of gasoline pool but over 90% of sulfur in gasoline. Deep reduction of gasoline sulfur (from 330 to 30 ppm) must be made without decreasing octane number or losing gasoline yield. The problem is complicated by the high olefins contents of FCC naphtha which contributes to octane number enhancement but can be saturated under HDS conditions. Deep reduction of diesel sulfur (from 500 to <15 ppm sulfur) is dictated largely by 4,6-dimethyldibenzothiophene, which represents the least reactive sulfur compounds that have substitutions on both 4- and 6-positions. The deep HDS problem of diesel streams is exacerbated by the inhibiting effects of co-existing polyaromatics and nitrogen compounds in the feed as well as H₂S in the product. The approaches to deep desulfurization include catalysts and process developments for hydrodesulfurization (HDS), and adsorbents or reagents and methods for non-HDS-type processing schemes. The needs for dearomatization of diesel and jet fuels are also discussed along with some approaches. Overall, new and more effective approaches and continuing catalysis and processing research are needed for producing affordable ultra-clean (ultra-low-sulfur and low-aromatics) transportation fuels and non-road fuels, because meeting the new government sulfur regulations in 2006–2010 (15 ppm sulfur in highway diesel fuels by 2006 and non-road diesel fuels by 2010; 30 ppm sulfur in gasoline by 2006) is only a milestone. Desulfurization research should also take into consideration of the fuel-cell fuel processing needs, which will have a more stringent requirement on desulfurization (e.g., <1 ppm sulfur) than IC engines. The society at large is stepping on the road to zero sulfur fuel, so researchers should begin with the end in mind and try to develop long-term solutions.     

特征化学反应增强的吸附法燃油深度脱硫

我国的商品燃油虽已经过加氢脱硫处理,但汽油的总硫含量仍有数百mg/L,柴油更高达1000～2000 mg/L,使车辆尾气成为我国城区空气的主要污染源。鉴于加氢精制后残存的硫化物以噻吩及其衍生物为主,本文采用介孔中发生的在强酸催化下与甲醛的缩合反应作为增强吸附的机理,使噻吩类硫化物得以脱除。与氧化/吸附法配合,可使市售燃油的总硫含量降到15 mg/L以下。     

A PM 2.5 Inlet Impactor Designed for a High Flow Application

Two potential strategies for reducing diesel emissions are exhaust aftertreatment and the use of reformulated or alternative fuels. Little is yet known about the impact on ultrafine particle emissions of combining exhaust aftertreatment with such increasingly common fuels. This paper reports ultrafine particle size distribution measurements for a study in which the impact of such fuels on emissions from a heavy duty diesel engine employing different aftertreatment configurations was evaluated. Eight different fuels were tested: Canadian No. 1 and No. 2 diesel; low sulfur diesel fuel; two different ultra low sulfur diesel fuels (< 30 ppm S); Fischer-Tropsch diesel fuel; 20% biodiesel blended with ultra low sulfur diesel fuel; and PuriNO_x?. The fuels were tested in combination with four exhaust configurations: engine out, diesel oxidation catalyst (DOC), continuously regenerating diesel particle filter (CRDPF), and engine gas recirculation with CRDPF (EGR-DPF). In general, aftertreatment configuration was found to have a greater impact on ultrafine particle size distributions than fuel composition, and the effects of aftertreatment tended to be uniform across the entire particle size distribution. Steady state tests revealed complex behavior based on fuel type, particularly for PuriNOx. This behavior included bimodal particle size distributions with modes as low as 8–10 nm for some fuels. Unlike previous results for gravimetric PM from this study, no significant correlation for ultrafine emissions was found for fuel properties such as sulfur level.     

Combined PFPD–FID assessment of sulfur in liquid fuels

A pulsed flame photometric detector (PFPD) was calibrated using standard sulfur compounds present in gasoline and diesel fuels, in combination with a flame ionization detector (FID). Gasoline range standards were added to a hydrocarbon mixture simulating gasoline, with individual sulfur concentrations from 3 to 80 ppm. Diesel range standards were added to a low sulfur commercial diesel fuel, with sulfur concentrations from 10 to 100 ppm. In gasoline, both the chromatographic areas calculated with the linearized signal (data points elevated to a given power), and reported by the instrument were regressioned with the sulfur mass concentrations. In both cases the areas were normalized with the FID areas to reduce deviations. Results were better when using the linearized signal. Only the normalized areas calculated with the linearized signal can be used in the case of the diesel, due to significant peak coelution. Individual calibration coefficients were calculated for each standard, but overall coefficients can be used safely in each of the boiling ranges. The compliance of regulations about sulfur was verified in commercial fuels and the different sulfur compounds were inspected. The simultaneous combined FID-PFPD use allows adding the sulfur to the conventional analysis of liquid fuels (e.g. composition, simulated distillation).     

High quality diesel via the Fischer–Tropsch process – a review

The Fischer–Tropsch (FT) synthesis is used to produce chemicals, gasoline and diesel fuel. The FT products are predominantly linear, hence the quality of the diesel fuel is very high, having cetane numbers of up to 75. Since purified synthesis gas is used in the FT process all the products are S‐ and N‐free. In this review the production of syngas and the various options used in the FT process (reactors and catalyst types, and high and low temperature operation) are discussed. The best FT option for producing high quality diesel is using cobalt‐based catalyst in slurry phase reactor, gearing the process for high wax production and then selectively hydrocracking the wax to diesel fuel. The overall diesel pool has a high cetane number, the aromatic S and N contents are zero and the exhaust emissions are significantly lower than for standard diesel fuels. © 2001 Society of Chemical Industry     

CuO‐filled aminomethylated polysulfone hybrid membranes for deep desulfurization

CuO‐filled aminomethylated polysulfone hybrid membranes were prepared for sulfur removal from gasoline. The as‐prepared membranes were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X‐ray diffraction (XRD). The separation performance of the hybrid membranes was evaluated by pervaporation (PV) separation of n‐heptane/thiophene binary mixture. CuO‐filling leads to a decrease in permeation flux. The sulfur‐enrichment factor increased first and then decreased with increasing CuO loading, and it is worth noting that there is a rebound in enrichment factor above 8 wt % CuO loading. Influencing factors such as nitrogen content, feed temperature, sulfur content, and various hydrocarbons on membrane PV performance were also evaluated. Permeation flux of 23.9 kg·μm·m^?2·h^?1 and sulfur‐enrichment factor of 3.9 can be achieved at 4 wt % CuO loading in PV of n‐heptane/thiophene binary mixture with 1500 μg·g^?1 sulfur content. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3718–3725, 2013     

AlCl3-磺酸树脂催化噻吩类硫化物与异丁烯烷基化硫转移反应

选择以噻吩的甲基取代衍生物(包括2-甲基噻吩、3-甲基噻吩及2,5-二甲基噻吩)与异丁烯的烷基化反应为模型反应,考察了经三氯化铝气相固载法改性的CT175树脂催化剂催化噻吩的甲基取代衍生物与烯烃的烷基化反应性能. 研究结果表明,负载AlCl3的CT175树脂催化剂对催化2-甲基噻吩、3-甲基噻吩及2,5-二甲基噻吩与异丁烯的烷基化硫转移反应均具有很高的活性,在80℃、常压、异丁烯(与氮气按摩尔比1:1配制的混合气)流量5.0 mL/min、液体(含模型硫化物2-甲基噻吩、3-甲基噻吩及2,5-二甲基噻吩的浓度分别为2033, 2045, 1543 mg/g的苯溶液)质量空速为2.5 h-1的条件下,上述5种模型硫化物均接近于完全转化. 对催化剂的活性稳定性进行了为期30 d的连续考察,结果表明,3种模型硫化物的烷基化转化率均高于99%,且催化剂活性未见下降趋势.     

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.     

硫化物在OTA催化剂上催化转化性能

考察了催化裂化(FCC)汽油中硫化物和模型硫化物在OTA(Olefin To Aromatics)催化剂上的催化转化性能.结果表明FCC汽油硫化物总脱硫率为86.3 %,其中,硫醚和四氢噻吩的转化率都达到100 %,硫醇硫转化率96.6 %,噻吩硫转化率78.8 %,烷基噻吩转化率85.8 %,苯并噻吩转化率81.4 %.3-甲基噻吩在OTA催化剂上的转化产物中含有小分子(噻吩),异构硫化物(2-甲基噻吩),以及大分子异构硫化物(如2,5-二甲基噻吩、2,4-二甲基噻吩和2,3-二甲基噻吩).烷基噻吩和苯并噻吩硫化物在OTA催化剂上脱硫反应网络一方面含有直接加氢脱硫反应,另一方面经历歧化、异构化和裂解等反应.     

The impact of catalytic materials on fuel reformulation

Fuel reformulation has been seeded by the growing consciousness of the potential damages mankind was causing to the ecosystem and to itself. Fuel reformulation means that fuels are defined on a chemical composition base with additional engine-technology related standards rather than on pure performance bases. These standards, which are getting more and more stringent, can be met by different leverages, mainly catalysts and processes operating conditions.

This survey reviews the contribution of catalytic materials to the production of cleaner fuel components through some significant examples selected from scientific and technical literature. Having described the trends in automotive fuels quality, production of gasoline and diesel pool components is discussed relating the required properties to the material active site configuration, i.e. acidity/basicity, structural parameters, physical constraints. While distinctions are made between pathways leading to gasoline and those leading to diesel, sulfur removal is faced on a more generalized approach.     

表面活性剂对微生物脱除柴油中有机硫的影响

采用假单胞菌(Pseudomonas delafieldii)菌株R-8和红色红球菌(Rhodococcus erythropolis)菌株N1-36研究了加氢精制柴油脱硫工艺，两株菌脱除柴油中有机硫的活性相近. 添加表面活性剂能提高菌株对柴油的脱硫率；当Tween80存在、搅拌转速为250 r/min时，菌株R-8最高可脱除硫含量<300 mg/L的柴油中72%的有机硫；但当硫含量超过1000 mg/L时，微生物脱硫率极低.     

Oleochemicals as a fuel: Mechanical and economic feasibility

The status of vegetable oils as diesel fuel substitutes is currently dubious. Although it is fair to consider them as short-term emergency fuels (or, more desirably, low proportion supplements to diesel fuels), they present mechanical problems in long-term use that have not yet been solved. It is preferable to use these oils blended in small proportions with diesel fuels. Indirect-injection diesel engines have had fewer problems than direct-injection engines, whether the tests were performed with pure vegetable oil fuel or with vegetable oil/diesel fuel blends. The economic prospect for these fuels is not promising. In general, they are not and have not been economical alternatives to diesel fuel. Exceptions appear to have occurred recently in Brazil and the Philippines where low local prices for vegetable oils combined with high petroleum prices encouraged officials to use low proportion vegetable oil/diesel fuel blends. Nonetheless, current and long-term trends in petroleum and oilseed prices indicate that these fuels will probably not be price competitive within the near future. Emergency disruption of petroleum supplies completely changes the economic situation. Vegetable oils would be worth much more as a fuel during disruptions than otherwise; thus incentives could be strong to include these oils in the fuel supply, diverting them from the food supply.     

Sulfur specificity in the bench‐scale biological desulfurization of crude oil by Rhodococcus IGTS8

Biological removal of organic sulfur from petroleum feedstocks may offer an attractive alternative to conventional thermochemical treatment due to the mild operating conditions and greater reaction specificity afforded by the nature of biocatalysis. Previous investigations have either reported the desulfurization of model sulfur compounds in organic solvents or gross desulfurization of crude oil without data on which sulfur species were being removed. This study reports initial sulfur speciation data for thiophenic sulfur compounds present in crude oil which may be used as a guide both as to which species are treated by the biocatalyst investigated as well as to where biocatalyst development is needed to improve the extent of biological desulfurization when applied to whole crudes. Biodesulfurization of two different crude oils in the 22–31 ° API specific gravity range with total sulfur contents between 1 and 2% is demonstrated in 1‐dm³ batch stirred reactors using wild type Rhodococcus sp IGTS8. While analysis of the crudes before and after biodesulfurization did not reveal a decrease in total sulfur, GC–MS did reveal significant (43–99%) desulfurization of dibenzothiophenes (DBT) and substituted DBTs. Fractionation of the whole crude, followed by analysis using gas chromatography–sulfur chemiluminescence detection (GC–SCD) of the aromatic fraction of the Van Texas crude oil, demonstrated a reduction of sulfur in this fraction from 3.8% to 3.2%. This research indicates that IGTS8 may be capable of biodesulfurization of refined products such as gasoline and diesel whose predominant sulfur species are dibenzothiophenes. Further biocatalyst development would be needed for effective treatment of the spectrum of sulfur‐bearing compounds present in whole crudes.     

Modeling of the Adsorptive Desulfurization of Diesel Fuel in a Fixed‐Bed Column

Adsorptive desulfurization enables the attainment of ultra‐low sulfur content in hydrocarbon fuels by removing the refractory sulfur compounds, which are difficult to remove in hydrodesulferization (HDS) processing when sulfur concentrations below 10 mg kg^–1 must be attained. In this work, diesel fuel was desulfurized by adsorption using activated carbon as an adsorbent and the adsorption was carried out in a fixed‐bed column. The output sulfur content of less then 0.7 mg kg^–1 was achieved for the lowest flow rate of 1.0 cm³min^–1 and the highest bed depth of 28.4 cm at 50 °C. In all the experiments, at least one output sample contained less then 10.0 mg kg^–1 of sulfur with a longest achieved breakthrough time of 11.8 h. A mathematical model of the fixed‐bed adsorber was applied to describe the kinetics and to estimate the breakthrough curves. The model equations included a differential material balance for a liquid phase and a mass transfer rate expression. The ability of the model to fit the experimental data was shown to be satisfactory.     

Emission Reduction of Regenerative Fuel Powered Co-Generation Plants with SCR- and Oxidation-Catalysts

Since the beginning of combustion engine development in this recent century various different fuels have been successfully tested. Diesel engines have been adapted to fuels made from mineral oils because of the rising importance and the cheapness in comparison to other fuels. On the other hand, it is possible to burn regenerative fuels in engines and achieve some significant advantages in comparison to fossil diesel fuel. This is, for example, a closed carbon dioxide (CO₂) cycle which causes no green house effect. It is possible to extract oil from various seeds like rapeseed. It is also possible to burn used oil from the food processing industry or waste grease and oil from food recycling companies. The great advantages: (1) food recycling oils can produce energy instead of use as animal food, and (2) as nobody knows exactly the consistency of the collected oils, poisonous pollution is possible. These regenerative fuels can be burned without any further processing in special adapted diesel engines, for example an Elsbett engine, or in precombustion engines with large swept volumes. Most researchers focused on operating diesel engines with regenerative fuels and reducing the emissions caring only about regulated exhaust components. In comparison to these studies it is necessary to learn more about the emissions beyond the exhaust regulations. Additionally emission reduction is possible by using an SCR-catalyst (selective catalytic reduction) to reduce the NO₂ combined with an oxidation-catalyst which reduces any kind of oxidisable emissions. The TU München, Lehrstuhl für Energie- und Umwelttechnik der Lebensmittelindustrie, operates a small co-generation plant with the ability of analysing the standard emission components (CO, NO₂, HC, particles, CO₂, O₂) and unregulated components (SO₂, NH₃, polycyclic aromatic hydrocarbons (PAH), aldehyde, ketone). The emissions show some significant differences in comparison to fossil diesel fuel which is caused by the diversity of each fuel. Results of an investigation on four different fuels (wastefat methyl ester (WME), rapeseed methyl ester (RME), rapeseed oil and diesel fuel) burned in a small co-generation plant with a SCR- and oxidation-catalyst will be presented. A comparison to the emissions before and after the catalysts will be shown additionally to the results of the different reduction potential of diesel fuel, methyl ester or untreated oils. The combination of regenerative fuel and catalyst shows good potential for reducing the emissions. Furthermore the use of regenerative fuels is a sustainable production of energy with an overall efficiency of almost 90%. Regenerative fuels based on vegetable oils and waste fat are a valuable form of energy and have some significant advantages in comparison to diesel fuel, like an almost closed carbon dioxide cycle, rapid biological decomposition and lower CO, HC and particle emissions. Regenerative fuels should also meet minimum standards discussed in the paper to avoid the risk of engine damage and to reduce emissions.     

Effects of olefin on adsorptive desulfurization of gasoline over Ce(IV)Y zeolites

Effects of olefin on adsorptive deep desulfurization of gasoline over Ce(IV)Y zeolites have been studied via a FT-IR spectrometry and a fixed-bed adsorption technique at room temperature and atmosphere pressure by using model fuels containing thiophene and 1-octene as model compounds. The adsorptive selectivity for thiophene decreases significantly as the concentration of 1-octene increases. The difference in the FT-IR spectra between the Ce(IV)Y zeolite samples adsorbing the model fuels with and without 1-octene can be attributed to the stronger adsorption interactions of 1-octene with the Ce(IV)Y zeolite than those for thiophene. For minor content (500 µg/g) of thiophene and 1-octene, the FT-IR spectra show that the Ce(IV)Y zeolites have the preference to adsorb thiophene rather than 1-octene. However with the content of 1-octene increasing in the model fuel up to 150 mg/g, 1-octene can be adsorbed on the Ce(IV)Y zeolites remarkably, resulting in a descending adsorptive selectivity of the Ce(IV)Y for removing thiophene from the model fuel.