Deep Desulfurization of Light Oil Using the Imitating Silver Salt ILs Method

Abstract

Sulfides in oils are harmful in many ways, in particular, deterioration of the environment resulting from sulfur dioxide. A novel desulfurization process for light oil has been investigated. A mixture consisting of benzothiophene (BT), dibenzothiophene (DBT), and oil fractions (235°C–270°C) refined by acid–alkali treatment was employed for alkylation desulfurization tests in a nitrogen atmosphere. The results showed that at a reaction temperature of 30°C, ratio of bromoethane (CH₃CH₂Br) to sulfur of 30:1 (mol/mol), ratio of silver tetrafluoroborate (AgBF₄) to sulfur of 6:1 (mol/mol), and reaction time of 16 hr, the desulfurization yield could reach 76.3%.     

模拟轻质油品烷基化沉淀法脱硫

 以精制油品为溶剂,苯并噻吩(BT)、二苯并噻吩(DBT)、4,6—二甲基二苯并噻吩(4,6—DMDBT)作为模型含硫化合物组成模拟轻质油品,以卤代烃和四氟化硼钾为烷基化剂对模拟轻质油品烷基化沉淀脱硫进行了研究。考察了反应温度、反应时间、烷基化剂种类及其用量、溶剂等因素对总硫脱除的影响。实验结果表明：在反应温度30℃,CH3CH2Br：S=80：1(mol/mol),KBF4：S=30:1(mol/mol),反应时间在24h的条件下,总硫脱除率可以达到76.5%。     

Oxidative-extractive desulfurization of liquid fuel using stannous chloride-acetic acid mixture as catalyst

Present study reports catalytic oxidative-extractive desulfurization (COEDS) of model oil (dibenzothiophene (DBT) dissolved in iso-octane) using an acid mixture (composed of Lewis acid and organic acid (glacial acetic acid)) as catalyst and inorganic oxysalt, potassium dichromate, as oxidant. A series of acid mixtures were prepared by mixing different amount of Lewis acids (SnCl₂, CaCl₂ or CuCl₂) in specific amount of acetic acid and tested for the removal of sulfur from model oil. SnCl₂, which performed best as a Lewis acid, was used in further studies. Effect of Lewis acid to sulfur (molar) ratio was studied in the range of 1–5. Effects of other parameters i.e. oxidant to sulfur (O/S) molar ratio, temperature and time on desulfurization efficiency were also investigated. Fourier transform infrared (FTIR) spectroscopy of SnCl₂-CH₃COOH mixture, model oil (before COEDS), raffinate and extract layers was carried out to understand the removal mechanism. Apparent activation energy for COEDS process with SnCl₂-CH₃COOH system was calculated as 11.65 kJ/mol. At the optimized conditions of oxidant to sulfur molar ratio (O/S = 2:1) and Lewis acid to sulfur molar ratio (SnCl₂/S = 5:1), maximum 61.3% sulfur removal was observed from model oil containing 1000 ppm of sulfur at 308 K.     

Kinetics of desulfurization by electrochemical oxidation in an emulsifying electrolyte

Diesel with S content 624.4 µg/g was directly used, and a constant current of 500 mA was proposed in this work. Emulsification as an enhancement method was used to enhance the interphase mass transfer. After emulsifying electrochemical oxidation–extraction, the sulfur content of diesel decreased to 8.1 µg/g and the desulfurization efficiency reached 98.71 %. On comparingwith the non-emulsifying electrochemical oxidation–extraction, it has a highly efficient deep desulfurization.

The analysis also found that the effect of emulsion and non-emulsion extraction desulfurization process on electrochemical oxidation has great difference under the same operating conditions, and parameters such as the order, reaction rate and activation energy of the two kinds of oxidation desulfurization reaction were studied. The results showed the oxidative desulfurization reaction is the first reaction. When the temperature reached T₂, the oxidation rate constant of the emulsion/non-emulsion system was 0.0199 min^?1 and 0.0179 min^?1, respectively. When the temperature reached T₁, the oxidation rate constant of the emulsion/non-emulsion system was 0.0375 min^?1 and 0.0346 min^?1, respectively. According to Arrhenius' law, the apparent activation energy of sulfur compounds in the raw oil is E_a (emulsion) = 6.9783 kJ/mol and E_a (non-emulsion) = 9.1826 kJ/mol, respectively.     

One-Step Oxidation–Desulfurization of FCC Gasoline Catalyzed by Tungstophosphoric Acid

Abstract

The sulfur compounds in fluid catalytic cracked (FCC) gasoline were removed with a one-step oxidation–extraction method. Tungstophosphoric acid (HPWA), tert-butyl hydroperoxide (TBHP), and ethanol were used as catalyst, oxidant, and solvent, respectively. TBHP has a higher desulfurization degree and oil yield than hydrogen peroxide, and HPWA exhibited higher desulfurization degree and oil yield than the other kinds of acids. The one-step process has a higher desulfurization degree than the two-step process. The optimal operating parameters were obtained as follows: the catalyst amount was 5 wt%, the mole ratio of oxygen in the oxidant to the sulfur in the gasoline (O/S) was 10, the reaction temperature was 60°C, and the reaction time was 2 hr. Under these conditions, the desulfurization degree and yield of oil were both in the range of 85–90%.     

钨酸铋的制备及其催化氧化脱硫性能

催化氧化脱硫法因反应条件温和、可高效深度脱除燃料油中二苯并噻吩(DBT)类硫化物,是一种有潜力的非加氢脱硫方法。以钨酸钠和五水合硝酸铋为原料,采用直接沉淀法和水热法制备钨酸铋(Bi₂WO₆)。采用傅里叶变换红外光谱(FT-IR)、X-射线衍射(XRD)、电子扫描显微图像(SEM)、能量色散X射线光谱(EDS)和N₂等温吸附-脱附等分析方法对其结构、组成、表面形貌和比表面积进行表征。分别以DBT、苯并噻吩(BT)、4-甲基-二苯并噻吩(4-MDBT)和4,6-二甲二苯并塞吩(4,6-DMDBT)为代表性硫化物,以正癸烷为溶剂、十四烷为内标物配制含硫模拟油,以制备的Bi₂WO₆为催化剂、过氧化氢(H₂O₂)为氧化剂、乙腈(CH₃CN)为萃取剂构建催化氧化脱硫体系,系统地考察了其催化氧化脱硫性能。结果表明,水热法制备的Bi₂WO₆(BWO-2)表现出较优的脱硫性能。在反应温度...     

Mo/γ-Al2O3催化剂制备及催化氧化船用燃料油脱硫

以γ-Al2O3为载体,采用浸渍法制备了负载型催化剂Mo/γ-Al2O3。利用X-射线衍射仪(XRD)、N2-吸附脱附、H2程序升温还原(H2-TPR)等手段对催化剂进行了表征。分别以二苯并噻吩(DBT)、4,6-二甲基二苯并噻吩(4,6-DMDBT)、苯并噻吩(BT)和噻吩(Th)的正辛烷溶液作为模拟燃料油,异丙苯过氧化氢(CHP)为氧化剂,评价了Mo/γ-Al2O3的催化氧化脱硫(ODS)活性;并将Mo/γ-Al2O3催化剂应用于馏分型船用燃料油氧化脱硫。结果表明：Mo/γ-Al2O3催化剂对不同结构的含硫化合物的催化脱硫活性由大到小的顺序为DBT、4,6-DMDBT、BT、Th;Mo/γ-Al2O3上的Al2(MoO4)3为主要活性中心;在反应温度80 ℃、氧/硫原子比5、催化剂用量1.0 g时,硫质量分数为1.6%的船用燃料油的脱硫率可达到82.6%,硫质量分数可以降至0.3%,达到了最新船用燃料油标准硫质量分数低于0.5%的规定。催化剂重复使用10次后,催化剂活性没有明显的降低。     

Hydrodesulfurization of Dibenzothiophenic Compounds in a Light Cycle Oil

Abstract

A hydrotreating study was conducted in a bench-scale hydroprocessing reactor, over a wide range of operating conditions of industrial interest, to look in detail at hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and aromatics hydrogenation, and the interactions between these reactions. This article focuses on preliminary HDS results and some general findings. The feed used was a fluid catalytic cracking (FCC), light cycle oil (LCO) and the catalyst was a commercial NiMo/Al₂O₃ hydrotreating catalyst. The HDS results were analyzed by focusing on individual dibenzothiophenic sulfur species in the feedstock and products. Some of those species were positively identified while others were grouped into classes. It was observed that above 385°C, the assumption of irreversible pseudo-first-order reaction is not applicable for both total sulfur removal and sulfur removal of individual dibenzothiophenic species. All HDS reactions involving dibenzothiophenic structures reach a point where they are affected by hydrogenation/dehydrogenation equilibrium. Among all the 14 difficult-to-remove sulfur species identified in this work 4-methyldibenzothiophene (4-MDBT) has the highest HDS reactivity, while 4,6-dimethyldibenzothiophene (4,6-DMDBT) has the lowest HDS reactivity attributable to steric hindrance by methyl substitutes at 4 and 6 positions. It was also found that H₂S significantly reduces the reaction rates of HDS. However, this effect reaches a plateau as H₂S concentration in the gas phase increases. At low reactor temperature, HDS rates linearly increase with the increase in hydrogen partial pressure. At high temperature it reaches the limit of complete conversion.     

Ni-MoO3/SG的制备及其催化氧化脱硫性能

以Ni-MoO₃为活性组分、硅胶（SG）为载体,采用溶胶-凝胶法合成Ni-MoO₃负载量（w）为n%的催化剂n%-Ni-MoO₃/SG（n＝2.0,5.0,7.0）。利用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、扫描电镜（SEM）、N₂吸附-脱附及X射线光电子能谱（XPS）对催化剂的结构进行表征。以Ni-MoO₃/SG为催化剂、H₂O₂为氧化剂、乙腈为萃取剂研究了模拟油中的二苯并噻吩（DBT）的脱除,分别考察了Ni-MoO₃负载量、反应温度、催化剂用量、氧硫比（O/S）、萃取剂加入量及硫化物类型对脱硫效果的影响。试验结果表明,在最佳反应条件下Ni-MoO₃/SG对DBT、4,6-二甲基二苯并噻吩（4,6-DMDBT）、苯并噻吩（BT）模拟油的脱硫率分别为99.4%,93.6%,99.1%,且回收利用5次后对DBT模拟油的脱硫率仍可达到93.7%。     

超声波辐照浸渍法制备MnO2/γ-A12O3催化剂及其柴油催化氧化脱硫性能

 分别采用超声波辐照浸渍法和普通浸渍法制备了MnO₂/γ-Al₂O₃催化剂,运用电感耦合等离子体原子发射光谱（ICP-AES）和X射线衍射（XRD）对催化剂进行表征,在空气-异丁醛-MnO₂/γ-Al₂O₃体系中评价其对加氢柴油的氧化脱硫催化性能,并考察了反应温度、异丁醛用量、空气流量、溶剂类型和剂/油体积比对柴油氧化脱硫反应的影响。结果表明,超声波辐照浸渍法制备的MnO₂/γ-Al₂O₃催化剂对柴油氧化脱硫的催化性能明显优于普通浸渍法制备的催化剂。最适宜的催化柴油氧化脱硫反应的条件为：乙腈为溶剂、加氢柴油30 mL、温度35℃、异丁醛20 mmol、空气流量0.06 L/min、超声波辐照浸渍法制备的MnO₂/γ-Al₂O₃催化剂0.08 g、剂/油体积比1/6和催化氧化时间10 min。在此条件下可将柴油硫质量分数从542μg/g 降至31μg/g,柴油脱硫率和回收率分别为94.3%和93.3%。     

N-甲基咪唑氟硼酸盐基低共熔溶剂的制备及其氧化脱硫性能

以N-甲基咪唑氟硼酸盐(［HMIM］BF4)和苯丙酸(C9H10O2)为原料合成了［HMIM］BF4/xC9H10O2(x=0.5、1、2)型低共熔溶剂(DESs);对其进行FT-IR、1H NMR和TGA表征分析;将［HMIM］BF4/0.5 C9H10O2低共熔溶剂作为萃取剂和催化剂、H2O2作为氧化剂脱除模拟油中的二苯并噻吩(DBT),分别考察了n(C9H10O2)/n(［HMIM］BF4)、反应温度、n(H2O2)/n(S)、低共熔溶剂的加入量和不同含硫化合物对脱硫率的影响。结果表明：在模拟油体积为5 mL、n(C9H10O2)/n(［HMIM］BF4)=0.5、反应温度为60 ℃、n(H2O2)/n(S)=8、反应180 min、［HMIM］BF4/0.5 C9H10O2的加入量为1.0 mL的最佳反应条件下,［HMIM］BF4/0.5 C9H10O2对DBT、4,6-二甲基二苯并噻吩(4,6-DMDBT)和苯并噻吩(BT)的脱硫率分别达98.4%、93%和89.6%;红外分析表明DBT与DESs之间存在较强的相互作用,可使DBT的结构发生畸变;在5次循环反应后,［HMIM］BF4/0.5 C9H10O2的脱硫率仍高达90.2%,表明其具有较高的稳定性。     

Synthesis of H_2WO_4/GO and Its Oxidative Desulfurization Activity

H_2WO_4/GO catalyst was synthesized by the immersion method and was characterized by using X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), and nitrogen adsorptiondesorption measurements(BET). The characterization results show that H_2WO_4 has been dispersed on GO(grapheme oxide). H_2WO_4/GO was used as catalyst in the oxidative desulfurization of dibenzothiophene(DBT), with H2 O2 acting as oxidant and acetonitrile acting as extraction agent. The experimental results show that the sulfur removal rate for DBT reach 99.2%, that for 4,6-dimethyldibenzothiophene(4,6-DMDBT) reach 95% and that for benzothiophene(BT) reach 42.8% under the optimal reaction conditions. Meanwhile, the recycled catalysts still exhibits good desulfurization performance after four operating cycles. The high activity and stability of catalysis is attributed to a small dose of H_2WO_4, which is highly dispersed inside the layers of GO. This desulfurization reaction follows the pseudo-first-order kinetics, and the apparent activation energy of the desulfurization reaction is 18.515 kJ/mol, which indicates that the H_2WO_4/GO used as desulfurization catalyst has demonstrated good desulfurization property for DBT.     

Optimization of Oxidative Desulfurization of Dibenzothiophene Using a Coordinated Ionic Liquid as Catalytic Solvent

Abstract

Oxidative desulfurization (ODS) of dibenzothiophene (DBT) in n-octane with hydrogen peroxide/acetic acid using a quaternary ammonium coordinated ionic liquid (IL) (C₄H₉)₄NBr · 2C₆H₁₁NO as catalytic solvent has been studied. The ODS mechanism by coordinated ionic liquid [(C₄H₉)₄NBr · 2C₆H₁₁NO] was also carried out. The sulfur-containing compounds in model oil were extracted into ionic liquid phase and oxidized to their corresponding sulfones by H₂O₂. The effect factors for desulfurization of model oil were investigated in detail by means of monofactorial and orthogonal experiments (L₁₆(4)⁴). The results showed that the desulfurization efficiency of model oil could reach 98.6% under the optimal conditions of oxidation time, oxidation temperature, molar ratio of H₂O₂/sulfur (O/S), and volume ratio of model oil to coordinated ionic liquid were 30 min, 50°C, 16, and 1, respectively. The influences to the desulfurization efficiency of DBT decreased in the following order: volume ratio of model oil to coordinated ionic liquid (C₄H₉)₄NBr · 2C₆H₁₁NO (V_{model oil}/V_IL) > molar ratio of O/S > oxidation temperature > oxidation time, according to extreme analysis of the orthogonal test. The coordinated ionic liquid (C₄H₉)₄NBr · 2C₆H₁₁NO can be recycled 5 times without a significant decrease in desulfurization.     

以磷钨酸/半焦为催化剂对模拟油氧化脱硫的研究

以双氧水为氧化剂、磷钨酸/半焦(HPW/Sc)为催化剂、N-甲基吡咯烷酮为萃取剂、Span60为乳化剂,对以苯并噻吩(BT)、二苯并噻吩(DBT)、 4,6-二甲基二苯并噻吩(4,6-DMDBT)为模型含硫化合物的模拟油进行氧化脱硫研究,考察磷钨酸负载量、氧化温度、氧化反应时间和模拟油中烯烃、芳烃和含氮化合物对含硫化合物脱除的影响。结果表明：催化剂的最佳磷钨酸负载量（w）为30%;在反应时间为60 min、反应温度为60 ℃、HPW/Sc2用量（w）为1.0%、Span60用量（w）为0.36%、n(H2O2)/ n(S)=3的条件下,DBT脱除率可达到99%,含硫化合物的氧化活性由大到小的顺序为DBT?4,6-DMDBT＞BT;模拟油中的苯可促进DBT脱出,而喹啉和环己烯则抑制DBT的脱除。     

乳酸基低共熔溶剂中钼酸铵催化氧化脱硫性能研究

以己内酰胺为氢键受体、乳酸为氢键供体,合成了乳酸基低共熔溶剂,通过傅里叶变换红外光谱和氢核磁共振波谱分析表征确定了己内酰胺和乳酸间的氢键作用。以二苯并噻吩（DBT）与正辛烷混合得到的模拟油（简称DBT模拟油）为原料,以乳酸基低共熔溶剂为萃取剂和助催化剂、过氧化氢（H₂O₂)为氧化剂、钼酸铵为催化剂进行氧化脱硫试验,考察反应温度、n(H₂O₂)/n(DBT)、钼酸铵加入量、剂油体积比及硫化物类型对模拟油脱硫率的影响,确定最佳反应条件：反应温度为70 ℃,反应时间为100 min,n(H₂O₂)/n(DBT)为6∶1,钼酸铵质量浓度为4 g/L,剂油体积比为1∶10。在最佳反应条件下,DBT模拟油、4,6-二甲基二苯并噻吩模拟油和苯并噻吩模拟油的脱硫率分别为100%,98%,78%。脱硫反应重复进行5次后,乳酸基低共熔溶剂对DBT模拟油的脱硫率仍可达到95%,具有较好的重复使用性能。     

裂解C5脱有机硫实验研究

针对炼油厂裂解C₅馏分脱除有机硫,对脱硫剂、最佳脱硫条件以及脱硫剂循环回收利用进行了研究。结果表明,质量分数5%复合胺溶液（TSC5）为最佳脱硫剂,在0.1 MPa、30℃、反应时间20 min和剂/油体积比0.3条件下,可使裂解C₅馏分的硫质量分数从106 μg/g降至8.7μg/g,脱硫率91.8%,收率99.4%。以洗涤水/油体积比1.5（其中循环再生水/油体积比1.3,去离子水/油体积比0.2）对脱硫后C₅馏分进行水洗,可将脱硫C₅馏分中的复合胺质量分数降至2 μg/g以下。在80℃、空速180 h^-1条件下,采用N₂汽提法对复合胺富液和洗涤水的混合液进行分离回收利用,其重新配制的TSC5脱硫剂的脱硫效果与新鲜剂相当。提出了裂解C₅深度脱有机硫的原则工艺流程。     

Desulfurization of Simulated Oils by Microwave Chemical Methods

Abstract

Microwave technology was introduced for the desulfurization of sulfurous crude oil and the influence of microwave processes on removing benzothiophene sulfur and bi-benzothiophene sulfur in simulated oils was studied in this article. The results manifested that the desulfurization efficiencies of BBPV, formylhydroperoxide and peroxyacetic acid for an oil sample (simulated oil 2) containing bi-benzothiophene were better than for the oil sample (simulated oil 1) containing benzothiophene. When dosages of BBPV increased from 0.5% to 4%, the desulfurizing efficiencies of simulated oil 1 and 2 were raised from 19.8% to 53.7%, and 48.0% to 64.2%, respectively. With the increase of temperature, the reaction order desulfurization of the simulated oils by microwave increased, and the rate of the microwave reaction increased. The desulfurizing efficiency increases along with the temperature in the same time.     

The Oxidation-Extraction Desulfurization of FCC Gasoline

Abstract

With increasing environmental concern and stricter regulations, sulfur content is restricted in a low range. So there are many studies on the desulfurization methods to light oils. The oxidation-extraction desulfurization method for light oils provided a prospective way to reduce the sulfur content. The effects of the oxidation-extraction system were studied in this article. The results showed that the best oxidation time is 25 min, the best proportion of oil, catalyst, and oxidant is 50:5:1, temperature nearly has no effect on the oxidation desulfurization. This research provided a good prospect for the industrial application of the oxidation-extraction desulfurization.     

炼厂轻烃吸附脱硫工艺研究

以降低炼厂轻烃的总硫含量为目标,使用四种吸附剂分别进行吸附脱硫实验,并考察吸附温度、体积空速(LHSV)、反应时间对脱硫效果的影响。实验结果表明TCN-2为四种吸附剂中脱硫效果较好的吸附剂,其最佳吸附条件为高温120℃,压力0.6MPa,体积空速1h-1～3h-1,反应时间16h。在此吸附条件下TCN-2脱硫率达到95%(质量分数)左右,脱硫后轻烃总硫含量降低至20μg/g～30μg/g。     

Oxidative Desulfurization of Fuel Oil: Modeling Based on Artificial Neural Network

Abstract

Oxidative desulfurization of fuel oil was investigated using a process consisting of oxidation and distillation steps. In the oxidation step, various organic carboxylic acid/H₂ O₂ systems, especially acetic acid/H₂ O₂, were used as oxidant. They oxidize both easy and refractory sulfur compounds and convert them into oxidized sulfur compounds. The oxidized sulfur compounds are finally removed from fuel oil by distillation in the presence of water. The sulfur content of fuel oil was decreased to levels as low as 20 ppm (up to 90%) in a short contact time, ambient temperature, and atmospheric pressure. The results showed that applying this process did not have any deleterious influence on the distillation characteristic, composition, and content of fuel oil that was examined. An artificial neural network, using back propagation (BP), was also utilized for modeling oxidative desulfuration process of fuel oil. The comparison between the output of ANN modeling and the experimental data showed satisfactory agreement.