An optimization of process parameters for deep desulfurization of model fuel by ZSM-5/ZnO photocatalyst using response surface method

One of the major factors that causes air pollution are sulfur oxides) SO_x) that exiting from vehicles exhaust by combustion of fossil fuel. Although hydrodesulfurization method has always been the option in oil refineries to reduce sulfur contents, but it is almost impossible to meet stringent new environmental regulation by this method. The Achilles heel of the conventional method is weakness in removing aromatic sulfur recalcitrant compounds. In the present research, photocatalytic oxidative desulfurization (PhOD) based on the ZSM-5/ZnO catalyst is developed. n-Decane as the model fuel and benzothiophene (BT) and dibenzothiophene (DBT) as the sulfur compounds are used. Then by the response surface method the optimum conditions were developed. The result indicates that catalyst with 6%wt Zn/ZnO, 45 min reaction time, UV power of 32 watts and catalyst to fuel ratio of 2 gr/L is able to remove BT and DBT with efficiency of 86.1% and 74.0%, respectively.     

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。     

Modification and characterization of NaY molecular sieve by Cr3+ and its adsorptive denitrogenation from model fuel

Abstract

The CrY, which was modified by Cr³+ from NaY, was confirmed by characterization with FT-IR, XRD, N₂ adsorption-desorption, and it was used to adsorb quinoline from model fuel. The suitable modification conditions were modified twice by 0.5?mol/L cobalt nitrate solution at 40?°C. The FT-IR spectra indicated the disappearance of 1147?cm^?1 peak and the blue shift of 1024?cm^?1, implying that Cr³+ had exchanged Na⁺ and successfully incorporated into the framework of NaY. The static denitrogenation experimental results indicated that the adsorption between quinoline and CrY was the coordination adsorption and π complex adsorption. The suitable conditions were 30?min at room temperature and the adsorption temperature had minor effect on denitrogenation. The kinetic model of CrY adsorbing quinoline belonged to Langmuir and Freundlich adsorption model.     

NiW/Al2O3上喹啉对二苯并噻吩 加氢脱硫的抑制作用及反应动力学

 以二苯并噻吩(DBT)为含硫模型化合物，在中压滴流床反应装置中研究了工业NiW/Al₂O₃催化剂(RN-10)上喹啉对DBT加氢脱硫(HDS)的抑制作用，考察了喹啉质量分数(0.5%~1.5%)、反应温度(290~380℃)、反应压力(4.0~5.6MPa)对DBT的HDS的影响。结果表明，喹啉的存在对于DBT的HDS反应有很强的抑制作用，且喹啉浓度越高，抑制作用越大；对DBT的先加氢饱和再脱硫路径(HYD)的抑制作用比对直接脱硫路径(DDS)更大；提高反应温度对DDS和HYD路径的脱硫活性均有提升，但由DDS路径生成联苯的选择性降低；较高反应压力有利于提高HYD路径产物的选择性。采用带有氮化物吸附(中毒项)的拟一级反应动力学模型对实验数据进行拟合，得到不同喹啉质量分数下DBT的HDS表观反应速率常数。经检验，模型计算结果与实验结果吻合。     

甲苯和吡啶对Ag/TiO2-NaY吸附脱硫性能的影响

 以溶胶-凝胶法制备了TiO₂-NaY(TY)分子筛载体,采用浸渍法制备了Ag/TiO₂-NaY(AgTY)吸附剂,并用X射线衍射、傅里叶变换红外光谱和X射线光电子能谱技术对吸附剂进行了表征。在固定床吸附床上考察了含氮化合物和芳香族化合物对AgTY选择性吸附噻吩（TP）和苯并噻吩（BT）性能的影响,并研究了其吸附机理。结果表明,AgTY吸附剂中TiO₂主要以锐钛矿型存在,与NaY相比,TY分子筛的骨架结构并未发生明显的改变;在吸附温度50℃时,AgTY吸附剂对噻吩、苯并噻吩的穿透硫容分别为0.45%和0.63%;对噻吩模拟油,吡啶对吸附脱硫影响比甲苯的影响大,而对于苯并噻吩模拟油,甲苯的影响比吡啶的影响大。噻吩类硫化物与AgTY吸附剂之间主要以π络合及S—M配位作用机理吸附。     

Oxidative Desulfurization of Fuel Catalyzed by Amphiphilic Peroxomolybdate

Abstract

The oxidation of sulfur-containing compounds (benzothiophene [BT], dibenzothiophene [DBT], and 4,6-dimethyldibenzothiophene [4,6-DMDBT]) was studied in an emulsion system composed of model oil, hydrogen peroxide, and an amphiphilic catalyst [C₇H₇C₁₂H₂₅(CH₃)₂N]₂Mo₂O₃(O₂)₄. The most suitable conditions were suggested: n (DBT): n (catalyst): n (H₂O₂) = 1:0.1:10, at 60°C for 2 hr. Under optimized experimental conditions, the removal of DBT, BT, and 4,6-DMDBT could reach 98.0, 94.0, and 62.7%, respectively. The oxidation product sulfones could be readily separated by extraction. The catalyst could be recycled five times without a significant decrease in catalytic activity.     

杂原子介孔分子筛Ba-MCM-41的制备及其吸附脱氮性能

采用水热合成法制备了介孔MCM-41和Ba-MCM-41分子筛,并利用X射线衍射、N2吸附-脱附、傅里叶变换红外光谱对介孔MCM-41和Ba-MCM-41分子筛进行了表征.将Ba-MCM-41分子筛用于对模拟油的静态吸附脱氮试验,结果表明,当模拟油用量为15 mL时,较适宜的吸附脱氮条件为分子筛用量0.3 g、吸附温度...     

氮化物对NiW/Al2O3上DBT和4,6-DMDBT加氢脱硫反应活性的影响

以碱性氮化物喹啉和非碱性氮化物吲哚为杂质,考察DBT和4,6-DMDBT在NiW/Al2O3上的加氢脱硫活性和选择性。结果表明,氮化物对DBT和4,6-DMDBT的加氢脱硫反应存在截然不同的作用结果。氮化物存在条件下,DBT的加氢脱硫反应通过直接脱硫路线活性的提高得到改善,而4,6-DMDBT的加氢脱硫反应由于氮化物的存在受到抑制。这主要是因为氮化物在加氢活性位上的吸附抑制了硫化物在加氢活性位上的吸附,从而抑制了加氢路线的进行。但氮化物使催化剂表面结构重排使硫化物氢解活性提高成为可能,此时硫化物的分子大小和分子结构起到了决定性作用。DBT由于分子体积小、通过S原子与氢解活性位接触容易而使氢解活性提高,4,6-DMDBT由于分子体积大和4、6位的位阻效应以及氮化物的拥塞效应使氢解活性随N含量的升高而减小。     

磁性γ-Al2O3固载BMIMPF6离子液体吸附剂的吸附脱硫选择性

 采用内凝胶法（油中成型法）制备超顺磁性 γ-Al₂O₃颗粒。用浸渍的方法在磁性γ-Al₂O₃表面负载BMIMPF₆ (1-丁基-3-甲基咪唑六氟磷酸, 1-Butyl-3-methylimidazolium hexafluorophosphate)得到离子液体改性的BMIMPF₆/γ-Al₂O₃吸附剂。分别用XRD、SEM和VSM等手段对磁性γ-Al₂O₃和BMIMPF₆/γ-Al₂O₃的晶体结构、表面形貌和磁性能进行表征。以噻吩(T)、苯并噻吩(BT)和二苯并噻吩(DBT)的正辛烷溶液为模型化合物,考察了BMIMPF₆/γ-Al₂O₃对这3种硫化物的饱和吸附量和吸附选择性。结果表明,随着BMIMPF₆负载量的增加,BMIMPF₆/γ-Al₂O₃对T的饱和吸附量下降,对BT和DBT的饱和吸附量先增大后减小。与T相比的DBT的吸附选择性S_DBT/T随着BMIMPF₆负载量增加而增大;与BT相比的DBT的吸附选择性S_DBT/BT随着BMIMPF₆负载量增大先增加,当BMIMPF6负载量达到磁性γ-Al₂O₃的10%(质量分数)后,S_DBT/BT不再变化。采用10%BMIMPF₆/γ-Al₂O₃对柴油样品吸附脱硫重复使用4次后,仍可将柴油的硫质量分数从69.0 μg/g下降到24.7 μg/g。     

新型离子液体对苯并噻吩、二苯并噻吩的萃取性能研究

离子液体是一种优良的绿色溶剂，可应用在石油油品脱硫工艺中，以降低燃油对环境的污染。本文合成了五种新型离子液体[bmim]AlCl4, [bmin]TBP, [bmim]BeS, [bmim]PF6, [bmim]BF4，并将他们用于油品脱硫的模拟体系。比较了五种离子液体萃取性能，结合分子间作用力的理论和价键理论阐述了离子液体萃取脱硫的机理。结果表明，离子液体的萃取性能与其阴离子结构有关，其中[bmim]TBP适宜作萃取脱硫溶剂。苯并噻吩(BT)、二苯并噻吩(DBT)在模拟油品中的初始浓度分别为1000μg/g时，用[bmim]TBP经四级错流萃取和5级逆流萃取，含硫量均能降至50μg/g以下。     

变色硅胶对模拟柴油中喹啉或吡啶的吸附行为研究

采用XRD、FT-IR、低温N2吸附-脱附和NH3-TPD等方法对硅胶和变色硅胶进行了较详细的表征。XRD和FT-IR表征结果表明硅胶和变色硅胶都具有非晶态结构。硅胶和变色硅胶的平均孔径分别为18.46 nm和1.80 nm,BET比表面积分别为437.86 m2/g和623.39 m2/g,孔体积分别为0.972 4 cm3/g和0.344 2 cm3/g。NH3-TPD的表征结果表明变色硅胶的酸性远大于硅胶的酸性。研究了氧化铝、硅藻土、硅胶及变色硅胶对模拟柴油中的喹啉的吸附脱除效果,结果表明,变色硅胶吸附脱除喹啉的效果远远好于其它吸附剂,较强的酸性大大增强了变色硅胶吸附脱除碱性氮化物喹啉的能力。进一步研究了变色硅胶吸附脱除模拟柴油中的喹啉或吡啶的动力学,结果表明：喹啉和吡啶在变色硅胶上的吸附等温线均属于S型;采用Freundlich（F型）和Langmuir（L型）方程对喹啉吸附数据拟合所得到的R值几乎相同,说明变色硅胶吸附喹啉的动力学符合L型和F型混合模型;对吡啶数据拟合所得Freundlich方程的R值远大于Langmuir 方程的R值,说明变色硅胶吸附吡啶更接近于F型模型。     

Absorptive Denitrogenation of Diesel Oil Using a Modified NaY Molecular Sieve

Y molecular sieve, modified by NH₄⁺, Zn²⁺, Cu²⁺, or Cr³⁺, were characterized by X-ray diffraction, infrared spectrum, and nitrogen adsorption, and used to adsorb denitrogenation from model fuel containing quinoline and diesel oil. The molecular size of quinoline, calculated by using density functional theory, was 7.116×5.002 Å, implying that it does not access easily to 7.4 Å microporous pores of Y molecular sieve. The adsorption denitrogenation of CrY was the best due to some mesoporous pores, followed by CuY, ZnY, and NH₄Y, implying that the absorption denitrogenation related to valence state metal ion, the better adsorption denitrogenation performance, the higher valence of metal ions. The basic nitrogen removal of diesel oil on CrY, CuY, ZnY, or NaY is 56.58%, 60.16%, 37.41%, and 23.72%, respectively.     

Main and Interactive Effects of Polyaromatic Sulfur Heterocyclic Compounds on Growth and Biodegradation Efficiencies of Bacillus sphaericus HN1: Modeling and Statistical Analysis

Bioremediation is an effective technique to remediate soil and water contaminated with a mixture of recalcitrant polyaromatic sulfur heterocyclic (PASH) compounds. Based on two levels of full factorial design, a statistical design of experiments was used in this study to investigate the interactive effects of three PASHs; thiophene (Th), benzothiophene (BT), and dibenzothiophene (DBT) on their biodegradation in multisubstrate batch process using Bacillus sphaericus HN1. Kinetic modeling was performed to estimate the rate of biodegradation of each PASH in single-, binary-, and tertiary-substrate systems. Biodegradation of BT, DBT, and total PASHs follows the first order kinetic reaction in the single- and multisubstrate batch systems, while biodegradation of Th follows the first-order kinetic reaction, in single-substrate system, but second-order kinetic reaction in multisubstrate batch system. Four linear interaction regression models were estimated and validated to describe the interactive effect of the three PASHs on their biodegradation. Statistical analysis of the results in the form of analysis of variance and Student t test indicated significant role played by the main effects of Th, BT and DBT on their biodegradation (p < 0.01). Th and the interactive effect between Th and DBT has statistically significant negative effect on DBT removal (p = 0.0665). However, DBT expresses higher statistically significant positive effect on total PASHs removal than that of Th (p = 0.0178 and p = 0.026, respectively), but their interaction has a significantly negative effect (p = 0.0143).     

直馏柴油和焦化柴油中含氮化合物类型分布

采用中性硅胶柱分离、富集直馏柴油和焦化柴油中的含氮化合物,进一步用酸改性硅胶柱将含氮化合物分离成碱性含氮化合物和中性含氮化合物,利用GC-MS定性,结合含氮化合物的GC保留特性和沸点分布规律,确定直馏柴油和焦化柴油中含氮化合物的类型。结果表明,直馏柴油中中性含氮化合物占总含氮化合物的质量分数在70%以上,主要是苯并咔唑类含氮化合物;焦化柴油中含氮化合物包括吡啶类、苯胺类、吲哚类、喹啉类和咔唑类等含氮化合物,其中中性含氮化合物的含量比碱性含氮化合物稍高,占总含氮化合物的质量分数在50%以上。     

存在4,6-DMDBT时喹啉、吲哚和咔唑在Ni-Mo加氢催化剂上加氢脱氮自抑制作用

 在S质量分数(w(S))为849μg/g的4,6-DMDBT甲苯溶液中,分别添加不同量的喹啉、吲哚和咔唑,采用Ni-Mo加氢催化剂,在280℃、总压力2 MPa、V(H2)/V(Oil)为300、液时空速5 h-1的条件下进行加氢实验,考察4,6-DMDBT存在时喹啉、吲哚和咔唑在Ni-Mo加氢催化剂上加氢脱氮自抑制作用。结果表明,添加喹啉当N质量分数达到455 μg /g时没有出现加氢脱氮自抑制现象,脱氮率在3种氮化物中最低。喹啉的部分加氢产物四氢喹啉是产生自抑制的主要物质。添加吲哚和咔唑在实验的N质量分数范围内均出现加氢脱氮自抑制现象,其部分加氢产物二氢吲哚、吲哚氮烷基取代产物N-乙基-吲哚、四氢咔唑是产生自抑制的主要物质。咔唑的加氢脱氮自抑制作用比吲哚低。     

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。     

催化裂化柴油中氮化物分布规律的研究

采用气相色谱-原子发射光谱联用技术，对几种不同催化裂化（FCC）柴油中的含氮化合物进行了研究。结果表明：FCC柴油中氮化物包括苯胺类、喹啉类、吲哚类和咔唑类；吲哚类和咔唑类氮含量占总氮的90％以上；咔唑类是含量最多的氮化物。     

吡啶基离子液体与噻吩类化合物相互作用的理论研究

采用密度泛函理论考察了N-丁基吡啶醋酸盐离子液体(［BPY］［Ac］)和噻吩(TS)、苯并噻吩(BT)、二苯并噻吩(DBT)、萘(NAP)的相互作用,并进行了NBO和AIM分析。［BPY］［Ac］离子对最稳定的结构表明,［Ac］阴离子的O原子优先与吡啶环上C2—H2发生氢键作用。在分子水平上,NBO和AIM分析证实了TS、BT、DBT、NAP和［BPY］［Ac］中的阴离子发生氢键作用、与吡啶环发生π…π相互作用,阴、阳离子均影响脱硫效果。但NAP与阴离子的氢键作用、与吡啶环π…π相互作用较弱,造成NAP与［BPY］［Ac］相互作用能小,而DBT则优先吸附在［BPY］［Ac］离子液体上。     

Study on a new desulfurization method based on imitating ionic liquids for light diesel oil

A simulated light oil consisting of model sulfur compounds of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) and straight-run light diesel oil fractions as solvent was employed for desulfurization tests imitating silver-salt method for ionic liquids (ILs). Under the conditions of a nitrogen atmosphere, reaction temperature of 303 K, reaction time of 24 h, the effects of different alkylating agents and amount of agent on the sulfur removal were investigated in more details. The results showed that when ratio of bromoethane (CH₃CH₂Br) to sulfur is 80: 1 (mol/mol) and ratio of potassium tetrafluoroborate (KBF₄) to sulfur 30: 1 (mol/mol), the desulfurization yield were 72.6%.     

以四硫代钼酸铵为前躯体制备的MoS2和Ni-Mo-S催化剂加氢脱硫反应性能研究

以四硫代钼酸铵为前躯体制备二硫化钼（MoS2）催化剂,并引入Ni金属作为助剂合成Ni-Mo-S催化剂,以二苯并噻吩质量分数为0.8%的十氢萘溶液为模型化合物,考察了这两种催化剂的加氢脱硫性能,同时考察喹啉的存在对于这两种催化剂加氢脱硫反应性能的影响。结果表明：Ni助剂的引入增强了催化剂的加氢脱硫反应活性;喹啉的存在抑制了加氢脱硫反应活性,在MoS2上,喹啉的存在同时抑制了催化剂的预加氢脱硫和直接脱硫两条路径的活性,而在Ni-Mo-S催化剂上,喹啉只抑制了预加氢脱硫路径的活性,而直接脱硫路径的活性反而得到提高;喹啉的存在对于Ni-Mo-S催化剂活性的抑制作用明显小于MoS2,说明Ni助剂的引入有效地提高了硫化钼催化剂的耐氮性能。