柴油馏分加氢脱硫动力学及反应器研究进展

当前各国环保法规对柴油中硫的质量分数的限制越来越严格。催化加氢脱硫是实现柴油低硫化的重要途径,动力学和新反应器的研究受到了研究者的广泛关注。本文介绍了柴油馏分中两种典型的难脱除含硫化合物二苯并噻吩和4,6-二甲基二苯并噻吩在各类催化剂上加氢脱硫的反应路径,比较了这两种模型含硫化合物的直接脱硫（DDS）和先加氢再脱硫（HYD）路径相对快慢的影响因素。详细综述了假1级、假2级、快慢1级、n级、L-H以及抑制剂H2S存在下的动力学模型在描述二苯并噻吩类模型化合物及真实油品的加氢脱硫过程中的研究现状,介绍了神经网络在柴油加氢动力学和脱硫率预测方面的研究进展。还对催化精馏、并流-逆流滴流床、两相床反应器等新型加氢脱硫反应器的最新发展作了综述,展望了加氢脱硫动力学及反应器的研究方向和面临的挑战。     

馏分油浆态床加氢处理研究: II FCC柴油加氢工艺条件及动力学研究

对FCC柴油在浆态床柴油加氢催化剂SP25上的加氢工艺条件进行了优化,并考察了加氢脱硫（HDS）和加氢脱氮（HDN）动力学。结果表明,提高反应温度、提高反应压力、增加催化剂的加入量、延长反应时间都能提高催化剂的加氢精制活性,最佳的FCC柴油浆态床加氢工艺条件为,温度350℃、压力6MPa、催化剂加入量6%、反应时间2h。催化剂循环使用性能的考察结果表明,SP25催化剂具有良好的活性稳定性。动力学研究结果表明,FCC柴油的加氢脱硫反应过程可以分为两个阶段。第一阶段为较易脱除的苯并噻吩类（BTs）硫化物的加氢脱硫反应,反应活化能为70.00kJ/mol;第二阶段为较难脱除的二苯并噻吩类（DBTs）硫化物的加氢脱硫反应,反应活化能为85.65kJ/mol。FCC柴油HDN反应的活化能为79.91kJ/mol。烷基取代的二苯并噻吩类硫化物（特别是DMDBTs）是加氢精制反应中最难脱除的含杂原子（S或N）烃类化合物。     

工业NiW/Al2O3催化剂上二苯并噻吩的加氢脱硫动力学

以二苯并噻吩(DBT)为含硫模型化合物, 在高压滴流床反应装置中,考察了工业NiW/Al2O3催化剂（RN-10）的加氢脱硫(HDS)动力学规律,研究了氢分压（1.5 MPa～4.5 MPa）、氢油体积比（150~700）、液体质量空速(15 h-1~60 h-1）、反应温度（280 ℃~380 ℃）等对DBT的HDS反应结果的影响。结果表明,当氢分压和氢油体积比较大时,两者变化对DBT的转化率基本无影响;温度对DBT的转化率影响较大,提高温度可有效提高DBT的转化率,随着温度的升高,DBT转化率的增加逐渐变缓。采用2级平推流反应动力学模型对不同温度实验数据进行了拟合,求得了不同温度的表观反应速率常数,模型的相关系数>0.989。活化能计算结果表明,RN-10催化剂在高反应温度区(>330 ℃)的DBT的HDS活化能明显低于较低温度时的活化能,分别为13.4 kJ/mol和121.4 kJ/mol。对于RN-10催化剂,不可单纯地通过提高反应温度来大幅度提高HDS转化率。     

Support effects on the chemical property and catalytic activity of Co-Mo HDS catalyst in sulfur recovery

Effects of carbon nanotubes (CNT) and alumina (γ-Al2O3) supports on the catalytic activities of hydrodesulfurization (HDS) process over CoMo catalyst have been studied. XRD results indicated that the main active phases in CNT and γ-Al2O3 supported Co-Mo catalysts are MoO2 and MoO3, respectively. The TPR results reveal that the reduction peak temperatures of the active species on CNT supported Co-Mo catalyst is lower than those on alumina supported Co-Mo catalyst, indicating that the CNT supports favor the r...     

制备参数对β-Mo2N0.78催化剂加氢脱硫活性影响的研究

以N2与H2的混合气为反应气，和三氧化钼进行多段程序升温反应，制得一种β晶型的氮化钼。以噻吩为模型化合物的常压加氢脱硫反应表明，β-Mo2N0.78具有较强的加氢脱硫活性和强的抗硫化性能。同时考察了预还原、反应温度以及氮化末温、升温速率、反应气中N2-H2比及氮化时间等制备参数对β-Mo2N0.78加氢脱硫活性的影响。研究发现，β-Mo2N0.78的加氢脱硫活性在320 ℃～400 ℃随反应温度的升高增强，而还原预处理会降低催化剂的活性。氮化末温、氮化时间、反应气组成和升温速率等制备参数对催化剂的活性有明显的影响：随着氮化末温的升高，所制备的催化剂催化加氢脱硫活性降低；在氮化末温恒温较长时间，可以引起制备催化剂的加氢脱硫活性下降；存在最佳的反应气组成和各段升温速率。小晶粒的β-Mo2N0.78具有强的加氢脱硫活性。     

Investigation of the HDS kinetics of dibenzotiophene and its derivatives in real gas oil ??

Summary The hydrodesulfurization (HDS) of dibenzothiophene (DBT), 4-methyl-dibenzothiophene (4 M-DBT), 4,6-dimethyldibenzothiophene (4,6 DM-DBT) and 4,6-diethyldibenzothiophene (4,6 DE-DBT) as real gas oil components on NiMo/Al₂O₃ catalyst was investigated. On the basis of the first order rate constants of HDS of the individual sulfur compounds calculated by both integral and differential evaluations the reactivities of the investigated compounds decreased in the order DBT >> 4 M-DBT > 4,6 DE-DBT ? 4,6 DM-DBT. Additionally, results showed that product inhibition during HDS does not take place.     

催化柴油中硫化物的气相-原子发射光谱分析方法及应用

 建立了催化柴油馏分中各种硫化物类型分布的气相 原子发射光谱分析方法,考察了条件对各种硫化物分离的影响,定性(或归类)了催化柴油中的130多个硫化物,计算了程序升温条件下各种硫化物的保留指数,为不同实验室的定性比较和方法的转让提供了依据。硫化物中的硫在2mg/L～1000mg/L时其质量浓度与峰面积呈较好的线性关系,相关系数达0 997。几种硫化物(苯并噻吩、4 甲基苯并噻吩、二苯并噻吩、4 甲基二苯并噻吩、4,6 二甲基二苯并噻吩)6次测定所得峰面积的相对标准偏差均小于5 0%。当信噪比(S/N)为3时,测得苯并噻吩硫的检出限为0 1mg/L。     

Ultra Deep Hydrodesulfurization of Gas Oils Over Sulfide and/or Noble Metal Catalysts

Deep hydrodesulfurization (HDS) of sterically hindered sulfur compounds in gas oils will require enhanced hydrogenation activity to hydrogenate the aromatic rings of the sulfur compounds. Although H₂S is known to inhibit the direct HDS route for most of the sulfided catalysts, its promotion to the hydrogenation and subsequent HDS was newly observed for unsupported MoS₂. This promotion suggests that ultra deep HDS over sulfide catalysts can be achieved along with high metal loading, minimal support-metal interactions and optimal dependence on the Ni species. On the other hand, the strong hydrogenation activity of sulfur-tolerant noble metal catalysts suggests that ultra deep HDS as well as deep aromatics saturation can be achieved. This paper discusses recent catalytic approaches for ultra deep HDS using conventional sulfide catalysts and/or noble metal catalysts, such as the newly developed Pd-Pt/Yb-USY zeolite catalyst.     

Kinetic studies of Heck coupling reactions using palladacycle catalysts: experimental and kinetic modeling of the role of dimer species.

Experimental kinetic studies of the coupling of p-bromobenzaldehyde (1) with butyl acrylate (2) using the dimeric palladacycles complex (4) with chelating nitrogen ligands were carried out together with kinetic modeling using a reaction rate expression based on the mechanism shown in Scheme 2. The oxidative addition product of 1 was found to be the resting state within the catalytic cycle. The formation of dimeric Pd species external to the catalytic cycle helped to rationalize a non-first-order rate dependence on catalyst concentration. Theoretical modeling showed how the relative concentrations of the different intermediate species within the catalystic cycle can influence the observed rate dependence on Pd concentration. It was shown how conventional kinetic studies may give reaction orders in substrates which differ from those which would be observed under practical synthetic conditions. Comparison between phosphine- and nonphosphine-based palladacycles suggests that they follow the same reaction mechanism. The role of water in accelerating the initial formation of the active catalyst species is noted.     

Ni2P加氢脱硫催化剂

环境法规对硫氧化物脱出的限制日益严格以及原油品质的不断下降,使得有必要研发高效的加氢脱硫催化剂。Ni2P由于具有优异的加氢脱硫活性和稳定性,引起了广泛的关注。本文综述了Ni2P加氢脱硫催化剂的特性、反应活性相、制备方法、改进和加氢脱硫活性等方面的研究进展。在Ni2P中存在两种不同的初始活性位,四面体几何构型的Ni(1)初始活性位在加氢脱硫反应中参与直接脱硫反应,四方锥几何构型的Ni(2)初始活性位则与催化剂的高加氢活性有关。在加氢脱硫反应中,催化剂表面生成的NixSyP相被认为是真正的活性相。制备Ni2P的方法主要是程序升温还原和液相合成。载体、助剂和络合剂对Ni2P活性相的形成和催化剂的活性有重要影响。相比于商用硫化物催化剂,Ni2P催化剂对噻吩、二苯并噻吩和4,6-二甲基二苯并噻吩均表现出更高的加氢脱硫活性。     

Kinetics of thiophene hydrodesulfurization over a supported Mo–Co–Ni catalyst

In this study, the kinetics of thiophene (TH) hydrodesulfurization (HDS) over the Mo–Co–Ni-supported catalyst was investigated. Trimetallic catalyst was synthesized by pore volume impregnation and the metal loadings were 11.5 wt % Mo, 2 wt % Co, and 2 wt % Ni. A large surface area of 243 m²/g and a relatively large pore volume of 0.34 cm³/g for the fresh Mo–Co–Ni-supported catalyst indicate a good accessibility to the catalytic centers for the HDS reaction. The acid strength distribution of the fresh and spent catalysts, as well as for the support, was determined by thermal desorption of diethylamine (DEA) with increase in temperature from 20 to 600 °C. The weak acid centers are obtained within a temperature range between 160 and 300 °C, followed by medium acid sites up to 440 °C. The strong acid centers are revealed above 440 °C. We found a higher content of weak acid centers for fresh and spent catalysts as well as alumina as compared to medium and strong acid sites. The catalyst stability in terms of conversion as a function of time on stream in a fixed bed flow reactor was examined and almost no loss in the catalyst activity was observed. Consequently, this fact demonstrated superior activity of the Mo–Co–Ni-based catalyst for TH HDS. The activity tests by varying the temperature from 200 to 275 °C and pressure from 30 to 60 bar with various space velocities of 1–4 h^?1 were investigated. A Langmuir–Hinshelwood model was used to analyze the kinetic data and to derive activation energy and adsorption parameters for TH HDS. The effect of temperature, pressure, and liquid hourly space velocity on the TH HDS activity was studied.     

Studies of Surface Sulfidation and Distribution of Sulfur on Cu-ZnO Catalysts

The changes in the surface areas of copper and zinc oxide have been measured to evaluate the individual rates of sulfur coverage of each of these phases during catalyst exposure to sulfur-containing gas. Zinc oxide surface areas have been measured by CO₂ adsorption and copper surface areas by measurement of the nitrogen formed by exposure to nitrous oxide. The surface areas of both components decreased exponentially with increasing exposure time to the sulfur-containing gas. The zinc oxide component is more sulfur-resistant than copper. This is attributed to either kinetic limitation or the more stable surface sulfides of zinc.     

气相色谱-原子发射光谱联用技术测定柴油中硫化物

采用气相色谱－原子发射光谱（GC－AED）联用技术对柴油中硫化物进行了定性定量研究，考察了柴油加氢脱硫处理前后硫化物的变化及不同柴油原料硫化物的分布情况。结果表明，1＃柴油可定性出33类硫化物，经加氢脱硫处理后，1－1＃和1－2＃样品硫含量可由1497mg/L分别降到165.1mg/L和90.4mg/L，平均脱除率为89.0%和94.0%。其中噻吩或苯并噻吩的脱除率为100％；C1二苯并噻吩的肿除率为90.0%和96.2%;C2二苯并噻吩的脱除率为80.6%和91.7%；C3二苯并噻吩的脱除率为72.6%和84.4%；C4二苯并噻吩的脱除率为79.0%和90.3%;C5或C6二苯并噻吩的脱除率为58.4%和68.4%；未知硫化物脱除率95.7%和97.9%。噻吩类脱除率视取代基的大小、个数和取代位置的不同脱除率不同；不同原料 总硫和各种硫化物含量差别很大，应根据其硫化物的分布特点，有针对性地研制开发加氢脱硫的催化剂及选择合适的加工工艺。     

银离子修饰的介孔磷钨酸/二氧化硅催化剂氧化脱硫性能研究

采用银修饰介孔磷钨酸/二氧化硅（mesoporous HPW/SiO₂）催化剂,并研究了其在模拟柴油和真实柴油氧化脱硫反应中的催化性能。通过银修饰介孔HPW/SiO₂,结合银离子对有机硫化物的选择吸附性和HPW对有机硫化物的催化氧化活性,以达到选择氧化脱硫的目的。模拟柴油分别采用石油醚、苯、1-辛烯和二苯并噻吩配制,当银离子与HPW的摩尔比为2时,催化剂具有最高的选择催化氧化活性。采用N₂ 吸附-脱附、XRD、UV-vis和EDS表征了银修饰的介孔HPW/SiO₂催化剂,结果表明,银物种分散均匀且以Ag⁺形式存在。真实柴油的脱硫研究表明,相比介孔HPW/SiO₂催化剂,修饰的催化剂介孔Ag₂-HPW/SiO₂脱硫率提高了4.6%,初始硫含量为1800×10^-6的直馏柴油能被脱除至228×10^-6,脱硫率为87.3%。介孔Ag₂-HPW/SiO₂催化剂具有良好的再生性能,经再生处理后,Ag的损失量极少,其三次脱硫率达到84.8%。     

Catalytic adaptive recognition of thiol (SH) and selenol (SeH) groups toward synthesis of functionalized vinyl monomers

An unprecedented sustainable procedure was developed to produce functionalized vinyl monomers H(2)C═C(R)(FG) starting from a mixture of sulfur and selenium compounds as a functional group donor (FG = S or Se). The reaction serves as a model for efficient utilization of natural resources of sulfur feedstock in oil and technological sources of sulfur/selenium. The catalytic system is reported with amazing ability to recognize SH/SeH groups in the mixture and selectively incorporate them into valuable organic products via wastes-free atom-economic reaction with alkynes (HC≡CR). Formation of catalyst active site and the mechanism of the catalytic reaction were revealed by joint experimental and theoretical study. The difference in reactivity of μ(1)- and μ(2)-type chalcogen atoms attached to the metal was established and was shown to play the key role in the action of palladium catalyst. An approach to solve a challenging problem of dynamically changed reaction mixture was demonstrated using adaptive tuning of the catalyst. The origins of the adaptive tuning effect were investigated at molecular level and were found to be governed by the nature of metal-chalcogen bond.     

黏胶废液对福建无烟煤水蒸气催化气化的动力学和补偿效应

采用黏胶废液为催化剂,对福建尤溪无烟粉煤在常压热分析仪中的水蒸气催化气化动力学进行了研究。在850℃～950℃测定了黏胶废液催化剂添加量（NaOH浓度为计算基准）从0～12%时的碳转化率随气化时间的变化,表明黏胶废液具有提高碳转化率和气化速率的作用,同时确定了该黏胶废液催化剂的加载饱和浓度。基此得出的尤溪无烟粉煤水蒸气催化气化反应动力学符合缩芯模型,并给出相应的动力学参数。进而分析表明,该催化气化过程存在明显的补偿效应,最后给出黏胶废液对尤溪无烟粉煤水蒸气催化气化包括补偿效应的动力学方程。     

柠檬酸对Ni2P/TiO2-Al2O3催化剂加氢脱硫性能的影响

采用溶胶-凝胶法制备了TiO2-Al2O3复合载体,以柠檬酸(CA)为络合剂采用浸渍法制备了Ni2P负载的TiO2-Al2O3复合载体催化剂,并用X射线衍射(XRD)、N2吸附比表面积测定、H2程序升温氢还原(H2-TPR)、程序升温氧化(TPO)、X射线光电子能谱(XPS)技术对催化剂的结构和性质进行了表征,考察了CA/Ni摩尔比对在Ni2P/TiO2-Al2O3催化剂上进行的二苯并噻吩(DBT)加氢脱硫(HDS)性能的影响.结果表明:适量的CA可以丰富催化剂的孔道,提高催化剂的比表面积.当n(CA)/n(Ni)=2:1时,催化剂的比表面积达到126.75m2·g-1,与不加CA时相比,提高了57.05m2·g-1.调节n(CA)/n(Ni)能够改善活性相的分布,改变活性相的种类;引入CA使Ni和P前驱体的还原温度明显降低,促进活性相Ni2P的生成,一定程度上能够抑制催化剂表面炭的形成和沉积,提高其稳定性.n(CA)/n(Ni)=2:1时,催化剂具有最好的加氢脱硫活性,在360°C,3.0MPa,氢油比为500(V/V),液时体积空速为2.0h-1的条件下,二苯并噻吩转化率为99.5%,可将模拟油中硫含量由2%(w)降低到0.01%(w).     

Hydrodesulfurization of Selective Catalytic Cracked Gasoline

Hydrodesulfurization (HDS) reaction of catalytic cracked gasoline (CCG) on Co–Mo/γ-Al₂O₃ was investigated in detail to make clear the important factors for deep HDS of CCG. A CCG containing 229 ppm sulfur and 30.4 vol% olefins was used in this study. Eleven alkylthiophenes and 2 alkylbenzothiophenes, 3 alkylthiacyclopentanes, and 2 disulfides were identified in this CCG by means of GC-AED analyses. In the reaction at 220 °C and 1.6 MPa using a conventional flow reactor of bench pilot scale, these sulfur compounds were hydrodesulfurized, whereas thiols were produced from H₂S and olefins. The reactions of thiophene HDS, isoolefin and n-olefin hydrogenation (HG) were studied to clarify the active sites on the catalyst. First, the effect of H₂S on the reaction was examined. The HG of n-olefin as well as thiophene HDS was inhibited by H₂S, while the HG of isoolefin was promoted. The effects of Co on these three reactions were also examined over the catalysts with different Co/(Co + Mo) ratios. Thiophene HDS was promoted by Co, while isoolefin HG was little affected and n-olefin HG was largely retarded. From these examinations, three types of active sites for thiophene HDS, isoolefin HG and n-olefin HG were proposed. Oligomers of isoolefins were found in the isoolefin hydrotreated product. The possibility of improving the HDS selectivity by carbonaceous deposit was investigated for HDS reactions of CCG and model compounds. The coking pretreatment was carried out on the catalyst and each reaction was examined. HDS selectivity (higher activity for HDS and lower activity for olefin HG) on CCGHDS was improved. Relative deactivation was in the following order, isoolefin HG > thiophene HDS > n-olefin HG. Pyridine modification (i.e. pyridine injection at 150 °C and partial pyridine desorption at 300 °C) was investigated on thiophene and olefins reaction. Thiophene HDS was little affected. Olefin HG and thiol production reaction were strongly inhibited. Improvement of HDS selectivity was observed in the reactions of CCG after pyridine modification. Improvement of HDS selectivity by pyridine modification was considered to result from the selective deactivation of the active sites for olefin reactions (hydrogenation and thiol production).     

High-efficiency process for production of sulfur from metallurgical sulfur dioxide gases

Process in which sulfur is produced from a gas containing 25–55% SO₂ was studied in order to evaluate the real efficiency of the catalytic post-reduction of sulfur dioxide in a pilot unit with gas flow rate of up to 1.2 nm³ h^–1 at the following temperatures (°C): thermal stage 850–1100, catalytic conversion 350–570, and Claus reactor 219–279. It was found that the conversion at 400–550°C and space velocity of 1600 h^–1 on AOK-78-57 promoted aluminum oxide catalyst provides full processing of organosulfur compounds (CS₂ and COS). The temperature dependence of the conversion/generation of hydrogen sulfide on AOK-78-57 catalyst corresponds to the equilibrium model. It was experimentally confirmed that the homogeneous reduction of sulfur dioxide gas with methane at T ≈ 1100°C, with catalytic post-reduction at 400–550°C and subsequent Claus-conversion of the reduced gas at 230–260°C, provide a sufficiently deep (by 92–95%) general processing of sulfur dioxide gas to sulfur.     

钒氧化物催化剂上NH3-SCR反应物的吸附-脱附

对于钒氧化物负载型催化剂在NH3-SCR过程中的反应机理和动力学已有较多研究。研究表明反应气体在催化剂表面的吸附-脱附过程对于SCR催化反应具有重要意义。本文概述了钒氧化物催化剂载体和表面物种在催化反应中的作用机理,以及H2O、SO2对NH3-SCR反应的影响,重点阐述了各种气相反应物的吸附形式以及反应作用机理。