噻吩脱硫过程中钒氧化物晶格氧的作用

以γ-Al₂O₃、VO₂和V₂O₅为催化剂,在连续固定床微反装置上、500℃下,考察了噻吩在常压下的脱硫反应过程,并进行了噻吩原位吸附红外光谱、XPS光电子能谱、XRD等表征。结果表明,在催化裂化反应条件下,采用具有单纯L酸中心的催化剂时,噻吩脱硫反应的转化率很低;采用具有单纯氧化-还原中心的催化剂时,噻吩可被氧化成CO、CO₂及SO₂,但转化率也较低;采用既具有酸中心又具有氧化 还原中心的V₂O₅时,由于酸中心和氧化-还原中心的协同作用,噻吩脱硫反应的转化率最高,H₂S和SO₂的产率也最高。催化裂化反应条件下,噻吩可以被钒氧化物的晶格氧氧化,同时V₂O₅与VO₂失去部分晶格氧被还原为V₂O₃等低价态产物;由于V₂O₅比VO₂活泼晶格氧数目多,较易被还原,因此噻吩脱硫反应的SO₂产率更高。V₂O₅表面存在的L酸中心Vⁿ⁺－O－V为噻吩的初始吸附中心,L酸中心与临近的V=O双键的作用促进了噻吩的氧化。     

催化裂化条件下噻吩在氧化钒上的反应机理研究

利用噻吩原位吸附红外光谱、常压连续固定床反应等研究手段，结合吡啶吸附程序升温脱附红外光谱、XPS光电子能谱等表征手段对噻吩与五氧化二钒的反应机理进行了初步研究。研究发现：500℃下，噻吩能够与V2O5发生氧化还原反应，噻吩被氧化成CO、CO2以及SO2，转化率可达到41．2％，同时V2O5的氧化数下降。V2O5表面存在少量B酸中心，这一特征使噻吩的反应产物中H2S的产率增加。     

Ni-Zn复合氧化物用于反应吸附脱除噻吩

采用均匀共沉淀法制备了Ni-Zn复合氧化物吸附剂,并在固定床上考察了预还原、吸附条件、模拟油的不同组分对其吸附脱硫性能的影响。结果表明,还原态的Ni是吸附剂的主要活性成分,吸附反应最适宜的温度和压力分别为673 K、1.0 MPa,模拟油中的烯烃组分对吸附剂脱硫性能的影响比芳烃的影响大。吸附剂在温度673 K、压力1.0 MPa、液时空速60 h^-1、氢气与模拟油的体积比为200（氢气体积为标准状态下的体积）时对含硫质量浓度100 mg/L的模拟油A的硫容为360 mg/g。噻吩首先在Ni原子上进行氢解生成H₂S,然后H₂S快速与ZnO结合生成ZnS。此外该吸附剂对原料有很好的适应性,并具有很好的再生性能。     

Effects of Reaction Temperature on Distribution of Aromatization Reaction Products of Lanlian FCC Gasoline

Abstract

By using Lanlian FCC gasoline as a feedstock, the effects of temperature on the product distribution, light oil compound (gasoline and diesel), off-gas, and liquefied gas were researched in a confined fluidized bed reactor. The experimental results showed the off-gas, liquefied gas, and coke conversion were slowly increased with increasing temperature; the gasoline conversion had a maximum with increasing temperature; the diesel conversion showed no change; the olefins conversion was increased with increasing temperature; the aromatics yield was increased from 390°C to 430°C and from 430°C to 490°C, respectively; and the FCC gasoline Research Octane Number (RON) increased value was increased almost linearly with increasing the temperature. Aromatization index (AI) was put up in order to judge the aromatization degree of the FCC gasoline. The method obtained provided technical instruction for the petroleum chemical plant.     

催化裂化汽油烷基化脱硫技术研究及进展

介绍了催化裂化汽油烷基化脱硫的特点及原理,综述了近年来国内外烷基化脱硫的工艺现状及脱硫催化剂的研究发展情况。认为烷基化脱硫具备了脱硫效率高、可降低油品烯烃含量且辛烷值损失小、操作费用低、投资设备少等优点,适合大力开展研究。     

Preparation of the complex metallic oxides additive for naphtha sulfur reduction in FCC

The M/USY/Al2O3/kaolinite sulfur reduction additive systems containing vanadium were prepared by different methods. The influence of the preparation methods, the active constituent forerunners, the vanadium content and the type of molecular sieves on sulfur reduction of fluid catalytic cracking （FCC） gasoline were studied by a small fixed bed. The results showed that when FCC catalyst was blended with the sulfur reduction additives prepared by the special method at the ratio of 95：5, the relative sulfur reduction rate reached 35% and there was little influence on distribution of the products and quality of the gasoline. The XRD analysis indicated that the Y molecular sieve crystal structure in the additives prepared by the specific method retained integrity.     

Effects of Reaction Condition on the Secondary Aromatization Reaction of Lanlian FCC Gasoline Products

By using Lanlian catalytic gasoline aromatization production as a feedstock, the effects of reaction conditions on the aromatization product yield, conversion, motor octane number (MON), research octane number (RON), and solvent product compound were researched in a confined fluidized bed reactor. The experimental results show that the changeable trend of secondary aromatization yield of Lanlian FCC gasoline are the same with FCC gasolines under the operation condition. Although the aromatics contents of FCC gasoline after the secondary aromatization are about 5%, MON value of production decreases and RON value of production remain no change and coke yield contents are very high. These show that the qualities of secondary aromatization of FCC gasoline are very poor.     

Study on Disproportionation Reaction of FCC Gasoline on Acid Catalyst

Based on the experimental data relating to the reaction of FCC gasoline on acid catalyst the analysis of product distribution, and composition of gasoline and diesel fractions have been analyzed. The occurrence of disproportionation reaction of FCC gasoline on acid catalyst and the network of disproportionation reaction have been identified. Study has also shown that different reaction temperatures can result in different pathways of disproportionation reactions on acid catalyst.     

用芳构化增强的反应吸附剂对催化裂化汽油改质的实验研究

用固相混捏法制备了耦合芳构化功能的反应吸附脱硫催化剂,研究了该催化剂对FCC汽油的改质性能。采用XRD和Py-IR表征了吸附剂的晶体结构和酸性特征,在高压微反装置上对其进行了活性评价,研究了吸附剂组成与工艺条件对FCC汽油改质的影响,结果表明:制备的吸附剂的活性组分由结晶良好的ZnO和ZSM-5分子筛及Ni活性组分构成。随着吸附剂中HZSM-5含量的增加,吸附剂酸性增强,芳构化反应功能提高。工艺条件对FCC汽油改质影响的研究表明,升高温度有利于芳构化反应的进行,但会加速催化剂的结焦失活,影响吸附剂的脱硫效果;增加压力可以使反应中的氢分压升高,减缓吸附剂的失活,有利于反应吸附脱硫,但不利于芳构化反应;增加氢油比可以抑制生焦,保持吸附剂活性,有利于反应吸附脱硫和芳构化反应,但会造成氢耗增加和烯烃饱和;空速增加可提高处理量,但由于原料与吸附剂的接触时间减少,导致反应物分子不能充分与吸附剂上的活性位反应,不利于芳构化和反应吸附脱硫反应的进行。采用研制的芳构化增强的反应吸附脱硫工艺及其吸附剂处理胜华FCC汽油的结果表明,在反应温度为425℃,反应压力为1.0 MPa,氢油比为200∶1,反应空速为6 h-1条件下,达到产物硫质量分数10μg/g以下时,异构烷烃和芳烃含量明显提高,可以较好的保持汽油辛烷值。     

催化裂化汽油加氢装置的安全联锁特点

介绍了国内某炼油厂新建催化裂化汽油加氢装置的安全联锁方案。针对国内一些催化裂化汽油加氢装置流程较简单,安全联锁系统设置薄弱的情况,设置了装置特有的安全联锁保护方案,如紧急泄压、反应器保护、机泵保护、密封保护和塔顶超压保护联锁方案。这些安全联锁方案的设置对于催化裂化汽油加氢装置的设计和安全操作具有重要作用,有效地降低了工艺过程中潜在的危险。大量的安全联锁系统会造成装置投资较高在设计过程中应结合国内具体情况,综合考虑安全、风险和投资等因素,系统分析装置内各联锁的安全等级并确定最终的安全联锁方案。     

FCC汽油深度脱硫技术研发现状概述

FCC汽油作为车用汽油产品硫含量的主要来源,其深度脱硫技术越来越受到人们的重视。介绍了FCC汽油硫化物的组成,同时以代表性技术为例介绍了选择性加氢脱硫、深度加氢脱硫结合辛烷值恢复组合技术、催化蒸馏脱硫技术和吸附脱硫技术等现代炼油工业所应用的主要的深度脱硫技术,并对四种不同的技术进行了对比分析。建议炼油企业根据自身的特点和现有装置的改扩建需要,从整体经济效益考虑,选择适当的脱硫技术。     

FCC催化剂钒氧化数对轻烯烃选择性的影响

Effects of vanadium on light olefins selectivity of FCC catalysts were investigated with vanadium having different oxidation numbers(hereinafter abbreviated as Oxnum).Molecular modeling studies showed that vanadium with low Oxnum could affect the chemical conversion of large-size hydrocarbon molecules.However,the vanadium deposited on equilibrium catalyst had high Oxnum because of the oxidation reaction taking place in the regenerator,so an activation method to reduce vanadium Oxnum named "selective activation" was introduced.It was proved by means of Electron Paramagnetic Resonance(EPR) and Temperature-Programmed Reduction(TPR) methods that the vanadium Oxnum was decreased,when the catalyst was activated.The molecular modeling studies are consistent well with the lab evaluation results.The light olefins selectivity of activated equilibrium catalysts was better than that achieved by the inactivated catalysts.Similar results were observed with the lab vanadium-contaminated catalyst.The light olefins selectivity of the catalyst was optimized when the vanadium Oxnum was close to 2(VO).     

Alkylation desulfurization of FCC gasoline catalyzed by glycerol-based solid acid catalyst

A novel high acid site density carbon-based solid acid catalyst was prepared and first applied in the FCC gasoline alkylation desulfurization. The catalyst was synthesized by a facile approach and characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), Brunauer–Emmett–Teller analysis (BET) and Gas Chromatography-Mass Spectrometer (GC-MS). The desulfurization performance of this solid acid catalyst was investigated and optimized.     

Modeling of the FCC Gasoline Desulfurization Process by Liquid Extraction with Sulfolane

Abstract

Extractive desulfurization of fluid catalytic cracking (FCC) gasoline with sulfolane was studied in a batch apparatus. The influence of three inlet parameters (temperature, inlet sulfur content, and solvent ratio) on the process response, that is, desulfurization efficiency, was investigated with the use of a Box-Behnken experimental design by response surface methodology. A mathematical model that can be used for predicting sulfur content in raffinate after extractive batch processing with sulfolane was statistically developed and proven with analysis of variance. Statistical analysis showed that the largest influence on desulfurization efficiency was solvent ratio, the second most significant influence was inlet sulfur content, followed by temperature, and last the interaction between solvent ratio and inlet sulfur content. The obtained second-order polynomial model shows that maximum desulfurization efficiency of 65.34% can be achieved at temperature of 50°C and higher values of inlet sulfur content and solver ratio in the researched range of inlet parameter values.     

工艺条件对降低催化汽油烯烃过程中汽油烯烃分布的影响

着重考察了在使用降烯烃催化剂GOR-Q和常规催化剂MLC-500时工艺条件对催化汽油烯烃分布的影响。结果表明：GOR-Q催化剂具有明显降低催化汽油各类烯烃的效果。从碳数分布看,催化汽油中的烯烃主要集中在C5～C7之间。从类型看,单烯烃是催化汽油烯烃的主要存在形式,其中又以正构烯烃和单支链烯烃为主。降低催化汽油烯烃主要是通过小分子烯烃或单烯烃、正构烯烃、单支链烯烃的降低来实现。低温、低空速、高剂油比有利于降低催化汽油中单烯烃、正构烯烃、单支链烯烃和二烯烃含量,但为了减少辛烷值的损失,在降低催化汽油烯烃时首先应采用提高剂油比的方式。     

HCHO-H2SO4缩合-萃取脱除汽油中噻吩硫化物

 缩合-萃取脱硫是利用 FCC 汽油中的噻吩类硫化物与 HCHO 在 H₂SO₄存在下发生缩合反应,生成的噻吩缩合物被抽提至水相,从而达到脱硫的目的。考察了 HCHO-H₂SO₄体系对 FCC 汽油缩合 萃取脱硫的效果。当 HCHO-H₂SO₄体系中 HCHO 占模拟汽油的体积分数为1.5%、H₂SO₄ (质量分数55%)占模拟汽油的体积分数为10%、反应温度70℃、反应时间60 min 时,缩合 萃取脱硫后模拟汽油的硫质量分数由1163 μg/g 降至139 μg/g,脱硫率为87.96%;但是对硫质量分数为652 μg/g 的 FCC 汽油的脱硫率仅为10.74%;固定 HCHO 与 H₂SO₄的体积比,增加二者的用量有助于提高 FCC 汽油的脱硫率。该体系对硫含量低的 FCC 汽油以及 FCC 重汽油脱硫效果较好,当 HCHO-H₂SO₄占 FCC 汽油的体积分数为40%时,FCC 中汽油硫质量分数由164 μg/g 降至65 μg/g,脱硫率达到60.37%。     

Investigation on Modification of NaY Zeolite and Its Behaviors in Selective Adsorptive Desulfurization of FCC gasoline

NaY zeolite was modified with oxalic acid, and Ce(IV)Y(1) zeolite was obtained via liquid phase ion exchange between the modified NaY zeolite and cerium nitrate. The Ce(IV)Y(2) zeolite was obtained via liquid phase ion exchange between NaY zeolite and cerium nitrate. The performance of two Y zeolites [Ce(IV)Y(1) and Ce(IV)Y(2)] was compared through static selective adsorptive desulfurization of FCC gasoline at room temperature and normal pressure. The sulfur compounds and contents of the FCC gasoline were a...     

操作参数对FCC汽油烯烃度的影响

在XTL-5小型提升管催化裂化试验装置上,考察了操作条件对汽油烯烃度的影响。在此基础上,分别构造了两个表示烯烃含量大小和氢转移反应强弱的参数——烯烃度和氢转移指数。还探讨了反应温度和剂油比等操作条件对FCC汽油烯烃度的影响规律及机理。     

Effect of Olefins on Formation of Sulfur Compounds in FCC Gasoline

The effect of olefins on formation of sulfur compounds in FCC gasoline was studied in a small-scale fixed fluidized bed （FFB） unit at temperatures ranging from 400℃ to 500℃, a weight hourly space velocity （WHSV） of 10 h-1, and a catalyst/oil ratio of 6. The results showed that C4--C6 olefins contained in the FCC gasoline could react with HzS to form predominantly thiophenes, alkyl-thiophenes as well as a fractional amount of thiols, while large molecular olefins such as heptene could react with hydrogen sulfide to form benzothiophenes. The amount of sulfur compounds formed at different tem- peratures over different catalysts were in proportion to the mass fractions of olefins in the feedstock, with the amount of sulfur compounds formed over REUSY catalyst exceeding those formed over the shape selective zeolite catalyst owing to the effect of catalyst performance and the impact of catalyst on the degree of olefin conversion. The amount of sulfur compounds generated and their increase reached a maximum at 450℃ and a minimum at 400℃ because of the influence of temperature on the thermodynamic and kinetic constants for formation of sulfur compound as well as on the olefin conversion degree. Based on the above-mentioned study, a reaction network and a model for prediction of sulfur compounds generated upon reaction of olefins in FCC gasoline with HES were established.