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。     

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.     

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。     

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.     

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.     

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...     

Deep desulfurization of FCC gasoline by extraction with dicarboxylic acid-based deep eutectic solvents

A highly efficient extractive desulfurization system with dicarboxylic acid-based deep eutectic solvents (DESs) as extractants has been developed. A series of dicarboxylic acid-based DESs were synthesized by mixing n-butylpyridinium bromide ([BPY]Br) with different dicarboxylic acids. The extraction desulfurization performance of these DESs was investigated and optimized.     

The Effects of Weight Hour Space Velocity on the Products Distribution of Aromatization Reaction of Lanlian FCC Gasoline

Abstract

By using Lanlian fluid catalytic cracked (FCC) gasoline as a feedstock, the effects of weight hour space velocity (WHSV) on the product distribution, light oil compound, off-gas, and liquefied petroleum gas were researched in a confined fluidized bed reactor. The equation of off-gas yield, liquefied petroleum gas yield, coke yield, and light oil yield with increasing WHSV were established in the experimental data. The experimental result showed that with increasing WHSV, coke, off-gas, and liquefied petroleum gas yield decreased gradually, and light oil yield increased piece by piece; the amount of olefin was enhanced step by step, that of aromatics dropped slowly, and that of saturated hydrocarbon did not change. However, olefin conversion and increasing ratio of aromatics presented a slowly decreasing trend and increasing ratio of saturated hydrocarbon showed no change; hydrogen yield was low and did not change; i-butane and propane decreased, but n-butane increased gradually; C⁰ ₃/C⁼ ₃ and nC⁰ ₄/nC⁼ ₄ values did not change, iC⁰ ₄/iC⁼ ₄ variety had no order; C⁰ ₃/C⁼ ₃, C⁰ ₄/C⁼ ₄, and (C⁰ ₃ + C⁰ ₄)/(C⁼ ₃ + C⁼ ₄) values showed a decreasing trend.     

催化裂化汽油芳构化影响因素研究

以催化裂化汽油为原料,采用小型固定流化床和中型提升管为芳构化反应装置,考察空速、温度、剂油比、反应时间、汽油馏分切割温度等反应试验条件对催化汽油二次改质产物性能以及汽油组成的影响。结果表明,随着空速的降低和反应温度的升高,汽油烯烃含量降低,芳烃含量增加,汽油辛烷值增加;随着反应时间的延长,烯烃转化率和芳烃增加率提高;催化汽油77.5%的烯烃存在于<110℃的馏分中,这部分烯烃是芳构化改质的主要目标。     

Study on Reaction Mechanism for Cracking FCC Gasoline on Acid Catalyst

This article is based on the experimental data on reaction of FCC naphtha in the presence of acid catalysts. The data published in the literature were reprocessed and compared with experimental data and the relationship of hydrogen and methane contained in the dry gas with the conversion rate was identified. The similarity between the route for cracking of olefin enriched FCC gasoline and the route for reaction of individual hydrocarbons was deduced, while the route for formation of ethylene in dry gas was also proposed to identify the relationship between the reaction path for formation of ethylene and the conversion rate.     

Desulfurization of FCC Gasoline Over Mordenite Modified with Al2O3

Mordenite modified with Al₂O₃ (Al₂O₃/mordenite) was synthesized and used for the desulfurization of FCC gasoline. The influences of operating parameters on the results were studied for the model solution composed of dibenzothiophene (DBT) and isooctane. Al₂O₃/mordenite exhibits higher sulfur capacity than other kinds of chemisorbents. The suitable composition of the chemisorbent is 30 wt% Al₂O₃ to 70 wt% mordenite. The optimal operating parameters are: temperature 160°C; velocity 3 h^-1 (WHSV). Under the stated conditions, desulfurization was carried out for the FCC gasoline with sulfur content of 220.4 μg/g. The chemisorbent can maintain the sulfur content under 50 μg/g for 40 h and has good regeneration ability after desorption using benzene.     

Investigation of the Operating Conditions on Decreasing FCC Gasoline Olefin Content by GOR-Q Catalyst

Abstract

Based on a fixed-fluid-bed reactor and a GOR-Q catalyst, the influence of process parameters on decreasing gasoline olefin content was studied. The results show that the catalyst had an obvious effect on the decreasing gasoline olefins. A higher catalyst-to-oil ratio, lower weighted hourly space velocity, and lower reactor temperature give rise to lower gasoline olefin content. The reduction of fluid catalytic cracking (FCC) gasoline olefin content is achieved by decreasing olefins of low carbon number. Reaction temperature under 520°C and catalyst-to-oil ratio = 7.0 for a GOR-Q catalyst are advantageous for decreasing olefin content of FCC gasoline.     

催化汽油加氢精制加氢异构化工艺

为了降低催化汽油中的烯烃含量、硫含量，进行了催化汽油加氢精制加氢异构化的研究。结果表明．采用KT加氢异构化催化剂，通过加氢精制加氢异构化反应，液体产品收率在99％以上，脱硫率在80％以上，汽油的硫含量降到了50μg/g以下，汽油烯烃含量降低了7．25％，辛烷值损失0．8。     

Preparation of the Modified Y Zeolite for Removal of Organic Sulfur Compounds from FCC Gasoline

Abstract

Ce(IV)-loaded modified NaY (NH₄Y) zeolite was prepared for selective adsorptive desulfurization from fluid catalytic cracked (FCC) gasoline. Ce(β)Y was obtained from NH₄Y using a liquid-phase ion-exchange method. Ce(IV)Y was obtained from calcining Ce(β)Y at 550°C. The structures of the Ce(IV)Y and NaY samples, selective adsorption of organic sulfur compounds on Ce(IV)Y and NaY zeolite, sulfur content of FCC gasoline, and mechanism for adsorption of thiophene on Ce(IV)Y and NaY zeolite were investigated using X-ray diffraction (XRD), gas chromatography–sulfur chemiluminescence detection (GC-SCD), sulfur analysis, Fourier transform infrared (FTIR), frequency response (FR), and intelligent gravimetric analysis (IGA). The selective adsorption desulfurization from FCC gasoline containing organic sulfur compounds (S = 135 μg/g) was investigated with Ce(IV)Y adsorbent for removal.

The sulfur content was reduced to 20.14 μg/g. The thiophene adsorption mechanism showed that Ce(IV)Y can adsorb thiophene via π electronic interaction directly, and thiophene and Ce(IV) can form a stable sulfur–metal bond (S-M bond) that enhances the adsorption capacity of Ce(IV)Y for thiophene. This method for the modification of NaY zeolite provides a promising selective desulfurization process to prepare clean fuels.