流化催化裂化汽油含硫化合物生成规律的考察

在小型固定流化床装置上采用流化催化裂化(FCC)催化剂、以FCC汽油轻馏分和H2S标准气为原料,考察了催化剂类型、原料组成和反应条件(反应温度、催化剂与原料油的质量比(剂油比)和重时空速)对硫化物生成的影响。实验结果表明,FCC汽油中的烯烃与H2S反应主要生成噻吩类硫化物和部分硫醇;在REUSY分子筛催化剂(催化剂A)上的硫化物收率比在ZRP型择形分子筛催化剂(催化剂B)上的高;且硫化物收率随H2S和烯烃含量的增加呈线性增长。受反应温度对烯烃转化程度的影响,较高的反应温度有利于抑制烯烃与H2S反应。因为反应机理及催化剂性质对噻吩类硫化物和硫醇的生成影响不同,两者收率随剂油比和重时空速的变化趋势不同,但变化幅度均不大,因而总硫化物收率随重时空速和剂油比的变化幅度也不大。     

FCC Gasoline Sulfur Reduction by Additives: A Review

Abstract

This review covers publications in the open literature and patents issued during the last 10 years on issues related to fluid catalytic cracking (FCC) gasoline sulfur reduction. Emphasis was placed on FCC additives, their composition and performance. An attempt was made to elucidate the mechanism for sulfur reduction at FCC cracking conditions. Fluid catalytic cracking technology advances, both process and catalyst, have historically worked together to achieve significant improvements in FCC performance. There is every reason to expect that this will continue to be the case in the future. These advances will have an impact on the volume and quality of the FCC gasoline produced and will offer additional operating flexibility.     

FCC Gasoline Sulfur Reduction by Additives: A Review

This review covers publications in the open literature and patents issued during the last 10 years on issues related to fluid catalytic cracking (FCC) gasoline sulfur reduction. Emphasis was placed on FCC additives, their composition and performance. An attempt was made to elucidate the mechanism for sulfur reduction at FCC cracking conditions. Fluid catalytic cracking technology advances, both process and catalyst, have historically worked together to achieve significant improvements in FCC performance. There is every reason to expect that this will continue to be the case in the future. These advances will have an impact on the volume and quality of the FCC gasoline produced and will offer additional operating flexibility.     

FCC汽油降烯烃技术进展

随着环保意识的加强 ,对汽油中的烯烃含量限制越来越严格 ,针对近期的发展动态 ,从催化裂化 (简称FCC)技术、醚化技术、芳构化技术和烷基化技术等方面介绍了FCC汽油降烯烃生产技术的进展。同时比较了各种方法的优缺点。     

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。     

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.     

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.     

Study on Reduction of Sulfur Content in FCC Gasoline

Reduction of sulfur content in FCC gasoline was studied in a fixed fluid bed (FFB) unit by using metal-modified LV-23 FCC catalyst. The results showed that the sulfur content in FCC gasoline could be reduced with LV-23 catalyst modified with zinc, palladium, zinc-palladium, zinc-cobalt, and zinc-nickel. Among these metals or metal combinations, palladium-containing catalyst was the most effective. Desulfufization of the heavy fraction of FCC gasoline was more effective than full-range gasoline under the same conditions with palladium-containing catalysts. A high reaction temperature was favorable to desulfurization, but it would reduce the yield of liquid product. After desulfurization reaction, the olefm content of product gasoline decreased while the aromatic and iso-alkane contents increased. Removal of thiophene and benzothiophene is higher.     

催化裂化汽油脱硫降烯烃助剂的研制

本研究旨在开发一种能同时降低FCC汽油中硫和烯烃含量的助剂,该助剂配方含强度和含量适中的L酸、B酸组分,有较高的噻吩饱和能力和氢转移能力,对FCC催化剂活性和选择性以及汽油性质不会产生明显不利影响。研究中将助剂按一定比例与FCC平衡剂混合装入固体流化床反应器（FFB）进行催化裂化反应,评价了几种金属组分和载体的脱硫和降烯烃性能及对FCC产品分布的影响。不但筛选了合适的金属和载体组分,而且作了必要的改性研究,多个样品小试结果表明,该助剂脱硫和降烯烃均超过30％,产品分布基本没有恶化,汽油辛烷值不下降。     

Study on Olefin Decrement Reformulation and Increasing Light Olefins of FCC Gasoline by Catalytic Cracking

Abstract

Catalytic upgrading of fluid catalytic cracked (FCC) gasoline obtained from Huabei Petrochemical Company, PetroChina (Renqiu, Hebei, China), was investigated using a microreactor and gas chromatograph integrated unit in order to decrease the content of olefins in gasoline and increase the light olefins (ethylene, propylene, and butylene) content. The experimental results showed that the olefin content in upgraded gasoline can be decreased from 42.6% in raw material to nearly 10%, meeting the requirements of the new gasoline standard, whereas iso-alkane and aromatics contents were markedly increased, from 28.4 and 18.2% to 47 and 36.1%, respectively, so the octane number of gasoline should not be reduced. In addition, higher yields of light olefins were obtained after FCC gasoline was reformulated under laboratory conditions. Higher reaction temperature, longer reaction time, higher weight ratio of catalyst to oil, and higher catalyst activity were beneficial to decrease the olefin content of FCC gasoline and increase the yields of light olefins.     

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。     

Improving Stability of FCC Gasoline Using Ionic Liquids Catalyst After Treating

Abstract

The ionic liquids used herein were alkyl-containing ammonium-aluminum chloride ionic liquids system, which were made by the reaction of short-chain alkyl ammonium salts and aluminum chloride. The factors influencing stability of gasoline and the importance of improving it were described in this article, so was the characteristic of ionic liquids. A novel way to improve the stability of gasoline using ionic liquids was studied herein, as well as the study of decreasing the basic nitrogen content and the sulfur content of mercaptan, treating the gasoline and decreasing the olefin content of gasoline with supported ionic liquids catalyst on a small scale. After treating, the sulfur content of gasoline decreased to 0 nearly, and the basic nitrogen content decreased greatly too, whereas the octane number (RON) of gasoline increased a little. To improve the catalysis of ionic liquids and prolong the using life of ionic liquids, a buffering agent was added into ionic liquids. Ionic liquids catalyst, as a green catalyst friendly to environment, can displace many other alkylation catalysts, decrease the olefin content of gasoline, and show their notable advantages: mild conditions, short reaction time, simple operation, easy separation of the products and the catalyst.     

Improving Stability of FCC Gasoline Using Ionic Liquids Catalyst After Treating

The ionic liquids used herein were alkyl-containing ammonium-aluminum chloride ionic liquids system, which were made by the reaction of short-chain alkyl ammonium salts and aluminum chloride. The factors influencing stability of gasoline and the importance of improving it were described in this article, so was the characteristic of ionic liquids. A novel way to improve the stability of gasoline using ionic liquids was studied herein, as well as the study of decreasing the basic nitrogen content and the sulfur content of mercaptan, treating the gasoline and decreasing the olefin content of gasoline with supported ionic liquids catalyst on a small scale. After treating, the sulfur content of gasoline decreased to 0 nearly, and the basic nitrogen content decreased greatly too, whereas the octane number (RON) of gasoline increased a little. To improve the catalysis of ionic liquids and prolong the using life of ionic liquids, a buffering agent was added into ionic liquids. Ionic liquids catalyst, as a green catalyst friendly to environment, can displace many other alkylation catalysts, decrease the olefin content of gasoline, and show their notable advantages: mild conditions, short reaction time, simple operation, easy separation of the products and the catalyst.     

催化裂化汽油的下行床催化转化

以循环下行床为反应器,催化裂化汽油为原料,在工业催化裂化(FCC)催化剂和催化裂解(DCC)催化剂作用下,研究了催化裂化汽油的催化转化过程。实验结果表明,在下行床反应器中,催化裂化汽油中的烯烃能显著降低,主要转化为低碳烯烃产品,同时得到富含芳烃的液体产品,副产干气和焦炭量很低。催化裂化汽油在FCC催化剂和DCC催化剂上表现出不同的反应机理。FCC催化剂孔道大,可以发生双分子裂化反应和单分子裂化反应,而DCC催化剂孔道小,以单分子裂化反应机理为主,同时DCC催化剂低碳烯烃选择性更高。     

FCC轻汽油C_5和C_6烯烃异构化表观反应动力学的研究

采用管式滴流床反应器,在反应压力1.5 MPa、反应温度313～333 K、液态空速15～30 h-1的范围内,对C5和C6烯烃在LNEH-1镍基催化剂上的异构反应进行了研究。实验结果表明,烯烃只发生双键异构和顺反异构,没有发生骨架异构;1-戊烯、3-甲基-1-丁烯、2-甲基-1-丁烯、1-己烯双键异构反应对烯烃浓度的反应级数均为1,异构反应表观活化能分别为27.60,42.24,79.62,27.71 kJ/mol;随烯烃碳数的增加,异构反应阻力增大,同碳数支链烯烃比直链烯烃更难异构化;由实验数据的拟合得到烯烃异构反应动力学方程,1-戊烯转化率的计算值与实验值的相对偏差基本在10%以内,烯烃异构反应动力学方程可用于反应过程模拟和反应器的设计。     

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。     

催化汽油选择性加氢脱硫工艺中床层结焦机理

 采用 SEM、XRD、FT IR、XPS 等表征手段分析了 FCC 汽油选择性加氢脱硫工艺中床层结焦的结构和形态,并由此探讨了结焦机理。结果表明,焦的外观表现为松散的簇状物质,为无定型焦炭包裹在铁的硫化物外的结构;无定型焦炭由高度聚合的烯烃及高度缩合的芳香烃组成,并含有大量S、N、O等杂原子化合物。由于在 FCC 汽油前脱臭过程中,其中的二烯烃生成了一些低聚物,而在加氢反应过程中,这些低聚物在铁的硫化物及热的作用下迅速生成高聚物而结焦。     

第二代降低FCC汽油烯烃助剂的研制

LAP-1助剂可有效降低FCC汽油烯烃含量,但影响FCC产品分布。新开发的LAP-2助剂在LAP-1的基础上对催化剂的活性组分和载体进行了改进,提高了助剂水热稳定性、氢转移活性和异构化能力,协调芳构化与氢转移反应,提高了降烯烃能力,改善了FCC产品分布。     

FCC汽油在ZSM-5分子筛上的芳构化反应

考察了全馏分催化裂化（FCC）汽油的芳构化改质反应，结果表明，在三种不同硅铝比的分子筛中，以硅铝比为50的分子筛为载体所制备的催化剂性能较好。对Ni、Mo、Zn、Co4种金属活性组分的选择考察，以Zn为活性组分的催化剂芳构化性能最好，以Ni为活性组分的催化剂液收最高。分析了FCC汽油中不同烃类的芳构化反应历程．得出金属组分应有适宜的含量。