不同方法合成β沸石的FCC反应性能

报道了不同方法合成β沸石的FCC反应性能,并考察了β沸石的硅铝比对FCC反应产品分布的影响。结果表明:β沸石应用于FCC,与高硅ZSM-5相比,具有提高汽油产率及辛烷值的功能;另外β沸石较高硅ZSM-5表现出更强的异构化功能,具有提高异丁烷和轻汽油异构烯烃(或叔碳烯烃)产率的作用,可丰富烷基化技术和醚化技术的原料来源。     

我国FCC催化剂的发展近况

阐述了国内近几年FCC催化剂在重油催化裂化、汽油降烯烃、脱硫及多产低碳烯烃方面的进展.提高抗重金属污染能力、用中孔沸石代替 ZSM-5小孔沸石及大幅度提高催化剂基质的活性仍是今后研发 FCC催化剂的热点.     

催化裂化汽油降烯烃技术进展及新技术探讨

综述了目前国内外主要的降低催化裂化(FCC)汽油烯烃的方法和工艺。针对我国汽油池的特殊性,提出现阶段我国开发汽油降烯烃工艺需要遵循以下原则：降低烯烃幅度大,辛烷值损失小,高液收和低氢耗,工艺简单,兼有脱苯和脱硫功能。并对最近报道的有关纳米ZSM-5沸石用于FCC汽油降烯烃方面的研究进行了讨论。     

分子筛催化剂上催化裂化汽油掺混甲醇的改质研究

以实现甲醇制取低碳烯烃转化工艺和FCC汽油降烯烃工艺的有效组合为目的,在固定床微型反应装置上,使用SAPO-34、ZSM-5、DOCO以及分子筛组合催化剂,对FCC汽油掺混甲醇改质进行了研究。主要对反应温度、空速和混炼比等影响因素进行了考察。结果表明,SAPO-34分子筛上甲醇制取低碳烯烃效果较好,高烯烃含量汽油在SAPO-34分子筛上的氢转移和芳构化效果显著,ZSM-5分子筛上的芳构化反应效果和DOCO的异构化反应效果较显著,甲醇转化与汽油转化反应间的相互协同作用,既有利于甲醇转化成低碳烯烃又能提高汽油降烯烃转化深度。适宜的混炼条件:反应温度400℃,m(甲醇):m(汽油)=0.05,空速3h~(-1),组合催化剂上,产物汽油中烯烃含量较FCC粗汽油下降23%以上。     

催化裂化汽油在磷改性Ni/ZSM-5催化剂上的降烯烃工艺研究

采用浸渍法制备了Ni/ZSM-5和NiP/ZSM-5催化剂,其中Ni、P分别为HZSM-5质量的3％和0.5％。以锦州石化公司重油FCC汽油为原料,考察了助剂P加入前后催化剂的降烯烃反应性能。结果表明, NiP/ZSM-5催化剂具有较好的加氢降烯烃、异构化和芳构化活性,液体收率较高;考察了工艺条件对NiP/ZSM-5催化剂降烯烃反应的影响。在温度310 ℃、液时质量空速3 h^－1、氢油体积比300和反应压力2.5 MPa的最佳反应条件下,FCC汽油烯烃转化率、液体收率、产品中异构烷烃和芳烃的质量分数分别为72.9％、82.1％、45.84％和30.44％,而产品辛烷值不降低,达到了既降烯烃又不损失辛烷值的预期目的。     

不同ZSM-5分子筛对增产低碳烯烃的性能对比及改性研究

低硅择形分子筛在增产液化气和丙烯方面优于高硅择形分子筛,但加入低硅择形分子筛助剂后汽油收率降低幅度较大。改性后ZSM-5分子筛制备的催化剂与未改性ZSM-5分子筛制备的催化剂相比,液化气和丙烯产率均有明显提高,重油产率明显降低,转化率升高,总液收基本不变,汽油中烯烃含量有所降低,芳烃含量提高。     

催化裂化汽油的二次反应

从降烯烃、降硫和增产丙烯的现实需要出发,分析了FCC汽油二次反应中的理想和非理想反应.用小型提升管催化裂化实验装置考察了FCC粗汽油在REUSY、ZRP和MO-REY沸石催化剂上二次反应的产品分布和改质汽油组成;探讨了操作强度对二次反应转化率和选择性的影响.结果表明：在Y型或ZRP沸石催化剂作用下,FCC汽油二次反应不仅产生更轻的干气和富含丙烯的液化气,也产生更重的柴油和焦炭.二次反应得到的改质汽油与原料汽油相比,其烯烃含量和硫含量降低,芳烃含量和辛烷值明显提高.二次反应的转化深度和选择性取决于原料汽油的烯烃含量、催化剂沸石类型和操作强度.     

高硅ZSM-5在辛烷值助剂中的应用

研究了不同硅铝比ZSM-5分子筛的催化裂化反应性能,结果表明,高硅铝比ZSM-5分子筛能实现提高汽油辛烷值的同时控制液化气产率增幅较小。考察不同硅铝比的高硅ZSM-5分子筛的反应性能,高硅ZSM-5助剂在ACE装置上的评价结果表明,助剂能使液化气和汽油辛烷值小幅增加,同时也能增加汽油中的芳烃含量。随着ZSM-5分子筛硅铝比的增加,助剂控制液化气的性能逐渐增强,但同时提高汽油辛烷值的性能逐渐减弱。在实际应用中,适宜的ZSM-5分子筛硅铝比应根据目标用户的实际情况和要求灵活选择。     

流化催化裂化汽油改质和增产低碳烯烃的研究

采用GL型催化剂,在小型固定流化床实验装置上考察了反应温度、剂油比、空速和水油比等操作条件对流化催化裂化(FCC)汽油催化改质汽油的产品分布、低碳烯烃(丁烯、丙烯和乙烯)产率和族组成的影响。实验结果表明,在一定反应条件下,FCC汽油通过催化改质可以降低烯烃含量,提高芳烃含量和辛烷值,在满足新汽油标准的同时提高了低碳烯烃的产率。此外,较高的反应温度、剂油比和水油比以及较低的空速有利于FCC汽油催化改质和增产低碳烯烃。     

国内外化工简讯

工业化应用的高硅择形催化剂大连理工大学王祥生教授领导的课题组,经过多年攻关,研制成功ZSM-5、超细粒子ZSM-5以及钛硅沸石三种分子筛,并利用我国丰富的混合稀土资源改性,获得了合成高纯度对二乙苯催化剂、汽油降烯烃催化剂以及丙烯选择氧化制环氧丙烷催化     

ZSM-5分子筛在炼油工业中的应用

介绍了ZSM-5分子筛在炼油工业中的应用,包括柴油加氢降凝、润滑油加氢脱蜡、汽油恢复辛烷值和催化裂化（FCC）汽油降烯烃。     

沸石的改性技术

本文以大量文献为基础,总结了重质原料流化催化裂化催化剂所用Y型沸石分子筛的改性技术。改性技术包括水热改性法,用EDTA、SiCl₄、（NH₄)₂SiF₆、光气或草酸等化学脱铝改性法,以及使用酸、碱、盐式络合剂的水热与化学脱铝相结合的改性方法。     

β分子筛的催化裂化性能考察

以重油（70%新疆蜡油掺和30%新疆渣油）为原料,在FFB和ACE装置上对3种不同硅铝质量比β分子筛和工业应用的ZSM-5分子筛制备的催化裂化助剂的反应性能进行对比评价。结果表明,β分子筛对重油组分的裂化能力强于ZSM-5,对汽油组分的选择裂化能力弱于ZSM-5,液化气增加量小于ZSM-5,提高汽油辛烷值能力与ZSM-5相当。同时,随着β分子筛硅铝质量比升高,其催化裂化产物中汽油和总液收增加,重油减少。因此,β分子筛助剂适用于以追求燃料汽油生产为主的炼油企业,满足液化气增加不多和提高汽油辛烷值的需要。     

催化裂化汽油在多元沸石基催化剂上加氢改质研究

采用浸渍法分别制备了以丝光沸石（HM）、Hβ和HZSM-5及其组合为载体的沸石基Ni-Mo-P催化剂,考察了载体组成对催化裂化汽油加氢改质反应性能的影响。结果表明,由适宜比例的三者组合得到的沸石基Ni-Mo-P催化剂具有良好的加氢异构化、脱硫、芳构化活性及稳定性,可在催化裂化汽油脱硫降烯烃的同时保证产品的辛烷值不降低。考察了工艺条件对三元沸石基Ni-Mo-P催化剂反应性能的影响。在温度300 ℃、氢油体积比350、液相体积空速2.5 h-1和反应压力1.5 MPa反应条件下,催化裂化汽油异构烷烃收率、芳烃收率、脱硫率及液相收率分别达41.9%、31.7%、51.0%和98.3% 。     

Behavior of sulfur species present in atmospheric residue in fluid catalytic cracking

The selective removal of sulfur species in atmospheric residue (AR) is strongly wanted since the species of the hydrodesulfurized AR (HDS-AR) define the sulfur content of the product gasoline in the subsequent fluid catalytic cracking (FCC). Hence, the correlations between sulfur species in HDS-AR and FCC gasoline were explored in the present study. HDS-AR was fractionated into vacuum gas oil (VGO) and vacuum residue (VR) by distillation. Reactivities of HDS-AR (S = 3000 mass ppm) and its VGO (S = 900 mass ppm) were measured by micro activity test to clarify which fractions and sulfur compounds in HDS-AR were converted into gasoline and its sulfur species. The yields and sulfur contents of the product gasoline were 45.0 mass% and 52 mass ppm from HDS-AR and 47.7 mass% and 14 mass ppm from VGO, respectively. The sulfur content of the gasoline from HDS-AR was markedly higher than that from HDS-VGO. The saturate and aromatic fractions in HDS-AR are mainly converted to the gasoline in the FCC process, providing similar gasoline yields from HDS-VGO and HDS-AR. Thiophene, methylthiophenes, and benzothiophenes were major sulfur species in both gasolines from HDS-AR and HDS-VGO. Such sulfur species are concluded to be derived from benzothiophenes in VGO and dibenzothiophenes in VR fractions, respectively through hydrogen transferring ring opening and dealkylation during FCC. Sulfur compounds are also produced from H₂S and olefins in FCC, increasing the sulfur content in the product gasoline. The larger sulfur content in the gasoline from HDS-AR than that from HDS-VGO is ascribed to more H₂S being produced during the FCC process as well as dibenzothiophenes being present in the feed.     

劣质原料催化裂化脱硫降烯烃生产清洁汽油技术

介绍了劣质催化裂化原料的特点,分析了催化裂化汽油清洁化对策,应从提高FCC汽油质量关键应从FCC进料预处理、优化FCC加工过程以及FCC汽油精制等3方面出发．采用有效的降烯烃技术以及选择性加氢和氧化一萃取等脱硫技术对催化裂化汽油进行清洁化处理。认为应注重发展加氢技术,增强加氢在清洁油品生产中的作用;适当减少FCC汽油所占比例,增加异构化油、烷基化油、重整汽油比例,缩小与国外成品油结构组成的差距。     

Hydrodesulfurization and hydroconversion of heavy FCC gasoline on PtPd/H-USY zeolite

In the search for catalysts suitable for upgrading fractions of FCC gasoline, PtPd/USY zeolite was investigated. The objectives of the work were to reduce simultaneously the sulfur, nitrogen and aromatic contents of heavy FCC gasoline having various sulfur (30–203 ppmw) and 28 ppmw nitrogen contents. The process conditions were the following: temperature: 200–300 °C; pressure: 30 bar; liquid hourly space velocity: 1.0–3.0 h⁻¹; H₂/hydrocarbon ratio: 500 m³/m³. The results indicated that PtPd/H-USY zeolite catalyst can be applied for the desulfurization of heavy FCC gasoline up to 203 ppm sulfur content. When a base heavy FCC gasoline fraction of 30 ppmw sulfur content was used the catalyst was able to reduce the aromatic content by 14 abs.% as well as sulfur and nitrogen contents to <1 ppmw in one step. Blending calculations were made to evaluate the quality of a full range FCC gasoline obtained by mixing the desulfurized heavy FCC gasoline and the untreated light cut.     

Cleaner gasoline production by using glycerol as fuel extender

Glycerol, a major by-product of biodiesel production, was employed as a fuel extender in this study. The process was originally investigated by etherifying the entire fluidized catalytic cracking (FCC) gasoline with glycerol. The reactions were carried out in a pressurized liquid phase reactor in the presence of three different catalysts (i.e. Amberlyst 16, Amberlyst 15, and β-zeolite) at 70 °C and 2.6 MPa with a volume ratio of FCC gasoline to glycerol ratio of 84:16 for 10 h. The catalytic activity could be ordered as Amberlyst 16 > Amberlyst 15 >> β-zeolite. The properties of FCC and etherified FCC products were determined by the standard analysis of Research Octane Number (RON), blending Reid vapor pressure (bRvp), distillation temperature following the standard methods of ASTM D-2699, ASTM D-5191 and ASTM D-86, respectively. It was found that the olefin content decreased opposing with increasing of octane number due to ethers of glycerol formation and the etherified gasoline product has lower bRvp than that of original FCC gasoline. The process of FCC gasoline etherification with glycerol showed great environmental benefits; in addition, ethers produced renewably from glycerol could extend the gasoline volume.     

Study on reformulation of fluid catalytic cracking gasoline and increasing production of light olefins

The effects of reaction temperature, mass ratio of catalyst to oil, space velocity, and mass ratio of water to oil on the product distribution, the yields of light olefins (light olefins including ethylene, propylene and butylene) and the composition of the fluid catalytic cracking (FCC) gasoline upgraded over the self-made catalyst GL in a confined fluidized bed reactor were investigated. The experimental results showed that FCC gasoline was obviously reformulated under appropriate reaction conditions. The olefins (olefins with C atom number above 4) content of FCC gasoline was markedly reduced, and the aromatics content and octane number were increased. The upgraded gasoline met the new standard of gasoline, and meanwhile, higher yields of light olefins were obtained. Furthermore, higher reaction temperature, higher mass ratio of catalyst to oil, higher mass ratio of water to oil, and lower space velocity were found to be beneficial to FCC gasoline reformulation and light olefins production. __________ Translated from Chemical Reaction Engineering and Technology, 2006, 22(6): 532–538 [译自: 化学反应工程与工艺]