INTEGRATING ALBEMARLE RESOLVE DESULFURIZATION TECHNOLOGY WITH NOVEL PETRO-CANADA PROCESS CONCEPTS IN COMMERCIAL FCCU OPERATIONS

The gasoline and distillate sulfur regulations promulgated throughout the world to reduce tail-pipe emissions are now strongly impacting refinery operations and investments. FCC gasoline is recognized as the principal contributor of sulfur to the gasoline pool and has become the focus for meeting the new specifications. The difficulty in removing sterically hindered sulfur species in the fluid catalytic cracking unit (FCCU) cycle oil drives up the hydrogen and investment costs for treating the distillates. Although installation of pre- and post-treatment facilities is planned by many refiners, other non-capital approaches such as undercutting are being evaluated to meet interim and future sulfur levels. Even when expensive treatment facilities are installed, operating costs can be lowered and the flexibility of the facility increased with improvements in the ability to remove sulfur in the FCCU. In this article, we detail Petro-Canada's experience in integrating Albemarle's RESOLVE sulfur reduction technology with a combination of innovative process ideas. These concepts include heavy naphtha recycle, coprocessing of hydrogen donor feeds, and recycle of light cycle oil (LCO) to a specially designed stripper reactor. Special attention is paid to the interaction of deep FCC feed hydrodesulfurization with the FCC performance. The results demonstrate that very low FCC gasoline sulfur levels can be achieved without significant capital investment through novel approaches to recycle, creative integration of cat feed hydrotreating unit (CFHTU)-FCCU designs and operations, and application of state-of-the-art sulfur reduction additive technology. An added benefit of the RESOLVE 950 sulfur reduction technology is the substantial elimination of sulfur oxides in the FCC flue gas. This has been observed in Petro-Canada operations and numerous other RESOLVE 950 applications around the world.     

Fluid catalytic cracking technology: current status and recent discoveries on catalyst contamination

The fluid catalytic cracking (FCC) technology is one of the pillars of the modern petroleum industry which converts the crude oil fractions into many commodity fuels and platform chemicals, such as gasoline. Although the FCC field is quite mature, the research scope is still enormous due to changing FCC feedstock, gradual shifts in market demands and evolved unit operations. In this review, we have described the current status of FCC technology, such as variation in the present day feedstocks and catalysts, and particularly, great attention is paid to the effects of various contaminants of the FCC catalysts of which the latter part has not been sufficiently documented and analyzed in the literature yet. Deposition of various contaminants on cracking catalyst during FCC process, including metals, sulfur, nitrogen and coke originated from feedstocks or generated during FCC reaction constitutes a source of concern to the petroleum refiners from both economic and technological perspectives. It causes not only undesirable effects on the catalysts themselves, but also reduction in catalytic activity and changes in product distribution of the FCC reactions, translating into economic losses. The metal contaminants (vanadium (V), nickel (Ni), iron (Fe) and sodium (Na)) have the most adverse effects that can seriously influence the catalyst structure and performance. Although nitrogen and sulfur are considered less harmful compared to the metal contaminants, it is shown that pore blockage by the coking effect of sulfur and acid sites neutralization by nitrogen are serious problems too. Most recent studies on the deactivation of FCC catalysts at single particle level have provided an in-depth understanding of the deactivation mechanisms. This work will provide the readers with a comprehensive understanding of the current status, related problems and most recent progress made in the FCC technology, and also will deepen insights into the catalyst deactivation mechanisms caused by contaminants and the possible technical approaches to controlling catalyst deactivation problems.     

LGSA降低催化裂化汽油硫含量助剂的工业应用

由石油化工科学研究院研制、中国石化长岭炼化公司催化剂厂生产的LGSA降低催化裂化汽油硫含量助剂,在中国石化长岭分公司第一催化裂化装置和石家庄分公司第一催化裂化装置上进行了工业试验。结果表明,LGSA助剂能有效降低催化裂化汽油中的硫含量。当LGSA助剂占系统藏量的10%时,两套装置汽油脱硫率分别为21.1%和15.9%。汽油、柴油中脱除的硫转移到干气、油浆和烟气中。该助剂对催化裂化产品分布和产品质量影响不大。     

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.     

催化裂化汽油脱硫技术进展

随着环保法规的日益严格,对汽油的质量要求越来越高,全世界都在为降低汽油硫含量而不懈努力。降低汽油硫含量是改善空气质量的有效手段。脱硫技术已经成为各炼油企业的关键技术。汽油中的硫化合物主要来自FCC(流化催化裂化)汽油,因此FCC汽油脱硫技术的研究与开发具有重要意义。目前,减少FCC汽油硫含量的技术主要有：FCC原料油加氢脱硫、FCC汽油加氢脱硫、溶剂萃取脱硫、催化裂化脱硫、氧化脱硫、生物脱硫和吸附脱硫等。笔者综述了国内外FCC汽油脱硫技术进展。     

Correlation between feedstock SARA components and FCC product yields

Daqing, Shengli, Liaohe, Gudao, Dagang and Huabei vacuum residua were subjected to deep solvent fractionation by using the supercritical fluid extraction and fractionation, a novel separation technology recently developed by the State Key Laboratory of Heavy Oil Processing. Each residuum was fractionated to produce deasphalted oil (DAO) at four yield levels: 30, 40, 50 and 60 wt%. The saturates, aromatics, resins and asphaltenes (SARA) composition of each DAO sample was determined, indicating that the saturates and aromatic contents of DAO decreases with increased DAO yield.The DAO samples were reacted in a laboratory scale confined fluidized bed, fluid catalytic cracking (FCC) reactor. The results show that most of the gasoline yields originates from the saturate fraction of DAO. The aromatics fraction of DAO contributes to gasoline and diesel yields. Most of the coke yield is from resin fraction of DAO.Generalized empirical correlations were developed for predicting the FCC gasoline, diesel, light oil and coke yields as a function of feedstock SARA composition. These yield correlations can be used to set the upper limit of feedstock resins content for commercial FCC operations. The implications of feedstock properties on FCC products were discussed.     

降低我国车用汽油烯烃含量的措施探讨

降低我国车用汽油烯烃含量的关键是降低催化裂化汽油的烯烃含量,而国内目前广泛采用的在催化裂化装置上使用降烯烃催化剂的方法是降低FCC汽油烯烃含量,此外国内开发的一些新型的催化裂化反应工艺,如MIP、MGD、FDFCC等也能明显降低FCC汽油的烯烃含量。指出为了进一步降低汽油烯烃含量,以应对更加严格的车用汽油标准,我国炼油业应在大力推行加氢工艺的基础上优化加工流程,发展重整、烷基化、醚化等多种工艺,彻底改变我国车用汽油池组成单一的现状。     

催化裂化原料加氢预处理

选择适宜的催化剂和工艺条件,采用催化裂化原料加氢预处理技术可拓宽催化裂化原料的范围,生产优质的催化裂化原料,改善催化裂化产品分布,提高催化裂化汽、柴油产品质量。     

脱除催化裂化汽油中硫含量的技术及其新进展

介绍国外在降低催化裂化汽油中硫含量的技术及其新进展。包括新的催化剂和助剂技术、膜分离、Unipure ASR汽油氧化法工艺及传统的选择性加氢工艺等。并指出加大新型高效催化剂及助剂的研制与开发,与膜分离技术、选择性加氢技术等相结合．将是解决汽油中硫含量的长期对策：根据不同技术的特点优化装置配置,确定最佳的方案进行汽油调和,是满足不同阶段的清洁汽油中硫含量标准的一条经济的、有效的途径。     

LGO系列降低汽油烯烃含量催化剂的开发与应用

降低FCC汽油烯烃含量的关键是要增加FCC反应中的氢转移能力，以饱和汽油中的烯烃。由石油化工科学研究院和兰州石化公司催化剂厂合作开发的LGO-20、LGO-21系列降烯烃重油裂化催化剂和LGO-A降烯烃助剂，适用于降低汽油烯烃含量，可根据装置特点及目的产品要求灵活调变活性组分及其配比，并通过不同的基质改性技术生产具有针对性的产品，该系列催化剂普遍具有显著的降低催化汽油烯烃的性能，在装置维持掺渣量较高（约65%～70%）的条件下，通过调整工艺操作条件，可以将催化汽油中烯烃含量降低10～15个百分点，使汽油烯烃控制在40vol%左右，RON在90以上。LGO- 21更具有提高柴油产率的性能。     

Five-lump kinetic model with selective catalyst deactivation for the prediction of the product selectivity in the fluid catalytic cracking process

The effective simulation of the fluid catalytic cracking (FCC) operation requires a good understanding of many factors such as, reaction kinetics, fluid dynamics, and feed and catalyst effects. The different product slates that can be obtained are the consequence of a complex reaction scheme including cracking, isomerization, hydrogen transfer, oligomerization, etc. Furthermore, the catalyst deactivation may affect each one of the reactions in different ways, which creates an additional reason for different variation with time-on-stream of the yield to each product. On the basis of the experimental data of the FCC pilot plant operated in Chemical Process Engineering Research Institute (CPERI, Thessaloniki, Greece), a lumping model was developed for the prediction of the FCC product distribution. The lumped reaction network involved five general lumps (gas oil, gasoline, coke, liquefied product gas, and dry gas) to simulate the cracking reactions and to predict the gas oil conversion and the product distribution. The paths of catalyst deactivation were studied and a selective deactivation model was adopted that enhances the fundamentality and accuracy of the lumping scheme. The hypothesis of selective catalyst deactivation was found to improve the product slates prediction. Models with different assumptions were examined, regarding the behavior of the catalyst, as deactivated, and its effect on the reactions of the lumping scheme. A large database of experiments, performed in the FCC pilot plant of CPERI was used to verify the performance of the models in steady state unit operation. The simulation results depict the importance of incorporating selective catalyst deactivation functions in FCC lumping models.     

FCC原料加氢预处理生产超低硫汽油技术措施综述

阐述了超低硫汽油的生产对现有FCC原料加氢预处理技术的影响以及世界各国的技术策略,并指明了FCC原料加氢预处理技术在生产超低硫汽油中的发展方向和主要技术措施。研究表明:从生产30μg/g的清洁汽油到生产硫含量小于10μg/g的超低硫汽油会造成FCC原料加氢预处理装置氢耗高、运转周期短、加氢预处理-催化裂化联合装置经济性差等问题。FCC原料加氢预处理生产超低硫汽油的主要技术措施有:优化现有的FCC原料加氢预处理装置、对现有FCC原料加氢预处理装置增加一个反应器、增加现有FCC原料加氢预处理装置的进料量、开发FCC原料加氢预处理-FCC组合工艺、新建或改造成缓和加氢裂化装置、新建或改造成部分转化加氢裂化、新建或改造FCC汽油后处理装置。     

LBO-16型FCC催化剂复配RE-Ⅱ稀土助剂技术的开发和应用

介绍了复配新型三效稀土FCC助剂(RE-Ⅱ)的LBO-16型催化剂在中国石油兰州石化公司的工业化开发和应用。工业应用结果表明,使用该技术在不改变FCC生产装置任何设备、操作条件和原料油等的情况下,产品的轻质油(汽油＋柴油)收率增加1.5个百分点以上,取代贵金属助燃剂而使烟气中CO完全燃烧。     

FRS全馏分FCC汽油加氢脱硫技术开发及工业应用

抚顺石油化工研究院(FRIPP)开发的FRS全馏分FCC汽油加氢脱硫技术具有大幅度降低催化汽油硫含量和烯烃含量而辛烷值损失较低的特点.在中国石油化工股份有限公司九江分公司0.4 Mt/a装置上的工业应用结果表明,FRS技术能够为我国炼油厂生产清洁汽油提供灵活、经济的技术解决方案.     

YD-CADS汽油超深度催化吸附脱硫技术中试研究

陕西延长石油（集团）有限责任公司炼化公司和中国科学院大连化学物理研究所共同开发的YD-CADS汽油固定床超深度催化吸附脱硫组合技术,以全馏分FCC汽油为原料生产超低硫清洁汽油,采用脱二烯烃和催化吸附脱硫串联固定床工艺,具有流程短、投资低、占地少和操作简单等优点。中试结果表明,处理硫含量约100 μg·g^-1的FCC汽油时,汽油产品硫含量小于10 μg·g^-1,烯烃饱和小于2%,研究法辛烷值损失小于0.8个单位,目的产品汽油收率大于99%,化学氢耗小于0.2%。     

Fluid catalytic cracking feed hydrotreatment and its severity impact on product yields and quality

This paper investigates the effect of fluid catalytic cracking (FCC) feed hydrotreatment and its severity increase on product yields and quality obtained in a commercial and a laboratory MAT FCC units. The hydrotreatment of Ural heavy vacuum gas oil reduces not only sulfur, nitrogen, Conradson carbon and metals content in the FCC feed but also increases the mononuclear aromatic hydrocarbons content by 8% absolute at almost no change in the total aromatics content. Regardless of this 8% increase of the mononuclear aromatics in the hydrotreated FCC feed the conversion increase in both commercial and laboratory MAT units was only 2%. The severity increase in the FCC feed hydrotreater leads to a higher conversion in the FCC, higher hydrogen transfer rate that results in higher isobutane/butylenes ratio, lower gasoline olefins content, and higher gasoline motor octane number. The hydrotreatment of the Ural heavy vacuum gas oil exhibited the same changes in FCC catalyst selectivities: lower coke and LCO selectivities and higher gasoline selectivity in both commercial riser FCC unit that has between 2 and 3 s time on stream, and the fixed bed reactor MAT unit, that has 30 s time on stream.     

催化裂化生产清洁燃料

介绍了当前轻质油品脱硫的一些方法,包括传统的加氧脱硫和吸附脱硫等工艺过程。21 世纪的炼油企业将围绕炼油厂清洁化生产和生产更加清洁的燃料方向发展,重点发展各种汽油加氢技术并开发非加氢技术、发展轻烯烃改质以及催化汽油降烯烃技术。     

Study of direct and indirect naphtha recycling to a resid FCC unit for maximum propylene production

To satisfy the increasing propylene demand, direct and indirect naphtha recycling schemes around an existing resid fluid catalytic cracking (FCC) unit were investigated. To this aim, light cracked naphtha (LCN), heavy cracked naphtha (HCN) and a PolyNaphtha (PN) oligomerisation product were cracked under a wide range of operating conditions over a commercial Y zeolite based equilibrium catalyst. Experimental data were acquired in three different units: a fixed bed bench scale unit, a fixed fluidised bed unit and an adiabatic circulating fluidised bed pilot plant. It was shown that FCC naphthas require high operating severities to crack, and that even then their conversion remains relatively moderate. Hence, direct recycling to the main riser does not seem a viable pathway to increase propylene product. Feeding FCC naphthas to a second reaction zone operating at high severity allows to increase the propylene yield in a significant manner. Increasing conversion, however, not only leads to higher LPG and propylene yields, but also results in very high dry gas yields. An alternative scheme was proposed, in which the olefinic C₄ and C₅ fractions are converted into a naphtha fraction through oligomerisation in a dedicated unit before being recracked in the secondary riser. As the highly olefinic oligomerised effluent mainly consist of dimerised and trimerised butenes and pentenes, this feed is more easily cracked and high conversions can be achieved. This indirect interconversion of butenes and pentenes into propylene therefore effectively allows to convert these butenes and pentenes into propylene, resulting in a significant increase in propylene yield. Each of the three main naphtha recycle options (directly to the main riser, directly to a secondary riser or indirectly via a light olefin oligomerisation unit) have been analysed and compared to a base case. In the evaluation of each of these schemes, all heat balance effects, both on the riser and the regenerator side, have been accounted for. The proposed process scheme with an indirect recycle via an oligomerisation unit enhances the already inherent flexibility of the FCC unit. The naphtha recycle can be turned on or off, the second reaction zone can be used to crack naphtha or to crack resid feed to maximise throughput, while the effluent of the oligomerisation unit can be recycled to the FCC unit for propylene production or hydrogenated and sent to gasoline and kerosene pool.     

催化裂化汽油降硫剂的制备与应用

为降低汽油硫含量,以锌和镧为有效元素合成了催化裂化汽油脱硫钝化剂,在催化裂化装置上进行了工业应用试验。结果表明,当加入量为300×10^-6时,汽油中总硫可以从204×10^-6降低到140×10^-6,脱硫率达36.37%;当加入量为（500～600）×10^-6时,脱硫率可达到50%以上。汽油中的噻吩硫主要以硫化氢形态转移至干气、液化气中。脱硫钝化剂对平衡催化剂的主要性质和FCC产品分布没有明显影响,亦有良好的金属钝化效果。     

Dependence of Fluid Catalytic Cracking Unit Performance on H-Oil Severity,Catalyst Activity,and Coke Selectivity

The effect of the quality of ebullated bed vacuum residue H-Oil hydrocracking gas oils cracked in a commercial fluid catalytic cracking unit (FCCU) on its performance was studied. Six different catalysts were employed in this study. Four catalysts were tested in a commercial FCCU, and two in a laboratory FCCU. An increase of the H-Oil hydrocracker reaction temperature was associated with a decrease in the K_W factor of the H-Oil gas oils. The diminished K_W factor of H-Oil gas oils resulted in lower FCCU conversion and higher regenerator temperatures. The FCC conversion at maximum gasoline yield is best predicted by the feed K_W factor. The higher-activity, higher-Δcoke catalyst is unfavorable for FCCU performance because the excessive regenerator temperature excursions require reduction of the throughput.