灵活多效催化裂化工艺及其工业应用

灵活多效催化裂化技术采用并联双提升管反应器及相应的工艺条件,选择性地控制裂化、氢转移等反应,实现了降低汽油烯烃和硫含量、增产丙烯的目的。工业应用结果表明,该工艺可使汽油烯烃体积分数降低至16%以下,硫质量分数降低22%~24%,研究法和马达法辛烷值分别提高1~2个单位,催化裂化装置的丙烯产率提高2~3个百分点。     

Researches on improving the quality and quantity of the feed for catalytic cracking

Studies have been carried out on the influence of cumene hydroxperoxide at high temperatures on the properties of the atmospheric residue of crude oil and on the composition and quantity of the fraction obtained at 350–490 °C during its vacuum distillation. This treatment results in an increase in the yield of the fraction boiling at 350–490 °C and a decrease in coke and heavy metals contents.     

催化裂化汽油催化氧化及萃取脱硫的研究

以分子氧为氧化剂,将催化氧化与萃取分离相结合,开展催化汽油氧化萃取脱硫研究。结果表明,与直接萃取相比,汽油经过氧化及溶剂萃取,汽油脱硫率有所提高,并且随着氧化温度的提高而增大,氧化过程对催化汽油脱硫有贡献。催化剂能够加速硫化物氧化反应,几种催化剂的汽油脱硫率从大到小顺序为：氧化铈＞碳酸锰或四硼酸钠或氧化锌＞硼酸或过硼酸钠。使用氧化锌或碳酸锰催化剂时,随着催化剂用量的增加,汽油脱硫率总体呈现降低的变化趋势。以硼酸为催化剂时,脱硫率随着催化剂用量的增加先增加后降低,认为催化汽油中硫化物的氧化反应符合连串反应机制。     

钒对裂化催化剂的影响及流化催化裂化抗钒助剂的开发

研究了钒对分子筛和催化剂性能的影响 ,并开发出一种高活性固体的流化催化裂化抗钒助剂。随着钒含量的增加 ,分子筛的结晶度、比表面积、孔体积呈单调下降 ;而催化剂的催化活性大幅降低 ,选择性变差。抗钒助剂与其他类型的催化剂复配后 ,显示出较强的抗钒性能 ,能明显改善裂化产物的汽油、焦炭的选择性。     

Simultaneous enhancement of ethanol supplement in gasoline and its quality improvement

Ethanol and ethanol derivatives are attractive renewable energy resources nowadays. Even though ethanol can be blended directly into gasoline (called “gasohol”), many recent researches have reported disadvantages of gasohol. Apart from immiscibility and corrosion problems, overall air pollutant emissions from the use of gasohol are usually higher than those from the use of conventional gasoline because of its higher blending Reid vapor pressure (bRvp). Ethers derived from ethanol may overcome these drawbacks. Direct etherification of FCC gasoline with ethanol was investigated in this work. The reactions were carried out in a pressurized liquid phase reactor at 0.8 MPa and catalyzed by two commercial catalysts, i.e., β-zeolite and Amberlyst 16. The bRvp of etherified FCC gasoline was found to be lower than that of gasohol (20 vol.% ethanol), indicating that the gasoline from this process is more suitable than gasohol especially for the tropical zone or in summer. The decrease of bRvp was due to the consumptions of both ethanol and olefins. In case of β-zeolite catalyst, ethanol conversion was 36.3% while olefins content was decreased from 25.7 to 13.9 vol.%. However, as expected, etherified FCC gasoline gave slightly lower RON than gasohol. It was found that β-zeolite was a more suitable catalyst than Amberlyst 16 for the etherification of FCC gasoline with ethanol because it offered products with higher RON and higher ethanol conversion.     

粗汽油进提升管改质对汽油烯烃及产品分布的影响

催化装置粗汽油回炼技术在有效降低催化稳定汽油烯烃含量的同时,对催化装置产品分布产生明显的影响,继而影响到装置的综合经济效益。本文对不同粗汽油回炼量条件下,催化装置稳定汽油性质和产品分布变化趋势进行分析,对经济效益进行对比,阐明应用粗汽油回炼降低汽油烯烃技术时,要选择合适的操作条件,以期得到较好的综合经济效益。     

还原条件对脱硫吸附剂Ni/ZnO-SiO2-Al2O3结构和脱硫性能的影响

采用浸渍法制备了复合氧化物吸附剂Ni/ZnO-SiO2-Al2O3,采用XRD和压汞对吸附剂进行表征,利用小型固定床反应器考察了还原条件对吸附剂脱硫性能的影响。结果表明,还原后吸附剂的XRD谱图中出现了Ni的衍射峰,说明还原过程有利于NiO转化为活性Ni,吸附剂的比表面积和孔体积基本不变,还原前为62.16 m~2/g...     

新型流化催化裂化汽油脱硫降烯烃催化剂的研究

以L沸石作为活性组分负载Co-Mo氧化物制备了改性L沸石催化剂,并用X射线衍射、BET测试和红外光谱等方法对催化剂进行表征。以全馏分流化催化裂化(FCC)汽油为原料,临氢条件下,在固定床连续微反应装置上对催化剂脱除硫和烯烃的性能进行了评价,考察了n(Co)∶n(Mo)、金属含量、温度、压力、体积空速和氢油比对催化剂反应性能的影响。结果表明,当催化剂中n(Co)∶n(Mo)=1∶2,w(CoO)=2.5%时,在温度320℃、压力1.5 MPa、体积空速4.0 h-1、V(H2)∶V(FCC汽油)=600∶1的条件下,FCC汽油质量脱硫率达92%左右,烯烃体积饱和率42%左右,汽油抗爆指数损失小于1.0个单位,液体质量收率97%~98%,且催化剂的稳定性好。     

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]     

催化汽油氧化及萃取脱硫的反应条件研究

催化汽油氧气氧化及萃取脱硫的实验结果表明,随着催化剂用量增加、氧气分压增大、氧化温度提高、氧化时间延长,汽油脱硫率均持续增大,而汽油收率逐渐降低.对脱硫率和收率影响程度从大到小的顺序均为氧化温度＞催化剂用量＞氧气分压＞氧化时间.随着催化剂水溶液重复使用次数增加,汽油脱硫率呈现先降低然后趋于稳定,而汽油收牢先增人后趋于不变.催化汽油经过催化剂用量3.0 g、温度140℃、氧气分压2.0 MPa、时间40 min条件的氧化处理,接着进行水洗及萃取,脱硫率和收率分别为91.57%和67.66%.     

Molecular-level kinetic modeling of heavy oil fluid catalytic cracking process based on hybrid structural unit and bond-electron matrix

In this presented work, a heavy petroleum fluid catalytic cracking (FCC) process model based on the use of a hybrid structural unit and bond-electron matrix (SU-BEM) framework on a molecular level has been developed. The SU-BEM uses a simplified structural unit to represent the petroleum's molecular structure and chemical conversion, while retaining substantial details regarding atom-connectivity. The chemical reaction information from the FCC unit was characterized in terms of reaction rules, indicating the conversion between structural units. After implementing via iteration the reaction rules on feedstock molecules, a complex molecular reaction network was created, containing all the primary product molecules (~3,800) and the reactions (~7,500). Next, the process mathematical model was built, including the micro-kinetic model and the FCC unit reactor model. For validation purposes, the product yield was selected as a predicted variable. Following a parameter estimation procedure, a good agreement between the calculated and experimental values was observed.     

废塑料裂化生产汽柴油工业化装置研究

报道了废塑料炼油工艺中连续法、间歇法、半连续法等各种方法的特点 ;重点对各工业化流程中存在的问题和解决的方法进行了讨论 ,并提出了一些合理化的建议。     

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.     

The role of kinetics and hydrocarbon distribution in the multiplicities of a two-bed catalytic distillation column for deep hydrodesulfurization

The Damköhler number (Da) is used to research the physical mechanisms leading to multiplicities and the effect of the hydrocarbon distribution on a light gasoil (LGO) deep hydrodesulfurization (HDS) two-bed catalytic distillation column. In doing so, three hydrocarbon mixtures are studied: a real LGO fraction, a synthetic gas oil mixture (SGO), and hexadecane (n-C₁₆). The parametric planes, Da(RR) and Da(B), were obtained for the three mixtures as a function of the reflux ratio, RR, and the bottom flow rate, B. The total sulfur regions (C_s) with respect to Da and RR, and Da and B, were also obtained. RR and B were chosen as bifurcation parameters, since they are frequently used for column operation.Results show that this system is controlled kinetically because the operating point and the multiplicity region lay on the kinetically controlled region (Da ? 1). Results also show that the hydrocarbon distribution plays an important role in the occurrence of multiplicities, as well as exhibiting the importance of choosing a realistic gasoil fraction during process design and lab scale experiments.     

A novel method for enhancing on-stream stability of fluid catalytic cracking (FCC) gasoline hydro-upgrading catalyst: Post-treatment of HZSM-5 zeolite by combined steaming and citric acid leaching

This article describes a novel modification method consisting of steaming and subsequent citric acid leaching to finely tune acidity and pore structure of HZSM-5 zeolite and thereby to enhance the on-stream stability of the zeolite derived fluid catalytic cracking (FCC) gasoline hydro-upgrading catalyst. A series of dealuminated HZSM-5 zeolites and their derived catalysts were prepared and characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), ²⁷Al MAS NMR, nitrogen adsorption, temperature programmed desorption of ammonium (NH₃-TPD) and infrared (IR) spectroscopy of chemisorbed pyridine. The results showed that the citric acid leaching could preferentially remove the extra-framework Al (EFAl) species formed by steaming treatment and thus reopen the EFAl-blocked pore channels of the steamed zeolite. The steaming treatment at a suitable temperature and subsequent citric acid leaching not only decreased the strength of acid sites to a desirable degree but also increased the ratio of medium and strong Lewis acidity to medium and strong Brönsted acidity, both of which conferred the resulting catalyst with superior selectivity to aromatics, good hydroisomerization activity and gasoline research octane number (RON) preservability, as well as enhanced on-stream stability. The results fully demonstrated that the treatments by steaming and followed citric acid leaching can serve as an important method for adjusting the physicochemical properties of HZSM-5 zeolite.     

混合废塑料与焦化蜡油共催化裂解制取燃料油

以混合废塑料和焦化蜡油为原料,共催化裂解制备燃料油,克服了废塑料裂解中塑料粘稠度大且传热效率低、裂解炉中温度极不均匀、反应时间长、气体和固体收率高、液体收率低和易结焦等难题。详细考察焦化蜡油与混合废塑料质量比和催化剂用量对产物组成的影响以及FCC催化剂的重复使用性能。结果表明,在焦化蜡油与混合废塑料质量比为2、FCC催化剂用量为混合废塑料质量的10%、终温460 ℃并保持4 h条件下,燃料油收率达到96.67%,气体收率和釜残率分别仅有0.27%和1.53%。焦化蜡油的添加使液相产物中重组分增多,轻组分减少。FCC催化剂的重复使用性能好,催化剂重复使用5次,液体收率大于85%。采用混合废塑料与焦化蜡油共催化裂解的工艺不仅为“白色污染”的处理开辟了一条新途径,而且扩大了焦化蜡油的应用范围。     

Oxidative desulfurization of synthetic diesel using supported catalysts: Part II. Effect of oxidant and nitrogen-compounds on extraction–oxidation process

Oxidative desulfurization (ODS) of a synthetic diesel was carried out at mild conditions (atmospheric pressure and 60 °C) in presence of V₂O₅/Al₂O₃ and V₂O₅/TiO₂ catalysts. Two main aspects were studied: the effect of the oxidant reagent and the presence of nitrogen compounds on ODS of benzothiophenic compounds prevailing in diesel, such as benzothiophene, dibenzothiophene and alkyl substituted in positions 4 and 6. Results show that activity is improved when using hydrogen peroxide, as oxidant reagent, and V₂O₅/Al₂O₃, as catalyst. This result was attributed to the high decomposition of peroxide due to the presence of catalyst. In presence of nitrogen compounds, the ODS activity decreases in the order: quinoline > indole > carbazole. In order to explain this effect, successive chemisorption of DBT and quinoline on V₂O₅/Al₂O₃ catalyst was evaluated by FT-IR, and the results show that DBT is displaced by quinoline, occupying the adsorption sites of catalyst. N-compound effect could be explained by strong adsorption of nitrogen compounds on catalytic sites.     

A comparative study of liquid product on non-catalytic and catalytic degradation of waste plastics using spent FCC catalyst

Non-catalytic and catalytic degradation of waste plastics (high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS)) using spent fluid catalytic cracking (FCC) catalyst into liquid product were comparatively studied with a stirred semi-batch reactor at 400 ‡C, under nitrogen stream. Liquid product characteristics were described by cumulative distribution as a function of lapse time of reaction, paraffin, olefin, naphthene and aromatic (PONA) composition, and also carbon number distribution on plastic type of reactant. For degradation of waste PE with relatively high degradation temperature, the effect of adding spent FCC catalyst greatly appeared on cumulative distribution of liquid product with a reaction lapse time, whereas those for waste PP and PS with low degradation temperature showed a similar trend in both non-catalytic and catalytic degradation at 400 ‡C. In PONA and carbon number distribution of liquid product, the characteristics of waste PS that was mainly degraded by end chain scission mechanism were not much altered in presence of spent FCC catalyst. However, waste polyolefinic polymer that was degraded by a random chain scission mechanism significantly differed on PONA and carbon number distribution of liquid product with or without spent FCC catalyst. The addition of spent FCC catalyst in degradation of polyolefinic polymer, which economically has a benefit in utilization of waste catalyst, significantly improved the light olefin product by its high cracking ability and also the aromatic product by cyclization of olefin as shape selectivity in micropore of catalyst.     

催化剂制备中的磨损强度及其对催化性能的影响

催化裂化（FCC）催化剂制备装置的催化剂损耗主要取决于催化剂的粒度分布、磨细粉量和沸石催化剂的活性稳定性。考察了不同工艺制备的催化剂耐磨性能和反应性能的差异。