A new generic reaction for modeling fluid catalytic cracking risers

A new generic reaction in the form of PCi → PCm + [i,m] → PCm + λi,m coke + surplusage has been proposed for describing the catalytic cracking behavior of petroleum narrow cuts or pseudo-components (PCs),where the rate constant formula is derived from the transition state theory and the coking amount is correlated to the properties of the intermediate substance [i,m].In composing the cracking reaction network for feedstock and product oils,only the product PCm of the proposed generic reaction is used,which together with a criterion for excluding exothermic reactions,distinctly reduces the number of reactions in the network.With the proposed cracking reaction scheme coupled with special pseudo-components,a predictive one-dimensional steady state model for fluid catalytic cracking risers is formulated in the sense that for a given riser and given catalyst,the model parameters are independent of stock oils,product schemes and other operational conditions.The great correlating and predicting capability of the resulted model is tested with production data in different scenarios of four commercial risers.     

石油加工中的催化裂化技术分析

现代石油加工工业的技术发展中,催化加工工艺的重要性越来越明显。催化加工对原料具有更好的适应能力,产品也具有清洁纯净和耗能较低的特点。文章分析了影响石油加工中催化裂化的影响因素,分析了反应一再生装置的技术不同特点和催化剂的发展过程,提出了石油加工催化裂化的发展目标。     

Computational fluid dynamics modeling of biomass catalytic fast pyrolysis in bubbling fluidized reactor: Effects of catalyst parameters on process performance

In this study, a computational fluid dynamics mathematical model has been developed for catalytic fast pyrolysis (CFP) of biomass based on multiphase flow, transfer process, and biomass pyrolysis reactions in a bubbling fluidized bed reactor. The multiphase fluid flow, and the inter-phase momentum and energy transfer processes are modeled with Eulerian multiphase formulas, representing the flows of gases and solids (catalyst and biomass) within the reactor. The biomass CFP reactions are described by using a two-stage, semi-global model. Specified secondary tar catalytic cracking process, which considers both intrinsic reaction rates and mass-transfer process, is embedded to the developed model by user-defined function. The model simulation results of pyrolysis product yield and distribution are compared with the experimental data with close agreement. The model is then employed to investigate the effects of structural properties of catalyst, such as specific internal area, average size of active sites, pore diameter, and tortuosity, on products yields and composition. The tar cracking process by the selected catalyst is proposed and the influences of adsorption capability of tar molecule on catalyst surface and external film mass transfer are also analyzed. The developed model can be solved with short computational time and thus it can be employed for further research and engineering designs of the catalytic pyrolysis of carbonaceous materials.     

磷酸二异辛酯的合成研究

乙烯裂解生产过程中存在的一个突出的问题是结焦,磷酸二异辛酯的吗啉盐是一种新型的结焦抑制剂.本实验就是以磷酸和异辛醇为原料,通过改变催化剂的种类、酸醇比、催化剂用量、反应时间等条件来合成磷酸二异辛酯.钨磷酸含量为5.0％时催化剂活性最好;产品收率随催化剂用量的增大而提高,当催化剂用量超过2.0％时,产品收率基本不变;增大...     

催化裂化过程中的热裂化与催化裂化

研究了催化裂化过程中热裂化反应和催化裂化反应的特点和影响因素 .结果表明反应温度、剂油比和反应时间能显著地影响热裂化反应和催化裂化反应 .采用适当的催化剂和短反应时间能抑制催化裂化过程中不利的热裂化反应 ,达到调整产品分布和产品组成的目的 .     

催化裂化过程中的热裂化和二次反应研究

研究了催化裂化过程中热裂化反应和催化裂化反应的特点和影响因素。结果表明,反应温度、剂油比和反应时间能显著地影响热裂化反应和催化裂化反应。采用缩短反应时间的方法,能抑制催化裂化过程中不利的热裂化反应和二次裂化反应,达到调整产品分布和产品组成的目的。     

生物质炭在焦油裂解脱除领域的研究进展

基于生物质焦油的组成特性、危害及其处理方法,简单介绍了生物质焦油催化裂解脱除的机理及近年来的研究进展,重点阐述了生物质炭对焦油的催化转化机理(主要涉及裂解、重整和缩合3种反应)、生物质炭对焦油的吸附和重整作用,以及在催化转化过程中,生物质炭的催化性能受原料、裂解温度、加热速率和停留时间等因素的影响.通过分析生物质炭改性...     

催化裂化多产丙烯技术研究进展

丙烯是重要的基本有机化工原料,近年来由于受到其下游衍生物需求的驱动,全球丙烯的年需求量一直持续增长。我国重油资源丰富,价格相对低廉,重油催化裂化多产丙烯技术受到广泛关注。本文主要论述了催化裂化增产丙烯技术的工艺和催化剂研究进展情况。     

The effect of pre‐coking on the activity and selectivity of the catalytic cracking of squalane

The pre‐coking of cracking catalysts has been reported to increase the yield of light cycle oil from fluid catalytic cracking. The present studies investigating an equilibrated catalyst show that this is not the case. The effect of pre‐treating equilibrated catalysts with coke and with ammonia shows that conversion was decreased in both cases and the product selectivity of the process changed. Both coke and ammonia were found to decrease site density, reducing the importance of hydrogen transfer reactions. Increased yields of light cycle oil as a result of pre‐coking can only be expected with fresh catalyst, where small amounts of coke deactivate the most acidic sites. Such sites have already been deactivated on equilibrated catalyst. Copyright © 2004 Society of Chemical Industry     

烟气轮机结垢原因分析及预防措施

通过对中国石油吉林石化公司炼油厂140万t/a催化装置烟气轮机结垢实例进行详细的数据分析,结果表明铁、钠、钙等金属污染催化剂造成的后果不容忽视。针对催化裂化装置原料中重金属发生变化,导致催化剂骨架强度降低、催化剂破碎、并伴生有低熔点共熔物与催化剂细粉结合导致的烟机结垢,经过优化原料性质、增加系统催化剂置换、监控催化剂粒度及重金属含量等措施可以有效预防,解决烟机结垢问题。     

A molecular kinetic model incorporating catalyst acidity for hydrocarbon catalytic cracking

This work built a molecular-level kinetic model for hydrocarbon catalytic cracking, incorporating the catalyst acidity as the parameter to estimate reaction rates. The n-decane and 1-hexene co-conversion catalytic cracking process was chosen as the studying case. The molecular reaction network was automatically generated using a computer-aided algorithm. A modified linear free energy relationship was proposed to estimate the activation energy in a complex reaction system. The kinetic parameters were initially regressed from the experimental data under several reaction conditions. On this basis, the product composition was evaluated for three catalytic cracking catalysts with different Si/Al. The Bronsted acid and Lewis acid as the key catalyst properties were correlated with kinetic parameters. The built model can calculate the product distribution, gasoline composition, and molecular distribution at different reaction conditions for different catalysts. This sensitive study shows that it will facilitate the model-based optimization of catalysts and reaction conditions according to product demands.     

Kinetic study of propane dehydrogenation and side reactions over Pt–Sn/Al2O3 catalyst

The kinetics of reactions involved in dehydrogenation of propane to propylene over Pt–Sn/Al₂O₃ catalyst was studied. The simultaneous deactivation of individual dehydrogenation, hydrogenolysis and cracking sites was also studied. A model was developed to obtain the transient conversion of propane, product selectivity and catalytic site activity. The dehydrogenation reaction was considered as the main reaction governing propane and hydrogen concentrations along the reactor. Catalytic test runs were performed in a fixed-bed quartz reactor. The kinetic expressions developed for the main and side reactions were verified by integral and a combination of integral–differential analysis of reactor data, respectively, and the kinetic parameters were obtained. The deactivation of the active sites for the three reactions was found to follow a first-order independent decay law. The rate constants of deactivation were found to decrease in the order of dehydrogenation, hydrogenolysis and cracking. Noncatalytic thermal cracking was found to be comparable to the catalytic route resulting in a very low apparent deactivation rate constant for cracking reaction.     

催化精馏技术在酯化反应中的应用

催化精馏技术应用于酯化反应体系,提高了反应的转化率,原材料利用率和产品收率。与传统工艺相比,具有生产流程简单、能耗低,设备投资和操作费用低、无环境污染等优点。催化精馏技术应用于酯化行业生产,对提高酯化行业的技术水平和经济效益具有积极意义。     

轻汽油催化裂解生产丙烯催化剂的研究

采用HZSM-5和改性的HZSM-5催化剂,以抚顺石油二厂初馏点~75℃的催化裂化轻汽油馏分为原料,在实验室连续固定床反应装置上进行了催化裂化轻汽油的催化裂解反应,考察了反应条件对催化裂化轻汽油裂解及芳构化反应的影响和A l2O3作为催化剂的载体对HZSM-5催化剂上催化裂解产品分部的影响,并且考察了载镧HZSM-5催化剂上主要产品分布的影响。研究结果表明,在载镧量5%左右的催化剂上,丙烯产率比改性前下降5%、芳烃产率下降15%;当催化剂中载体组分为30%时,丙烯产率最高为38.26%,芳烃产率为26.26%,同不使用载体相比,芳烃产率下降了5.1%。     

过滤技术在油浆分离中的应用

在催化裂化、加氢裂化等催化反应过程中,产品油浆中催化剂细粉不仅会导致下游设备的腐蚀和堵塞,也限制和降低了其直接作为产品、副产品的应用领域和经济价值。而对于低温费托合成反应而言,将费托合成蜡从气液固三相的浆态床反应器内分离出来,是整个费托合成工艺的的技术难点和关键之一。由此看出,油浆分离和净化技术的选择关系到以上催化反应的稳定运行和产品质量。本文回顾了目前国内外油浆过滤技术的研究及工业应用现状,总结了以美国MOTT公司为代表的金属烧结粉末和Pall公司为代表的金属烧结丝网两种主流滤芯的机械加工特性和过滤精度等特点,从操作条件、分离效率、反冲洗方式等方面进行比较,分析了各种油浆过滤技术的工艺特点,以及过滤工艺与参数对过滤效果和过滤技术选择的影响,可以为传统石油化工油浆过滤以及费托合成浆态床过滤分离技术在滤芯和过滤工艺选择等方面提供参考。     

Secondary Cracking of C4 Hydrocarbons from Heavy Oil Catalytic Pyrolysis

For C4 hydrocarbons from heavy oil catalytic pyrolysis, the cracking behaviours on catalyst CEP‐1 and quartz sand were investigated in a confined fluidized bed reactor. C4 hydrocarbons show a good cracking ability on CEP‐1, and butene is easier to convert than butane. Only at high reaction temperatures can butane present a good cracking ability. On catalyst CEP‐1, C4 hydrocarbons can undergo not only cracking reactions, but also such reactions as hydrogen transfer, polymerization and aromatization. The conversion of C4 hydrocarbons thermal pyrolysis is high, indicating that free radical reactions play an important part in the secondary cracking of C4 hydrocarbons. The product yields of C4 hydrocarbons pyrolysis on quartz sand are usually lower than those on catalyst CEP‐1. For both catalytic pyrolysis and thermal pyrolysis of C4 hydrocarbons, the selectivity of propene is higher than that of ethene.     

长庆原油适宜加工方案分析

摘要：介绍了对长庆原油进行的综合评价。结果表明：长庆原油属于优质的轻质低硫含蜡原油,馏分分布状况好。在生产装置炼制时,常、减压负荷均衡,易于平衡操作。初馏点-180℃馏分可做大乙烯裂解原料,但更适合做重整原料;145-240℃喷汽燃料组分收率较高,铜片腐蚀、硫醇硫不合格,说明长庆原油喷汽燃料中活性硫化物较多,在精制时应注意;柴油馏分柴油指数高、十六烷值大,腐蚀、酸度均符合成品柴油的标准。减压蜡油酸值小、粘度指数高,是生产润滑油基础油的理想原料,同时其Cp高、残炭值低,重金属含量不高,也是理想的催化裂解原料;〉520℃的渣油沥青质含量较高,是生产沥青的理想原料,如果作为催化裂化原料,必须考虑调配比例,以防催化剂中毒。     

Biofuel potential production from cottonseed oil: A comparison of non-catalytic and catalytic pyrolysis on fixed-fluidized bed reactor

Conversion of vegetable oils predominantly composed of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to compare catalytic cracking with thermal cracking on production of gaseous hydrocarbon and gasoline conversion by cottonseed oil, and to discuss the difference on composition of products from catalytic cracking and thermal cracking. Reaction products are heavily dependant on the catalyst type (catalyst activation) and reaction conditions. They can range from dry gas to light distillate, such as dry gas, liquefied petroleum gas and gasoline. When the temperature of catalytic cracking is over 460 °C, the effects of thermal cracking must be considerable.     

CGP-C催化剂提高汽油辛烷值的工业应用

加工大庆类原料的催化裂化装置产品收率中汽油辛烷值普遍较低,中国石油吉林分公司炼油厂三催化装置加工原料为大庆常渣,催化装置通过MIP改造,催化稳定汽油辛烷值提高至约91.5,使用新配方CGP-C催化剂,稳定汽油辛烷值又提高1.6个单位,装置年增加经济效益超过9 000万元。     

经济型轻蜡油加氢改质降凝工艺的开发及工业应用

一重集团大连工程建设有限公司开发的轻蜡油加氢改质降凝工艺具有对原料油和已有加氢装置适应能力强、操作灵活性大及柴油产率高等特点。该工艺技术关键是使用自主开发的HPH型加氢精制催化剂及具有异构和裂化多功能的HPC型加氢改质催化剂。工业应用结果表明,该工艺能够对原料油进行深度加氢精制脱硫、脱氮,芳烃深度加氢饱和,产品收率高,有效降低柴油产品的凝点、密度和馏程,显著提高柴油的十六烷值,是经济型生产清洁柴油的优选工艺,具有广阔的应用前景。