FDFCC工艺中汽油提升管催化裂化反应动力学模型研究

利用中国石化长岭分公司1号催化裂化装置实测数据，采用集总理论研究FDFCC工艺汽油提升管内的催化反应行为。根据集总原则，将汽油提升管内反应系统的原料和产品按馏程及烃族组成划分为九个集总组分，通过合理简化反应网络，建立九集总反应动力学模型，并求取25组反应动力学参数，并对不同性质原料在不同操作条件下的产品分布进行验证。结果表明，该模型能较好预测汽油产品组成及液化气中高附加值的丙烯产率。对FDFCC模型的进一步开发研究和FDFCC工艺的汽油降烯烃生产具有一定的指导意义。     

直接生产清洁汽油的FDFCC工艺

FDFCC是理想的降低FCC汽油烯烃和硫含量的工艺技术。中试及工业应用结果表明:FDFCC装置操作稳定可靠、工艺参数调节灵活。汽油提升管反应器对催化汽油的改质效果十分显著,改质汽油烯烃含量可下降至18%(φ)以下,芳烃增加13个百分点以上,硫含量下降20%～30%,改质汽油诱导期>1000min,MON和RON不下降,苯含量<1%。采用适当的FDFCC工艺形式,可直接生产满足国内清洁燃料或欧洲Ⅲ类燃料标准的清洁汽油。     

灵活双效催化裂化技术的开发

洛阳石化工程公司开发的灵活双效催化裂化(简称FDFCC)工艺,设有两根提升管反应器,它兼有催化裂化和汽油改质、增产烯烃的功能,操作灵活。该公司还与兰州炼化总厂共同开发了适合FDFCC工艺的LL型催化剂.介绍了该工艺的中试和工业试验结果.     

国内催化裂化装置降低汽油烯烃技术进展

介绍了国内催化裂化装置降低汽油烯烃含量的新丁艺及催化剂,包括辅助反应器改质降烯烃技术、灵活多效催化裂化工艺(FDFCC)、两反应区(MIP)工艺、两段提升管工艺(TSRFCC)、多产柴油液化气并降烯烃(MGD)技术等.对各种工艺的特点以及工业应用情况进行了对比.     

降低催化裂化汽油烯烃技术--FDFCC工艺

根据催化裂化过程中烯烃转化机理，提出了一种并联双提升管催化裂化反应体系——FDFCC工艺，其中一根提升管用于重油裂化，另一根用于汽油改质。工业实施结果表明，该工艺可以显著降低催化裂化汽油的烯烃含量，烯烃体积分数降低20～30个百分点，硫含量下降15％～20％，改质汽油诱导期增加，MON和RON略有增加，芳烃中苯含量基本维持不变，芳烃含量虽有所提高，但远远小于规定指标。与常规FCC工艺相比，FDFCC工艺的汽油产率下降4～5个百分点，液化气和柴油产率均增加2个百分点左右，(焦炭 干气)产率增加小于1个百分点。     

利用FDFCC工艺降低FCC汽油硫含量

降低FCC汽油硫含量是降低车用成品汽油硫含量、减少汽车尾气污染的关键。FDFCC工艺采用双提升管反应器并采用和分别适宜于重油裂化和汽油改质的工艺条件 ,可使FCC汽油硫含量下降 2 0 %～4 0 % ,烯烃含量降低 2 0 %～ 30 % ,汽油诱导期和辛烷值增加 ,苯含量基本维持不变 ,是降低FCC汽油硫含量的有效措施。     

利用FDFCC工艺降低FCC汽油硫含量

降低FCC汽油硫含量是降低车用成品汽油硫含量、减少汽车尾气污染的关键。FDFCC工艺采用双提升管反应器并采用和分别适宜于重油裂化和汽油改质的工艺务件，可使FCC汽油硫含量下降20％～40％，烯烃含量降低20％～30％，汽油诱导期和辛烷值增加，苯含量基本维持不变，是降低FCC汽油硫含量的有效措施。     

增产丙烯和生产清洁汽油新技术—FDFCC-Ⅲ工艺

 在对目前国内外先进的催化裂化技术分析的基础上,结合FDFCC工艺特点,提出了 实现"低温接触、大剂油比"的创新思想,开发了增产丙烯和生产清洁汽油的FDFCC-Ⅲ工艺。中试结果表明,FDFCC-Ⅲ工艺能大幅度减少热裂化反应,增强催化裂化反应,促进原料硫向裂化气中转移。在中国石化长岭分公司1号催化裂化装置上进行工业应用的结果表明,重油提升管底部催化剂温度为630℃,剂油比为9.82;液化气及丙烯产率分别为26.66%和10.23%,干气产率仅为为4.33%,汽油中烯烃体积分数为17.7%,汽油硫含量为0.032%。因此,该工艺技术能显著改善产品结构和产品性质,实现清洁汽油生产,具有良好的社会效益和经济效益。     

FDFCC汽油改质机理及反应条件探讨

分析了FDFCC工艺汽油改质的反应机理和热力学。提出了降低催化裂化汽油烯烃、提高辛烷值及增产丙烯所应采取的反应条件,列出了工业试验结果。     

FDFCC—Ⅲ专用催化剂研究

介绍了FDFCC-Ⅲ专用催化剂各组分的筛选及制备方法，并对其物性进行了考察。选择参比催化剂在固定床及提升管催化裂化试验装置上进行了评价。结果表明，研制的FDFCC—Ⅲ专用催化剂具有较好的重油裂化能力，同时对降低焦炭产率和增产丙烯都具有显著的效果；在汽油提升管中可以同时实现汽油降硫、降烯烃和提高汽油辛烷值等目标，具有良好的汽油改质效果。     

A Kinetic Model for Flexible Dual-riser Fluid Catalytic Cracking Process

According to the mechanism of catalytic cracking reactions, the characteristics of flexible dual-riser fluid catalytic cracking (FDFCC) process, a 10-lumped kinetic model for heavy oil riser reactor and a seven-lumped kinetic model for gasoline riser reactor were developed in the article to simulate the FDFCC process. Based on the data from a commercial FDFCC unit, 43 kinetic parameters for the ten-lumped kinetic model and 18 kinetic parameters for the seven-lumped kinetic model were calculated by the stepwise method. The validity check of the model show that the calculated values of the models are close to the commercial data. In general, the two models could not only describe reaction rules of the FDFCC process correctly but also give good prediction for the distribution and composition of main products, especially for gasoline and propylene.     

Study on Lumped Kinetic Model for FDFCC I. Establishment of Model

According to the process features and the reaction mechanism of FDFCC technology, its two reaction subsystems, one for heavy oil riser reactor, the other for gasoline riser reactor, were respectively studied. Correspondingly, a 12-lump kinetic model for heavy oil FCC and a 9-lump kinetic model for gasoline catalytic upgrading were presented. Based on this work, mathematical correlation of the lumps in the feeds and products involved in the reaction subsystems and those of the overall reaction system were analyzed in detail. Then, a combined kinetic model for FDFCC, which was based on the data recovered from a commercial unit, was put forward. The reaction performance embodied by the kinetic constants for the combined model of FDFCC was in accordance with catalytic cracking reaction mechanism. The model-calculated values were close to the data obtained in commercial scale. The model was easy to be applied in practice and could also provide some theoretical groundwork for further research on kinetic model for FDFCC.     

Study on Lumped Kinetic Model for FDFCC II. Validation and Prediction of Model

On the basis of formulating the 9-lump kinetic model for gasoline catalytic upgrading and the 12-lump kinetic model for heavy oil FCC, this paper is aimed at development of a combined kinetic model for a typical FDFCC process after analyzing the coupled relationship and combination of these two models. The model is also verified by using commercial data, the results of which showed that the model can better predict the product yields and their quality, with the relative errors between the main products of the unit and commercial data being less than five percent. Furthermore, the combined model is used to predict and optimize the operating conditions for gasoline riser and heavy oil riser in FDFCC. So this paper can offer some guidance for the processing of FDFCC and is instructive to model research and development of such multi-reactor process and combined process.     

A lumped kinetic model for heavy oil catalytic cracking FDFCC process

Based on the reaction mechanisms and the characteristics of flexible dual-riser fluid catalytic cracking (FDFCC) process, the reaction networks of 10 lumps for heavy oil and seven lumps for gasoline were put forward. The cracking reactions of resin and asphaltene into gasoline and gases in heavy oil riser reactor were considered as second-order ones while the other reactions were described as first-order ones. The kinetic parameters indicate good consistence with the reaction rules of heavy oil catalytic cracking. The relative errors between calculated values and actual values of products are all less than 4%, which shows the reliability of the models.     

FDFCC工艺中重油提升管催化裂化反应动力学模型

 以国内首套FDFCC(灵活多效催化裂化)工业化装置—中国石化长岭分公司1^#重油提升管催化裂化装置的标定数据为基础，根据催化裂化反应机理，针对提升管内重油催化裂化特点及产品应用需要，采用集总理论，合理简化反应网络，建立了重油12集总催化裂化反应动力学模型。该12个集总为：原料饱和分[S_S]、芳香分[S_A]、胶质及沥青质[S_R]、柴油[D_I]、汽油饱和烃[G_S]、烯烃[G_O]、芳烃[G_A]、液化气中烷烃[L_P]、丙烯[L_O3]、丁烯[L_O4]、干气[D_R]和焦炭[C_K]。求取了56组动力学参数，并对不同原料、不同工况下的2组工业数据进行了验证。结果表明，模型能够预测重油提升管出口主要产品分布及其性质，相对误差均小于5%。本研究结果对FDFCC工业装置重油催化裂化提升管操作具有指导意义。     

A lumped kinetic model for heavy oil catalytic cracking FDFCC process

Based on the reaction mechanisms and the characteristics of flexible dual-riser fluid catalytic cracking (FDFCC) process, the reaction networks of 10 lumps for heavy oil and seven lumps for gasoline were put forward. The cracking reactions of resin and asphaltene into gasoline and gases in heavy oil riser reactor were considered as second-order ones while the other reactions were described as first-order ones. The kinetic parameters indicate good consistence with the reaction rules of heavy oil catalytic cracking. The relative errors between calculated values and actual values of products are all less than 4%, which shows the reliability of the models.     

MIP技术在提高液体产品收率上的先进性分析

对具有代表性的工业MIP装置与FDFCC装置、FCC装置和TSRFCC装置的液体产品收率进行对比分析。结果表明：无论是以加氢重油还是以加氢蜡油或者是常压渣油为原料,采用MIP工艺时,汽油与液化气产率均较高,而干气与油浆产率较低,液体产品收率较高;与其它同类技术相比,其液体产品收率最少提高2百分点;且MIP技术的汽柴比高,所生产汽油硫含量低、烯烃含量较低而辛烷值与其它技术相当或较高。这主要是由于MIP技术采用具有独特的双反应区的提升管反应器,并在不同反应区内设计了与烃类反应相适应的工艺条件,可强化重油转化能力,减少干气和焦炭产率,从而提高总液体产品收率。