灵活多效催化裂化工艺反应动力学模型研究

根据催化裂化反应机理和灵活多效催化裂化(FDFCC)工艺特点,结合中试数据,分别确定了针对FDFCC工艺重油提升管的10集总和汽油提升管的7集总反应网络。将重油提升管中胶质沥青质向汽油、气体的裂化作为二级反应,其余(包括汽油提升管中全部反应)均作为一级不可逆反应,分别建立了10集总和7集总反应动力学模型。通过Runge-Kutta法与变尺度法(BFGS)相结合求取了模型的动力学参数。对动力学参数的分析表明,所求得的模型参数能够较好地反映催化裂化反应规律和FDFCC-Ⅲ工艺特点。模型对产品的计算值与实际值的相对偏差均小于5%,表明所开发的集总模型是可靠的。     

FDFCC多产汽油工艺研究

在多产优质汽油的背景形势下,提出了灵活多效催化裂化多产汽油工艺,即FDFCC工艺第二提升管加工催化柴油或其加氢精制柴油,通过劣质柴油裂化生产汽油。通过不同反应条件下的中试考察,得到了相应的中试产品分布和产品性质,同时结合FDFCC工艺装置,给出了优化的反应条件及建议:推荐FDFCC装置第二提升管加工加氢精制柴油轻馏分,反应温度480℃,第二提升管生成汽油RON为96.1,FDFCC全装置汽油产率达到65%以上。     

工业渣油催化裂化过程六集总组合反应器模型

工业渣油催化裂化反应主要发生在提升管段和出口的沉降器段的复杂流体动力学区域。通过对工业现场装置流程和过程数据的分析,将发生裂化反应的整个反应器中提升管部分作为活塞流反应器(PFR)和沉降器部分作为全混流反应器(CSTR)的串联组合反应器,并按照渣油催化裂化反应特点建立了简化的6集总组分的串行和并行动力学反应网络模型。所建立的稳态催化裂化反应产率预测模型在数学上表现为提升管部分的微分方程组和沉降器部分的代数方程组。模型设置7个装置因数来校正模型的计算产率与实测产率之间的偏差,并采用工业现场数据回归装置因数。通过对工业装置数据的计算比较,得到的模型产率预测精度很好地满足在线软测量计算要求。     

催化裂化提升管反应器建模研究

根据提升管反应器的动态机理,考虑反应对压力的影响,结合物料平衡、能量平衡方程,建立了馏分油5集总催化裂化反应动力学模型。使用Nelder-Mead最优化法进行了参数的拟合,并用MATLAB对模型进行了仿真。通过对工业装置数据的计算比较表明,该模型能较好的预测催化裂化产品产率,可用于实际催化裂化过程。     

基于汽油烯烃转化的催化裂化动力学模型

以催化裂化反应机理为基础,把FCC原料及产品按馏程和化学组成进行集总划分.考虑氢转移、芳构化等二次反应,通过对反应网络的合理简化,提出了一种分子水平的动力学模型.通过参数估计求取18个动力学速度常数,建立集总动力学模型以预测汽油的化学结构组成.研究结果表明：该模型能较好预测不同条件下的产率分布,而且可以预测汽油组成分布,有助于降低汽油烯烃含量的研究.     

稠密气体理论在催化裂化提升管中的应用

运用已建立的颗粒动力学模型并耦合催化裂化反应的十三集总动力学模型，建立了催化裂提升管反应器内反应油气和催化剂颗粒的传质，反应的数学模，结合工业提升管的操作参数，模拟预测了速度场，温度场和组分分布。     

提升管催化裂化反应过程数值模拟

在气固两相流体动力学模型的基础上.采用基于机理反应的FCC14集总模型.考虑了反应温度、局部固体浓度变化以及流动对反应的影响,建立了重油流化催化裂化流动一一反应耦合模型.模拟结果表明,重油裂化反应主要发生在喷嘴附近区域,在喷嘴附近已经有45%的重油转化为汽油和柴油.随着距离喷嘴位置的增加,汽油产率逐渐上升,但距离喷嘴位置12m以后,汽油产率基本保持不变.从汽油组成变化来看,在整个提升管内汽油中烯烃含量一直处于下降趋势,由喷嘴区域的60wt%降低到提升管出口位置的42wt%左右.汽油烷烃含量一直呈增加趋势,而汽油中环烷烃含量和芳烃含量变化较小.     

FCC汽油二次反应动力学模型研究进展

介绍了针对催化裂化汽油二次反应降烯烃及增产丙烯过程的动力学模型,包括各种集总动力学模型、结构导向集总与蒙特卡洛相结合的分子尺度动力学模型,以及可以预测汽油二次反应产物分布的人工神经网络和预测丙烯产率的支持向量机等黑箱模型。     

催化裂化助剂CXM—03的实验室评价及工业应用

对新型高效催化裂化助剂CXM -03的小型提升管催化裂化试验装置进行了评价 ,并在一催化装置上进行了工业应用。结果表明 ,在催化原料油中加入6×10 -5～8×10 -5该助剂后 ,总轻油收率上升2.1个百分点。气体中 ,丙烯产率上升1个百分点 ,干气及焦炭产率降低1.2个百分点 ,催化汽油烯烃含量、硫含量都有不同程度的降低。使用该助剂具有明显的经济效益和社会效益     

工业催化裂化过程在线工艺计算技术开发与应用

针对MIP工艺的原料（减渣／油浆层、蜡油／回炼油层、柴油层）和产物（汽油、液化气＋干气、焦炭）六个集总组分渣油催化裂化动力学模型,并根据某工业催化裂化提升管反应器流场特性应用序列理想平推流反应器与理想全混流反应器模型的混合反应器模型,建立了工业渣油催化裂化装置反应再生过程工艺计算模型。结合采用由化验值校正和模型参数交替校正的双重校正策略,在某工业连续催化裂化装置上进行在线工艺计算应用,以在线预测过程的裂化产物收率与产物分布。在进料和反应操作条件较大的变化范围内,在线预测趋势和预测精度均令人满意,符合工业过程先进控制的工艺计算精度需求。     

Modelling the kinetics of fast catalytic cracking reactions

Instantaneous kinetic constants and gasoline selectivities have been determined for catalytic cracking of n-hexadecane. The pulse technique was used in order to model the sequential build-up of coke which occurs on cracking catalyst within a riser transport-line reactor. The total amount of hydrocarbon injected per unit weight of catalyst was between 0 and 10. The mathematical model used to analyze the data was based on the unsteady state mass balance of the microcatalytic reactor with the assumption of plug flow. Results suggest a fast deactivation process during the run with fresh catalyst, while regenerated catalyst showed a slower deactivation. The catalyst regenerated three times evidenced a low apparent activation energy when temperature was increased from 500°C to 550°C.     

Kinetic modeling of FCC process

Catalytic cracking of petroleum fractions a process termed as FCC is usually carried out in a reactor block with somewhat complicated hydrodynamic regime. The reactor block is considered as a combination of two different reactors. The riser is a near ideal plug-flow displacement of the catalyst and reaction mixture, while the main reactor vessel (separator) is considered as an ideal mixing CSTR. Temperature gradient along the plug-flow riser can vary on a linear and non-linear dependence. This is reflected by the thermal effect on the cracking products, along the altitude of the riser. Moreover, it can exert a considerable influence on the selectivity of the process in general, as characterized by the diversity of different hydrocarbon groups both in the gaseous and liquid products. The fluid catalytic cracking (FCC) is a process of conversion of a heavy oil fraction into lighter products in a catalytic fluidized reactor. The chemical composition and the structure of the feed are reflected on the catalyst's selectivity and the amount of coke deposited. It is, therefore, necessary to consider the feed type on modeling the process. Cracking reaction in the model was represented as a five-stage process. Reaction rates for the plug-flow riser and the ideal mixing separator are described mathematically in differential and algebraic forms. The model takes into account, exponential dependence of the specific reaction rate on temperature, as well as reflects the influence of the real and bulk catalyst densities, circulation rate, equilibrium and fresh catalyst's activities, reactor pressure, feed rate and unit construction. The model was developed based on a data taken from an industrial FCC unit, that were used to compute the kinetic constants and other parameters. Concrete computed kinetic parameters were compared with corresponding experimental data for adequacy. FCC process is in constant technological development with modernization of especially the riser reactor. Kinetic modeling of the catalytic FCC reactor will give a further understanding of the process and explain the complicated mechanism involved for an efficient and optimal conversion of the feed stock.     

汽油催化改质反应过程数值模拟

在汽油催化反应动力学模型和气固两相流动模型的基础上，建立了汽油改质反应过程流动-反应耦合模型。针对不同的转化反应器构型（提升管、提升管-床层反应器），对汽油改质过程进行了数值模拟。模拟结果表明，对提升管反应器而言，汽油经过低温改质反应后，烯烃含量可以从35.1%降低到18%左右，烯烃降低幅度可达48%，汽油中烯烃主要转化为异构烷烃。另外，随着反应温度的升高，汽油转化反应中的裂化反应增强，导致汽油收率下降。对于提升管-床层反应器而言，汽油中的烯烃含量可以降得更低，在床层空速4时，烯烃含量可以降低到5%左右，汽油收率为80%左右。     

大庆常渣催化裂解反应动力学模型

An 8-lump kinetic model was proposed to predict the yields of propylene,ethylene and gasoline in the catalytic pyrolysis process of Daqing atmospheric residue.The model contains 21 kinetic parameters and one for catalyst deactivation.A series of experiments were carried out in a riser reactor over catalyst named LTB-2.The kinetic parameters were estimated by using sub-model method,and apparent activation energies were calculated according to the Arrhenius equation.The predicted yields coincided well with the experimental values.It shows that the kinetic parameters estimated by using the sub-model method were reliable.     

下行式循环流化床用于催化裂化过程的数学模拟

采用十一集总动力学,结合气固流体力学行为和轴、径向扩散行为,建立了适合于提升管及下行式循环流化床催化裂化的数学模型,采用此模型对催化裂化过程计算的结果表明,下行床内目的产品选择性显著高于提升管,但在与工业提升管相同的操作条件下,下行床内原料转化率较低,优势不能发挥。适当增加下行床长度、增大床径、使物料循环反应、增加剂油比、提高反应温度或反应压力等可以改善下行床的反应效果。下行床用于催化裂化过程,与之较匹配的应该是具有更高活性的催化剂,研制新型高活性催化剂也是下行床推向工业的重要措施之一。     

A novel conceptional process for residue catalytic cracking and gasoline reformation dual-reactions mutual control

Based on the subsidiary riser FCC (SRFCC) process for gasoline reformation [Y.H. Bai, J.S. Gao, S.C. Li, C.M. Xu, Petrol. Process. Petrochem. (China) 35 (2004) 17–21, J.S. Gao, C.M. Xu, Y. Mao, et al., Petrol. Refin. Eng. (China) 35 (2005) 7–9], a novel conceptional process for residue catalytic cracking and gasoline reformation dual-reactions mutual control (DMC) was proposed and relevant experimental researches were carried out in a Technical Pilot Scale Riser (TPSR) FCC apparatus. The goals of DMC were to improve product quality and increase desirable product yield in residue catalytic cracking as well as in FCC gasoline upgrading. The experiments showed that the decrease of temperature difference between feedstock and regenerated catalysts in DMC by directly leading the cooled regenerated catalysts into riser reactor or feeding gasoline into riser reactor in vapor phase could decrease the amount of dry gas and coke and obtain a better quality of upgraded gasoline. Moreover, the spent catalysts still retaining high level of activity could be recycled to the base of the main riser reactor treating heavy oil and mixed with regenerated catalysts in DMC, it allows residue catalytic cracking to operate at high catalyst-to-oil ratio and the relatively low inlet catalysts temperature. The experimental results also showed that the mixed catalysts could improve the product selectivity in residue catalytic cracking, especially for light oil (gasoline and diesel). In addition, compared with the routine RFCC, the product distribution from the residue catalytic cracking in DMC contains more liquid products, less dry gas, and a better gasoline quality.     

催化裂化汽油降烯烃改质过程的能量优化

针对催化汽油辅助提升管改质降烯烃技术(ARFCC)存在能耗偏高的特点,采用"三环节"模型和经济理论对辅助系统的用能状况进行了研究,提出了以优化的辅助分馏塔热量为热源,粗汽油为主要热阱的换热网络,以最大限度地提高辅助分馏塔能量的利用效率,实现粗汽油气相进料的汽油改质过程的能量优化。研究表明:通过降低辅助提升管油剂接触温差,将辅助分馏系统的较低品质热量转换成等量的反再系统高品质热量,可达到催化裂化装置的能量升级利用;并使油剂混合过程中的损降低85%;回收环节的回收率从44%提高到57%,从而降低了汽油降烯烃改质过程的能耗。     

A new generic approach for the modeling of fluid catalytic cracking (FCC) riser reactor

A new kinetic model for the fluid catalytic cracking (FCC) riser is developed. An elementary reaction scheme, for the FCC, based on cracking of a large number of lumps in the form of narrow boiling pseudocomponents is proposed. The kinetic parameters are estimated using a semi-empirical approach based on normal probability distribution. The correlation proposed for the kinetic parameters’ estimation contains four parameters that depend on the feed characteristics, catalyst activity, and coke forming tendency of the feed. This approach eliminates the need of determining a large number of rate constants required for conventional lumped models. The model seems to be more versatile than existing models and opens up a new dimension for making generic models suitable for the analysis and control studies of FCC units. The model also incorporates catalyst deactivation and two-phase flow in the riser reactor. Predictions of the model compare well with the yield pattern of industrial scale plant data reported in literature.     

催化重整集总动力学模型的建立及其在线应用

按照集总理论的指导原则,在原17集总反应网络的基础上,提出了一种包含20个集总组分、31个反应的催化重整动力学模型.该模型进一步细分了八碳芳烃组分,并考虑了烷烃组分的所有加氢裂化反应.在某工业连续重整装置上的验证结果表明,所建立的20集总模型可以精确地模拟包括八碳芳烃4个异构体在内的反应产物组成;与原17集总模型相比,裂化产物的预测精度明显提高.随后,采用特定的在线预测和校正策略,将该模型用于在线预测此连续重整过程的总芳烃收率、各芳烃组分收率以及重整油辛烷值,在进料和反应操作条件较大的变化范围内,在线预测趋势和预测精度均令人满意.总芳烃收率和重整油辛烷值的平均预测偏差仅分别为0.52 %和0.36,与离线模拟精度相当.