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。     

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。     

渣油催化裂化提升管反应器组成分布的数值模拟

在流动模型和集总反应动力学模型的基础上,将流动、传热、反应综合考虑,建立了渣油催化裂化提升管反应器的数学模型,通过对4套不同工况进行数值模拟,考察了反应器内气相组成分布和催化剂颗粒的温度、速度分布,得到了与工业装置基本一致的提升管出口参数,从而验证了模型的可靠性.     

无沉降器催化裂化装置的必要性和可行性分析

目前的分子筛催化裂化工业装置基本上是沿用微球合成硅铝催化裂化工艺的装备,保留再生器和反应器,增加提升管.结果油气的反应过程转移至提升管反应器内,原来的反应器蜕变为沉降器.随着催化裂化工艺技术的改进,这些装备的不适应性逐渐凸现,有些甚至形成了工艺运行的瓶颈,如沉降器中大空间的存在造成了油气的二次裂化反应和油气结焦等问题,尤其是对于重油催化裂化工艺.在叙述沉降器的演变,油气的二次裂化反应,停留时间,结焦等问题的基础上,分析了取消沉降器的必要性,同时提出几种无沉降器催化裂化工艺装置方案,讨论了技术上的可行性,以期能从装备上提高催化裂化工艺技术的水平.     

流化催化裂化反应器的技术进展

介绍并讨论了近期开发的流化催化裂化反应器,包括两段串联反应器、双提升管反应器、下行式反应器、多段进料反应器以及新型提升管反应器端口结构技术。以新型反应器为核心技术的各种催化裂化新工艺可以有效地提高催化裂化反应的转化率和选择性,减少非理想产品产率,也可以改善产品质量,生产环境友好的清洁燃料油品。此外新型提升管反应器端口结构还可以抑制设备结焦,延长流化催化裂化(FCC)装置的开工周期。     

同轴式催化裂化反应系统机理模型建立及分析

催化裂化工艺技术是原油炼制工业中重要的技术之一,其中提升管及再生反应系统是反应装置内的核心部分,在工业模拟过程,需要对装置过程控制建立数学模型,进而实现软件化的过程控制,因此,对催化裂化反应系统的数学建模具有重要的意义。本文分析了催化裂化装置的工艺流程,对同轴式催化裂化反应装置提升管和再生器反应系统进行了数学建模,并进行了相应的模型参数估计。     

渣油催化裂化反应技术新进展

重油催化裂化技术作为主要的重质油轻质化手段得到了迅速的发展,国内外围绕重油催化裂化的提升管反应器开发了许多新技术。概括介绍了渣油催化裂化提升管反应系统的最新进展,如新型进料喷嘴、轻烃预提升技术、两段提升管催化裂化、提升管末端快分技术、MTC等,并对目前工业提升管存在的问题和有待开发的技术领域进行了讨论。     

重油催化裂化装置反应器结焦的原因及对策

随着原料油劣质化、重质化,催化裂化装置反应器结焦状况尤为突出。以重油催化裂化装置反应器为研究对象,通过实地考察、资料收集、检修观测等研究方法,对提升管进料喷嘴、沉降器、沉降器出口油气大管线的结焦进行分析,并提出对策。     

灵活多效催化裂化工艺集总动力学模型

针对灵活多效催化裂化(FDFCC)工艺,以工业装置数据为基础建立了重油提升管催化裂化10集总和汽油提升管催化裂化7集总动力学模型,求取了10集总模型的43个动力学参数和7集总模型的18个动力学参数.结果表明,所获得的模型动力学参数是可靠的,所建立的模型能够较好地预测FDFCC装置的产品产率,并对汽油组成和丙烯产率具有良好的预测性.     

100万吨/年大型催化裂解装置反再系统工艺设计

工业催化裂化装置从技术发展的角度来说,最基本的是反应—再生形式和催化剂性能两个方面的发展。催化裂化装置一般由三个部分组成,即:反应—再生系统,分馏系统,吸收稳定系统。先后经历了固定床催化裂化、移动床催化裂化和流化床催化裂化。60年代出现了分子筛催化剂,由于它具有活性高、选择性和稳定好,占据主导地位的流化床反应器又发展为提升管反应器。同时还促进了再生技术的发展。陆续出现了两段再生、高效再生和完全再生等新技术。本设计结合当今世界的新工艺,新设备。在反应器、再生器、旋风分离器和提升管等设备方面都有很详细的大量计算。在工艺技术方面到达了装置技术先进,经济合理。     

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.     

加氢渣油催化裂化14集总动力学模型的建立

以加工加氢渣油的茂名石化3#重油催化裂化装置（RFCC）的工业数据为基础，针对加氢渣油的特点，提出了以渣油4组分作为划分原料集总的催化裂化14集总动力学模型，通过分步求解法求取动力学参数，并应用工业实测数据进行验证，验证结果表明该模型不仅能较好地预测催化裂化产品分布，而且还能较准确预测主要产品性质，较好地反映了加氢渣油催化裂化反应规律，可为工业装置操作的优化提供指导。     

粒子群优化算法在催化裂化模型参数估计中的应用

参数估计是化工模型工业应用中的重要课题,有相当的难度。针对催化裂化八集总模型的动力学参数估计问题,考察了不同类型优化算法的应用效果,结果表明,粒子群优化算法简单、容易实现,而且可以避免传统方法对初始值的依赖,并进一步提出用结合Levenberg-Marquardt算法的混合粒子群优化算法提高参数估计效果。工业实例表明,用混合粒子群优化算法得到的动力学参数可以保证模型的预测精度。     

Modeling, simulation and control of dimethyl ether synthesis in an industrial fixed-bed reactor

Dimethyl ether (DME) as a clean fuel has attracted the interest of many researchers from both industrial communities and academia. The commercially proven process for large scale production of dimethyl ether consists of catalytic dehydration of methanol in an adiabatic fixed-bed reactor. In this study, the industrial reactor of DME synthesis with the accompanying feed preheater has been simulated and controlled in dynamic conditions. The proposed model, consisting of a set of algebraic and partial differential equations, is based on a heterogeneous one-dimensional unsteady state formulation. To verify the proposed model, the simulation results have been compared to available data from an industrial reactor at steady state conditions. A good agreement has been found between the simulation and plant data. A sensitivity analysis has been carried out to evaluate the influence of different possible disturbances on the process. Also, the controllability of the process has been investigated through dynamic simulation of the process under a conventional feedback PID controller. The responses of the system to disturbance and setpoint changes have shown that the control structure can maintain the process at the desired conditions with an appropriate dynamic behavior.     

Dynamic modeling and simulation of a riser-type fluid catalytic cracking unit

A dynamic model is developed for a fluid catalytic cracking (FCC) unit to describe the dynamic behavior of both the riser and the regenerator reactors and their interactions. The cracking reactions are simulated by the four-lumped kinetic model [1]. The reactions in the riser occur in a transported bed with the fluid and the solids in ideal plug flow. The two-phase nature of the regenerator-fluidized bed is considered and the kinetic model for the coke combustion on the cracking catalyst [2,3] is incorporated. The proposed model is validated using steady-state plant data from an industrial unit and the results are found to be in good agreement. One of the main advantages of the model is that it does not include any partial differential equations. This facilitates the solution of the equations and makes the model particularly suitable for control studies. Simulation studies are performed to investigate the effect of changing various process variables, such as catalyst circulation rate, gas oil feed rate, and oxygen feed concentration.     

催化重整反应38集总动力学模型及其在连续催化重整中的应用

根据集总理论和催化重整的反应机理,基于工业连续重整装置,提出了一个包含38个集总组分、86个反应催化重整反应动力学模型。该模型将重整物料按碳原子数集总为C6～C11+组分,相同碳原子数的物料又划分为正构烷烃、异构烷烃、五元环烷烃、六元环烷烃和芳烃,裂化产物细分为C1～C5组分。通过合理简化,确定了86个待估模型参数,并在工业现场数据的基础上,利用分层策略与BFGS算法对其进行了估计。通过对某炼厂连续重整反应器的模拟计算对该模型进行了验证,计算值与实际值吻合较好,表明该模型具有较好的可靠性与准确性,达到了工业应用的要求。将模型用于芳烃收率的预测,在较大的时间跨度内,精度与趋势均令人满意。最后,利用该模型对芳烃收率进行了优化计算,经优化后芳烃收率提高0.17%,该结果可为连续重整装置的优化操作提供参考。     

乙烯裂解炉反应与传热耦合的智能混合建模与模拟

乙烯裂解炉辐射段的过程模拟,一般由管内反应过程模型与管外传热模型两部分组成,具有非线性、强耦合的特点。其中管外传热模型涉及变量参数众多、求解过程耗时长。针对这一问题,提出了一种智能混合建模方法,在构建基于区域法的管外传热计算模型的基础上,利用该模型产生的数据,设计构造了针对管外传热计算的神经网络模型。利用该模型与管内反应过程模型相耦合,实现对乙烯裂解炉辐射段的智能混合建模与模拟。结合工业实际算例,验证了基于机器学习和机理模型的智能混合建模的可行性,裂解产物预测精度良好,且混合模型可以大大缩短计算时间,更加符合工业计算的要求。     

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.     

Modeling,simulation and structural analysis of a fluid catalytic cracking (FCC) process

Fluid catalytic cracking (FCC) is an important chemical process that is widely used to produce valuable petrochemical products by cracking heavier components. However, many difficulties exist in modeling the FCC process due to its complexity. In this study, a dynamic process model of a FCC process is suggested and its structural observability is analyzed. In the process modeling, yield function for the kinetic model of the riser reactor was applied to explain the product distribution. Hydrodynamics, mass balance and energy balance equations of the riser reactor and the regenerator were used to complete the modeling. The process model was tested in steady-state simulation and dynamic simulation, which gives dynamic responses to the change of process variables. The result was compared with the measured data from operating plaint. In the structural analysis, the system was analyzed using the process model and the process design to identify the structural observability of the system. The reactor and regenerator unit in the system were divided into six nodes based on their functions and modeling relationship equations were built based on nodes and edges of the directed graph of the system. Output-set assignment algorithm was demonstrated on the occurrence matrix to find observable nodes and variables. Optimal locations for minimal addition of measurements could be found by completing the whole output-set assignment algorithm of the system. The result of this study can help predict the state more accurately and improve observability of a complex chemical process with minimal cost.