共查询到16条相似文献,搜索用时 171 毫秒
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催化裂解过程分子尺度反应动力学模型研究 总被引:2,自引:0,他引:2
以工业数据为基础,运用结构导向集总方法来构造烃分子,对催化裂解原料油进行了分子尺度上的Monte Carlo模拟.在深入研究催化裂解反应机理的基础上,以原料油模拟产生的分子矩阵作为反应物分子,将结构导向集总方法与Monte Carlo方法相结合,建立了催化裂解过程分子尺度的反应动力学模型.结果表明:Monte Carlo方法可以在分子尺度上实现对催化裂解原料较好的模拟,产品产率和汽油组成与实际值能较好地拟合.且随着虚拟分子数的增加,对原料油性质和反应结果的模拟计算精度提高;模型具有较好的适应性和外推性. 相似文献
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利用结构导向集总与Monte Carlo模拟方法相结合构建了废弃油脂催化裂化反应的分子尺度动力学模型。模型选取17个结构向量表示废弃油脂分子,生成1000个原料分子表示废弃油脂原料,利用模拟退火算法对原料矩阵进行优化,同时针对废弃油脂体系的脱氧反应新增12条反应规则,利用Materials Studio 8.0软件求取其速率常数,完成动力学模型的构建。结果表明模型可以很好地对原料性质和产物分布进行预测,模拟值与实验值的绝对误差都在比较合理的范围内,说明求取的速率常数和编制的反应规则是合理的。 相似文献
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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。 相似文献
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大庆常压渣油催化裂解反应动力学模型研究 总被引:5,自引:0,他引:5
针对大庆常压渣油催化裂解反应体系,建立了大庆常压渣油催化裂解五集总动力学模型,推导出了各集总组分在反应器出口处的浓度表达式,给出了一种用于求取集总模型参数的简单方法。结合实验数据,编程计算求取了该五集总反应网络的速率常数、指前因子和活化能,并对所建集总模型的预测效果进行了初步检验,结果表明该模型对催化裂解汽柴油、气体烷烃和气体烯烃具有较好的预测能力,短停留时间有利于多产低碳烯烃。 相似文献
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重油催化裂解集总动力学模型研究 总被引:1,自引:0,他引:1
建立了重油催化裂解七集总动力学模型,给出了模型的反应网络和数学表达式.利用小型固定流化床实验装置对大庆常压渣油进行了催化裂解实验,获得求取动力学参数的实验数据.提出了一个新的基于原料性质和操作条件的裂解催化剂失活模型.结合实验数据,编程求取了集总模型的动力学参数,催化裂解的反应活化能基本上都大于100kJ/mol,介于催化裂化活化能和热裂化活化能之间.根据所建立的集总动力学模型,预测了原料转化率、裂解产品产率和分布随操作条件的变化趋势,发现重油催化裂解宜采用高温、短油气停留时间的操作方式. 相似文献
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Zhengyu Chen Gang Wang Suoqi Zhao Linzhou Zhang 《American Institute of Chemical Engineers》2023,69(8):e18116
Petroleum catalytic pyrolysis to light olefin technology has received wide-ranging research interest in the refining industry. This work built a molecular kinetic model for the catalytic pyrolysis of a heavy gas oil from bitumen synthetic crude oil (SCO) to light olefins. A feedstock compositional model was constructed containing 1311 molecules using bulk properties information. A variety of reaction rules was summarized and digitized, and from which, a reaction network involving 2631 substances and 6793 reactions was generated via a reaction network autogeneration algorithm. The reaction network for the catalytic pyrolysis was transformed into reaction rate equations. Systematical pilot-scale catalytic pyrolysis experiments were carried out, which were used to regress the molecular kinetic model parameters. The tuned model is able to predict the product yield and molecular distribution. Moreover, a range of sensitivity analysis was performed, revealing the dependence of light olefins yields on the reaction conditions. 相似文献
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Zhengyu Chen Song Feng Linzhou Zhang Gang Wang Quan Shi Zhiming Xu Suoqi Zhao Chunming Xu 《American Institute of Chemical Engineers》2021,67(1):e17027
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. 相似文献
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Jafar Towfighi Aligholi Niaei Ramin Karimzadeh Giti Saedi 《Korean Journal of Chemical Engineering》2006,23(1):8-16
Pyrolysis of hydrocarbons is an important commercial process for the production of ethylene, propylene and 1,3 butadiene.
These low molecular weight olefins are among the most important base chemicals for the petrochemical industries for polymer
production. A simulation program of the reaction kinetics and coke formation inside the coils of a thermal cracking unit can
provide information on the effects of operating conditions on the product distribution. The aim of this study was to develop
a mechanistic reaction model for the pyrolysis of LPG that can be used to predict the yields of the major products from a
given LPG sample with commercial indices. A complete reaction network, using a rigorous kinetic model, for the decomposition
of the LPG feed has been developed, which is used for the simulation of industrial LPG crackers. This model has been adapted
using industrial data for the pyrolysis yields of LPG. The present paper attends on the asymptotic coking mechanism and describes
the development of a kinetic coking model in the pyrolysis of LPG. Detailed and accurate information about the product distribution,
growth of coke layer, the evolution of the tube skin temperatures can be obtained from this simulation. Simulations of this
kind can be used to optimize the furnace operation. They can be used as a guide for the adaptation of the operating variables
aiming at prolonging the run length of the furnace. The reactor model, as well as kinetic scheme, is tested in an industrial
cracking furnace. 相似文献
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由于热裂解存在反应时间短、自由基数量多、浓度小,且不同原料产生的不同自由基之间、反应深度较大时管壁处于高温和停留时间所生成的不同自由基与主流体间的相互作用会随时改变反应路径,并影响到产物分布,因此造成了用实验方法研究单体烃热裂解反应机理的困难。将Materials Studio软件与Aspen Plus软件相结合来研究单体烃热裂解的自由基反应机理,并通过对乙烷热裂解一次反应机理、乙烷和丙烷混合热裂解相互作用机理、动力学数据准确性对比及正已烷空间位阻的影响,对研究方法进行了论述。结果表明,数值模拟的理论方法与实验方法相比,可以深入了解实验研究不可能达到的一些机理细节问题,如果将实验研究和模拟研究相结合,可避免目前动力学模型研究中的各种假设,提高机理模型研究的准确性,为工业生产预测提供高精度的机理模型。 相似文献
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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. 相似文献