Parameter Optimization And Process Optimization Analysis Of N-butane Isomerization Reaction Model

N-butane and isobutane are two kinds of alkanes containing 4 carbon atoms,but n-butane is much less valuable in industry than isobutane.In order to improve economic efficiency,n-butane is converted to isobutane.necessary.The optimal identification of the kinetic model parameters of the isomerization of n-butane allows the laboratory researchers to more accurately predict the experimental results,thereby obtaining the best process parameters by calculation,which can improve the atomic economy of the reaction.Avoid the production of a large number of low value added by-products.First of all,in order to solve the problem of intelligent optimization algorithms(such as particle swarm optimization algorithm,genetic algorithm,etc.)in the optimization process of dynamic model parameters,the problem of insufficient search power after the common optimal solution and the high number of iterations are affected by the fruit fly.The optimization algorithm inspires a biogeographic optimization algorithm based on three-dimensional variation.At the same time,the original BBO algorithm and improved algorithm are used in the optimization of many different types of test functions.It shows that the improved Tdv-BBO algorithm can generate rich combination solution space,which greatly improves the optimization ability of the original algorithm and shortens the iteration.frequency.Secondly,the improved algorithm is used to estimate and identify the parameters of the n-butane isomerization chemical kinetics model.The reaction kinetics model is optimized by this method.The model has high precision and strong generalization ability.Finally,in this paper,the optimal process parameters of the reaction were identified for the established reaction kinetics model.The performance index function was chosen as the product of the reactant conversion rate and the product selectivity,which is the final yield of isobutane.The optimized process temperature,pressure,hydrogen ratio and n-butane mass space velocity were optimized.The main research contents are as follows:(1)In order to solve the problem that the biogeographic optimization algorithm reduces the global search performance when the number of iterations is large,the global search performance is degraded.The three-dimensional variation biogeography is formed after the development of the olfactory and visual collection of the fruit fly foraging in the FOA algorithm.Learning optimization algorithm,and comparing the improved algorithm with other optimization algorithms and other improved algorithms of BBO algorithm,showing the superiority of the improved algorithm.(2)The n-butane isomerization kinetic model structure is expressed in the form of a general power function,and the improved Tdv-BBO algorithm is applied to the parameter optimization of the n-butane isomerization reaction kinetic model.The Runge-Kutta-merson method is used to numerically solve the differential equations of the molar concentration of each product in the isomerization of n-butane.The maximum likelihood estimation method is used to calculate the value of the error squared at the model output and the reaction exit.The BBO algorithm and the Tdv-BBO algorithm are used to optimize the model parameters of the five reaction rate equations.The simulation experiment shows that the improved reaction model optimizes the reaction kinetic model,the model is more accurate and the performance is better..(3)After obtaining the accurate reaction kinetics model,the optimal combination of process parameters was obtained by optimization calculation,and the four process manipulated variables of temperature,pressure,hydrogen ratio and n-butane mass space velocity were obtained.As a verification,the idea of multi-objective optimization was used to optimize the pareto frontier of n-butane conversion and isobutane selectivity by NSGA2 algorithm.The quantitative relationship between n-butane conversion and isobutane selectivity was established by Gaussian fitting.The model thus obtains the maximum value of the ratio of the mole fraction of the outlet isobutane to the inlet n-butane.The simulation results show that the values of n-butane conversion and isobutane selectivity obtained by Tdv-BBO algorithm and NSGA2 algorithm are basically equal,and the four operating conditions are the optimal process operation variables for this model.