A Sequential Variable Decoupling Method for Rigorous Calculation of Molecular Weight Distribution of Batch Free Radical Polymerization

作者：Chen, Xi^*; Jiang, Feijun; Yao, Zhen

来源：10th International Symposium on Process Systems Engineering, Salvador, BRAZIL, 2009-08-16 To 2009-08-20.

• free radical polymerization
• molecular weight distribution
• sequential variable decoupling method

This paper introduces a new method on calculating the Molecular Weight Distribution (MWD) of free radical polymerization, termed the Sequential Variable Decoupling (SVD) method. The original model of MWD calculation in free radical polymerization is based on fundamental reaction mechanism and diffusion controlled reaction rate coefficients, resulting in a group of large scale differential algebraic equations (DAEs). However the traditional DAEs solvers always require huge computer memory to solve this kind of model simultaneously, making it impossible to implement on a normal PC. The SVD method decomposes the large DAEs model into a small scale DAEs model and a series of small scale ordinary differential equations (ODEs) models. This decomposition reduces computer memory greatly and makes it executable on a normal PC. As an example, the SVD method has been used to calculate the MWD of methyl methacrylate (MMA) homopolymerization with good precision. To further reduce computation time cost, techniques with variable step size in the numerical integration along time and chain length of the polymers are also proposed. By using the methods, the computational efficiency is improved by 8.2 times at a cost of increasing the relative error only by 0.56%.

• 出版日期2009
• 单位化学工程联合国家重点实验室; 浙江大学; 工业控制技术国家重点实验室