Simulation of non-vaporizing tubular nylon-6 reactors with radial gradients: finite-difference computations

Abstract

This work presents a comprehensive computer simulation study for the hydrolytic polymerization of ε-caprolactam without water removal in a continuous tubular reactor. It incorporates a laminar (Hagen-Poiseuille) or plug flow velocity profile, as well as radial thermal diffusion. The solution of the balance equations is carried out using two types of finite-difference techniques coupled with Gear's method for solving the ordinary differential equations so generated. Simulation results are obtained for various operating conditions. A comparison is made of the different methods used and their limitations are discussed. These results will form the basis for a comparison of the numerical results that could be generated using far more powerful computational tools like orthogonal collocation or finite-element techniques.