A simplified mathematical model to predict PVC photodegradation in photobioreactors

A simplified mathematical model to predict transparent poly(vinyl chloride) (PVC) degradation in photobioreactors under the incidence of sunlight is proposed. The model is based on the widely accepted theory of photochemistry degradation, which states that HCl is produced as an intermediate compound yielded in a propagation reaction, taking into account the entire dehydrochlorination process. A system of ordinary differential equations for concentrations and energy with respect to time results from the application of the principles of species and energy conservation, which is integrated explicitly and accurately with low computational time. Previously published experimental data were used to validate the numerical simulation results obtained with the model, with good quantitative and qualitative agreement. The developed model is expected to be a useful tool for simulation, design, and optimization of PVC for minimum photodegradation.