Computational mass transfer moduling of flow through a photocatalytic oxygen generator

Abstract

A self-contained, portable oxygen generator would be extraordinarily useful across a broad spectrum of industries. Both safety and energy-efficiency could be enhanced tremendously in fields such as coal mining, commercial airlines, and aerospace. A novel device is proposed which employs a photocatalytic process to produce oxygen from water. Oxygen is generated through a reaction that utilizes the interaction between an ultraviolet light and a titanium dioxide thin film to catalyze the decomposition of water into dissolved oxygen and hydrogen ions. The dissolved oxygen is then transported into a volume of gaseous nitrogen through a diffusion process. A pair of parallel microfluidic channels is employed to expedite the oxygen transport by reducing diffusion lengths, and thereby diffusion times. In the following, a computational simulation of the convection-diffusion relation was developed in order to characterize the performance of the proposed microfluidic chip. Specifically, the time to reach airflow steady state is determined for several geometries. Information from fluid dynamic modeling was then used to estimate the system performance characteristics such as power requirements, output oxygen concentration, output flow rate, and rise time of the proposed oxygen generator in a variety of applications.