Reduction in Energy Consumption Using Fuel Cells in Nonthermal Plasma-Based Water Sterilization by Bubbling Ozone

Abstract

Plasma sterilization technologies have been the subject of several studies and remarkable developments over the last few years. Ozone (O3) is an effective sterilizer, and its range of applications has extended to include water purification. Ozone is typically generated from oxygen (O2) in nonthermal plasma (NTP). However, this process requires the use of an additional gas cylinder or supply device for O2, thereby entailing increased costs of operation and energy consumption. Air can be used as an alternative to O2 as a source gas for O 3 production. However, this leads to the generation of nitrogen oxide (NOx), an air pollutant, during plasma discharge. Hence, it is vital to develop a method for O3 generation that addresses the challenges of energy costs and emission of air pollutants. This study, therefore, proposes an energy-efficient NTP sterilization system. The system is based on electrolysis of water to produce O2 and hydrogen (H2 ). The O2 produced is used to generate O3 for sterilization, and H2 is used in fuel cells to generate electric power. The present study details the characteristics of energy consumption and efficiency in O3 production and elucidates the proposed NTP sterilization system. Reduction in energy consumption for O3 production is achieved with a power recovery rate of more than 11.1% in the present high-efficiency water sterilization system.