Reaction Kinetics of Ozone Gas in Paddy Grains

Abstract

AbstractThe present study was carried out to evaluate the effect of ozone on paddy grains in an airtight acrylic bin with the following three aspects: saturation time, decomposition kinetics and half‐life of ozone. Experiments were performed in different bed thickness (5 and 10 cm) and moisture content (11.2 and 14.3% w.b.) at atmospheric condition. The lowest saturation time of ozone was 71 min with concentration of 773 ppm for paddy grains ozonated at 5 cm bed thickness with 11.2% (w.b.) moisture content. The decomposition kinetics obtained was first‐order model. As regard the half‐life of ozone, the lowest value obtained was 6.32 min for paddy grains ozonated at 10 cm bed thickness with moisture content of 14.3% (w.b.). In the process, half‐life of ozone in paddy grains, bed thickness (P ≤ 0.01) and moisture content (P ≤ 0.01) were found to be the key factors.Practical ApplicationsOzone is a highly reactive and strong oxidizing agent with insecticidal activity. For large volumes of stored grains, studies of ozone gas application are mostly experimental so they cannot be universal and applied to different storage systems. Reaction kinetics of ozone gas can be used to understand the effect of ozone on stored grains, optimize the design of ozone fumigation systems and find out the total fumigation time of farm‐level storage bin. An application method needs to be developed to minimize loss and distribute the fumigant evenly and quickly throughout the chamber. The effectiveness of ozone also depends on the moisture content and depth of the grains. Hence to verify the adaptability of ozone fumigation system to a large‐scale study on reaction kinetics is highly essential.