The IR dryer was comprised of two main components, IR emitter and drying bed. A catalytic emitter provided by Catalytic Industrial Group (Independence, Kansas) generated IR radiation energy by catalyzing natural gas to produce heat along with small amounts of water vapor and carbon dioxide as by-products. The dimensions of the emitter were 30 × 60 cm, and it had a surface temperature of approximately 650 °C with corresponding peak wavelength 3.1 μm, assuming the emitter is a blackbody. An aluminum box with dimensions of 65 cm (length) × 37 cm (width) × 45 cm (height) was installed around the emitter as a wave guide to achieve uniform IR intensity at the rice bed surface. The dimensions of the drying tray, constructed of aluminum plate of 3 mm thickness, were 65 cm (working length) × 36 cm (width) × 3 cm (depth). Aluminum was selected as its high reflectivity due to shining surface for minimized the radiation energy loss through the drying tray. The reflected radiation also heated the bottom side of the rice kernels. A piece of plywood was installed beneath the aluminum plate to reduce conduction losses. Two type-T thermocouples (time constant of 0.15 s) were embedded on the drying tray surface to measure the bed temperature. The rice bed was located at 5 cm below the bottom edge of the wave guide with average IR intensity of 5348 W/m2 at the rice bed surface. The radiation intensity was measured with an Ophir FL205A Thermal Excimer Absorber Head (Ophir, Washington, MA).