Mass Transfer Through Microwave-Treated Fir Wood (Abies alba L.): A Gymnosperm Species with Torus Margo Pit Membrane

Abstract

In this research, the effect of microwave pretreatment on mass transfer coefficients of Abies alba L. was investigated. For this purpose, wood specimens with dimensions of 340 × 100 × 50 mm and average moisture content of 50% were exposed to a microwave with 2450 MHz frequency for time durations of 7 and 10 minutes. After drying, the air permeability and water vapor diffusion coefficients were measured through the longitudinal and radial directions of the specimens and results were analyzed using chemical composition measurement, FT-IR (Fourier Transform Infrared) test, and SEM (Scanning Electron Microscope) studies. The FT-IR study of pretreated samples showed no specific change, although SEM photographs proved the hydrolyzation of bordered pits as a result of microwave heating. Results revealed that microwave pretreatment had no effect on the longitudinal permeability and diffusion coefficients. In contrast, the radial mass transfer rates were improved due to the microwave pretreatment. Although the microwave pretreatment had no noticeable influence on the chemical compositions of the treated specimens, the torus of some bordered pits was hydrolyzed due to microwave radiation.

Keywords:

• Abies alba
• Diffusion
• Drying
• FT-IR
• Microwave
• Permeability
• SEM