Comparative study of mathematical and experimental models of coffee bean drying rate in a solar dryer simulator

Abstract

The drying process of coffee beans requires heat energy to evaporate the moisture content in the material to be dried. Arabica coffee is dried at controlled temperatures (50°C, 60°C and 70°C) and wind speeds (0.4 m/s, 0.8 m/s and 1 m/s). The initial moisture content of the coffee bean test of 70% was dried to a moisture content of 11%. The drying air temperature is important for drying at high temperatures using a solar dryer simulator, which results in rapid moisture removal and reduced drying time. Drying was carried out to obtain the rate of reduction of moisture content experimentally compared to theoretically on mathematical models of drying agricultural products (Newton, Modified Henderson and Pabis and Modified Midili). Drying parameters are related to mass loss, temperature and humidity. From the results of the calculation of the experimental water content reduction rate with 3 formulas, the closest equation is Modified Midili.