Semina: Ciências Agrárias (May 2022)
Drying kinetics of olive pomace-derived charcoal briquettes with energy consumption
Abstract
The drying experiments were performed at different temperatures of the drying air (40, 50, and 60°C) and air velocity of 2.5 and 3.5 m/s. Six thin-layer drying models were evaluated and fitted to the experimental moisture data. The fit quality of the models was evaluated using the determination coefficient, chi-square, and root mean square error. Among the selected models, the Midilli et al. model was found to be the best model for describing the drying behaviour of olive pomace. Charcoal is used as a domestic fuel for cooking and heating in many developing countries. It is an important green source for making barbecue, which is obtained from agricultural waste. Due to less CO2 emission, it reduces health risk and deforestation. The coal briquette carbonisation production process consists of a carbonisation stage and a forming stage. During the forming stage, the raw material is mixed with a suitable binder. The final stage of the charcoal process after formation is drying. In this study, the drying parameters of charcoal briquettes made from the olive pomace-making process were evaluated. Three different temperatures and velocities were selected for the drying applications. The low temperature drying process was performed at 60, 50, and 40°C with air velocities of 3 and 2.5. The results were in the range of 3 to 8 hours of drying time. The drying data were applied to six different mathematical models, namely 1Diffusion Approach, 2Henderson and Pabis, 3Two term exponential, 4Midilli et al., 5Page, and 6Wang and Singh Equation Models. The performances of these models were compared according to the coefficient of determination (R2), standard error of estimate (SEE), and residual sum of squares (RSS) between the observed and predicted moisture ratios. The Midilli et al. Diffusion Approach, and Page models described the drying curve satisfactorily in all drying methods.
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