Performance Assessment of Drying Machine Using CFD

The need for coal in Indonesia based on ESDM data has increased from 24% in 2011 to 30% in 2025. The environmental impact caused by coal is not linear with the increasing demand. Therefore, it is necessary to replace coal or commonly known as co-firing which uses biochar which is more environmentally friendly. In this study, the thermo-fluid performance of the biochar dryer was carried out with the addition of a numerical design disturbance by solving the mass, momentum, energy, and turbulence equations. The Eulerian multiphase model was used to determine the volume fraction of the product. The effect of grid density is carried out to determine the validation of the outlet temperature value. The addition of baffles with angles of 30°, 45°, and 60° was carried out around the outlet area to determine the increase in performance. In addition, several variations of the input temperature and gas velocity were carried out to determine the exergy efficiency value for thermo-fluid performance expressed in Nusselts number. The addition of baffles with the best exergy efficiency value is the angle of 30° with 90.45% found at a temperature variation of 364 K, while the speed with the best result of the Nusselt number is at a speed of 1.2 m/s of 21.4.