One way to use biomass waste is to convertit into solid fuel or commonly called briquettes. To obtain good quality biomass briquettes, the biomass raw material is processed in biochar through a slow heating process at low temperatures known as to reflation. One of the efficient heating technologies to carry out the to refaction process is to use microwave radiation. In addition, the purpose of this study is one of the results of applied research funded by Ristekdikti through DPRM in 2019. The purpose of this study Is to determine the temperature required by a microwave transformer using the computational fluid dynamics method ( CFD). The variables in this study were variations in powerof 100 W, 150 W and 200 W with time variations of each power of 30 minutes, 60 minutes, 90 minutes and 120 minutes. The results showed that the best temperature was reached by a device with a voltage of 150 W with a burning time of 90 minutes. A good material used for reactors with low conductivity (glass) produce shigh temperatures (45, 105, 165, 225 oC) at 30, 60, 90, 120 minutes
