More than 41% of households and 2.8 billion people worldwide depend on solid fuels including coal. The available coal reserves in Indonesia are 31.7 billion tons and only enough for the next 65 years. This makes the government encourage the development of research on the utilization of biomass waste as alternative energy. Efforts are made to convert biomass waste in the form of rubber wood into alternative solid fuels through the pyrolysis process. Biochar is produced from biomass through pyrolysis, resulting in excellent combustion quality. Biochar from pyrolysis is combined with brown coal and molasses adhesive to create coal biobriquettes as an alternative solid fuel. The purpose of this study was to identify the optimal composition of brown coal and biochar in producing coal biobriquettes with the best quality. The pyrolysis process of rubber wood waste was carried out at a temperature of 350-400°C for 2 hours. This study used variations in the composition of biochar (75%, 80%, 85%, 90%, and 95%) and brown coal (5%, 10%, 15%, 20%, and 25%) and 15 mL molasses adhesive. Testing the combustion quality of coal biobriquettes through proximate analysis and value. The results showed that the most optimal product was a sample with a composition of 85% biochar and 15% brown coal.