Abstract Biobriquettes were produced from brown seaweeds (Phaeophyta) collected from the Bosphorus which is a natural channel between Black Sea and Marmara Sea. For this purpose, pre-dried seaweeds were characterized by several techniques including X-Ray Diffraction (XRD), X-Ray Florescence (XRF), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and thermal analysis techniques under nitrogen and dry air. Seaweeds were subjected to carbonization in a tube furnace up to 900 °C under nitrogen atmosphere. Then the carbonized residue pressed in a steel mold using hydraulic press under 187 MPa pressure. Some binding agents such as sulfide liquor, molasses, and Linobind were added to improve the durability of the briquettes. Some tests such as falling stability and compressibility strength were performed to determine the mechanical strength of the briquettes. Also, water resistance of the briquettes was checked. It was concluded that carbonization so improved the fuel quality of seaweed that problematic sodium content reduced considerably, while increases took place in fixed carbon and calorific value. However, inorganics became concentrated after carbonization. All of the biobriquettes have satisfactory characteristics in terms of compressive strength regardless of the type of binder, while the falling stability was closely affected from the type of the binding material.