Wood briquettes are made of dry, untreated wood chips (e.g. wood shavings). They are pressed with high pressure without any binder. By compacting the wood with this high pressure, it turns into a fuel like brown coal.
The advantages of the wood briquettes are that they have a lower ash and sulfur content, compared to the fossil fuels. The carbon dioxide (CO2) balance is even, because wood briquettes release just as much CO2 to the atmosphere as the tree absorbs through growth by photosynthesis. In addition, briquettes have substantially higher BTU value per cubic foot due to their density which means less storage space and more heat released per lb.
The low moisture content of about 10% leads to an energy content of around 5,0 kWh per kg, depending on the type of wood. Green firelogs have a water content of around 50% with 2,5 kWh/kg energy content.