Name the (potential) heat sources and sinks in a typical torrefaction process.

To begin with, we need to identify the potential heat sources that are present in the torrefaction process. The main heat sources are: 1. Combustion of biomass or fossil fuels: The heat generated from the combustion of fuels is used to raise the temperature of the biomass inside the torrefaction reactor. 2. Torrefaction process heat: The biomass inside the reactor generates heat itself due to the chemical reactions taking place during torrefaction. 3. External heating: Sometimes, additional heating systems like electrical heaters or steam could be used to supply heat into the reactor.

Heat sinks are places in the torrefaction process where heat is dissipated or lost. Some of the common heat sinks in the process are: 1. Heat losses from the reactor walls: As the torrefaction reactor has a high temperature, some heat will be radiated and lost through its walls and connections. This heat is then absorbed by the surrounding environment. 2. Cooling of produced bio-coal: After the torrefaction process is complete, the produced bio-coal needs to be cooled down. This cooling process transfers the heat to a cooling medium, usually water or air. 3. Heat carried away by exhaust gases: Some heat is carried away by the combustible and non-combustible gases generated during torrefaction. These gases are usually vented out of the process, taking heat away from the system.