carbonize

Carbonize is the process of converting an organic substance into a carbon-rich residue or exposing it to carbon-containing conditions. In practice, carbonization often occurs by heating materials in limited or no oxygen, a process called pyrolysis. The volatile components are driven off, leaving a solid char with a high proportion of carbon. The temperature, duration, and feedstock influence the char’s structure and potential uses.

In coal and metallurgy, carbonization describes the destructive distillation of coal to produce coke, a carbon-rich solid used as a fuel and reducing agent in ironmaking. In biomass processing, carbonization yields biochar, a stable form of charcoal used as a soil amendment and for carbon sequestration. Activated carbon is produced by carbonizing a precursor and then activating it to create a highly porous material for filtration and adsorption.

Carbonization also plays a role in surface heat treatments such as carburization, where a metal surface is exposed to a carbon-rich environment to increase hardness by introducing carbon into the alloy.

Environmental and safety considerations include emissions of tar, volatile organic compounds, and other gases during carbonization. Sustainable feedstocks, proper containment, and regulatory compliance are important for industrial applications. The term may also be used in non-technical contexts to describe charring or browning of foods, though such usage is less formal.