Difference Between Biochar and Charcoal

The key difference between biochar and charcoal is that biochar is a type of charcoal that is made via the modern pyrolysis method, whereas charcoal is produced either from the older method or from the modern method.

Charcoal is a substance that is high in carbon, and it is obtained via the pyrolysis of biomass in the absence of oxygen.

1. Overview and Key Difference
2. What is Biochar
3. What is Charcoal
4. Side by Side Comparison – Biochar vs Charcoal in Tabular Form
5. Summary

What is Biochar

Biochar is a type of charcoal that is used for soil amendment. This is important in both carbon sequestration and for soil health. It is a stable solid substance that is rich in carbon, and it can endure in soil for a very long time (e.g. thousand years). Similar to most of the charcoal types, biochar is also made from the pyrolysis of biomass.

Moreover, biochar is important in increasing soil fertility (of acidic soil types), increasing soil productivity, providing protection against some soil-borne diseases, etc. We can define biochar as a high-carbon, finely grained residue that is made from the modern pyrolysis process. Here, the direct thermal decomposition of biomass in the absence of oxygen forms a mixture of solids, bio-oil and syngas. The solid residue in this mixture is the biochar. The yield of this pyrolysis depends on the temperature, pressure, residence time, heating rate, etc.

What is Charcoal?

Charcoal is a porous black solid, consisting of an amorphous form of carbon. We can obtain this material as a residue when wood, bone, or other organic matter is heated in the absence of air. There are different types of charcoal, as follows:

Pyrolysis is the process we can use to produce charcoal. It can be done in two ways: the older method and the new/modern method.

The older method of pyrolysis is done using a clamp. In this process, we need a pile of wood logs leaning against a chimney. Here, we need to place the wood logs in a circle, and then we have to cover the logs with soil to avoid air entering the pile. Thereafter, we can light it using a chimney. Then the logs burn slowly and turn into charcoal within a few days.
The modern method of charcoal production is retorting. Here, heat is recovered from and solely provided by the combustion of gas released during carbonization.

According to the source of the charcoal, we can categorize it into several forms such as,

Common charcoal that is made from wood, peat, petroleum, etc.
Sugar charcoal that is made from carbonization of sugar.
Activated charcoal that is made by heating common charcoal in the presence of some gases that cause the formation of “pores” on the surfaces that cause adsorption. This type is made, especially for medical and research uses.
Lump charcoal made by burning hardwood material. This is also named as traditional charcoal.

When considering the uses of charcoal, it is mostly important as a fuel. Charcoal is useful for blacksmiths since charcoal burns at higher temperatures such as 2700^oC. As an industrial fuel, charcoal is used for smelting of iron. A more common use of charcoal, especially activated charcoal, is its use for purification purposes. Activated charcoal readily adsorbs chemical compounds such as organic impurities. Charcoal can also be used as a source of carbon in chemical reactions.

What is the Difference Between Biochar and Charcoal?

Charcoal is a substance that is high in carbon, and it is obtained via the pyrolysis of biomass in the absence of oxygen. Biochar is a type of charcoal that is used for soil amendment. The key difference between biochar and charcoal is that biochar is a type of charcoal that is made via the modern pyrolysis method, whereas charcoal is produced either from the older method or from the modern method.

Below infographic presents more details about the difference between biochar and charcoal.

Summary – Biochar vs Charcoal

Biochar is a type of charcoal. The key difference between biochar and charcoal is that biochar is a type of charcoal that is made thought the modern pyrolysis method, whereas charcoal is produced either from the older method or from the modern method.

Reference:

1. “Biochar.” Wikipedia, Wikimedia Foundation, 27 June 2020, Available here.

Image Courtesy:

1. “Biochar sample size” By Oregon Department of Forestry – (CC BY 2.0) via Commons Wikimedia
2. “Coals, black, background, carbon, charcoal, energy, dark, stone, texture, Coal” (CC0) via Pxfuel.com