Do we really know charcoal?

Charcoal is a material highly used since ancient times and still widely utilized in many countries for domestic activities such as cooking food but also for industrial applications.

However, a lot of aspects related to this material, including production processes, procurement, international trade and its qualitative characteristics, are still not fully clear.

Charcoal production

Charcoal is obtained through a pyrolytic process, with the combustion of the wood in reduced presence of oxygen and providing energy from the outside, on a closed place such as an oven.
The little presence of oxidizing involves an incomplete combustion of biomass woody and its chemical breakdown. From this process is obtained a mixture of gases, liquids and charcoal. The yields vary from 10% to about 30%, depending on the production technique used. Indeed, despite the production principle is generally common among the various techniques, the methods that could be applied often differ on the basis of the socio-economic context where the production is carried out. For example, in the countries of Africa or America Latina, due to the large availability of cheap manpower, traditional production techniques are often used.
These are characterized by high simplicity from a technological point of view and low costs. The production, indeed, takes place inside rudimentary kilns made as mound kilns or brick kilns. The material that is obtained has poor quality due to the incomplete carbonization of the woody biomass, which is also combined with a reduced yield.
On the other hand, modern industrial processes use large steel kilns where internal processes can be regulated and controlled. These systems ensure high efficiency levels and the potential to obtain a higher quality product.
They are based on the use of more sophisticated equipment and mechanized processes; however they are also combined with an increase in costs and timing.

Availability

Most of the charcoal commonly available in Italy has an uncertain origin.
Almost all of the material marketed is produced outside the European Union. Indeed, a lot of this comes from the tropical forests of Africa, Latin America and the South-East Asia where production can involve strong repercussions on the fragile local ecosystems. Referring to the average annual data provided by FAO, in the period between 2000 and 2019, Italy is one of the 15 main global importers of charcoal, with an average of 59 Mt/year of imported material.

From a production point of view, the world scene is dominated by nations such as Brazil (644 Mt/year), Nigeria (388 Mt/year) and Ethiopia (371 Mt/year).
However, much of the production of these countries is intended to satisfy their internal demand.
Therefore, when international exports is concerned, there are other countries that excel. These include, for example, Indonesia (255 Mt/year), Paraguay (127 Mt/year) and Myanmar (117 Mt/year). They devote most of the material to industrialized countries such as Germany (182 Mt/year), Japan (144 Mt/year) and United States (69 Mt/year).

Qualitative aspects of charcoal

The quality of charcoal commonly used for barbecues can be determined by referring to a specific technical standard, namely UNI EN ISO 17225-1:2014.
The standard lists fixed carbon, ash content, water content, granulometry, volatile substances and bulk density among the parameters that have to be analyzed. However, despite the large use of charcoal, the tests performed by producers and sellers are slightly diffused.
Data, as well as analysis reports, are not easily available for the end-users. This involves the possibility to buy an uncertain quality material.
So it is very appropriate to encourage an analysis campaign on the products available on the market also aimed to define a quality brand.
This can be a guarantee not only for the consumers but also for the environment.
In this regard, the Biofuels Analysis Laboratory is conducting a study to deepen and enhance knowledge on charcoal from a qualitative point of view. Table 1 shows some of the main parameters that were determined on five samples. In particular, the charcoal samples come from South America and from Europe, for four of which woody species of origin were known.
From this preliminary tests it is possible to highlight how the origin and the wood species are two important parameters because of their influence on the heating value.
This consideration supports the importance of point out the qualitative characteristics of the material used for cooking food and reaching at the definition of a quality brand.