Fire prevention is being treated as a first priority in Portugal, namely after the dramatic forest fire episodes of 2017. This has to be done in full consideration of the key elements of fire – heat, oxygen and fuel – meaning that a low risk of fire involves removing one or more of these elements. Hence, public entities are presently asking urgent action to reduce the amount of biomass that is available in the forest, which demands for a strategy to correctly manage the biomass that will be collected.
From what is known, presently, forest biomass residues are mostly used for combustion purposes, which is a mature technology, with applications spanning from residential heating to industrial heat and power. Apart from combustion, other technologies that are being considered to valorize forest biomass include gasification and pyrolysis, to produce syngas and bio-oil/charcoal, respectively. Syngas and bio-oil are still technically difficult to obtain, which makes it of little interest considering the urgent need for action. Instead, charcoal production is common in many Portuguese villages, even if it is based in archaic methods. Major charcoal production spots are known, for instance those in the regions of Abrantes and Coruche with a large number of kilns being operated the whole year round. This infrastructure is historically linked to the valorization of forest and agricultural residues and can play an important role in the present context of fire prevention in Portugal since it is already set in the places where biomass is produced, as well as it can be viewed as complementary to small combustion units; for example, larger trunks of wood (including partially burnt wood from fires) can be better suited for carbonization since combustion appliances generally requires chipped wood. However, charcoal making is often associated to environmental impacts since the process is conducted under a lack of oxygen, which is the reason why charcoal production in Portugal has been in the shadow for decades.
This project aim at raising the awareness to the current situation of charcoal production in Portugal and contribute to its modernization within an integrated strategy for biomass management. The first objective is then to contribute to establish the country status for this activity. This initial task of the project is also crucial to guide the following laboratory work that will focus on the pyrolysis behavior of the widely used biomasses, with specialized facilities enabling to investigate the pyrolysis process in detail, thus providing adequate benchmarks for the existing charcoal kilns. Besides, the operation of a full-scale charcoal kiln will be characterized, which is expected to reveal key opportunities to improve traditional carbonization methods.