Anatomy of Charcoal and Carbonization Effect under Eucalyptus Fibers’ Dimensions

Marina Donária Chaves Arantes,Jordão Cabral Moulin,Edy Eime Pereira Baraúna,Selma Lopes Goulart,Paulo Fernando Trugilho,Raul De Abreu Neto

doi:10.1590/2179-8087.064317

Abstract

Abstract The anatomy of wood and charcoal was analyzed by scanning electron microscopy in three radial positions of E. urophylla and E. Grandis in different diameter classes at six years. The carbonization process was given in the muffle with an average rate of 0.5 °C increment per minute, using initial temperature of 150 °C and maximum of 450 °C. It was observed that the pore diameter presented higher values in the samples obtained in the internal position. The diameter classes of the trees almost did not influence the characteristics of the fibers. In the external position (close to the shell) fibers with higher values of cell wall thickness and smaller values of lumen diameter and width were identified. The fiber lumen diameter was not affected by the wood carbonization process, whereas the cell wall thickness and fiber width were reduced.

Highlights

AND OBJECTIVESCharcoal is widely utilized in Brazil because of its good qualities as fuel and in the reduction of iron ore
There is a lot of knowledge available on wood anatomy variation in radial and longitudinal direction, little is known about the variation effect of wood anatomy structure under high temperatures and even less regarding anatomy and structure of charcoal
It was used a 10 × 10 trees plot where the diameter at breast height (DBH) of all 100 trees was measured at DBH regarding the classification in three distinct tree diameter classes

Summary

Introduction

AND OBJECTIVESCharcoal is widely utilized in Brazil because of its good qualities as fuel and in the reduction of iron ore. There are some specific requirements regarding the final quality of charcoal, which is affected by wood and species characteristics from its origin. The search for the quality of charcoal promotes chemical and anatomical studies of wood, considering that the knowledge of the raw material promotes the convenient use of the commercial qualities of the final product. The wood undergoes modifications in its coloration, as well as changes in the physical and mechanical characteristics that generate a product with greater dimensional stability, lower hygroscopicity and greater resistance against fungi (Moura & Brito, 2011; Moura et al, 2012). The influence of tree diameter especially over wood drying process and its liability to produce anatomic deformation of the material are well known. Wood may crack under temperature influence and modify fiber structure and collapse vessels (Rémond et al, 2007), besides other effects in the porous structure. There is a lot of knowledge available on wood anatomy variation in radial and longitudinal direction, little is known about the variation effect of wood anatomy structure under high temperatures and even less regarding anatomy and structure of charcoal

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Methods

Conclusion