Canonical correlation analysis of the characteristics of charcoal from Qualea parviflora Mart.

Abstract

This study aimed to examine the relationships between the characteristics of charcoal from Qualea parviflora Mart. using canonical correlation analysis. Five trees were analyzed in such way that 5-cm thick discs were removed from each tree at the base, DBH (1.30 m), middle and top sections. The wood was carbonized in a muffle furnace at a heating rate of 1.67 °C min-1. A canonical correlation analysis was conducted to investigate the relationships between the group formed by fixed carbon, volatile matter, ash, elemental carbon, hydrogen, nitrogen, sulfur and oxygen levels and a second group formed by the gravimetric yield, higher heating value and relative bulk density of the charcoal. A tendency was noted for high levels of fixed carbon and elemental carbon to be associated to low levels of volatile matter, ash and oxygen and to low gravimetric yield. Fixed carbon and elemental carbon levels had a positive relation to higher heating value and to relative bulk density, whereas volatile matter, ash and oxygen levels had a negative relation to such characteristics. The higher the gravimetric yield from carbonization, the higher the volatile matter, ash and oxygen levels will be in the resulting charcoal.