Proximate, Ultimate and Calorific Analysis of European Beech Tree (Fagus sylvatica) Components for Fuel

Aims: The three different above ground biomass components (branch, crown, bark) of European Beech (Fagus sylvatica) were evaluated, regarding energy and combustion properties.
Study Design: The proximate, ultimate and calorific analysis conducted on components of European Beech tree from three different age stands (10-, 20-, 30 years old). For each group of sample, separate experiments were carried out under similar conditions and experimental findings presented comparatively. The results obtained may be suggested for the selection of the best parts and age group for the improvement of fuel properties of selected tree and could provide useful evaluation of the test methods employed.

Methodology: The three different above ground biomass components (branch, crown, bark) of European Beech (Fagus sylvatica) were selected for the investigation. For comparatively determining the combustion behavior and energy properties of the of European Beech tree components, the chips were prepared. These chips were dried (air dried, 12%) in laboratory conditions at 20 °C and 50% relative humidity before being subjected to evaluations. Typically, the combustion is preceded by evaporation of the moisture, distillation and burning of the volatiles before the fixed carbon burns. However, fixed carbon is the solid combustible residue that remains after a wood or bark are heated and the volatile matter is expelled. It is determined by subtracting the percentages of moisture, volatile matter, and ash from the sample. The combustion properties of a given substrate can be found by ultimate and proximate analysis. For determining volatile and ash contents, a TGA instrument (Leco TGA701 Thermogravimetric Analyzer) was utulized according to the ASTM D 5142 protocol. The moisture content determined at 105 °C, ash at 750 °C, volatiles at 950 °C in this experimental process. The heat values were determined by a calorimetry bomb instrument (Leco AC–500). At the end of the process, the energy levels of samples were found in calorific value (Kcal/Kg). The sulfur and carbon content were determined by using a carbon/sulfur analyzer instrument (Leco SC-144) and was determined at 1350 ºC at 3.0 min durations.
Experimental Findings: It has found that selected variables (European Beech components and age groups) have influenced combustion and calorific properties in some level. However, bark was found to be show the lowest fixed carbon ratio of 13.7% in 10 years old samples. The highest volatile matter content of 84.6% was obtained with a 30 years old branch wood sample. Moreover, the highest level of ash content (3.7-9.9%) was found to be with bark samples in all three age groups, regardless of conditions. The measured calorific values looks like very similar in crown wood (4207.8 kcal/kg to 4263.8 kcal/kg) and branch wood samples (4137.8 kcal/kg to 4563.5 kcal/kg) while considerably lower for bark (3776.6 kcal/kg to 4200.7 kcal/kg). It is also important to note that European Beech tree have only showed trace amount of sulfur element (0.03-0.13%) in regardless of maturity and parts of tree.