Bio-coal production with agroforestry biomasses in Brazil

The paper aims to analyze and classified some exotic wood species from tropical Africa, on regard to calorific features, in order to view the ability of their biomass to be a solid, natural and renewable fuel. The calorific values of wood wastes of eight tropical species were determined using an oxygen bomb calorimeter. The tested specimens were conditioned at a moisture content of 10%, 20%, and 50%. The influence of moisture content on calorific value and density, heat release rate and calorific efficiency were also analyzed. The biggest high calorific value and low calorific value were obtained by Guaiac and Rose species (21200-20700 kJ/kg). Acajou had the lowest values of high calorific value and low calorific value (18929 and 18456 kJ/kg, respectively). For higher wood density (Guaiac) the higher calorific density was obtained. The moisture content of specimens had negatively influenced the calorific efficiency and rate of energy release. The ash content was below 4% with highest values for Guaiac (3,6%) and the lowest for Acajou (0,5%). The results showed that the analyzed tropical wood species had a forest calorific capacity with 23-47% higher than of European beech, thus can be considered a good potential as renewable energy resources.

“…has of 4,1×10 -4 MJ/min. This result agrees with values found by de Freitas Fialho et al (2019) of 5,5-5,9 × 10 -4 MJ/min in briquettes made of spruce and oak.…”

Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Evaluation of the calorific values of wastes from some tropical wood species

Lunguleasa

Spirchez

Zeleniuc

2020

“…The remaining fibrous residue after the extractives, lignin, and ash-forming elements have been removed from the biomass is called holocellulose. Species with low percentages of holocellulose and high contents of lignin and extractives should be selected for charcoal as this increase resistance to thermal degradation (Fialho et al 2019, Pereira et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Selection of superior clones of Corymbia hybrids based on wood and charcoal properties

Loureiro

Vieira

Costa³

et al. 2019

The use of fast-growing trees is a good economic strategy for charcoal production. Wood with adequate chemical and physical properties generally is positively correlated with charcoal quality. The objective of this research was to evaluate wood quality from fast-growing hybrids for charcoal production. Three Corymbia citriodora x Corymbia torelliana and four Corymba torelliana x Corymba citriodora hybrid clones were evaluated. Parameters used to evaluate wood quality were wood basic density, elemental and structural chemical composition, energy efficiency and thermogravimetric analysis and the parameters evaluated for charcoal quality were apparent relative density, gravimetric yield, high heating value, proximate analysis and energy efficiency. All clones had wood basic density superior than 0,5 g cm-3 and ash inferior than 1%, which are desirable for a good quality of charcoal. Lignin content did not differ among clones with an average less than the 28% recommended for energetic use. Although clones differed in wood parameters, as dry matter, high heating value, energy density, total extractives, holocellulose content, it did not reflect in charcoal quality differences. Wood from all clones had equal and satisfying high heating value of charcoal and energy efficiency quality for charcoal production and differed in apparent relative density and ash content.

“…There are several studies reporting the effect of the main parameters of the torrefaction process on biomass but we could not identify reports on the characteristics of the Eucalyptus in the Paraíba Valley region in the main databases searched. There are many studies by a group of researchers evaluating the characteristics of the Eucalyptus in the state of Minas Gerais (Fialho et al 2019, Figueiro et al 2019, Pereira et al 2013, but due to the climatic differences, soil type and form in the planting (Santana et al 2008) it is important to know the behavior of biomass after torrefaction in the region that also has a significant Eucalyptus production. Therefore, the main objective of this work was to evaluate the characteristics of the of Eucalyptus spp.…”

Section: Introductionmentioning

confidence: 99%

Energy gains of Eucalyptus by torrefaction process

Romão

Conte

2020

The aim of this study was to evaluate the changes in the characteristics of Eucalyptus spp. from Paraíba Valley region, Sao Paulo -Brazil after torrification process. Torrification is a thermochemical process that occurs at temperatures lower than the pyrolysis process as a pretreatment to improve biomass characteristics for use as biofuel energy in power generation. An experimental study was carried out in a batch reactor at three temperatures (240 °C, 260 °C and 280 °C) with residence time of 30 and 60 minutes. At the indicated operating conditions by elemental analysis, higher heating value and thermogravimetric analysis were evaluated. Result showed that there was a reduction in the oxygen/carbon (O/C) and hydrogen/carbon (H/C) ratios, causing an increase in the thermal energy quality of torrified wood, about of 28 % and 47 % at temperatures of 260 °C with residence time of 60 minutes and 280 °C with 30 minutes, respectively. A thermogravimetric analysis showed that at 260 °C the hemicellulose was almost completely degraded leaving the fuel in better conditions for combustion or gasification processes.