Pretreatment Affects Activated Carbon from Piassava.

The specificity of activated carbon (AC) can be targeted by pretreatment of the precursors and/or activation conditions. Piassava (Leopoldinia piassaba and Attalea funifera Martius) are fibrous palms used to make brushes, and other products. Consolidated harvest and production residues provide economic feasibility for producing AC, a value-added product from forest and industrial residues. Corona electrical discharge and extraction pretreatments prior to AC activation were investigated to determine benefits from residue pretreatment. The resulting AC samples were characterized using elemental analyses and FTIR and tested for efficacy using methylene blue and phenol. All resulting AC had good adsorbent properties. Extraction as a pretreatment improved functionality in AC properties over Corona electrical discharge pretreatment. Due to higher lignin content, AC from L. piassaba had better properties than that from A. funifera.

Massaranduba Sawdust: A Potential Source of Charcoal and Activated Carbon.

This paper provides proof of concept that activated carbon (AC) may be readily produced using limited conversion methods and resources from sawdust of massaranduba (Manilkara huberi) wood, thereby obtaining value-added products. Sawdust was sieved and heat-treated in an oxygen-free muffle furnace at 500 °C to produce charcoal. The charcoal was activated in a tubular electric furnace at 850 °C while being purged with CO2 gas. Microstructural, thermal and physical properties of the three components: sawdust, charcoal and AC were compared by means of field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), density and water adsorption/desorption measurements. The resulting AC had a large surface area as measured by Brunauer-Emmett-Teller (BET) comparable to other such values found in the literature. The large surface area was due to pore development at the microstructural level as shown by FESEM. XRD illustrated that sawdust had a semi-crystalline structure whereas charcoal and AC evidenced mostly amorphous structures. TGA and DSC showed that AC had high reactivity to moisture compared to sawdust and charcoal.

Características de crescimento, composição química, física e estimativa de massa seca de madeira em clones e espécies de Eucalyptus jovens / Growing characteristics, chemical composition, physical and dry mass estimated of wood in young Eucalyptus species and clones

O objetivo deste trabalho foi avaliar o efeito do material genético, clones e espécies, e da classe de diâmetro nas características de crescimento, composição química, densidade básica e a estimativa de massa seca de madeira. Foram avaliados quatro clones e cinco espécies, aos quatro anos de idade, de Eucalyptus procedentes da empresa RIMA Industrial S.A. Foram avaliadas cinco árvores por clone e espécie em três e quatro classes diamétricas, respectivamente. Avaliaram-se as características individuais de crescimento da árvore, a densidade básica, a estimativa de massa seca, o teor de lignina, extrativos totais, holocelulose e cinzas. O volume, com e sem casca, e a estimativa de massa seca apresentaram efeito significativo de material genético (clone e espécie) e classe diamétrica. O teor de lignina não foi influenciado significativamente pelo material genético e classe diamétrica. A densidade básica apresentou efeito significativo de classe diamétrica para os clones e de material genético para as espécies. O teste de identidade de modelos somente foi não significativo para a estimativa de massa seca para as espécies, possibilitando usar a equação comum independente da espécie. Os clones apresentaram madeira mais homogênea, com menor densidade básica, extrativos totais e lignina total e maior teor de holocelulose, características mais adequadas à produção de polpa celulósica. As espécies apresentaram madeira mais heterogênea, com maior densidade básica, estimativa de massa seca, extrativos totais e lignina total e menor teor de cinzas e holocelulose, características desejáveis à produção de bioenergia.

This research aimed to determine the basic density, the estimate of dry mass and the chemical composition of clones and Eucalyptus species. Four clones and five species of Eucalyptus were appraised, with four years old, coming from the RIMA Industrial Company S.A. Five trees were sampled for clone and species in three and four diametric classes, respectively. Wood characteristics as the basic density, the insoluble and soluble lignin in acid sulfuric, extractive total and ash content in the wood were available. The results showed that the volume, with or without bark, and estimated dry mass showed significant effects of genetic material (clone and species) and diameter class. The lignin content was not significantly influenced by both genetic material and diameter class. Wood basic density had a significant effect of diameter class for clones and genetic material for the species. The identity test for linear models was only not significant for estimated dry mass of the species, indicating to be possible to use the common equation independent of the species. The clones showed a more homogeneous wood with lower average basic density, extractives and total lignin content and higher holocellulose content, characteristics which are suitable for pulp production. The wood species showed more heterogeneous with highest average basic density, estimated dry weight, total lignin and extractives content and lower ash and holocellulose content, characteristics desirable for bioenergy production.

Babassu nut residues: potential for bioenergy use in the North and Northeast of Brazil.

Babassu is considered the largest native oil resource worldwide and occurs naturally in Brazil. The purpose of this study was to evaluate the potential of babassu nut residues (epicarp, mesocarp and endocarp) for bioenergy use, especially for direct combustion and charcoal production. The material was collected in the rural area of the municipality of Sítio Novo do Tocantins, in the state of Tocantins, Brazil. Analyses were performed considering jointly the three layers that make up the babassu nut shell. The following chemical characterizations were performed: molecular (lignin, total extractives and holocellulose), elemental (C, H, N, S and O), immediate (fixed carbon, volatiles and ash), energy (higher heating value and lower heating value), physical (basic density and energy density) and thermal (thermogravimetry and differential thermal analysis), besides the morphological characterization by scanning electron microscopy. Babassu nut residues showed a high bioenergy potential, mainly due to their high energy density. The use of this biomass as a bioenergy source can be highly feasible, given their chemical and thermal characteristics, combined with a low ash content. Babassu nut shell showed a high basic density and a suitable lignin content for the sustainable production of bioenergy and charcoal, capable of replacing coke in Brazilian steel plants.