ABSTRACT Background: The aim of this study was to investigate near infrared (NIR) spectroscopy ability to estimate nanofibril concentration, physical and mechanical properties of Kraft paper reinforced with cellulose nanofibrils (CNF). For this purpose, paper sheets were prepared by mixing unbleached Eucalyptus fibers and cellulose nanofibrils. Twelve treatments result from the combination of the nominal grammages 75, 85, 95 and 105 g m-² with the nanofibril concentrations of 1, 5 and 10wt%, with 7 sheets per treatment. NIR spectra measured directly on paper specimens were correlated with physical and mechanical properties values obtained through conventional laboratory analyzes. Results: Principal component analysis (PCA) revealed no separation among specimens related to nanofibril content. Partial least squares regression (PLS-R) models for estimating nanofibril content, tensile index, stretch and resistance to air passage yielded R 2cv ranging from 0.73 to 0.98. Partial least squares - discriminant analysis (PLS-DA) correctly classified up to 93% of the paper specimens both by grammage and nanofibril content using NIR spectra. Conclusion: This approach appears to be suitable for predicting physical and mechanical properties of Kraft papers and can detect cellulose nanofibril content in the cellulose handsheets.

Resumo Resíduos de bambu (Bambusa vulgaris) foram utilizados como matéria-prima para a produção de carvão ativado (CA). Os materiais foram coletados e transformados em CA mediante processos de carbonização (500°C, 1,67°C min-1, 60 min) e ativação (800°C, 10°C min-1, 60 min) com CO2 (100 mL min-1). O material obtido (CA CO2) foi caracterizado pelo seu rendimento, análise elementar, teor de cinzas, área superficial (SBET), método titulométrico de Boehm, microscopia eletrônica de varredura e utilizado como adsorvente para remoção dos contaminantes azul de metileno e fenol. Os modelos de isotermas de Langmuir e de Freundlich foram selecionados para entender o processo de adsorção. O CA CO2 produzido apresentou rendimento de 21,6%, teor de carbono de 82,13% e SBET de 856,78 m2 g-1, apresentando uma remoção rápida e elevada capacidade de adsorção para o azul de metileno (298,82 mg g-1) e fenol (558,29 mg g-1).

Abstract Bamboo (Bambusa vulgaris) wastes were used as raw material for producing activated carbon. The materials were collected and turned into activated carbons by carbonization (500 °C, 1.67 °C.min-1, 60 min) and activation (800 °C, 10 °C.min-1, 60 min) processes with CO2 (100 mL.min-1). The obtained material (CO2 AC) was characterized by its yield, elemental analysis, ash content, surface area (SBET), Boehm titration method, scanning electron microscopy and used as adsorbent for removing the methylene blue and phenol contaminants. The Langmuir and Freundlich isotherm models were selected for understanding the adsorption process. CO2 AC produced showed yield of 21.6%, carbon content of 82.13% and SBET of 856.78 m2.g-1, presenting rapid removal and high adsorption capacity for methylene blue (298.82 mg.g-1) and phenol (558.29 mg.g-1).

ABSTRACT This work aimed to chemically and energetically characterize palm waste in the municipality of Igarapé Açú-PA. The residue was crushed, sieved and acclimated up to 12% of humidity. Chemical analyses were performed in the fresh material, according to NBR standards. Part of the residue was transformed into charcoal at 450 °C, with heating rate of 1.67 °C.min-1 and residence time of 30 minutes. Elementary analysis (CHNS-O) was carried out in the fresh and carbonized material. For biomass, means of 32.67% of lignin and 2.58% of minerals were found. Means of 79.71% for volatile materials and 9.85% for fixed carbon were also found. In the elementary analysis, mean values of 53.79% for carbon and 0.7% for sulfur were found. Palm biomass residues presented high fixed carbon, structural carbon and lignin levels, thus presenting potential to be used in the direct production of energy, activated carbon and also biochar.

ABSTRACT This study aimed to determine the chemical and energetic composition of Brazil nut waste in the city of Castanhal-PA. Some of the material was crushed, sifted and stored for acclimatization and analysis. Molecular and immediate chemical analyses were performed on the raw material according to NBR standards. Another part was charred in Muffle furnace, with heating rate of 1.67 °C.min-1 and temperature of 450 °C for 60 minutes. For biomass, 55.76% of lignin and 2.61% of minerals were found. Means of 65.67% for volatiles were also found; 2.08% of ashes and 21.64% of fixed carbon. In the elementary, means of 53.54% of carbon and 0.11% of sulfur were found. For charcoal, 25.81% of volatiles were found; 1.76% of ashes and 67.50% of fixed carbon. Residues have high levels of lignin, fixed carbon and low ash contents, demonstrating potential for direct burning for energy, charcoal, activated carbon and biochar.

ABSTRACT In this work, two catalysts were produced to be used in hydrolysis of cellulose reactions to obtain glucose, a raw material used in the production of bioethanol. The heteropoly acid, H3PW12O40 (HPW), reported as strong and thermally stable acid, was supported on activated carbon (AC) in a ratio varying from 1:1 to 2:1 to produce the catalysts AC-HPW (1:1) and AC-HPW (2:1). The catalysts were tested in cellulose hydrolysis evaluating some reaction variables and the results show the remarkable dependence of reaction temperature, amount and acidity of the catalyst. The results indicate the advantage of supporting HPW on carbonaceous material for using as catalyst in hydrolysis of cellulose, showing better conversion rate into sugars comparing with unsupported HPW.

ABSTRACT Heteropoly salts containing different numbers of vanadium atoms (K4[PVW11O40] - KPWV1 and K6[PV3W9O40] - KPWV3) were synthesized from the heteropoly acid H3PW12O40 (HPW), and used as catalysts in hydrolysis of cellulose reactions in order to change the redox properties and verify whether the cluster of catalysts are involved in mechanism reaction. The hydrolysis reactions following a full 23 factorial design with the variables: mass ratio (catalyst/substrate), reaction time and temperature. The variables evaluated were significant at a 90% confidence level including second and third order interactions. According to the conducted experiments, the catalysts were all active in hydrolysis. The best results occurred when HPW was used suggesting that the redox properties did not have much influence in depolymerization of cellulose and the hydrolysis mechanism are assigned to acidic properties of the medium. The main products obtained from the reactions were glucose and HMF, which are products of great interest in the chemical industry.

RESUMO Carvões ativados em forma de briquetes foram preparados a partir do resíduo da madeira de candeia, gerado no processo de extração do óleo α-bisabolol. O material foi briquetado, carbonizado e ativado com CO2,variando-se a temperatura (700-900°C) e o tempo de ativação (1-3 horas). Para a caracterização dos carvões ativados foram realizadas análise elementar (CHN-O), análise dos grupos funcionais (titulação de Boehm), bur-off, área superficial BET estimada, índice de iodo, cálculo de área superficial com azul de metileno SAM, testes de adsorção com azul de metileno e fenol e índice de resistência mecânica. Os resultados mostraram que, com o aumento da temperatura e do tempo de ativação, ocorre aumento da área superficial, do volume de poros, da basicidade do carvão e da capacidade de adsorção de azul de metileno e de fenol.

ABSTRACT ThisActivated carbons briquette shaped were prepared from Candeia wood waste, generated in the extraction of α-bisabolol oil process. The material was briquetted, carbonized and activated with CO2, varying the temperature (700-900°C) and activation time (1-3 hours). The characterization of the activated carbons were performed by: elemental analysis (CHN-O), analysis of the functional groups (Boehm titration), Burn-off, estimated BET surface area, iodine index, calculation of surface area with methylene blue, adsorption tests with methylene blue (MB) and phenol and mechanical resistance (IRI).The results showed that increasing temperature and time of activation promoted an increased in the surface area, pore volume, basicity and adsorption capacity of AM and phenol.

Coffee fruit processing is one of the most polluting activities in agriculture due to the large amount of waste generated in the process. In this work, coffee parchment was employed as precursor for the production of carbons activated with ZnCl2 (CAP). The material was characterized using N2 adsorption/desorption at 77 K, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The material showed a surface area of 521.6 m²g-1 and microporous structure. CAP was applied as adsorbent for the removal of methylene blue dye in aqueous medium. The adsorption capacity was found to be about 188.7 mg g-1.

RESUMO A qualidade da madeira é definida pelas combinações entre as diversas características intrínsecas da árvore em função do seu uso. O objetivo do presente estudo foi avaliar essas características na madeira de clones de Eucalyptus visando à produção de polpa celulósica kraft de qualidade. Foram usados 15 clones, duas árvores de cada clone, num total de trinta árvores, todos com idades de 5,8 anos. As características avaliadas na madeira foram densidade básica, dimensões das fibras (comprimento da fibra, espessura de parede, diâmetro do lúmen) e composição química (teor de celulose, lignina, hemicelulose, extrativos e cinzas). Foram realizados quatro cozimentos Kraft para cada árvore, utilizando diferentes cargas de álcali ativo, para estabelecer a curva de deslignificação da amostra. Essas cargas de álcali foram selecionadas após realização de cozimentos exploratórios, objetivando obtenção de número kappa próximo a 18 na parte mediana da curva. Nos cozimentos, foram avaliados o rendimento depurado, a viscosidade da polpa celulósica e o álcali consumido. Os resultados de rendimento variaram de 43,4 a 52,0 %, o teor de álcali ativo utilizado de 17,5 a 23,4 %, o álcali consumido de 15,5 a 20,0% e a viscosidade de 19,9 a 61,4 cP.

ABSTRACT The wood quality is defined by combining several intrinsic characteristics of the tree to its use. This research aimed to evaluate some of the wood characteristics of Eucalyptus clones and its performance in kraft pulping. Fifteen clones, 5.8 years-old were used, two trees from each clone, totaling thirty trees. The evaluated wood characteristics were: basic density, fiber dimensions (fiber length, wall thickness, lumen diameter) and chemical composition (cellulose, lignin, hemicelluloses, extractives and ash contents). Four samples were cooked at the laboratory for each tree, using different active alkali, to establish the delignification curve. These alkali loads were selected after exploratory cooking to obtain an eighteen kappa number at the medium point of the curve. In the cooking were appraised the screened, the pulp viscosity and consumed alkali. The yield results varied from 43.4 to 52.0%, the active alkali from 17.5 to 23.4%, the consumed alkali from 15.5 to 20.0% and the pulp viscosity from 19.9 to 61.4 cP.

Este trabalho objetivou classificar e selecionar clones de Eucalyptus sp, tendo em vista a qualidade das polpas kraft obtidas a partir de cada material. Os clones foram classificados quanto a rendimento depurado, viscosidade da polpa e álcali ativo usado no processo de polpação. A classificação dos clones foi realizada por meio da análise de agrupamento, utilizando-se o método de otimização de Tocher. A análise de agrupamento permitiu a separação dos clones em cinco grupos distintos, sendo encontrados grupos de clones com alto, médio e baixo potenciais para produção de polpa celulósica. As características que mais contribuíram para a divergência foram o rendimento depurado (58,1%) e a viscosidade da polpa celulósica (35,0%). Em geral, nos clones avaliados foram verificadas grandes variações com relação aos parâmetros estudados.

The objectives of this study were to classify and select clones of Eucalyptus sp, aiming at pulp quality improvement. The clones were classified according to the screened yield, pulp viscosity and active alkali used for pulping. Classification of the clones was achieved by cluster analysis using the Tocher method. The clones were classified in groups having high, medium and low potential for pulp production. The results showed that the parameter that most contributed to group the different Eucalyptus sp clones was the screened yield (58,1%), followed by pulp viscosity (35,0%). In general, large variation was observed for the parameters evaluated.