Mariana Provedel Martins

Briquetes de Bagaço de Cana-de-Açúcar e Pó de Lixa de Eucalyptus spp: Caracterização e Equilíbrio Higroscópico

Univ Fed Sao Carlos, Dept Ciencias Ambientais, Rodovia Joao Leme dos Santos,Km 110,SP 264, Sorocaba, SP, Brazil

Caracterização Química de Resíduos de Eucalyptus sp. de Floresta de Curta Rotação para a Produção de Bioenergia

The use of biomass resources to generate energy has been growing as renewable alternative, foremost because of their promising properties. Nowadays, one of the newest alternative resources under study is the biomass from short-rotation forests. However, such process lacks development to be used in commercial scale in Brazil, despite its positive perspectives. The aim of the present study is to chemically characterize Eucalyptus sp. residues, in order to find their applicability potential as sustainable fuel. The material was collected in short-rotation forests in Taiobeiras, Minas Gerais State. Two treatments were tested, namely: residues collected in the harvester (T1) and 40-day-dried soil residues (T2). Firstly, the volatile matter and the ash content were analyzed in triplicate to determine the fixed carbon content. The results were 1.35%, 79.35% and 19.3%, in T1; and 1.30%, 80.60% and 19.2%, in T2, respectively. The extractive levels were 15.88%, in T1; and 12.37%, in T2. The lignin values reached 17.12% and 20%, in T1 and T2, respectively. The holocellulose and ?-cellulose levels were recorded and the hemicellulose level was found using the difference between the holocellulose and ?-cellulose values. The holocellulose reached 65.94%, in T1; and 61.34%, in T2; whereas the ?-cellulose presented values such as 40.64%, in T1; and 36.22%, in T2. Therefore, the hemicellulose content was 25.30% and 25.12%, in T1 and T2, respectively. Lastly, the calorific power levels were 18132.5 J/g and 18175.0 J/g, in T1 and T2, results that may be related to the chemical composition of short rotation timber.

Caracterização Físico-Química da Biomassa de Leucaena leucocephala para Produção de Combustível Sólido

The use of biomass as raw material in renewable energy production has been studied as alternative source to fossil fuels. The aim of the current study is to physicochemically feature the biomass of Leucaena leucocephala (leucaena) tree species in order to produce briquettes. Leucaena wood treated with three moisture levels - T1 (10%), T2 (12%) and T3 (15%) – was used to produce briquettes. The study was divided in the following stages: analyzing the grinding material and the lignin and cellulose particle size distribution, chemical analysis, calorific value determination, briquetting and mechanical testing. The results were statistically analyzed through ANOVA and Tukey tests. The species showed satisfactory performance in the following assessed aspects: lignin content (22.61%), ash content (2.15%), and calorific value (4442.29 kcal.kg -1 ). As for the influence of the moisture content, the best results were found in treatment T2 (12%), wherein the mean maximum force was 51.22 kgf, the maximum strain was 0.41 MPa, and friability was 4.07%. It was shown that the moisture content changes briquettes’ stability and strength. The species showed satisfactory features regarding the purpose suggested for all treatments, as well as potential to be used in bioenergy production.

Production and evaluation of charcoal fines briquettes compressed with cellulosic waste from paper and pulp industry.

Este trabalho teve por objetivo avaliar briquetes produzidos a partir de finos de carvao vegetal compactados com residuo celulosico gerado na decantacao dos efluentes da industria de papel e celulose. Foram realizados os seguintes tratamentos: briquetes produzidos com fino de carvao vegetal e residuo celulosico nas proporcoes de 25% (T1), 30% (T2), 35% (T3), 40% (T4) e 45% (T5) e briquetes produzidos com finos de carvao vegetal com 10% de amido e residuo celulosico nas proporcoes de 0% (T6), 5% (T7), 10% (T8), 15% (T9), 20% (T10) e 25% (T11). A caracterizacao dos briquetes foi realizada por meio de ensaios de analise quimica imediata, determinacao do poder calorifico superior, densidade aparente e avaliacao da resistencia mecânica apos a secagem dos briquetes em estufa ou ao ar livre. Observou-se que os briquetes com residuo celulosico e amido em sua composicao apresentaram maior densidade e resistencia mecânica a compressao, concluindo-se, assim, que a presenca do amido favoreceu a compactacao e estabilidade dos briquetes. Observou-se, tambem, que o processo de secagem em estufa prejudicou a qualidade dos briquetes, de modo que a secagem ao ar livre forneceu briquetes mais resistentes e estaveis.