Biochars are emerging ecological products that show excellent properties in areas such as carbon sequestration, soil improvement, bioremediation, activated carbon and bioenergy. These interesting materials can be synthesized from a wide variety of sources derived from waste, including lignocellulosic biomass waste. In this work, biochars were produced from residues from the Brazilian Amazon, such as green coconut, babassu and Brazil nuts. The synthesis of biochars was performed under pyrolysis conditions with a fixed time of 3 h and temperature variation of 250 ºC (T1) and 400 ºC (T2). Yields of biochar production >85%, carbon contents >56%, and oxygen contents >20% and calorific values >23 MJ.Kg -1 , demonstrate that biochars produced from residual biomass can be used as activated carbon and also as fertilizers in soils, thus adding value to such residues. Besides, the biomasses used were characterized and the achieved remarkable yields of fermentable sugars, reaching up to 70% in cellulose hydrolysis, which can be useful in the production of bioproducts. In addition, the efficient use of these biomasses will positively impact the productive chains involved, benefiting society, generating employment, income, Besides as mitigating an environmental liability.

O contínuo aumento de gases carbônicos na atmosfera, principalmente o CO2 e o CO, tem levado a discussões sobre medidas que reduzam a emissão destes gases e os impactos no meio ambiente. Dentre as ações que contribuem para a redução de CO2 na atmosfera podem se destacar: a conservação de estoques de carbono nos solos, a implantação de florestas e sistemas agroflorestais e a recuperação de áreas degradadas. Assim, este trabalho tem o objetivo avaliar o estoque de carbono em solos de cerrado sob pastagens. Foram estudados solos de três áreas: área com Batata doce (BD), Pastagem em Degradação (PD), Horta Agroecológica (HA). As características avaliadas foram: teor de matéria orgânica, densidade do solo, estoque de carbono e crédito de carbono. De acordo com os resultados obtidos neste estudo concluiu-se que em solos de cerrado ocupados com sistemas de pastagem degrada e horta agroecológica proporcionaram melhores condições de umidade, matéria orgânica e consequentemente estoque e crédito de carbono. Porém, é importante salientar que os solos de PD apresentaram maior estoque de carbono, pois as raízes da forrageiras se encontravam mais superficiais devido ao processo de degradação, não sendo esta a condição ideal para maior vida útil da pastagem.

The pequi (Caryocar brasiliense Camb) is a fruit native to the Cerrado, with a production of 765 tons per year. However, their peels (76% of the fruit) are generally discarded. In this study, the physical-chemical characterization of the biomass of the pequi was carried out and physical activation processes were developed through slow pyrolysis and physical chemical activation with zinc chloride (ZnCl2) to produce bio-based products, including bio-oil (30.5%) and biochar (34%). Analytical techniques, such as mid-infrared spectroscopy, gas chromatography coupled with mass spectrometry, surface area, pore size, approximate and elementary analysis, helped to elucidate, identify and quantify such compounds. The biochars produced showed a low surface area of 30,30 m²/g (BET) and 39.11 m²/g (Langmuir), however the superior calorific power of activated carbon (29.59 kJ.g -1 ) and raw coal (26,92 kJ.g -1 ) highlight the potential of biochar for use as a solid fuel. Bio-oil, on the other hand, presented valuable chemicals in its fraction, such as vaccenic acid (21.23%), palmitic acid (19.73%) and furfural acid (7.04%).

A batata-doce é um alimento, que possui uma grande variabilidade genética, no qual pode ser selecionadas para algumas finalidades como, por exemplo: maior resistência a pragas e doenças. Pesquisadores da Universidade Federal do Tocantins -UFT- vem realizando desde 1997, estudos com batata-doce, destinada a produção de etanol. Desde então vem sendo realizados melhoramento genético entre genótipos com o intuito de melhorar a produção do biocombustível. Entretanto, existem genótipos com características desejáveis ao consumo humano. Diante disso, o objetivo deste trabalho foi avaliar alguns desses genótipos, com intuito de encontrar características adequadas para mesa. As análises realizadas foram: formato, resistência a insetos, cor de casca e cor de polpa. Foram avaliadas 30 cultivares, nas quais duas morreram. As cultivares HSF 0506 e BDI 2011-52 apresentaram bom formato de raiz (nota 1). As cultivares BDI 2011-52 (nota 1,11) e HSF 0506 (nota 1,33) se destacaram com melhores notas em resistência a insetos. A cor predominante de casca e polpa foi branca (64%) e creme (71%), respectivamente. Segundo os dados avaliados, conclui-se que a cultivar HSF 0506 se mostrou superior às outras, atendendo os padrões de mesa solicitados pelo consumidor. Palavras-chave: Padrões de mesa da batata doce; Melhoramento genético

Lignocellulosic waste is a valuable source of energy, fuels, and raw materials for the chemical industry. In this study, the potential of cupuaçu husks, derivative from a typical fruit of the Brazilian Amazon, was evaluated. Therefore, biomass was submitted to acid hydrolysis and pyrolysis, and the contents of sugars, by-products, bio-oil compounds, and bio-oil theoretical energy potential were determined. X-ray diffraction, High performance liquid chromatography, Fourier-transform infrared and Gas chromatography mass spectrometry analyzes were used. The hydrolysate has considerable sugar levels (31.7%) and presence of relevant by-products including furfural, levulinic acid and hydroxymethylfurfural. Bio-oil contained a variety of phenolic compounds, and its theoretical energy potential suggested usability of cupuaçu husks for energy generation. Economic analysis showed that commercialization of bioproducts obtained by biomass hydrolysis and pyrolysis could be highly profitable. These outcomes indicate a range of applications for cupuaçu husks in biorefinery processes and potential to promote sustainability and social development.