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ResumoO objetivo deste trabalho é estudar a viabilidade do uso de resíduo da casca de acácia negra (RCAN) gerado na extração do tanino, para a produção de carvão ativado. No sul do Brasil cerca de 250 toneladas/dia de cascas são geradas pelo setor industrial e uma grande parte deste material é destinada à compostagem ou disposta em aterros. Visando aproveitar este resíduo foram realizados experimentos de pirólise e ativação com H 3 PO 4 , em atmosfera controlada. Os constituintes do RCAN foram avaliados por análise elementar e a caracterização dos carvões obtidos foi realizada por análises termogravimétricas (TGA), a área superficial e volume de poros (métodos BET e BJH), microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva (EDS). A análise elementar do RCAN indicou um teor de carbono de 51,4 % e a área superficial foi de aproximadamente 906 m²/g para o carvão ativado com H 3 PO 4 , valor este superior à área superficial do carvão ativado comercial (CAC). Nas imagens de MEV pode se observar a estrutura porosa bem desenvolvida do carvão ativado quimicamente o que corrobora com a elevada área superficial determinada pelo método BET. Palavras-chaveCarvão ativado; resíduo; acácia negra; ativação química.Study of activated carbon production from the black wattle shell waste with and without chemical activation AbstractThe purpose of this work is to study the viability of using waste of black wattle shell (RCAN) generated in the tannin extraction process, for activated carbon production. In southern of Brazil about 250 tons/day of shells are generated by the industrial sector and much of this material is intended for composting or disposed in landfills. Aiming to use this waste was carried out pyrolysis and activation experiments with H 3 PO 4 in a controlled atmosphere. The constituents of RCAN were evaluated by elemental analysis and coals characterization was obtained by thermogravimetric analysis (TGA), the surface area and pore volume by the BET and BJH method, scanning electron microscopy (MEV) and energy dispersive spectroscopy (EDS). Elemental analysis of RCAN presented a 51.4% carbon and the surface area was approximately 906 m²/g for the activated carbon with H 3 PO 4 , value higher than the surface area of activated carbon (CAC). In the MEV images can be seen well-developed porous structure of chemically activated carbon which is in agreement with the high surface area presented by BET analysis.

The Brazilian savannah-like Cerrado is classified as a fire-dependent biome. Human activities have altered the fire regimes in the region, and as a result, not all fires have ecological benefits. The indigenous lands (ILs) of the Brazilian Cerrado have registered the recurrence of forest fires. Thus, the diagnosis of these events is fundamental to understanding the burning regimes and their consequences. The main objective of this paper is to evaluate the fire regimes in Cerrado’s indigenous lands from 2008 to 2017. We used the Landsat time series, at 30 m spatial resolution, available in the Google Earth Engine platform to delineate the burned areas. We used precipitation data from a meteorological station to define the rainy season (RS), early dry season (EDS), middle dry season (MDS), and late dry season (LDS) periods. During 2008–2017, our results show that the total burned area in the indigenous lands and surrounding area was 2,289,562 hectares, distributed in 14,653 scars. Most fires took place between June and November, and the annual burned area was quite different in the years studied. It was also possible to identify areas with high fire recurrence. The fire regime patterns described here are the first step towards understanding the fire regimes in the region and establishing directions to improve management strategies and guide public policies.

Aware of the harmful consequences of climate change, several industrial sectors search for alternatives to minimize the environmental impact of their production processes. The use of thermal solar collectors is a promising alternative for the heat supply in industrial processes, contributing to the reduction of fossil fuel consumption for this purpose and, consequently, mitigating the environmental impact caused by greenhouse gas emissions. The present research analyzes the contribution of a Solar Heating for Industrial Processes (SHIP) system in an industry’s environmental and economic spheres on the outskirts of Porto Alegre, south Brazil. A solar field of Linear Fresnel concentrating collectors is simulated in SAM software. The field has an aperture area of 352 m² and operates in the supply of saturated steam for a given industrial process. The results indicate that the SHIP system would be able to supply 729 GJth to the industrial process annually. It means a reduction of greenhouse gas emissions in the magnitude of tens of tons of CO2-equivalent each year, whose value increases as the operation of the conventional steam-generating boiler moves away from ideal (theoretical efficiency of 100%). Two methodologies are used to calculate LCOH, resulting in 52 and 54 U$D/MWhth values for the analyzed SHIP system. Compared with the heat supply through burning natural gas and mineral coal, a solar thermal heating system can be evaluated as an environmentally responsible and economically advantageous alternative for the industrial sector that decides on this investment.