Brazil is the world largest producer of sugarcane (Saccharum officinarum) leading to a great generation of residues such as bagasse and straw, which represent two thirds of sugarcane energetic potential. Regarding the...Brazil is the world largest producer of sugarcane (Saccharum officinarum) leading to a great generation of residues such as bagasse and straw, which represent two thirds of sugarcane energetic potential. Regarding these residues energetic potential, it is interesting to study their application in biorefinery processes. Thus, this work aimed at performing a chemical characterization of sugarcane straw and bagasse from RB867515 cultivar grown in Rio Grande do Sul-Brazil aiming at their use as feedstock in biorefinery processes. The obtained results were compared to data from other states and it was possible to conclude that edaphoclimatic conditions of Rio Grande do Sul have little influence in sugarcane residues chemical composition. Sugarcane bagasse presents larger potential for energetic use because of its volatiles content (74.82%) slightly higher than straw (68.90%), besides its high lignin content (21.85%) and higher calorific value (18.70 MJ/kg). Both sugarcane residues produced in Rio Grande do Sul have potential use as substrate in the obtainment of high value-added products from their cellulosic fractions (41.30% and 37.25%, respectively). The evaluation of energetic and chemical potential of sugarcane bagasse and straw produced in Rio Grande do Sul leads to the conclusion that these materials have high potential for use as feedstock in biorefineries.展开更多
In integrated factories of pulp and paper, the bleaching control is made by kappa number and/or brightness. However, the product paper is evaluated and valued for its whiteness. The level of final brightness of pulp c...In integrated factories of pulp and paper, the bleaching control is made by kappa number and/or brightness. However, the product paper is evaluated and valued for its whiteness. The level of final brightness of pulp certainly affects the demand for optical brighteners in paper manufacturing, nevertheless, there is not a direct correlation between consumption of optical brightener and final brightness, being the method of bleaching pulp, especially from the final stage of bleaching, also important in relation to this demand. Therefore, this study aimed to evaluate the potential of using the parameter whiteness as a tool to control bleaching pulp, instead of the traditional brightness and evaluate the impacts of different methods of bleaching and the pulp final brightness level in action of optical brighteners, to improve their performance. It was observed that the whiteness and brightness of the pulp are highly correlated and that the control of the bleaching plant can be done by any one of these two parameters. It was also concluded that, considering current prices of bleaching reagents and of optical brighteners, it is better to bleach the pulp up to lower brightness values (e.g. 88% ISO) and use larger amounts of optical brighteners to brighten the mass until the whiteness of 130 CIE. This conclusion is valid for whiteness measured before the size press. Further studies are needed to validate this conclusion considering the finished product.展开更多
文摘Brazil is the world largest producer of sugarcane (Saccharum officinarum) leading to a great generation of residues such as bagasse and straw, which represent two thirds of sugarcane energetic potential. Regarding these residues energetic potential, it is interesting to study their application in biorefinery processes. Thus, this work aimed at performing a chemical characterization of sugarcane straw and bagasse from RB867515 cultivar grown in Rio Grande do Sul-Brazil aiming at their use as feedstock in biorefinery processes. The obtained results were compared to data from other states and it was possible to conclude that edaphoclimatic conditions of Rio Grande do Sul have little influence in sugarcane residues chemical composition. Sugarcane bagasse presents larger potential for energetic use because of its volatiles content (74.82%) slightly higher than straw (68.90%), besides its high lignin content (21.85%) and higher calorific value (18.70 MJ/kg). Both sugarcane residues produced in Rio Grande do Sul have potential use as substrate in the obtainment of high value-added products from their cellulosic fractions (41.30% and 37.25%, respectively). The evaluation of energetic and chemical potential of sugarcane bagasse and straw produced in Rio Grande do Sul leads to the conclusion that these materials have high potential for use as feedstock in biorefineries.
基金Funding provided by the Minas Gerais State Research Foundation(FAPEMIG)from the Brazilian National Council for Science and Technology Development(CNPq)is greatly appreciated.
文摘In integrated factories of pulp and paper, the bleaching control is made by kappa number and/or brightness. However, the product paper is evaluated and valued for its whiteness. The level of final brightness of pulp certainly affects the demand for optical brighteners in paper manufacturing, nevertheless, there is not a direct correlation between consumption of optical brightener and final brightness, being the method of bleaching pulp, especially from the final stage of bleaching, also important in relation to this demand. Therefore, this study aimed to evaluate the potential of using the parameter whiteness as a tool to control bleaching pulp, instead of the traditional brightness and evaluate the impacts of different methods of bleaching and the pulp final brightness level in action of optical brighteners, to improve their performance. It was observed that the whiteness and brightness of the pulp are highly correlated and that the control of the bleaching plant can be done by any one of these two parameters. It was also concluded that, considering current prices of bleaching reagents and of optical brighteners, it is better to bleach the pulp up to lower brightness values (e.g. 88% ISO) and use larger amounts of optical brighteners to brighten the mass until the whiteness of 130 CIE. This conclusion is valid for whiteness measured before the size press. Further studies are needed to validate this conclusion considering the finished product.
