Time filter

Source Type

Furtado A.T.,University of Campinas | Scandiffio M.I.G.,CTBE - Brazilian Bioethanol Science and Technology Laboratory | Cortez L.A.B.,University of Campinas
Energy Policy | Year: 2011

Ethanol has recently been of great interest worldwide because it is a viable economic alternative to petroleum products and it is a renewable source of energy that mitigates the emission of greenhouse gases. Brazilian bioethanol from sugarcane is the most successful case at the world level because of its low cost and low level of greenhouse gas emissions. Brazil's success with sugarcane cannot be understood as based solely on a natural comparative advantage, but as a result of efforts that culminated in a positive trajectory of technological learning, relying mostly on incremental innovations. The purpose of this article is to analyze the key aspects of the innovation system built around the Brazilian sugarcane industry. It is based on the national innovation systems approach according to which innovation results from the interaction of different institutional actors. Institutional arrangements are analyzed as the basis for the innovative process, in particular R&D and the innovation policies and strategies of the main players in the sugarcane sector, including sugar and ethanol mills, industrial goods suppliers, public and private research institutions, and governmental agencies. © 2010 Elsevier Ltd. Source

de Vasconcelos S.M.,Federal University of Pernambuco | Santos A.M.P.,Federal University of Pernambuco | Rocha G.J.M.,CTBE - Brazilian Bioethanol Science and Technology Laboratory | Souto-Maior A.M.,Federal University of Pernambuco
Bioresource Technology | Year: 2013

The influence of time (8-24. min), temperature (144-186. °C) and phosphoric acid concentration (0.05-0.20%, w/v) on the pretreatment of sugarcane bagasse in a 20. L batch rotary reactor was investigated. The efficiency of the pretreatment was verified by chemical characterization of the solid fraction of the pretreated bagasse and the conversion of cellulose to glucose by enzymatic hydrolysis. Models representing the percentage of cellulose, hemicelluloses, lignin, solubilized hemicellulose and the enzymatic conversion of cellulose to glucose were predictive and significant. Phosphoric acid concentration of 0.20% at temperature of 186. °C, during 8 and 24. min, was shown to be very effective in solubilizing hemicellulose from sugarcane bagasse, reaching solubilization of 96% and 98%, respectively. Relatively low amounts of inhibitors were produced, and the phosphoric acid remaining in the hemicellulosic hydrolysate is at adequate levels for supplying phosphorous requirement during subsequent fermentation. © 2012 Elsevier Ltd. Source

Driemeier C.,CTBE - Brazilian Bioethanol Science and Technology Laboratory
Cellulose | Year: 2014

The Rietveld method is a versatile tool to parameterize the fine structure of crystallites analyzed by diffraction. The method relies on a crystallographic model representing what is known a priori, and free coefficients determined from fits to experimental data. This article provides an introduction to Rietveld analysis of celluloses from higher plants that are adequately described by the cellulose Iβ crystal structure. Possibilities of Rietveld analysis have been recently enhanced by a tailored crystallographic model and computational algorithm, named Cellulose Rietveld Analysis for Fine Structure (CRAFS). From each two-dimensional diffraction pattern, CRAFS automated analysis outputs unit cell parameters, crystallite sizes, peak profile functions, integrated crystalline intensity (proportional to cellulose degree of crystallinity), and crystallite orientation distribution function. Two of the major hurdles for analysis of plant cellulose-overlapping of diffraction peaks and preferred crystallite orientation-are consistently treated by the two-dimensional Rietveld analysis. Hence, the method is a unique tool to explore cellulose fine structural variability, with differences arising from specimen conditioning, processing, and biological origins. © 2013 Springer Science+Business Media Dordrecht. Source

Leal M.R.L.V.,CTBE - Brazilian Bioethanol Science and Technology Laboratory | Horta Nogueira L.A.,Federal University of Itajuba | Cortez L.A.B.,University of Campinas
Applied Energy | Year: 2013

Several key indicators of the sustainability of biofuels are related to the land used to produce the feedstock. Most of the agronomic costs and energy use (fertilizers, herbicides, soil preparation, and harvesting) are more related to the cropped area than to the feedstock quantity produced; this is also the case of soil greenhouse gas (GHG) emissions (CO2 and N2O) and land use change (LUC) impacts, both direct (dLUC) and indirect (iLUC), socio-economic impacts (land tenure, land prices and traditional crop displacement), impacts on biodiversity and on the environment (soil, water and air). Today, biofuels use only a little more than 2% of the world arable land but if their use to displace fossil fuels increases, as indicated by some low carbon scenarios, the land demand for the production of feedstocks could become a constraint to the expansion. It is quite apparent that the biofuel yields, present and future, should be one of the main characteristics to be evaluated in the initial screening process. This work uses the cases of corn and sugarcane ethanol to draw some comparisons on the use of these biofuels to meet the targets of some of the International Energy Agency (IEA) biofuel use scenarios in terms of land demand and also will use some of the most important study results concerning the GHG emission reduction potential, including LUC and iLUC impacts, when meeting the Renewable Energy Directive (RED) of the European Union (EU) and the Renewable Fuel Standard (RFS2) of the USA. Some technology improvements will be considered including the integration of first and second generation technologies in the same site processing corn or sugarcane for ethanol. The results of the simulations indicated that the land demands for the 2030 projected ethanol production in the two alternatives seems not to give reasons for concern on a global scale, but are large enough to produce significant local impacts. The GHG abatement potential is strongly dependent on the biofuel alternative considered. © 2012 Elsevier Ltd. Source

Moraes B.S.,CTBE - Brazilian Bioethanol Science and Technology Laboratory | Zaiat M.,University of Sao Paulo | Bonomi A.,CTBE - Brazilian Bioethanol Science and Technology Laboratory
Renewable and Sustainable Energy Reviews | Year: 2015

The replacement of fossil fuels by biofuels has been extremely important worldwide to stimulate the growth of economies based on the sustainability through the use of renewable resources. Anaerobic digestion for biogas production is recognized as a clean technology that allies the suitability of wastes with energy generation, fulfilling the requirements for a sustainable alternative to provide the optimization of the biofuels production. This alternative is especially interesting for the sugarcane ethanol production in Brazil, in which the generation of vinasse, the main liquid waste, is very expressive. Nevertheless, the use of vinasse for anaerobic digestion has been finding some challenges to its establishment in the Brazilian sugarcane biorefineries. This paper reviews the actual context of anaerobic digestion within the sugarcane ethanol production in Brazil, presenting the main obstacles for its full application and the directions to promote it as well. Alternatives for biogas use are also presented and compared, highlighting the environmental and energy advantages of applying anaerobic digestion in the sugarcane biorefineries. This scenario is envisaged as a suitable way to achieve the future biorefineries model, based on the use and recovery of renewable resources with economic, social, and environmental benefits. © 2015 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations