Elisa D. Cavalcanti-Oliveira
Federal University of Rio de Janeiro
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Featured researches published by Elisa D. Cavalcanti-Oliveira.
Enzyme Research | 2011
Elisa D. Cavalcanti-Oliveira; Priscila Rufino da Silva; Alessandra Peçanha Ramos; Donato A.G. Aranda; Denise Maria Guimarães Freire
The process of biodiesel production by the hydroesterification route that is proposed here involves a first step consisting of triacylglyceride hydrolysis catalyzed by lipase from Thermomyces lanuginosus (TL 100L) to generate free fatty acids (FFAs). This step is followed by esterification of the FFAs with alcohol, catalyzed by niobic acid in pellets or without a catalyst. The best result for the enzyme-catalyzed hydrolysis was obtained under reaction conditions of 50% (v/v) soybean oil and 2.3% (v/v) lipase (25 U/mL of reaction medium) in distilled water and at 60°C; an 89% conversion rate to FFAs was obtained after 48 hours of reaction. For the esterification reaction, the best result was with an FFA/methanol molar ratio of 1:3, niobic acid catalyst at a concentration of 20% (w/w FFA), and 200°C, which yielded 92% conversion of FFAs to soy methyl esters after 1 hour of reaction. This study is exceptional because both the hydrolysis and the esterification use a simple reaction medium with high substrate concentrations.
Biofuels#R##N#Alternative Feedstocks and Conversion Processes | 2011
Denise Maria Guimarães Freire; Joab Sampaio de Sousa; Elisa D. Cavalcanti-Oliveira
Publisher Summary This chapter discusses several methods for the production of biodiesel. Biodiesel can be produced using primary short-chain alcohols like methanol, ethanol, propanol, and butanol, as well as secondary alcohols like isopropanol and 2-butanol. The prerequisites for selecting the alcohol for industrial-scale biodiesel production are that it must be cheap and in plentiful supply. Currently, only methanol and ethanol meet these two requirements, and of these two substances, methanol is the more widely used as it is cheaper and more readily available in most countries although ethanol has the dual advantages of being renewable and less toxic. Organic solvents are also used in the enzymatic production of biodiesel to obtain a homogeneous reaction mediumby ensuring greater solubility of both the hydrophobic compounds and the hydrophilic compounds. Solvents also serve to reduce the viscosity of the reaction medium, enabling a higher diffusion rate to be achieved and reducing mass transfer problems. A suitable solvent must therefore be found, which both enhances the catalytic activity of the enzyme and keeps it stable.
Current Developments in Biotechnology and Bioengineering#R##N#Current Advances in Solid-State Fermentation | 2018
Erika C.G. Aguieiras; Elisa D. Cavalcanti-Oliveira; Magali Christe Cammarota; Denise Maria Guimarães Freire
Abstract This chapter reviews the current state-of-art and recent process developments in solid-state fermentation (SSF) for the production of lipases, focusing on its use for biodiesel purposes. Some important parameters for the production of lipase by SSF such as the choice of microorganisms and substrates are discussed, and several applications of the biocatalysts produced are outlined. The recent technology of simultaneous lipase production and immobilization by SSF is addressed, and the recent advances in the application of fermented solids with lipase activity for biodiesel synthesis are highlighted. Moreover, some variables that significantly affect the enzymatic processing biodiesel synthesis and the overall cost of biodiesel (i.e., raw material and alcohols, solvents, water content, and reactor configuration) are also pointed out. This chapter also addresses the application of lipase by SSF in the treatment of high-fat wastewater from the food industry. The generation of this type of wastewater is growing worldwide due to the increase in population and food production. The replacement of dissolved air flotation, a unit typically used in the conventional treatment of these wastewaters, by an enzymatic hydrolysis tank results in a lower fixed capital investment, eliminates a number of operational problems in the bioreactors, and allows greater energy recovery (of the fat contained in the wastewater) in the anaerobic biological treatment employed in the food industries.
Journal of Molecular Catalysis B-enzymatic | 2010
Joab Sampaio de Sousa; Elisa D. Cavalcanti-Oliveira; Donato A.G. Aranda; Denise Maria Guimarães Freire
Fuel | 2014
Erika C.G. Aguieiras; Elisa D. Cavalcanti-Oliveira; Aline Machado de Castro; Marta A. P. Langone; Denise Maria Guimarães Freire
Fuel | 2015
Erika C.G. Aguieiras; Elisa D. Cavalcanti-Oliveira; Denise Maria Guimarães Freire
Fuel | 2017
J. Greco-Duarte; Elisa D. Cavalcanti-Oliveira; J.A.C. Da Silva; Roberto Fernandez-Lafuente; Denise Maria Guimarães Freire
Industrial Crops and Products | 2015
Elisa D. Cavalcanti-Oliveira; Priscila Rufino da Silva; Taís S. Rosa; Nathalia Machado Lino De Moura; Bruno C.P. Santos; Danielle B. Carvalho; Joab Sampaio de Sousa; Maite Torres Jauregui Carvalhinho; Aline Machado de Castro; Denise Maria Guimarães Freire
Journal of the American Oil Chemists' Society | 2017
Erika C.G. Aguieiras; Elisa D. Cavalcanti-Oliveira; Aline Machado de Castro; Marta A. P. Langone; Denise Maria Guimarães Freire
Brazilian Journal of Chemical Engineering | 2018
Fernanda R.C. Damasceno; Elisa D. Cavalcanti-Oliveira; Ioannis K. Kookos; Apostolis A. Koutinas; Magali Christe Cammarota; Denise Maria Guimarães Freire