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Author(s): T. M. Mata
A. A. Martins
N. S. Caetano
D. Caldeira
Title: Valorisation of Spent Coffee Grounds: Production of Biodiesel via Enzymatic Catalysis with Ethanol and a Co-solvent
Issue Date: 2017-02-01
Abstract: This work aims to explore the production ofbiodiesel from oil extracted from spent coffee grounds(SCG) via enzymatic catalysis with the Lipozymes RM IM,TL 100L and CALB L, in the presence of a co-solvent, andto optimize the reaction conditions. A three factors designof experiments was performed to evaluate the influenceon the reaction performance of ethanol/oil molar ratio,enzyme concentration and reaction temperature. Oil wasextracted from air dried SCG with hexane in a pilot solid/liquid extractor, resulting in 6.4% (m/m oil) in dry SCG.The coffee oil was characterized for its kinematic viscosity (38.04 mm2/s), density (0.903 g/cm3), heating value(38 MJ/kg), iodine value (63 g I2/100 g oil), water content(0.1458%), acid value (44.78 mg KOH/g oil), flash point(>120°C) and triglyceride content (82.8%). Based on thedesign of experiments, the best conditions for the transesterification reaction are 5:1 molar ratio of ethanol/oil, 4.5%(m/m oil) of enzyme and 45 °C of temperature, resulting inan experimental yield of 96.7%, with 87.6% (m/m) of esterscontent. Additionally, it was studied the effect of water inthe transesterification reaction, using ethanol at 92, 85 and75% (v/v). Results show that the best reaction yield (97.2%)and esters content (92.1%) were obtained using ethanol92%. Although the esters content of the biodiesel obtainedfrom coffee oil does not accomplish the EN 14214:2009requirements, it is promising as there is the possibility to blend the coffee oil with oil from other sources in order tomeet the standard requirements.
Subject: Ciências Tecnológicas
Technological sciences
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projetos Estratégicos/UID/EQU/00511/2013 - POCI-01-0145-FEDER-006939/Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia/LEPABE
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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