Pereira da Silva Maciel G.,Federal University of Rio Grande do Sul |
Machado M.E.,Federal University of Rio Grande do Sul |
Barbara J.A.,Federal University of Rio Grande do Sul |
Molin D.D.,Federal University of Rio Grande do Sul |
And 4 more authors.
Biomass and Bioenergy | Year: 2016
GC × GC/TOFMS was applied in the characterization of organic extracts, which were obtained by solid phase extraction (SPE) with C18 commercial cartridges and liquid-liquid extraction (LLE) using three solvents of increasing polarities (hexane, dichloromethane and chloroform), from the aqueous phase generated during the pyrolysis of sugarcane straw. Many oxygenated compounds were identified and classified as acids, phenols, aldehydes and ketones, with a high predominance of phenolic compounds, mainly catechol. GC × GC/TOFMS coupled to some computational tools allowed the identification and classification of the compounds according to their chemical class, number of carbons, number of substituents in the alkyl chains, molecular weight and main peaks in fragmentation spectra. Some identifications were only possible to detect using spectral deconvolution of the mass spectra, and it was possible to clearly classify a series of alkyl phenols (from C1 to C4 alkyl substitutes) and alkyl benzenediols (probably catechols, from C1 to C3 alkyl substitutes). A sequential combination of the pre-concentration of the analytescombined with high-resolution techniques of separation and identification allowed the total characterization of these compounds in the aqueous phase. © 2015 Elsevier Ltd. Source
Tenorio Neto E.T.,State University of Maringa |
Kunita M.H.,State University of Maringa |
Rubira A.F.,State University of Maringa |
Leite B.M.,ITP UNIT |
And 4 more authors.
Journal of Chemical and Engineering Data | Year: 2013
This work reports phase equilibrium experimental data of binary and ternary systems involving carbon dioxide (CO2), 5-(2-propenyl)-1,3- benzodioxole (safrole), and ethenylbenzene (styrene). The experimental phase equilibrium data were measured using a high-pressure variable-volume view cell based on the static synthetic method in the temperature range of (303 to 343) K, at several CO2-overall compositions and pressures up to 16 MPa. For ternary system measurements, solutions of safrole and styrene with styrene mass fractions of 0.75 and 0.90 on CO2 free basis were prepared. The results showed that, in the experimental range investigated, only vapor-liquid equilibria (VLE) were detected with bubble (BP) and dew (DP) point transitions. The experimental data were satisfactorily represented by the Peng-Robinson equation of state (PR-EoS) with the classical quadratic mixing rules. The EoS interaction parameters were fitted from binary systems and then used to predict the phase behavior of the ternary system with a good agreement. © 2013 American Chemical Society. Source