Sustainable Strategy Based on Induced Precipitation for the Purification of Phycobiliproteins

Phycobiliproteins are fluorescent proteins mainly produced by red macroalgae and cyanobacteria. These proteins, essential to the survival of these organisms, find application in many fields of interest, from medical, pharmaceutical, and cosmetic to food and textile industries. The biggest obstacle to their use is the lack of simple environmental and economical sustainable methodologies to obtain these proteins with high purity. In this work, a new purification process is proposed based on the induced precipitation of the target proteins followed by ultrafiltration. Purities of 89.5% of both phycobiliproteins and 87.3% of R-phycoerythrin were achieved using ammonium sulfate and poly(acrylic acid) sodium salts as precipitation agents (followed by an ultrafiltration step), while maintaining high recovery yields and protein structure stability. Environmental analysis performed to evaluate the proposed process shows that the carbon footprint for the proposed process is much lower than that reported for alternative methodology, and the economic analysis reveals the cost-effective character associated to its high performance. This work is a step toward more sustainable and effective methodologies/processes with high industrial potential

Valorisation of red beet waste: one-step extraction and separation of betalains and chlorophylls using thermoreversible aqueous biphasic systems

Globally, up to 50% of root crops, fruits and vegetables produced is wasted. Beetroot stems and leaves fit into this scenario, with only a small fraction being used in cattle food. One way of approaching this problem is through their valorisation, by extracting and recovering valuable compounds present in this type of waste that could be used in other applications, while contributing towards a circular economy. In this work, a new integrated process using thermoreversible aqueous biphasic systems (ABS) composed of quaternary ammonium-based ionic liquids (ILs) and polypropyleneglycol 400 g mol−1 (PPG) is shown to allow the one-step extraction and separation of two pigment classes—betalains and chlorophylls—from red beet stems and leaves. The pigment extraction was carried out with a monophasic aqueous solution of the IL and PPG, whose phase separation was then achieved by a temperature switch, resulting in the simultaneous separation of chlorophylls and betalains into opposite phases. A central composite design was used to optimise the extraction parameters (time, temperature, and solid : liquid (S/L) ratio) of both pigment extraction yields, reaching at 20 °C, 70 min and a S/L ratio of 0.12 a maximum extraction yield of 6.67 wt% for betalains and 1.82 wt% for chlorophylls (per weight of biomass). Moreover, it is shown that aqueous solutions of ILs better stabilise betalains than the gold standard solvent used for the extraction method. Among the studied systems, the ABS comprising the IL N-ethyl-N-methyl-N,N-bis(2-hydroxyethyl) bromide ([N21(2OH)(2OH)]Br) presented the best separation performance, with an extraction efficiency of 92% and 95% for chlorophylls and betalains, respectively, for opposite phases. The pigments were removed from the respective phases using affinity resins, with high recoveries: 96% for betalains and 98% for chlorophylls, further allowing the IL reuse. Finally, the cyto- and ecotoxicities of the quaternary ammonium-based ILs were determined. The obtained results disclosed low to negligible toxicity in the thousands of mg L−1 range, with [N21(2OH)(2OH)]Br being harmless from an ecotoxicological point of view. Overall, it is shown here that the developed process is an innovative approach for the one-step extraction and selective separation of pigments contributing to the valorisation of waste biomass

Prediction of Ionic Liquids Properties through Molecular Dynamics Simulations

Ionic liquids (ILs) are a new generation of molten salts possessing unique physical and chemical properties, which have gained attention from the academic and industries researchers. The design of new products and processes requires the knowledge of transport and thermophysical properties, yet, due to the large number of potential ILs, their characterization by experimental means alone is not feasible. Computer simulations are being used with success for the prediction of structures and properties of many different molecular systems. Among different computational approaches, molecular dynamics simulation (MD) has proved to be capable of providing a good understanding at the molecular level of how the structure and properties of ILs are related. - See more at: http://www.eurekaselect.com/118935/article#sthash.VDpluw1J.dpu

The solid-liquid phase diagrams of binary mixtures of even saturated fatty acids differing by six carbon atoms

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)This study was aimed at using the solid-liquid phase diagrams for three binary mixtures of saturated fatty acids, especially the phase transitions below the liquidus line. These mixtures are compounded by caprylic acid (C(8:0)) + myristic acid (C(14:0)). capric acid (C(10:0)) + palmitic acid (C(16:0)), lauric acid (C(12:0)) + stearic acid (C(18:0)), differing by six carbon atoms between carbon chains. The phase diagrams were obtained by differential scanning calorimetry (DSC). The polarized light microscopy was used to complement the characterization for a full grasp of the phase diagram. Not only do these phase diagrams present peritectic and eutectic reactions, but also metatectic reactions, due to solid-solid phase transitions common, in fatty acids. These findings have contributed to the elucidation of the phase behavior of these important biochemical molecules with implications in various industrial production. (C) 2009 Elsevier B.V. All rights reserved.496416713037Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAEPEX/UNICAMP FEDERFundacao para a Ciencia e a Tecnologia [POCI/CTM/60288/2004]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CNPq [141607/2004-1, 142823/2005-8, 303649/2004-6]FAPESP [05/53095-2, 08/09502-0, 08/56258-8]CAPES [0148/06-7]Fundacao para a Ciencia e a Tecnologia [POCI/CTM/60288/2004

High carbon dioxide solubilities in trihexyltetradecylphosphonium-based ionic liquids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Due to the potential of ionic liquids for industrial application in CO(2) capture and gas separation processes, solubility of near or supercritical CO(2) in ionic liquids has been object of extensive research during the last few years. This work studies the solubility of CO(2) in phosphonium-based ionic liquids that, unlike imidazolium-based ILs, have received little attention in spite of their interesting characteristics. This work addresses the study of the gas-liquid equilibrium of two ionic liquids, trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide and trihexyltetradecylphosphonium chloride, in a wide range of temperatures, pressures, showing that phosphonium ionic liquids can dissolve even larger amounts of CO(2) (on a molar fraction basis) than the corresponding imidazolium-based ILs. In particular trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide seems to be the IL with the largest CO(2) sorption capacity reported up to present, revealing the potential of phosphonium-based ILs for CO(2) capture. A thermodynamic model based on the Peng-Robinson equation of state with the Wong-Sandler mixing rule, using the UNIQUAC model for the activity coefficients, was here adopted to describe the experimental data and for the estimation of the Henry's constants. A universal correlation, for the description of the solubility of CO(2) in ILs previously proposed by us was also applied to the description of the data here measured showing a good agreement with the experimental data. (C) 2010 Elsevier B.V. All rights reserved.523258265Fundacao para a Ciencia e a Tecnologia [PTDC/EQU-FTT/102166/2008]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)[SFRH/BD/41562/2007]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao para a Ciencia e a Tecnologia [PTDC/EQU-FTT/102166/2008]FAPESP [2006/037111][SFRH/BD/41562/2007

Evaluation of Predictive Models for the Viscosity of Biodiesel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Viscosity is an important biodiesel parameter, subject to specifications and with an impact on the fuel quality. A model that could predict the value of viscosity of a biodiesel based on the knowledge of its composition would be useful in the optimization of biodiesel production processes and the planning of blending of raw materials and refined products. This work aims at evaluating the predictive capability of several models previously proposed in the literature for the description of the viscosities of biodiesels and their blend with other fuels. The models evaluated here are Ceriani's, Krisnangkura's, and Yuan's models, along with a revised version of Yuan's model proposed here. The results for several biodiesel systems show that revised Yuan's model proposed provides the best description of the experimental data with an average deviation of 4.65%, as compared to 5.34% for Yuan's model, 8.07% for Ceriani's model, and 7.25% for Krisnangkura's model. The same conclusions were obtained when applying these models to predict the viscosity of blends of biodiesel with petrodiesel.25352358Fundacao OrienteUniversity of AveiroFundacao para a Ciencia e a Tecnologia [SFRH/BD/28258/2006]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao para a Ciencia e a Tecnologia [SFRH/BD/28258/2006

High pressure phase behavior of carbon dioxide in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1-butyl-3-methylimidazolium dicyanamide ionic liquids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The acidity/basicity of the reaction media has a substantial influence on the efficiency of many reactive processes: therefore, a new class of acidic or basic ionic liquids is gaining special attention due to the possibility of increasing the efficiency of many processes by a wise manipulation of their properties. The absorption of sour gases is one of the processes that can be enhanced by the basic character of the ionic liquid. The fluorination of the cation or anion can also contribute to the gas solubility enhancement. In this work, these two characteristics are evaluated and compared through the study of gas-liquid equilibrium of two ionic liquids, 1-butyl-3-methylimidazolium dicyanamide ([C(4)mim][DCA]) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C(4)mim]][Tf(2)N]), with carbon dioxide (CO(2)) at temperatures up to 363 K and pressures up to 74 MPa. A thermodynamic model based on the Peng-Robinson equation of state with the Wong-Sandler mixing rule, using the UNIQUAC model for the activity coefficients, was used to describe the experimental data and for the estimation of the Henry's constants. The solubility of CO(2) in 1-butyl-3-methylimidazolium dicyanamide is much lower than anticipated on the basis of the reported pK(a) of the anion when compared with the acetate anion. No chemisorption is observed and the solvation enthalpy is quite low, ruling out any Lewis acid/base interaction between the anion and the CO(2). The 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid, known to present one of the highest solubilities towards CO(2) due to the presence of fluoroalkyl groups, showed a much larger solubility for CO(2) than 1-butyl-3-methylimidazolium dicyanamide. (C) 2009 Elsevier B.V. All rights reserved.502105111Fundacao para a Ciencia e a Tecnologia [PTDC/EQU/65252/2006]Pedro J. Carvalho [SFRH/BD/41562/2007]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao para a Ciencia e a Tecnologia [PTDC/EQU/65252/2006]Pedro J. Carvalho [SFRH/BD/41562/2007]FAPESP [2006/03711-1

Low-Temperature Behavior of Biodiesel: Solid-Liquid Phase Diagrams of Binary Mixtures Composed of Fatty Acid Methyl Esters

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Although biodiesel is being widely used in blends with conventional diesel (Bx) as an automotive fuel, information on its low-temperature behavior is still scarce, in particular concerning the solid liquid phase behavior of the biodiesel components at temperatures below the cloud point. Although methyl oleate or methyl linoleate are typically components with the highest concentration in the biodiesel, its cloud point is much more influenced by saturated fatty esters because of their higher melting temperatures. The objective of this study is to present a detailed description of the solid liquid phase diagrams of selected binary mixtures containing the main saturated methyl fatty esters found in biodiesel. The liquidus lines and phase behavior below this transition were determined for the following binary mixtures: methyl myristate + methyl palmitate, methyl myristate + methyl stearate, and methyl palmitate + methyl stearate. It will be shown that these systems are not eutectic as previously admitted but, instead, have a complex phase behavior that may have unexpected impacts on the behavior of biodiesel at low temperatures.25732443250Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAEPEX/UNICAMPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CNPq [304495/2010-7, 480992/2009-6]FAPESP [08/09502-0, 08/56258-8