Hydrogen production utilizing glycerol from renewable feedstocks-The case of Brazil

Various reports concerning catalytic reaction of glycerol for hydrogen production is available. However, economic analyses of this activity are not found yet. The objective of this work is to evaluate the process of hydrogen production via steam reforming of glycerol obtained through transesterification process of bio-oils. The thermochemical process of steam reforming process was determined due to high efficiency, feasibility and lower cost of design, development, operation and maintenance. These bio-oils come from feedstocks largely encountered in Brazil such as soybean, palm, castor bean, peanut and cotton seed as also come from residues such as defective coffee, tallow beef, wastewater (scum) and others. Various findings were obtained such as potential of production of glycerol utilizing residues (considering available amounts in the Brazilian states) and some vegetable feedstocks (considering production of harvested feedstock per hectare). Subsequently, production of hydrogen via steam reforming of generated glycerol, and foreseen electricity production via fuel cells were also determined. An additional estimation was paid for production of H-BIO, an innovative fuel developed by PETROBRAS (Petroleo Brasileiro S.A.), where hydrogen and bio-fuel are utilized and generates propane as co-product. About this work, it was concluded that high amounts of hydrogen and electricity could be produced considering an enormous potential from each cited feedstock being an attractive alternative as distributed electricity source and as an additional source for some activities, inclusively those that produce their own feedstocks such as abattoirs (beef tallow), and wastewater treatment plants. (C) 2010 Elsevier Ltd. All rights reserved.

Effect of the addition of soy lecithin and Yucca schidigera extract on the properties of gelatin and glycerol based biodegradable films

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The shielding effect of glycerol against protein ionization in electrospray mass spectrometry

Most commercial recombinant proteins used as molecular biology tools, as well as many academically made preparations, are generally maintained in the presence of high glycerol concentrations after purification to maintain their biological activity. The present study shows that larger proteins containing high concentrations of glycerol are not amenable to analysis using conventional electrospray ionization mass spectrometry (ESI-MS) interfaces. In this investigation the presence of 25% (v/v) glycerol suppressed the signals of Taq DNA polymerase molecules, while 1% (v/v) glycerol suppressed the signal of horse heart myoglobin. The signal suppression was probably caused by the interaction of glycerol molecules with the proteins to create a shielding effect that prevents the ionization of the basic and/or acidic groups in the amino acid side chains. To overcome this difficulty the glycerol concentration was decreased to 5% (v/v) by dialyzing the Taq polymerase solution against water, and the cone voltage in the ESI triple-quadrupole mass spectrometer was set at 80-130 V. This permitted observation of a mass spectrum that contained ions corresponding to protonation of up to 50% of the ionizable basic groups. In the absence of glycerol up to 85% of the basic groups of Taq polymerase became ionized, as observed in the mass spectrum at relatively low cone voltages. An explanation of these and other observations is proposed, based on strong interactions between the protein molecules and glycerol. For purposes of comparison similar experiments were performed on myoglobin, a small protein with 21 basic groups, whose ionization was apparently suppressed in the presence of 1% (v/v) glycerol, since no mass spectrum could be obtained even at high cone voltages. Copyright (C) 2003 John Wiley Sons, Ltd.

Analyzing glycerol-mediated protein oligomerization by electrospray ionization mass spectrometry

Glycerol is widely used as protein stabilizer, in both local and commercial preparations, so it has become necessary to develop methods for mass spectrometric analysis of protein preparations in the presence of glycerol. However, this stabilizing agent may cause signal suppression when present in high concentrations, and is also known to induce protein supercharging even at low concentrations. This work reports the,use of electrospray ionization (ESI) mass spectrometry to characterize glycerol-mediated protein oligomerization. this phenomenon seems to involve the formation of strong non-covalent interactions between protein and glycerol involving close contact between the monomers, leading to formation of protein oligomers adducted with glycerol molecules under the characteristic analytical conditions of the ESI interface. At high orders of oligomerization a lower number of glycerol molecules is required to maintain the high oligomeric states than for the dimers and trimers, and it is possible that for the higher oligomers the monomers become so close to one another that non-covalent bonds between the side chains of the amino acid residues in the proteins may be established. Copyright (C) 2005 John Wiley & Sons, Ltd.

Glycerol: A promising and abundant carbon source for industrial microbiology

Petroleum is the main energy source utilized in the world, but its availability is limited and the search for new renewable energy sources is of major interest. Biofuels, such as ethanol and biodiesel, are among the most promising sources for the substitution of fossil fuels. Biodiesel can replace petroleum diesel, as it is produced from animal fats and vegetable oils, which generate about 10% (w/w) glycerol as the main by-product. The excess glycerol generated may become an environmental problem. since it cannot be disposed of in the environment. One of the possible applications is its use as carbon and energy source for microbial growth in industrial microbiology. Glycerol bioconversion in valuable chemicals, such as 1,3-propanediol, dihydroxyacetone, ethanol, succinate etc. is discussed in this review article. (C) 2008 Elsevier B.V. All rights reserved.

Interaction of amphiphilic derivatives of chitosan with DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

INFLUENCE of GLYCEROL and ORNITHINE FEEDING on CLAVULANIC ACID PRODUCTION BY Streptomyces clavuligerus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Optimisation of the glycerol-to-ornithine molar ratio in the feed medium for the continuous production of clavulanic acid by Streptomyces clavuligerus

Amino acids are well metabolized by Streptomyces clavuligerus during the production of clavulanic acid using glycerol as main carbon and energy source. However, only a few amino acids such as arginine and ornithine are favorable for CA biosynthesis. The aim of this work was to optimize the glycerol:ornithine molar ratio in the feed medium containing only these compounds to maximize CA production in continuous cultivation. A minimum number of experiments were performed by means of a simple two-level full-factorial central composite design to investigate the combined effect of glycerol and ornithine feeding on the CA concentration during the intermittent and continuous process in shake-flasks. Statistical analysis of the experimental data using the response surface methodology showed that a glycerol-to-ornithine molar ratio of approximately 40:1 in the feed medium resulted in the highest CA concentration when fermentation was stopped. Under these optimized conditions, in bench-scale fermentor runs, the CA concentration reached more than double the concentration obtained in shake-flasks runs. (C) 2009 Elsevier B.V. All rights reserved.

Determination of free glycerol in biodiesel at a platinum oxide surface using potential cycling technique

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Viscoelasticity of frozen/thawed egg yolk as affected by salts, sucrose and glycerol

Based on dynamic rheological measurements, sucrose, glycerol and magnesium chloride (MgCl2) prevented egg yolk gelation at concentrations of 2% and higher, These additives showed improved cryoprotectant effects as their concentrations were increased, Sodium chloride (NaCl) at higher than 2% also prevented gelation but at 10%, it caused a considerable increase in viscosity of unfrozen yolk, Calcium chloride (CaCl2) showed an opposite effect, promoting protein coagulation before freezing, Samples with 2% CaCl2 gelled completely after 36h at -24 degrees C, Before freezing, potassium chloride (KCl) in the range 2-10% had an effect similar to that of NaCl, However, after freezing its effect changed, Yolk with 2% KCl, frozen 36h at -24 degrees C, showed very elastic behavior.