Fast pyrolysis as a tool for obtaining levoglucosan after pretreatment of biomass with niobium catalysts.

Levoglucosan (LGA) is a promising chemical platform derived from the pyrolysis of biomass that offers access to a variety of value-added products. We report an efficient route to produce LGA via the pretreatment of biomass with niobium compounds (oxalate, chloride and oxide) followed by fast pyrolysis coupled with gas chromatography-mass spectrometry (Py-GC-MS) at temperatures of 350-600 °C. Catalytic pretreatment reduces the quantity of lignin in the biomass, concentrates the cellulose and enhance LGA formation during fast pyrolysis.

Environmental impact of combustion of ethanolic biodiesel/diesel blends from several feedstocks on the gas emission levels in the atmosphere.

The aim of this work was to evaluate simultaneously the effect of produced ethanolic biodiesel from several feedstocks (soybean, crambe, macaw, sunflower, and waste cooking oil) and engine operational conditions (low and high engine speed) during combustion of biodiesel/diesel blends on the NO, NO, NO, CO, and CO emission levels in the atmosphere. The biodiesel samples were prepared in one and/or two reaction steps, according to the acid index of each raw material, by esterification using HSO and/or chemical transesterification using sodium ethoxide, both, through ethanolic route. The quality of the produced biodiesels was confirmed by ASTM/EN specifications.

Drying kinetic of tucum fruits ( Meyer): physicochemical and functional properties characterization.

The aim of the present study was to assess the drying kinetic of tucum fruits (epicarp and mesocarp) Meyer at three different temperatures (50, 60, and 70 °C). The physicochemical characterization, water activity, moisture content, including β-carotene and vitamin C content - and dried fruits were analyzed. The fruit fractions presented high β-carotene, protein and lipid levels.

Effect of acid additives on sugarcane bagasse pyrolysis: Production of high yields of sugars.

The aim of this work was to improve sugarcane bagasse thermochemical conversion to pyrolytic sugars production, particularly to levoglucosan. The experiments were carried out evaluating the effect of acid washing with HNO (0.1wt.

Ion exchange kinetics of magnetic alginate ferrogel beads produced by external gelation.

This paper reports on a study of the influence of sodium alginate concentration and iron addition on the ion exchange kinetics of calcium alginate ferrogel beads produced by external gelation. The calcium absorption and sodium release of the beads were fitted to Fick's second law for unsteady state diffusion in order to obtain the effective diffusion coefficients of Na(+) and Ca(2+). The dried beads were characterized concerning their thermal stability, particle size distribution and morphology.

Growth of Escherichia coli under extremely low-frequency electromagnetic fields.

The influence of extremely low-frequency (ELF) electromagnetic fields on Escherichia coli cultures in submerse fermentation was studied. The fermentation processes were carried out recycling the culture medium externally through a stainless steel tube inserted in a magnetic field generator (solenoid). The exposure time and electromagnetic induction were varied in a range of 1 to 12 h and 0.