(Tuesday’s/9.30H/CEB anfitheatre)
Eduardo José Valença Cordeiro Pires | A new approach on the production of lignocellulosic yeast cells carriers based on Brewers´ spent grains
Results presentation
The major objective of this work is to improve the pre-treatments of Brewers´ Spent Grains (BSG) aiming at their use as a source for lignocellulosic yeast carriers’ (LCYC) production. Therefore, several pre-treatments of BSG have been designed aiming at obtaining various yeast carriers, differing on their physicochemical composition. Cellulose, hemicellulose, lignin, fat, protein and ash content, as well as long chain fatty acids profile on the crude BSG were analyzed. Chemical treatments’ successfully produced several different LCYC based on BSG. The highest cellulose content in LCYC was achieved upon application of caustic (NaOH) treatment during 40 min. Either caustic or combined acid/caustic treatments predominately generated hydrophobic, negatively charged LCYC. The feasibility of using BSG for LCYC production is strengthened by the fact that added-value by-products can be extracted before the chemical treatments are applied.
Filipa Maria Rodrigues Pereira | Effect of baffle design on CO2 mass transfer in a multi-orifice oscillatory flow column
Carbon dioxide is one of the synthesis gas components that can be assimilated by anaerobes to produce biofuels and other chemicals of interest. In the present work, CO2-water mass transfer and mixing performance in an oscillatory baffled column (OBC) were studied. Different combinations of oscillatory frequency and amplitude were tested and the effect in mass transfer performance was evaluated. The effect of other parameters, namely, gas flow rate, gas hold-up, bubble size and bubble size distribution (BSD), and gas interfacial area, have also been assessed. The effect of baffle design was evaluated and three geometries were used. Results have shown poor mass transfer for experiments using geometry 1 of baffles. Moreover, significant enhancement on mass transfer was obtained for geometry 2 of baffles and the amount of micro-bubbles in the column was almost dominant. Geometry 3, which have been designed in order to compensate de negative aspects of geometry 1 and 2, has revealed the more consistent results in mass transfer complemented with the smallest sized bubbles, well defined eddy formation and good mixing intensity.
